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    "title": "A Glossary of Civil Engineering, Comprising Its Theory and Modern Practice, 1841",
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    "ocrText": "Google\nThis is a digital copy of a book that was preserved for generations on library shelves before it was carefully scanned by Google as part of a project\nto make the world's books discoverable online.\nIt has survived long enough for the copyright to expire and the book to enter the public domain. A public domain book is one that was never subject\nto copyright or whose legal copyright term has expired. Whether a book is in the public domain may vary country to country. Public domain books\nare our gateways to the past, representing a wealth of history, culture and knowledge that's often difficult to discover.\nMarks, notations and other marginalia present in the original volume will appear in this file - a reminder of this book's long journey from the\npublisher to a library and finally to you.\nUsage guidelines\nGoogle is proud to partner with libraries to digitize public domain materials and make them widely accessible. Public domain books belong to the\npublic and we are merely their custodians. Nevertheless, this work is expensive, so in order to keep providing this resource, we have taken steps to\nprevent abuse by commercial parties, including placing technical restrictions on automated querying.\nWe also ask that you:\n+ Make non-commercial use of the files We designed Google Book Search for use by individuals, and we request that you use these files for\npersonal, non-commercial purposes.\n+ Refrain from automated querying Do not send automated queries of any sort to Google's system: If you are conducting research on machine\ntranslation, optical character recognition or other areas where access to a large amount of text is helpful, please contact us. We encourage the\nuse of public domain materials for these purposes and may be able to help.\n+ Maintain attribution The Google \"watermark\" you see on each file is essential for informing people about this project and helping them find\nadditional materials through Google Book Search. Please do not remove it.\n+ Keep it legal Whatever your use, remember that you are responsible for ensuring that what you are doing is legal. Do not assume that just\nbecause we believe a book is in the public domain for users in the United States, that the work is also in the public domain for users in other\ncountries. Whether a book is still in copyright varies from country to country, and we can't offer guidance on whether any specific use of\nany specific book is allowed. Please do not assume that a book's appearance in Google Book Search means it can be used in any manner\nanywhere in the world. Copyright infringement liability can be quite severe.\nAbout Google Book Search\nGoogle's mission is to organize the world's information and to make it universally accessible and useful. Google Book Search helps readers\ndiscover the world's books while helping authors and publishers reach new audiences. You can search through the full text of this book on the web\nathttp://books.google.com/\nLIBRARIES\n633855\n3\nDigitized by Google\nfir\ntized by Go\nDigitized by Google\nDigitized by Google\nDigitized by Google\nTHEN TW N Y ORK\nPUTT\nAST\nTILDEN C\nEn adidas THE 40\nDigitized by Google\nView, showing the progress of the Works of the LONDON AND BIRMINGHAM RAILWAY,\nnear the Hampstead Road, in the year 1836.\nA Glossary\nOF\nCIVIL ENGINEERING,\n1\nCOMPRISING ITS\nTHEORY AND MODERN PRACTICE.\nand\nBY\nS.C. BREES, C.E., &c.,\nAUTHOR OF \"RAILWAY PRACTICE.\"\nIllustrated bg numerous\nPUBLIC\nLONDON:\nTILT AND BOGUE, 86, FLEET STREET;\nAND JOHN WEALE, 59, HIGH HOLBORN.\nMDCCCXLI.\nDigitized by Google\nHENEW YORK\nUBLICLIERARY\n93485\nASTOR, L OX:ND\nTILDEN FOU' DATIO: 8.\n1897.\nDRURY, PRINTER,\n17, Bridgewater Square, Barbican, London.\nжоу Walli\nPLIEUR\nVRARELI\nDigitized by Google\nPREFACE.\nNOTWITHSTANDING the interest and importance which\nattaches to the science of Civil Engineering in the\npresent day, there has hitherto existed no elementary\nwork sufficiently popular in its character to serve as\nan introduction to the study, and at the same time\naffording to the younger members of the profession a\nready means of access to the various rules and formulæ\nwhich are in daily requisition in early practice.\nThis deficiency the Author has attempted to\nsupply. He has aimed at utility rather than origi-\nnality, and claims for his work little merit or consi-\nderation beyond that of comprising in a convenient\nform much information, the result of his own experi-\nence or collected from sources not readily accessible.\nDigitized by Google\niv\nPREFACE.\nIn the explanations and illustrations the Author\nhas endeavoured to render his work strictly practical ;\nfor this purpose he has made frequent reference to the\nvarious Public Works completed or in progress through-\nout the kingdom. He has also availed himself of the\nlabours of preceding writers, and has thus, he hopes,\nbrought within the limits of a single volume a larger\namount of elementary information on the science of\nCivil Engineering than is to be found in any work\npreviously published.\n12, SOUTH SQUARE, GRAY'S INN.\nDigitized by Google\nGLOSSTRY OF\nEnginerring\n-\nBBREVOIR, or ABBREUVOIR (in masonry), the\ninterstice or joint between two stones of an arch,\nand which is usually filled up with fine mortar, or\ncement.\nABUTMENT, a term much used in reference to\nany fixed points, from whence, or by which, any support or force\nis obtained; thus the extremities of a segmental arch are said to\nbe supported on abutments, upon which it rests, or abuts: the\nextremities of a bridge are also termed abutments.\nACRE, a measure of land amounting to four square roods, or\n160 square poles or perches; or 10 square chains: 4,840 square\nyards also form one acre.\nADHESION, the force acting on the surface of two separate\nbodies in contact with each other, which tends to bind them\ntogether, and which is proportionate to the number of touching\nDigitized by Google\n8\nADIT.\npoints. There are two kinds of adhesion : first, the natural\nattraction existing between the surfaces of unconnected bodies,\nand which is said to be greater with two bodies of a similar nature\nthan with two of a different kind, as the force which prevents\nthe wheels of a locomotive engine from slipping on a road or rail-\nway-(The adhesion of the wheels of the best modern locomotive\nengines to the rails, exclusive of the power to drive the engine\nitself, is supposed to be capable of overcoming a resistance equal\nto T½th part of the insistent weight of the engine upon a level\nplane, or in fine weather and 20ᵗʰ in very bad weather; and\nthat of common locomotives, working with vertical cylinders, to\n20ᵗʰ part of the weight pressing on the rails by the driving wheels;\nor, taking the friction as equal to 81 lbs. per ton, or the 263rd.\npart of the weight, a load equal to 16ᵗʰ or 263th of its weight re-\nspectively, or the weight acting upon the driving wheels. The\nwheels of railway locomotives are sometimes coupled, which\nnearly doubles the amount of adhesion. The degree of adhesion\nto the surface of an ordinary road is at least ten times more than\nupon a railway : that of one wheel of a road locomotive is gene-\nrally found sufficient but in passing up a very steep hill another\nis sometimes fixed)-which is greatest when the road or rails are\neither quite dry or thoroughly wet, the surface then being most\nfree from obstruction when partially wet it is much reduced, as\nthe wheels are more apt to catch up the dust.-The other de-\nscription of adhesion is artificial ; thus the surfaces of some bodies\nare brought to adhere together by the use of glue and other\ntenaceous substances : the adhesion between two flat pieces of\nglass or brass, when smeared with grease and rubbed together,\nis very great.\nADIT, DAY LEVEL, or SOUGH (in\nmining), a subterraneous gallery or pas-\nsage, extending from the lowest conve-\nnient point in a valley through a hill into\na vein of metal, forming the entrance to a\nmine, by which the water and minerals are\nconducted, or the miners enter and leave\nDigitized by\nGoogle\nAIR-ESCAPE-AJUTAGE.\n9\nit. Adits are either walled or timbered where the soil is bad,\nand they do not always run in direct lines; they also only\noccasionally form the entrance to the mine. The water of several\npits is frequently received by one large adit, extending many\nmiles. An air-shaft is also sometimes termed an adit.\nThe horizontal line at the upper part of the cut represents the\nadit.\nAIR-ESCAPE, a contrivance for passing the air from water-\npipes, without allowing the escape of the water; the air would\notherwise collect in the higher levels of pipes, and obstruct the\npassage of the water.\nAIR-PUMP (in reference to the steam-engine), the pump em-\nployed in drawing off the condensed water from the condenser,\ncommunicating therewith by a pipe at the bottom; the air-pump\nand condenser are usually of similar capacity, each being equal\nto gth of the contents of the cylinder.-See Steam-Engine.\nAIR-VALVE (in reference to the boilers of steam-engines),\na safety-valve fixed at the top of the boiler, and opening inwards,\nto prevent rupture from the pressure of the atmosphere upon the\nsides of the boiler, should a vacuum occur within from the steam\nbecoming condensed, or partially so. The valve is kept shut by\na counterweight placed at the end of a lever, in the usual manner.\nThere have been instances of boilers becoming collapsed by the\npressure of the air from without.\nAIR-VESSEL (as applied to pumps, &c.), a chamber con-\ntaining air, attached to the ejection-pipe of a pump, and commu-\nnicating with the pipes through which the water flows; its purpose\nbeing to obviate any irregularity in the supply of water, which\nit effects by its elastic force, the discharge is thereby rendered\nconstant and uniform-for instance, when the water enters, the\nair within it becomes compressed, and acquires a corresponding\ndegree of elastic force, which it exerts upon the water as it\nescapes up the pipes, thus a continuous stream is kept in the\nrising main.-See Pump.\nAJUTAGE, a tube fixed at the mouth of a hydraulic vessel for\nregulating the discharge of water.\nC\nDigitized by\nGoogle\n10\nANCHOR AND COLLAR-ANIMAL POWER.\nANCHOR AND COLLAR, or GATE HINGES,\n(sometimes called Collar and Clamp), the\nhinges employed in hanging lock-gates, &c.\nThe anchor is usually let into the stone\ncoping, and turned down into it at each\nend, and well run with lead. The collar is\nmade to fit the hooping on the top of the quoin-post; and is\nwedged up to the anchor, as may be required, by means of\nkeys, as shown on cut.\nANGLE-IRONS, the pieces employed to join the\nangles of iron frame-work, as boilers, &c., being\nrivetted to the iron side-plates.\nANGLE OF TRACTION, the angle formed by the inclination\nof the traces with the surface of the roadway.\nANGLE OF REPOSE (sometimes called the Angle of Friction),\nthe utmost inclination at which a carriage will stand at rest upon\na road or railway, and when upon the least increase of slope it\nis put in motion by the gravity of its weight; it consequently\noccurs when the gravity of the load and friction upon the road\nare equal.\nThe angle of repose, therefore, varies according to the amount\nof friction; taking the friction at 9tb. per ton makes it 1 in 250,\nor about 21 feet per mile, which is generally considered the angle\nof repose upon a railway; and taking it at 81 lb. per ton, gives\nit at 1 in 2631, or 20 feet per mile.\nThe angle of repose, upon a turnpike road with a good de-\nscription of carriage, is about 1 in 40, supposing the road to be\nperfectly hard.\nThe natural angle, at which the soil of a cutting or embank-\nment will stand without slipping immediately after teaming, is\nalso called the angle of repose.-See Friction and Railway.\nANIMAL POWER. The power of an animal is greatest when\nstanding still, it will consequently support a greater load than it\ncan carry: upon commencing motion its power is lessened, and it\ncontinues to decrease in proportion to the velocity of its motion;\na speed may at length be attianed at which it cannot carry any\nDigitized by\nGoogle\nAQUEDUCT-ARCH.\n11\nload, the whole of its strength being required to keep up its velo-\ncity. An animal has been stated to produce the greatest effect\nin a given time when moving at 3rd of its greatest velocity un-\nloaded, the load being 4ths of that which it can just move.\nAs the mechanical effect of an animal is according to the speed\nof its velocity, and the weight of the load, it may consequently\nbe ascertained by multiplying them together.\nMost authorities rate a horse equal to five men : some state it\nat six, and others at seven.-See Horse Power.\nAQUEDUCT, a term applied generally, either to a series of\narches over a valley, or to a tunnel through the earth, when\neither expedient is used for the conveyance of a body of water.\nThe ancient Roman aqueducts, some of which remain at the\npresent time, were constructed at a great expense, consisting very\nfrequently of several tiers of arches, supporting the water-way,\nwhich was intended for the supply of the several public fountains,\nbaths, &c. The supply of water to Rome was considerably\ngreater than the present supply of London, and that of Paris is\nmuch less than the latter. The Chirk Aqueduct, in Denbigh-\nshire, on the Ellsmere Canal, by Mr. Telford; and the Lune\nAqueduct, in Lancashire, on the Lancaster Canal, by Mr. Rennie,\nare among the most celebrated aqueducts of modern times. The\nwater-ways of modern canal aqueducts are usually formed of plates\nof cast iron rivetted together. The ancient aqueducts were not used\nas canals for the purpose of navigation, as those of the present\ntime, but for the conveyance of water for the use of the people.\nARCH, a certain arrangement of over-\nlapping wedged-shaped stones or bricks,\nusually commencing from two fixed points\nor abutments, the beds radiating and meet-\ning in the centre, thereby forming an equi-\nlibrium, when properly constructed, upon the\nDigitized by\nGoogle\n12\nARCH.\nremoval of the wooden frame or centre upon which the arch is\nturned.\nArches are of various shapes-as\nSemi-circular.\nSegmental.\nElliptical.\nPolated.\nThe abbrevoirs or joints of all arches should be perpendicular\nto the surface of the soffits.\nThe top of an arch is called the extrados or back, and the\nunderside the intrados or soffit ; the line from which they com-\nmence is called the springing-line, and the first arch stones on\neach side, the springers or reins, the which rest on the imposts, or\nabutments. The extreme width between the springers is called\nthe span of the arch; and the rise of the curve in the clear, the\nversed sine. The highest portion of the arch is called the vertex\nor crown, and the centre course of voussoirs, the key-course.\nThe side portions of all arches, extending from the crown to\nthe springing, are termed haunches or flanks; and all arches should\nbe well sustained by backing, carried up on the haunches. The\nwalls built on the haunches are called spandrel-walls; and it is\ncustomary to carry up spandrel-walls\nwith small arches turned over between\nthem, termed relieving arches, upon the\nbacking of arches of great span, for the\npurpose of preventing any irregular\npressure of earth upon the same. Arches\nare also either cylindrical or groined,\nthe former being an elongation of the same curve throughout\nits length, and where intersected by other arches cutting across it\ntransversely, the point of junction is termed\na groin, such being described as groined\narches.\nAn arch, equally balanced in all its\nparts, is called the arch of equilibrium,\nwhich is of similar strength throughout, or\nGroined Arch.\nDigitized by Google\nARCH.\n13\nnot more inclined to fracture in one part than in another. It is\nfound sufficient, in the practice of bridge-building, if the arch of\nequilibrium be comprised within the boundaries of the vous-\nsoirs, without forming the extrados and intrados of the necessary\nform, to constitute the same.-See Arch of Equilibrium.\nThe introduction of railways has led to numerous investiga-\ntions on the best system of building arches, and very fine spe-\ncimens are to be seen on most lines. The stone arch over the\nRiver Dee, at Chester, is the largest stone arch in the world,\nbeing a segment of 200 feet span and 41 versed sine: and the\ncentre arch of new London Bridge is the largest elliptical arch,\nbeing 152 feet span and 29 feet 6 inches rise. The construction of\nbrick arches should approximate as closely as possible to those\nof stone; in the common mode of building them the innermost\ncourses of bricks are laid very close, and pieces of tile or slate\nare filled in the outer parts of the joints; the bricks are, in other\ninstances, laid in separate rings, which system remedies the want\nof key in the former, but is defective from the want of connec-\ntion between each ring ; it is therefore best to employ built\nvoussoirs, by which the key is maintained throughout the whole\nthickness of the arch : this plan may be said to unite the advan-\ntages of each of the former methods, and it is somewhat followed\nin the construction of the arches on the Blackwall Railway, as\nshown on the cut (see next page) : the lines taken through the arch\nrepresent heading-courses laid in mortar to allow for settlement.\nBrick arches, of very great span, have been lately erected : those\nover the Thames, at Maidenhead, on the Great Western Railway,\nare 128 feet span and 24 feet 3 inches rise, and are the largest\nyet erected; they are turned in cement: the building of brick\narches in cement undoubtedly strengthens them, yet, as the\nremainder of the erection is generally carried up in mortar, an\nunequal settlement naturally follows, and consequent fracture,\nunless a proper provision be made for the same. Elliptical arches\nare therefore not unfrequently turned in mortar, from the spring-\ning to the haunches, and the remainder finished in cement ; the\nDigitized by\nGoogle\n14\nARCH.\narch is thus enabled to accommodate itself at the mortar joints\nto any pressure it may receive from the spandrels, or from any\nsinking of the abutments, which it may do without impairing its\nstrength or effect; sometimes a small portion only of the centre\nof an arch is turned in cement, in other cases a course of stone is\ncarried along the haunches of an elliptical arch to strengthen it.\nThere are some segmental arches on the Blackwall Railway built\nof brick, with a span of 86 feet and a rise of 16 feet, which are\nturned in cement in old English\nbond (the most general method\nof turning arches being in half-\nbrick rings) ; there are three\ncourses of bricks taken through\nthe whole thickness of the arch\n(4 feet 3 inches) upon each side,\ntheir lower beds and cross joints\nbeing laid in mortar, also the three courses next the springing\nof the arch. Some engineers consider it a good plan to lay in\nthe lower courses of the bricks dry, and grout them together, as\nit gives the bricks a more equable strain.\nIn reference to railway arches, it may be stated, that the\nTransverse Section.\nTransverse Section.\nElevation of back.\nDigitized by\nGoogle\nARCH OF EQUILIBRIUM.\n15\ngeneral size of the arches for occupation bridges over the London\nand Birmingham Railway, is 30 feet in width and 17 feet in\nheight to the crown; elliptic arches being adopted, having a\nrise of 9 feet, as shown on cut; and the arches under the railway\nare made 15 feet wide, and of various heights, according to that\nof the embankment. The arches erected over the metropolitan\nroads by railway companies are required by their acts to be\n30 feet wide and 18 feet high, in the vicinities of towns, which is\nnot too much, but 16 feet is generally sufficient for turnpike\nroads. The extreme height of Temple Bar, London, is 17 feet\n9 inches, which is not sufficient for some of the waggons to pass\nunder. A load of hay is from 16 to 17 feet high. The parlia-\nmentary guage for the height of luggage upon a stage-coach is\n9 feet 9 inches. Arches are also sometimes formed of iron, also of\nwood. - See Arch of Equipollence, Bridge, Catanarian Curve, and\nCentre of an Arch.\nARCH OF EQUILIBRIUM, an arch equally balanced in all its\nparts, and capable of standing of itself without the assistance of\nabutments. The accompanying sketches represent a semi-\ncircular arch of equilibrium, and an elliptical one, according to\nthe theory of Mr. Ware. In each case the intrados and direc-\nc\na\ne\nd\nb\nb\na\nb\ne\nc\nV\nR\nb\nd\ntions of the beds of the several voussoirs are given, also the thick-\nnesses of the crown ; therefore, by making b, c, equal in each case\nto d, e, and parallel thereto, and a, c, respectively horizontal to it,\nthe intersection at a, a, a, a, will give the line of curve for the\nextrados.\nDigitized by Google\n16\nARCH OF EQUIPOLLENCE-ARTESIAN WELL.\nAs an arch of equilibrium can stand of itself without abutments,\nit consequently follows that it would be able to sustain a greater\nweight than an arch formed in a different manner; yet, from the\ntime occupied in working the backs of the arch-stones to the\nrequisite form, it is seldom followed in practice.\nARCH OF EQUIPOLLENCE, an arch whose several parts are\nprevented from following their natural directions towards the\ncentre of the earth by mutual opposition. An arch may be equi-\npollent from either of the two following causes : 1st, from the\nrelation of the weight of the several voussoirs forming it, as\nin the arch of equilibrium (see Arch of Equilibrium) ; and\n2ndly, from the continuity of the several stones alone, the thrust\nfrom the crown being transferred from one stone to the other\nuntil it is received by the abutments.\nARCHITECTURE, the art of constructing and building edifices :\nall the several erections connected with civil engineering partake\nmore or less of architecture.\nARRIS, the angular line formed by the meeting of two surfaces,\nconstituting an edge; the term has more especial reference to\nthe angles of ashlar masonry.\nARROW (in surveying), a pin employed for marking the\nchainage, one being placed in the ground at the extremity of\nevery chain.\nThe arrows are ten in number, and are made of large iron wire,\nabout 16 inches long, with a loop at the top of each, sufficiently\nlarge to admit of the finger; a piece of red cloth is sometimes\ntied thereto, that they may be readily discerned in the field.\nARTESIAN WELL, the name given to artificial fountains, ob-\ntained by boring down vertically through the geological strata of\nthe earth with augers, or other instruments, into some porous bed,\nfor the procuring of water, the springs met with being nothing\nmore than the overflowing of the water which has fallen upon the\nearth at different times and sunk beneath the surface; thus, after a\ngreat drought, wells will frequently become exhausted. They are\nusually sunk through a deep stratum of clay into one of sand,\nDigitized by\nGoogle\nARTESIAN WELL.\n17\nand the water often rises to a considerable height, varying ac-\ncording to the elevation of the highest point of the sand, and the\namount of pressure exerted upon it by the superincumbent soil;\nit is desirable to go below the sand into the chalk if it be of a\nloose nature, as the fine sand is liable to be pumped away with\nthe water, whereby large cavities are left in the earth: there have\nbeen many instances of wells becoming useless on this account\nthe chalk also abounds more with springs.\nArtesian wells have been in use in the northern departments of\nFrance and Italy for several centuries, although not introduced\ninto Germany, or this country, above fifty or sixty years they are\nnow much adopted in the metropolis, where they pass through\nthe immensely thick bed of the London clay, and even through\nsome portion of the adjacent chalk they are also in general use\nat Paris. The hole is formed by chisels, gauges, and augers, a\npole being passed through the handle of the auger, and two men\nwork it round, one at each end, and pressing it down where there\nis rock; they also turn it round and lean their weight upon it,\naccordingly as may be required : another labourer is also placed\nover them, who, by means of a long timber spring-beam, lifts the\npole and assists the pecking. A small tin, copper, or lead pipe,\nis sometimes driven down the hole upon its completion, to ex-\nclude the land springs and preserve the water pure.\nThe practicability of supplying large cities by water derived\nsolely from artesian wells is extremely doubtful; and were it\npossible, other difficulties are not unlikely to arise, as the water\ncommonly obtained from springs is brackish or hard, and of an\nobjectionable quality for domestic purposes, and it partakes more\nor less of the nature of the soils through which it passes the only\nway of rendering it applicable to domestic purposes is by sub-\njecting it to a state of motion, and exposing it to the air and\nweather for a certain period of time, the which has the effect of\nsoftening it.\nIn forming wells, it may be observed that it is customary to\nwall or plank the upper part, as the water will seldom rise to the\nD\nDigitized by\nGoogle\n18\nASHLAR-ASSISTANT ENGINE.\nsurface of the ground it is, in fact, usual to perform this part of\nthe operation first, the building of such a wall being termed\nsteining the well : the wall is first carried up a certain height\nfrom the ground upon a strong curb, generally of iron ; the exca-\nvators then dig out the ground on the inside, and eventually from\nbeneath the ring itself, upon which the whole sinks, by the effect of\ngravity, and the brickwork is carried up at the top as it is lowered,\nuntil it will go no further; another ring is then steined within the\nfirst; if the latter should not be able to reach the proper depth the\nground is taken from beneath it, and the bricks added at this end,\nwhich operation is termed underpinning : cast-iron tubing is also\nmuch employed for this purpose, several lengths of it being some-\ntimes driven. A windlass, with buckets attached, or pumps are\ncommonly employed to take the water from the level at which it\nceases to rise, or bottom of the well, to the natural surface of the\nground.\nASHLAR, the term applied to cut stone, which description of\nmasonry is principally used for the facing of structures only.\nWhere great strength is required the ashlaring is carried up solid\nthroughout : tooled work is sometimes called tooled ashlar, the\nformer being distinguished by the name of plane ashlar.\nASPHALTUM, a hard black substance, resembling pitch in\nappearance, found in various parts of the globe; upon being\nbroken, the interior presents a highly polished surface, which has\nled to its being used in making black varnish.\nThe many cements, known at the present day by the name of\nasphalte, are not composed of this substance, neither are they\nsimilar to each other in their compotent parts. The asphalte of\nSeyssel is a natural combination of asphaltum, and other bitu-\nminous substances, with pure carbonate of lime, in the proportion\nof about 83 of the former to 17 of the latter; and it has been\nmuch employed in France and this country for several engineer-\ning and building purposes, and has been found to answer very\nwell, not having been affected by either cold or heat.\nASSISTANT ENGINE (on railways), an extra locomotive em-\nDigitized by\nGoogle\nATMOSPHERIC ENGINE-BALANCE GATES.\n19\nployed upon inclined planes on railways, or to assist the heavy\ntrains.\nATMOSPHERIC ENGINE.-See Steam Engine.\nAXLE, or AXLETREE, the pivot, centre, or transverse bar, con-\nnecting the naves of the opposite wheels of a carriage.\nThe axles of roadway carriages are secured in a different man-\nmer to those used upon railways : in the former they are fixed to the\ncarriage bearings, and the ends are fitted into boxes situated in\nthe centres of the naves of the wheels which revolve round the\nsame ; each of the wheels are enabled, by this method, to revolve\nseparately upon its own axis, and at different rates of speed as\nmay be required thus, in turning round, the inner wheels remain\nstationary, acting as a centre, while the others describe a circle\nround them. In railway carriages the axles are fixed immoveable\nin the naves of the wheels, the bearings of the carriages being on\nthe outside, and merely resting upon the same.-See Friction.\nBACKING.-See Arch.\nBACKWATER, or SCOURING POWER, the stream of water em-\nployed in connection with harbours, to carry away the shingle\nand prevent its accumulation at the mouth. They are employed\nwhere a great quantity of water can be obtained at high tides,\nlarge reservoirs being filled at such times, and the water is after-\nwards discharged on the bar at low water.-(For observations\nupon the same see Harbour).\nBALANCE BEAM.-(See Lock).\nBALANCE GATES, a certain de-\nscription of flood-gate, much used in\nHolland acting upon the following\nprinciple, the gates are fixed on a\nvertical shaft as a centre, and are\nH\nkept closed by the pressure of the\nwater against them, one side of each being larger than the other\nand in order to open them, when requisite, a sluice is constructed\nin the largest side, which, upon being opened, reduces the area\nof this side of the gate to less than that of the other side, upon\nD 2\nDigitized by Google\n20\nBALKS-BALLASTING.\nwhich the water consequently acts upon the gates, and opens them.\nMr. Wickstead has employed balance-gates in connection with\nthe works of the East London Water-works; but each side of his\ngates are of equal area, a very slight degree of power is therefore\nsufficient either to open or shut them, whatever the pressure of\nthe water may be, as they are equally balanced.\nBALKS, a term applied to long pieces of foreign timber, from\nabout 5 to 12 inches square.\nBALLAST LIGHTER, a description of open barge, employed in\nremoving sand, silt, or the like, from the beds of rivers, harbours,\ndocks, &c., which is effected by means of an iron hoop with a\nleathern bag sewn round the edge of the same, and fixed to the\nend of a long pole; the hoop is scraped along the bottom of the\nriver, the sand being thereby collected in the bag, from which it\nis discharged into the barge moored along side of it.\nBALLAST WAGGON, the wag-\ngon employed in removing earth\nin excavations, and the like, the\nwhich hold about 2 cubic yards,\nor 21, or 3 yards at the utmost,\neven by piling up. If they are\nfilled too full they are apt to tilt they are usually used without\nsprings, but they are better with them, particularly for those\nworking on permanent rails, as the former increases the wear and\ntear of the rails, and adds to the expense of maintaining the way\nconsiderably. The cut shows an improved form of ballast waggon.\nBALLASTING, or METALLING (sometimes called bottoming),\na term applied to the covering of roads generally, and to the\nfilling in material, above, below, and between the several stone\nblocks and sleepers upon railways, &c. ; it is laid for the purpose\nof keeping the road dry, as in the event of water lying upon it,\nthe rails invariably sink, as it causes them to rest unequally.\nBallasting is mostly composed of gravel, broken stone, or the\nlike, and is laid about 2 feet thick on railways, the finished sur-\nface of it being usually rather more than 1 inch below the level\nDigitized by\nGoogle\nBALLUSTRADE-BATH-STONE.\n21\nof the rails, and it is generally from 6 to 12 inches thick on\nroads.\nA longitudinal drain, 6 inches square, is sometimes laid within\nrailway ballasting, having cross drains, 15 feet apart, communi-\ncating with the same, to convey the water into the side ditches.\nThese drains should invariably be used in excavations, and when\nemployed in embankments the water is led down the slopes\nby drains.\nBALLUSTRADE, a series of ballusters situated and fixed under\nthe coping of the parapet of a bridge, &c., the which are not\nemployed in engineering works so frequently as formerly.\nBANK.-See Embankment.\nBAR, a piece of timber or metal placed horizontally, and\nrunning across from one part of any framework to another.\nBAR (in navigation), an accumulation of sand or shingle at\nthe commencement or mouths of rivers, harbours, &c., being\nformed by the action of the tides.\nBARREL (of a drum wheel), the cylindrical body, or axle,\nround which the rope is rolled.\nBARREL (of a pump), the cylinder or hollow part of the pump\nin which the piston works.-See Pump.\nBARROW, a machine generally used for carrying soil in the\nformation of excavations and other works at their commencement,\nbefore a road is formed.\nBASE LINES (in surveying), the main lines of a survey upon\nwhich the correctness of the whole depends; it is therefore neces-\nsary to proceed with the utmost care, in the laying out of the\nseveral base lines of a survey.\nBAT, the name given to a half or other portion of a brick.\nBATH-STONE, a very serviceable sand-stone, almost wholly\ncalcareous, although some of it is more silicious. It is extremely\nsoft when taken out of the quarry, but afterwards becomes hard:\nin setting the stones, it is very essential to lay them in their\nnatural or quarry bed, which remark may be applied to every\ndescription of stone, although not to the same degree as with\nBath-stone.-See Stone, Slope, and Soil.\nDigitized by\nGoogle\n22\nBATTER-BETON.\nBATTER, the face of a retaining or other wall when built in a\nleaning position, the top part falling back within the line of base\nwalls of this description, are sometimes termed tallus walls. The\nbatter of a wall is either straight or curved; the latter are also\ngenerally commenced straight from the top, the greatest degree\nof curvature being given to the bottom of the wall.\nThe average rate of the batter of the walls upon the London\nand Birmingham Railway is 21 inches to the foot, and 1 inch to\nthe foot for the wing walls of bridges.-See Retaining Wall.\nBATTER LEVEL.-See Clinometer.\nBEAM.-See Girder.\nBEARINGS, as applied to carriages, &c.\nThe chairs supporting the frame-work of the carriage, the which\nmerely rest on the axles and upon the outside of the wheels of\nrailway-carriages; but they are fixed to the axles of all common\nroad-carriages.-See Arle, Waggon, and Friction.\nBEETLE, a wooden instrument, or mallet, for driving piles,\nbeing raised by the help of ropes and pullies: the term is also\napplied to the rammer used for driving stones into the ground.\nBENCH, or BERM, a ledge left on the face of a cutting to\nstrengthen the same.\nSteep cuttings should always have ledges to support them, par-\nticularly in canal work, to prevent the mould from the upper\npart, falling down into the water; chalk may also be executed at\na very steep inclination by their assistance. Ledges are likewise\ngenerally made at a change of slope, occasioned by meeting with\na different soil.\nBENCH MARKS (in surveying), fixed points left on the line of\nsurvey for reference at any future time, consisting of cuts in trees,\npegs driven in the ground, and the like.\nBETON, a French concretion or mortar, used in the foundation\nof hydraulic works it consists of twelve parts of pozzylona, nine\nof quick lime, six of sand, thirteen of stone scrapings, none ex-\nceeding the size of an egg, and three parts of iron scales from the\nsmith's forge ; after being well mixed and indurated together, it is\nbroken in pieces, and a coffer having been previously prepared\nDigitized by Google\nBEVEL GEAR-BLASTING.\n23\nit is dropped by a proper box into the same, and laid in alternate\nlayers with rubble stones until sufficiently elevated to receive the\nmasonry.\nBEVEL GEAR.-See Gearing.\nBLAST PIPE, a pipe employed in locomotive engines to convey\nthe waste steam from the cylinders up the chimney, and to urge\nthe fire. Its invention is generally ascribed to Mr. George\nStephenson, and it is supposed to have doubled the power of the\nengines at the period of its introduction.\nBLASTING, the operation of detaching and separating blocks\n-of stone or earth from their natural or quarry beds, which was\nusually performed in former times by the following process :\nlong wooden wedges were driven, in a very dry state, into holes\nprepared for them, and previously well heated; a quantity of\ncold water was then poured over the wedges, which, upon be-\ncoming thoroughly saturated, swelled and caused a fracture of\nthe rocks. The same effects are now generally produced by the\nexploding force of gunpowder, which was first used for that pur-\npose in about the year 1820 a hole is first driven into the earth\nby a jumper, or chisel, which is held in a proper direction by one\nman while another strike it with a hammer, the former turning\nhis instrument at every blow, by which it is soon made; and it is\nformed of various depths, from 1 to 3 feet, according to circum-\nstances: if water appears in the hole some stiff clay is crammed\nin, by which it is absorbed, and the fissures through which it\nentered filled up when the hole is of some considerable size, and\nof great depth, a long jumper succeeds the first, the which is\n6 or 8 feet long, and pointed at both ends, with a projecting bulb\nin the middle, which serves as a handle for the men to lift it up,\nupon which it is dropped into the hole, and being heavy, it per-\nforates into the rock : a hole, of 5 feet depth, may be formed\nwithout much difficulty by a succession of these falls : the gun-\npowder enclosed in paper is then introduced into the bottom of\nthe hole which is properly adapted for it; a thin copper rod is\nnow connected with it, and some soft impervious substance\nDigitized by\nGoogle\n24\nBLOCK.\ncrammed into the remaining part of the hole when the rod is with-\ndrawn, by which a vent is obtained, connecting the charge with\nthe touch-hole into which a fusee is dropped and lighted, which\ncompletes the operation, when the men retire: crooked pieces of\niron are also sometimes introduced into the bottom of the hole\nto assist in detaching the masses of rock. The natural stratifica-\ntion of the rock is of course attended to, as a horizontal blast will\nfrequently bring down ten times as much as a vertical one.\nThe blasting of rock under water is usually performed by\nthe diving-bell, the communication with the gunpowder being\neffected by means of a tin tube: a galvanic battery has also been\nlately employed for that purpose by Colonel Pasley, and with\nconsiderable success; a much greater degree of safety is insured\nby this system of explosion.\nBLOCK (stone, as applied to railways), a foundation or support\nfor the tracks or rails of a railway upon which the chairs are\nsecured Stone blocks were introduced in place of wooden\nsleepers, in about the year 1800, and are now in general use\nbut it is not usual to place them upon embankments until suffi-\ncient time has elapsed after their formation to allow for settling,\noak or larch sleepers being generally laid down in the first\ninstance. The blocks are about 2 feet square, and are placed in\na diagonal direction at the present time,\n(which was first introduced upon the\nLondon and Birmingham Railway),\nhaving been previously set square, and\nat a distance of 3 feet, from centre to\ncentre. When heavier rails are used the bearings are made\ngreater. The 65 lb. rails on the London and Birmingham Rail-\nway are laid 4 feet apart, and the 75 lb. are made 3 feet 9 inches\nin cuttings, and 4 feet 6 inches on high embankments, the blocks\nbeing 1 feet 3 inches square.\nThe blocks are set or fixed by a cuddy, consisting of a stand\nand a timber spring lever, say 20 feet long, by which a labourer\nraises the block about 1 foot high, while the setter adjusts the\nDigitized by Google\nBLOCK-BOILER.\n25\nballasting beneath it, and by a succession of rises and falls it is\nat length brought to a solid bed, and at the level required.-See\nCuddy and Bearings.\nBLOCK, a piece of wood on which a sheave or pulley is run,\nand through which the rope passes.\nBOILER (in steam-engines), the vessel employed for containing\nthe water to be converted into steam. The boilers employed at\nthe present time are formed exclusively either of iron or copper,\nor of both, although brick and stone have been used for the same\npurpose. Copper is considered the best material, its power of\nconducting heat being nearly double that of iron ; a copper boiler\nof only one-half the superficial contents of an iron one will ge-\nnerate a similar quantity of steam. The power of copper in con-\nducting heat, according to the experiments of M. Despretz, is about\n898.2, and that of iron 374.3. Iron is said to possess the greatest\ncohesive strength, yet manufacturers generally construct their\ncopper boilers of thinner metal, on account of the greater uni-\nformity in the substance of copper plates, and probably for eco-\nnomy, copper being four times the cost of iron; but an old worn-\nout copper boiler is worth 4ths its original value, whereas the\nvalue of an old iron one is comparatively trifling, when the cost\nof removal is deducted; copper has also been proved to be the\nsafest: when a copper boiler bursts, it is merely rent open, but one\nof iron is often blown to pieces yet much depends upon the plan of\nconstruction : some boilers are also formed of both, as the boiler\nof a locomotive engine (the description of which will be found\nunder that head).\nThe great desideratum in the steam-engine appears to be in\nthe formation of a good boiler, one capable of generating the\ngreatest quantity of steam with the least degree of fuel, yet\nperfectly free from explosion. They should be constructed with\na view to provide against rupture, or rather, that in the event\nof the engine receiving a shock sufficient to rupture the boiler,\nthat it should occur in that part best calculated to prevent\nloss and fatal accidents, particularly in those for locomotive\npurposes, small boilers are therefore considered the best. If a\nE\nDigitized by\nGoogle\n26\nBOILER.\nlarge boiler with large tubes of separation bursts, the risk of\ndamage and loss of life is much greater than in the case of a small\nchambered boiler, as the tubes, being small, act like so many\nsafety-valves, occasioning nothing more than a stoppage. The\nreason of the boilers of locomotives not frequently bursting is\nprincipally owing to the slightness of the tubes, which are thereby\nthe parts soonest affected in the event of any unusual strains,\nwhen they merely let the water down upon the grate and put the\nfire out-their wear is, consequently, very great; but if they were\nmade sufficiently strong to resist, the bursting of the sides of the\nboiler might be reasonably expected, which would be attended\nwith great consequences.\nBoilers may be described generally as being of four kinds, viz.\n1st, globular; 2nd, cylindrical, with either flat or concave ends,\nas the Cornish boiler ; 3rd, waggon-shaped, having semi-circular\ntop and flat sides and ends, the invention of Mr. Watt they are,\nalso, sometimes termed oblong, or rectangular boilers ; and, 4th, the\ntubular, which is almost exclusively confined to locomotives, on\naccount of its small size and great evaporating capacity; the\nshape differs from the last two, principally in internal arrange-\nment.-(See Locomotive Engine). The first and second description\nof boilers are mostly employed for high-pressure engines, their\nform enabling them to withstand steam of great elastic force,\nalthough generally considered to cause a greater expense in fuel.\nThe waggon-shaped are those usually employed for ordinary\npurposes, and compensate, by their greater bulk, for the want of\nthe large evaporating surface possessed by the others-they are,\nalso, more adapted for fuel of a slow rate of combustion, and are\ntherefore suitable with all varieties of coal ; yet some engineers\nprefer the Cornish boilers, and maintain that they are most\neconomical.\nThe boilers of ordinary condensing engines have received\nvarious proportions ; some engineers give a capacity of 16, and\nothers extend it to 25 cubic feet per horse power; perhaps a me-\ndium may be the best, one-half of which should be appropriated\nfor water, and the other for steam ; and two small boilers are con-\nDigitized by\nGoogle\nBOILER.\n27\nsidered better than one large one, another being also provided\nas a reserve : the greatest effect has generally been produced by\nallowing 41 square feet of fire surface, or that in direct contact with\nthe fire, and 4½ square feet of flue surface, (or the space inter-\nposing between the former and the chimney-the which abstracts\nheat from the flame and heated air as it passes through), to one\nhorse power; and one cubic foot of water is also evaporated per\nhour by this arrangement. Mr. Watt allowed 5 feet of bottom\nsurface for the boilers of land-engines per horse power, and 3 feet\nfor marine ones; the space in the latter being more valuable.\nAbout one square foot of grate surface should be allowed for\none horse power; in marine boilers grds of a foot is sufficient,\nas they consume less coal per horse power than others, the space\nbetween the grate bars and the latter being of equal width.\nFrom 8 to 10 tb. of coke is generally allowed for each horse\npower of an engine per hour, although some consume consider-\nably less: 1 lb. of coke was allowed\nby Mr. Watt for the evaporation of\n7 lb. of water.\nB\nThe following is a representation\nof a waggon-shaped boiler of the\nFeed\nusual construction :-\nA, the supply-pipe from the hot\nwell, which terminates in the cis-\ntern at the top of the feed-pipe.\nPlpe\nC\nD\nB, the cistern at the top of the\nfeed-pipe, having a valve fixed at\nBoiler\nthe bottom.\nC, the float, which is employed\nto regulate the supply of water to\nthe boiler; the water is kept at the\nM\nsame constant height by its action\nupon the valve at the top of the\nfeed-pipe, thus -When there is not\nsufficient water in the boiler the\nTransverse Section.\nfloat sinks, and pulls down the arm\nDigitized by Google\n28\nBOILER.\nof the lever a, a, to which it is attached, and thereby opens\nthe valve, as the counter-balancing weight b, fixed at the other\nend of the lever, will only support the float when in its proper\nsituation in the boiler, and at the required level of the water.\nA\na\na\nB\nN\nFeed\nd\n*\n0\nT\nE\nI\nH\nG\nPipe\n[\nC\nD\nBeiler:\nM\nLongitudinal Section.\nD, the self-acting damper for regulating the consumption of\nfuel, which it effects by means of a chain connected with a\nweight situated in the feed-pipe. Now as the force of the steam\nacting upon the surface of the water forces a portion of it up the\nfeed-pipe, so is the weight within it raised or depressed, varying\naccording to its pressure; the which motion is communicated to\nthe damper, which opens or closes the aperture of the flue of the\nfurnace accordingly, whereby the draught, and consequently the\nfire, is regulated : the damper is so adjusted as to exactly balance\nDigitized by Google\nBOLTS.\n29\nthe weight when the latter is immersed in the water to a suitable\ndepth.\nE and F, the gauge-cocks.-See Gauge-cocks.\nG, the steam-gauge.-See Steam-gauge.\nH, the safety-valve. This valve can be regulated by the en-\ngineer.-See Safety-valve.\nI, the internal or atmospheric safety-valve, opening inwards,\nand fixed in the top of the man-hole or inlet into the boiler, for\nthe purpose of cleaning. See Air-valve.\nK, the lock-up safety-valve, which cannot be regulated by the\nengineer. A pipe is shown at the top which leads the steam that\nescapes into it to the flue, or into the air, as the case may be.\nThe steam passes from the boiler through the steam-pipe a\nvalve being placed in it, called a throttle-valve, L, for regulating\nthe amount of steam to the cylinder.\nM, the furnace-bars.\nN, the flue.\nThere are steam-engines which work with a pressure of 18or20tb\nupon a square inch of the boiler, and others which have upwards\nof 200 lb. : but it does not follow that the steam in the cylinder\nis of equal pressure, it may not be one quarter of that; a reserve\nis therefore always ready, the supply being regulated, in stationary\nengines, by a contrivance termed the governor, which operates upon\nthe throttle-valve, and by the engineer in locomotives; which\nprocess is sometimes called wiredrawing the steam. The strength\nof low-pressure boilers should be twice the regulated pressure on\nthe safety-valve ; and high-pressure boilers should be proved to\nat least three times their working power.\nBOLTS (iron), the pieces of iron used for secur-\nA\ning framing together, and much employed in\ntimber-work; they are formed of wrought iron,\neither square or cylindrical, with a square head at\none end and a screw and nut at the other; a plate\nof iron, termed a washer (A, in the cut), being\ninterposed between the surface of the wood and\nA, the Washer.\nDigitized by Google\n30\nBOLSTERS-BOND.\nthe head and nut, to protect the former from damage during the\nprocess of screwing up.\nBOLSTERS, the pieces of timber used in the construction of the\ncentres of arches, and running across from one rib to another,\nfor the purpose of supporting the voussoirs. A piece of timber,\nemployed in a somewhat similar manner to a corbel, is also termed\na bolster; the which are much employed in timber bridges.-See\nBridge.\nBOND, the union or tie of the several stones or bricks forming\na wall. The great principle in all bond is to provide against\nsettlements: the vertical joints of a course should, therefore, be\nexactly midway between those below-in other words, break joint\nwith them; and in no case should the joints of one course be\ncarried up over those of the one below it.\nThe bricks or stones lying lengthways, in the longitudinal\ndirection of the wall, are called stretchers; and those placed length-\nways across the wall, headers.\nBond may be described ge-\nnerally to be of two kinds,\nviz. English and Flemish. In\nEnglish bond the courses are\nalternately all headers and all\nOld English Bond.\nstretchers, and when the backs of each course are laid alternately\nheader and stretcher, it is\ncalled Flemish Bond; this de-\nscription of tie is also known\nby the name of header and\nstretcher, particularly in stone-\nFlemish Bond.\nwork.\nOld English bond is much the strongest, the tie being con-\ntinued throughout, yet Flemish bond seems to be preferred,\nsimply on account of its external appearance; the tie is confes-\nsedly inferior to the former, arising from its shortness; a far\ngreater number of vertical joints in the interior of the walls is also\nconsequent upon this plan, whereby the walls are rendered more\nDigitized by\nGoogle\nBONNET-BOUNDARIES\n31\nliable to split longitudinally, the face-work not being tied into\nthe interior. English bond may likewise be described as the\nsimplest in execution, and the least wasteful. The Romans em-\nployed bond of this description in their brick buildings.\nThe term perbend, or thorough, is applied to the heading stones\nforming a wall, when they are carried through the whole thickness,\nand the term binder, when they reach through only a part of that\ndistance.\nBONNET, a hole formed in iron pipes, and furnished with a\nsliding lid, for the purpose of cleaning out the inside when\nrequisite.\nBOOMS, the pieces of timber connected with fender-piles, and\nemployed to protect coffer-dams and the like from the effects of\nshocks from vessels, &c. : they are usually secured to the piles\nby chains, and rise and fall with the tide.\nBONING, the operation of finding a line parallel with the\nhorizon without the use of an instrument, but by means of the\neye only. It is much practised by workmen in building walls,\nfilling in earth, and the like.\nBORING, a vertical sinking, made in the earth by an auger, or\nother instrument, for the purpose of obtaining water, instead of\nsinking wells, and for other purposes.\nBorings are required to be made on the line of a proposed\nrailway or canal, previous to drawing up the necessary specifi-\ncation and estimate of the works, including the cuttings, founda-\ntions for bridges, &c.\nBOTTOMING.-See Ballasting.\nBOULDER PAVING, a description of paving consisting of round\npebbles or boulders.\nBOULDER WALLS, walls composed of boulders and flints set\nin strong mortar.\nBOUNDARIES (in surveying). In making a survey, the boun-\ndaries of the counties, parishes, and the several estates, are\nrequired to be marked correctly thereon; in ascertaining which,\nit is generally found necessary to procure the services of local\nparties well acquainted with the same.\nDigitized by\nGoogle\n32\nBOW-STRING BRIDGE-BRAKE.\nIn the case of property divided by hedge and ditch, the brow\nof the ditch is generally the boundary ; which, of course, forms the\nline to be measured. In some districts the roots of the quicks,\nor the foot of the bank, forms it : a width of 15 links is usually\nallowed for a hedge and ditch, and 6 links for ditches between\nneighbouring estates, and 7 for those nearest roads, &c., i. e. from\nthe roots of the quicks.\nBOWSTRING BRIDGE, or TENSION BRIDGE, a kind of suspen-\nsion bridge, the roadway being suspended from wrought-iron\nrods; but, instead of the usual suspension chains, cast-iron seg-\nments are thrown across the ravine, or river, as the case may be,\nthe which are rested on proper abutments upon each side.\nMr. Leather, C.E., was the first who applied this principle on\nan extensive scale, the two bridges erected by him at Leeds\nbeing after this plan, the which have a very elegant effect, and\nfully answer the purpose intended; they each consist of two seg-\nments, the carriage-way being situated between them, and the\nfootways are on the outside.\nThe Monk Bridge was executed first, the span of which is\n112 feet; the other, erected at Howslett, is the largest, being 152\nBridge at Howslett.\nfeet span, and the rise of the arch is 33 feet, the total height\nabove the level of the water is 43 feet, the width of the bridge is\n33 feet, and its cost did not exceed £4,200.\nBRAKE, or CONVOY, the drag applied generally to the wheels\nof carriages to check their velocity in passing down hills, by\nmeans of friction. The brake attached to railway carriages con-\nsists of a piece of wood, which is pressed upon the rim of the\nwheels of the carriages by a hand lever, worked by the brakesman.\nThe brake of the tender alone affords a sufficient resistance to\nstop a train under ordinary circumstances. The term is also used\nDigitized by\nGoogle\nBREAKWATER.\n33\nin reference to the contrivance for arresting the motion of machi-\nnery, which is effected generally by a simple or a compound lever\npressing forcibly upon the periphery of a broad wheel, fixed upon\none of the shafts or axles of the machine.\nBREAKWATER, a kind of artificial embankment, dike, or ram-\npart, formed of large stones, and erected for the purpose of\nprotecting the entrances of harbours, also roadsteads, from the\neffects of violent winds, by breaking the force of the waves of\nthe sea ; the shipping, moored behind them, laying perfectly\nsecure.\nThe most celebrated works of this description are those of\nCherburg, in France, and Plymouth, in this country.\nThat of Cherburg was the first executed, having been began\nin the year 1783: the building of the wall was commenced upon\nupright cones of timber, and each cone was intended to have been\nabout 150 feet diameter at the base, 60 feet at the top, and about\n60 or 70 feet high, the depth of water, at spring-tides in the line\nin which they were sunk, varying from 56 to 70 feet; they were\nalso intended to have been filled with stones to the top, and after\nallowing some time for settling, the masonry was intended to have\nbeen commenced upon them; but a few of these cones only were\nconstructed, when, in consequence of the difficulty of the under-\ntaking, the whole was covered with large stones, thrown in at\nrandom. This breakwater is 10 feet above the highest tides, and\nhas a roadway or platform, 20 feet wide, on the side next the\nshore, a parapet wall being built upon it, on that next the sea.\nThe Plymouth breakwater was commenced in 1812, from the\nplans of Messrs. J. Rennie and Whitbey. It is composed of\nblocks of stone, 11 to 2 and 3 tons weight, and consists of a central\nPlan of Plymouth Breakwater.\npart, 1000 yards long; and two wings, each 350 yards long, di-\nrected towards the sea, and forming angles of 158° with the\nF\nDigitized by\nGoogle\n34\nBREAKWATER GLACIS-BRICK.\ncentre portion. A transverse section taken through the break-\nwater shows an average base of 290 feet, and the breadth at the\nSection of Plymouth Breakwater.\ntop is 48 feet, with an average depth of water, at low spring-\ntides, of 36 feet; the side next the sea is sloped in the pro-\nportion of 1 perpendicular to 7 horizontal, and the side next the\nland is 1 to 5; these sides were not intended originally to have\nhad so great a slope, but, in consequence of the violence of the\nwaves during its construction, it was thought proper to increase\nthem, as executed.\nA, A, high-water spring-tides. B, B, low-water spring-tides.\nD, the foreshore.\nBREAKWATER GLACIS (some-\ntimes termed storm pavement), the\nstone paving next the sea, in\npier erections: they are mostly\nlaid upon a slope, or curved, the\nSection showing the Breakwater Glacis.\nstones being of sufficient weight to resist the action of the sea.\nBREASTS, the name given to the bushes connected with small\nshafts or spindles.\nBREAST WALL, a wall built up breast-high, as a parapet wall,\nor a retaining wall, placed at the foot only of a slope.\nBRICK, an artificial preparation of clay, sand, and ashes, burnt\nin a kiln, or clamp, and used for building, and for other pur-\nposes ; good brick earth is also sometimes found in a natural state.\nA good brick is about 84 inches long, 41 inches wide, and\n21 inches thick, when burnt.-(The Act of Parliament which\nregulates the size of bricks, states, that they shall not be less than\n81\" X 4\" X 21\").\nBrickwork is measured in London by the rod, and was taken\nfrom the original standard of 161 feet cube, which gives 272₫\nDigitized by\nGoogle\nBRIDGE.\n35\nsquare feet of 1½ bricks brickwork, or work 11 bricks thick,\nas the superficial contents of 1 rod of reduced brickwork. There-\nfore, as the standard thickness of a brick wall is 13} inches,\nthere are consequently 306 cubic feet in a rod of brickwork, and\na standard rod will require about 4,500 bricks, allowing for waste ;\nbut it depends on the closeness of the joints and the size\nof the bricks, as they sometimes vary a trifle; and 1 rod of brick-\nwork will take 1½ yards of chalk lime, or 1 yard of stone lime, and\n2½ yards of sand with stone lime, or 2 yards with chalk lime,\nfor the mortar: 1 foot of reduced brickwork will also require\n17 bricks.\nAs brickwork is generally measured by the yard in the country,\nit is therefore the general custom of engineers to adopt the latter\nmeasure : there are 11½ cubic yards in a rod.\nBricks are usually burnt in clamps, or stacks, in the vicinity of\nLondon, flues being made in the interior to contain the fuel, and\nthey take from twenty to thirty days burning; but they are burned\nin conical erections in the country, termed kilns, which will burn\nabout 20,000 at a time, consuming less fuel and occupying less\ntime than the former method, 48 hours being sufficient for the\nburning of them in kilns.\nLondon stocks, also those of Manchester, are the most durable.\nSuffolk bricks are very celebrated for their light colour and\neven form, also for their close texture, which renders them nearly\ntwice the weight of common bricks. The softest and most porous\nbricks made in this country, are those of the midland counties.\nBRIDGE, a very common engineering expedient employed for\npassing over rivers, canals, and roads. Rivers of great width were\nnot often crossed by bridges formerly, but ferries were usually\nestablished, at convenient spots, for the purposes of communi-\ncation (the scites of most river bridges were formerly occupied by\nferries), and shallow streams were commonly forded. The erec-\ntion of a bridge over a river occasions a great increase of traffic\nin the line of route, as may be naturally anticipated, in common\nwith all schemes for facilitating conveyance.\nDigitized by\nGoogle\n36\nBRIDGE.\nThe bridges employed in modern times\nare constructed after various methods, but\narches are mostly used. In most cases the\nroad is carried over at once by stone or brick\narches, or by iron or wood beams thrown\nacross and trussed, according to the span ;\nthe road is sometimes suspended from in-\nverted bows by rods, being usually formed\nof iron, the which are supported upon stone\npiers at each end, and from thence carried\ndown and secured in the ground, which are\ncalled iron suspension bridges-as the Menai\nbridge; this description is generally adopted\nwhere the span is very great. In other in-\nElevation of Menai Bridge.\nElevation of Bridge near Chalk Farm.\nDigitized by Google\nBRIDGE.\n37\nstances the road is suspended by rods, or otherwise, from trussed\nribs or girders occupying the space of the parapet walls, the which\nare termed bow-string, or tension bridges ; as the bridge over the\nRegent's Canal, near Chalk Farm, on the London and Birmingham\nRailway. The two bridges over the River Aire, near Leeds, may\nalso be cited as bridges of the latter description.\nAmong modern bridges may be mentioned the Rialto Bridge,\nover the Grand Canal, at Venice, which was commenced in 1588,\nby Michael Angelo, and is considered to be a very beautiful\nstructure.\nI\nElevation of the Rialto Bridge.\nThe bridge across the Seine, at Neuilly, built between the\nyears 1768 and 1780, by Péronett, is a very celebrated struc-\nture ; it is a level bridge, consisting of five elliptic arches, each\nof 128 feet span, and 32 feet rise.-See next page.\nWaterloo Bridge, London, by Mr. John Rennie, is considered\na masterpiece, it was commenced in 1810, and is also a level\nDetails of one of the Arches and Centreing of Waterloo Bridge\nDigitized by Google\n38\nBRIDGE.\nbridge, having nine arches, each 120 feet span, and 35 feet rise,\nand it is 42 feet 4 inches wide between the parapets.\nLondon Bridge, by the same engineer, is a fine work, and,\ntogether with the last-form excellent specimens of masonry, being\nElevation of one of the arches of Neuilly Bridge.\nTransverse Section of ditto.\nCentre Arch Enlarged of Southwark Bridge.\nDigitized by Google\nElevation of Waterloo Bridge.\nElevation of London Bridge.\nBRIDGE.\nDigitized by Google\nElevation of Southwark Bridge, and Plan showing Iron-Framing.\n39\n40\nBRIDGE.\nconstructed of granite. This bridge consists of five elliptic arches,\nthe centre one is the largest elliptic stone arch at present erected,\nbeing 152 feet span, and having a rise of 29 feet 6 inches above\nhigh water-mark; the two arches next the centre are each 140 feet\nspan and 27 feet 6 inches rise, and the abutment arches, each\n130 feet span, and 24 feet 6 inches rise the width between the\nparapets is 53 feet.\nSouthwark Bridge, London, also by Mr. Rennie, is a magni-\nficent bridge, it is formed of cast-iron, supported by granite piers,\nand consists of three arches, the centre one being 250 feet span,\nand the side arches 210 feet; the piers are 24 feet thick, and it is\n42 feet wide between the parapets: and Blackfriars and West-\nminster Bridges (which are now undergoing repair), also Vauxhall\nBridge, are very extensive works.\nThe stone bridge over the Clyde, at Glasgow, erected by\nMr. Telford, is considered to possess great merit, having seven\nsegmental arches, the centre one being 58 feet 6 inches span, and\n10 feet 9 inches versed sine.\nTimber bridges have been much more generally employed\nsince Mr. Kyan's invention for preserving timber, as the material\noffers very great advantages. In wooden bridges of small span,\nthe pieces running from pier to pier are termed sleepers, or string-\npieces, the which sup-\nport the cross-joists,\non which the planking\nis laid : small pieces\nof wood are some-\ntimes introduced un-\nder the string-pieces\nto shorten the bear-\nSmall Timber Bridge.\ning, which are termed bolsters, or corbels.\nA system of forming bridges and viaducts by laminating\ntimber arches, has been lately introduced by the Messrs. Green,\nupon the Newcastle and North Shields and Tynemouth Rail-\nways. The Ouse-burn Viaduct is 108 feet high, and consists of\nDigitized by Google\nBRIDGE.\n41\nfive arches, each 116 feet span, with two\nstone arches at each end, 45 feet span; and\nthe Wellington Dean consists of seven arches,\neach 120 feet span, the height up to the\nroadway being 82 feet. The piers and abut-\nments are of stone, and each arch consists of\nthree segmental ribs, each rib being com-\nposed of thirty 3 inch deck deals, being\ntwo deals in width and fifteen in height;\nthey vary in lengths from 20 to 45 feet :\nthe first course is formed of two deals in\nwidth, as before stated, bent over a light\nElevation of Glasgow Bridge.\nDetails of Centre Arch, and Centreing.\nTITLE\nG\nDigitized by Google\n42\nBRIDGE.\ncentre; the next course consists of one deal and two half ones,\nand so on, until the whole rib is formed, the ends breaking\njoint with each other; and they are connected together by 3 inch\nElevation of Centre Arch of the Wellington Dean Viaduct.\noak-trenails, each passing through three of the deals; a layer of\nbrown paper, dipped in boiling tar, is placed between the joints\nto prevent the wet from injuring them, and the timbers are\nbedded tightly on it; the ends of each rib are let into cast-iron\nshoes, which are fixed to the springing-stones of the masonry,\nand the which are secured with four long iron bolts and run with\nlead, and the three ribs are connected together by diagonal braces\nand iron ties; the spandrels are framed as shown in the cut, and\nthe whole of the timber is prepared with Kyan's patent prepa-\nration. The Messrs. Greens state the expence at considerably\nless than one of stone; they have also applied the same \"principle\nwith a more durable metal, viz. iron, the bars being grooved and\ntongued into each other.\nThe wooden bridge, erected by Mr. Bull, over the River\nCalder, at Mirfield, Yorkshire, for the use of the leading-horses,\nis also worthy of notice: it is 147 feet 6 inches span, and\n11 feet versed sine; the arch is composed of two ribs of fir\nDigitized by\nGoogle\nBRIDGE.\n43\ntimber, with cross stays and diagonal braces, the whole well\nbolted together.\nBridge at Mirfield.\nThere have been several arches of large span executed with\ntimber, in Germany and in America-as the Schuylkill Bridge,\nat Philadelphia, of three arches, the centre one of which is 195\nfeet span, and the side ones 150 feet; also, the upper Schuylkill\nBridge, of the same city, consisting of one arch, 340 feet span,\nthe rise being only 20 feet, the which is the largest arch in the\nworld.\nThe floods form the principal difficulties to guard against in\nbridges connected with rivers and canals; and their effect upon\nthe nearest adjacent bridges and arches should be carefully\nascertained previous to deciding upon the width of the arches\nor openings of the intended works. The traffic should be\nconsidered next, and sufficient width left for it between the\nparapets.\nThe number of bridges required for a railway varies in almost\nevery instance. There are about two in a mile on the Liverpool\nand Manchester Railway, exclusive of the viaducts. The pro-\nportion of bridges on the Leeds and Selby Railway is about\n21th; but the London and Birmingham does not average 11\nbridges 'per mile. The mean of nearly 100 railways have been\nfound to average 21 bridges per mile.\nThe term bridge is also applied to any horizontal beam sup-\nporting something.-See Arch, Bow-string Bridge, Draw-bridge,\nIron-bridge, Suspension-bridge, Swivel-bridge, and Catanarian Curve.\nBUFFER-HEADS.-See Buffing Apparatus.\nBUFFING APPARATUS, a contrivance for receiving the shock\nG 2\nDigitized by\nGoogle\nElevation of Schuylkill Bridge. Longitudinal Section.\nBRIDGE.\nDigitized by Google\nElevation of the Upper Schuylkill Bridge. Longitudinal Section.\nBUFFING APPARATUS.\n45\nof a coalition between railway carriages, con-\nsisting of powerful springs and framing.\nThe buffing apparatus, first used upon\nthe Liverpool and Manchester Railway,\nconsisted of elliptic iron springs, or bows,\nof several thicknesses, placed transversely\n:\nacross the middle of the frame-work of the\ncarriage which received the shock of what-\never blows or jirks the buffer-heads might\nreceive, by the aid of rods communicating\nwith the same, to which method the following\nhas been considered an objection :-If the\nseveral carriages are not loaded equally, the\nframes do not range upon the same level\nwith each other ; and when this is the case,\nthe buffer-heads consequently do not strike\nSection of Bergin's Buffing Apparatus.\neach other in the centre, whereby the rods\nbecome bent, and the whole apparatus is\nliable to get twisted to remedy which,\nMr. Bergin, of Dublin, contrived an im-\nproved buffing apparatus for the carriages of\nthe Dublin and Kingstown Railway. - See\ncut.\nIt is supported upon the axles of the\nwheels, and is totally unconnected with the\nframe of the carriage, whereby it does not\npartake of the rise and fall of the latter,\naccording to the weight acting upon the ver-\ntical springs; and two strong iron rods are\npassed through the whole length of the car-\nriage, which rest upon small rollers, to which\nthe buffer-heads are attached, spiral springs\nbeing wound round them, which receive the\neffect of all shocks, by the help of collars\nformed upon the rods, and the introduction\nof stops to the springs.\nDigitized by Google\n46\nBURN-BUSH.\na, a, are plates of sheet iron, 1ˢσth of an inch thick, and placed\n3 inches apart from each other (being fastened together by\nrivets) ; they rest on turned bearings on the middle of the axles,\nand are fixed to an iron frame, i, i, i, i, which rests against the\ncross sheaths, k, k, k, k, and framework of the carriage, but are\nnot attached to it. g,g, are strong iron rods, passing from one\nend of the frame to the other, the buffer-heads, h, h, with the\ndragging-chains attached, being fixed at each extremity ; these\nrods pass through the hollow tubes, d, d, d, d, resting upon rol-\nlers, f,f,f,f, which enables them to move backwards and forwards\nwith freedom. e, e, are the collars which compress the springs\nand b, b, are the axles of the wheels.\nThis system is found to answer very well, although there are\nseveral modifications of the former description of spring in\nsuccessful operation, as the following; and Mr. Booth's patent\ndraw-links are now always employed to conduct the carriages\ntogether (see Draw-link). A patent has lately been taken out by\nMr. Burstall for a pneumatic carriage-spring, railway-buffer, and\nelastic-drag, the elastic properties of air being taken advantage\nof for the same ; a flexible vessel, as catouch, is placed, air tight,\nin a metal cylinder, when the shocks of the buffer-heads are\ncommunicated to these elastic springs by means of piston-rods\nand pistons.\nBURN, a provincial name for a brook.\nBUSH, a piece of metal, usually made of hard\nbrass, and fitted into a plumber-block, in which\nthe journal turns ; they are also sometimes\ntermed pillows, and the blocks, pillow-blocks.\nThe guide of a sliding rod is also termed a bush,\nthus :-A, the piston-rod ; B, B, the bush.\nDigitized by\nGoogle\nBUTTERFLY VALVE-CANAL.\n47\nBUTTERFLY VALVE, a description of clack-valve.-See Clack-\nvalve.\nCAISSON, a large water-tight floating-box, used for the purpose\nof putting in the foundations of the piers of bridges, &c., which\nsystem is generally employed in rapid rivers: a suitable pit is\nfirst dug, to receive the caisson and after one or two experiments\nare made, to ensure that they perfectly suit each other, it is per-\nmanently sunk, and the masonry commenced from within it (the\ntop of the cassion being above high water-mark), and carried up\nlevel with the water, when, by a contrivance, the sides are re-\nmoved, and the pier is left resting firmly upon the bottom grating;\nand they should be protected by sheet-piling all round, similar\nto the piers of most river bridges. The bridges of Westminster\nand Blackfriars were built on caissons; but coffer-dams are gene-\nrally employed at the present time, as the foundations of both\nthe above bridges appear defective, and are now undergoing\nrepairs.\nCAMBER, a term applied to the rise given to girders and beams\nin their centre, as an allowance for the sinking, which usually\noccurs after being hoisted and fixed.\nCANAL, an artificial cut in the ground, prepared for the recep-\ntion of water, with which it is supplied, either by means of rivers\nor springs, &c., thereby constituting a means of internal commu-\nnication, the which is principally confined to the conveyance of\nheavy articles.\nCanals were not unknown to the ancients, although their re-\nvival in modern times is comparatively recent; they were not\nused in this country, at least since the time of the Romans, until\nthe year 1755, from which period they have spread throughout\nthe whole kingdom; and the competition, presented at the present\nday by the several railways, has given a great impetus to im-\nprovements upon them; the boats have been improved, and new\nmachinery employed at the locks, in order to accelerate the\ntraffic. Locomotive engines have also been tried, to propel the\nboats upon the Forth and Clyde Canal, by Mr. Macneill, and have\nDigitized by\nGoogle\n48\nCANAL.\ngiven every satisfaction : the engine runs upon a railway laid\ndown upon the towing-path.\nThe water-slopes of canals\ncan be constructed with a less\nslope than ordinary earth-\nwork, by reason of the sup-\nport which they receive from\nthe water, a proportion of 1½\nto 1 is generally found suffi-\ncient; and the water is pre-\nvented escaping by puddle-\ngutters and side lining, laid\nabout 2 or 3 feet in thickness :\nwhere the canal is in embank-\nment, bottom and side puddles\nare necessary, thus (see cut) ;\nSection of a Canal in Cutting. A, A,A, the Side Puddles.\nSection of a Canal on Level Ground. A, A, A, the Bottom and Side-lining.\nand where it is in cutting, or\nupon a level with the ground,\nvertical puddles on each side\nare generally sufficient; as\nshown on cut.\nBrooks are carried across\ncanals by culverts; or, in\nthe case of water being re-\nquired for its use, and the\nbrooks afford clear water, it\nmay run into a side basin\nto settle, and from thence\npassed into the canal, by pro-\nper sluices.\nThe sides and bottoms of a\ncanal are sometimes obliged\nto be walled throughout,\nowing to the filtering nature\nof the soil, the which is after-\nDigitized by Google\nCANAL.\n49\nwards lined over with good earth, to protect it from the effects\nof the boats, hooks, &c\nIn the practical execution of canals, a contrivance, called a lock,\nis usually resorted to, in order to convey the boats from one level\nto another; the several distances between them being termed\nreaches.\nThe resistance upon canals is generally allowed to be in pro-\nportion to the square of the velocity, provided the depth of\nimmersion remains the same; but if the vessel rises up in the\nwater by reason of the velocity, the resistance is lessened: thus,\nin some recent experiments made upon canals, it was found,\nthat, after a certain speed, the power of draught was dimi-\nnished instead of increased, which was caused by the gradual\nrise of the boat out of the water, owing to its particular con-\nstruction. A like effect is also supposed to take place with\nsteam-boats.\nThe power of draught of a horse upon a canal has been stated\nto be from 20 to 30 tons, at about two miles an hour; and a\nhorse can draw a greater weight on a wide canal than on a\nnarrow one, viz. about ¹ᵗʰ more.\nThe following Table will show the cost of conveying goods\nand passengers upon canals, at different rates of speed, accord-\ning to Mr. Macneill's tables :-\nRate of\nCost of\nResist-\nGeneral\nAggregate charges.\nDescription of\nspeed,\nCost of\nboat-hire,\nin miles\nance,\nhaulage, per ton\n&c.\nexpenses\nper ton,\nper mile.\nper ton\nper ton\nboats.\nUseful load,\nGross load,\nper\nin lbs.\nhour.\nper mile.\nper mile.\nper ton per mile.\nper ton\nper mile.\nd.\nd.\nd.\nd.\nd.\nSlow boats\n21\n2.73\n0.18\n0.32\n0.86\n1.36\n1.02\nFly boats.\n4\n7.07\n0.5\n0.66\n2.34\n3.5\n2.275\n0.275 per\n1.08 per\n10. per\nSwift boats\n10\n56.8\npassenger,\n9.7\npassenger,\nton.\n3.5 per ton.\n13.25 per ton.\nH\nDigitized by Google\n50\nThe following Table gives the comparative cost of goods and passengers on canals and upon\nrailroads, both with horse and locomotive power on the latter :-\nreception of a shaft or axle, in which the latter revolves.\nCARRIAGE, a seat formed in any framing, and adapted for the\nCANALS.-HORSE POWER.\nRAILWAYS.-HORSE POWER.\nRAILWAYS.-LOCOMOTIVE POWER.\nRate of speed in\nmiles per hour.\nResistance, per\nton in lbs.\nCost of\nCost of\nhaulage and\nconveyance,\nboat-hire, per ton\nper ton\nper mile.\nRate of speed in\nmiles per hour.\nResistance, per\nton per mile.\nCost of\nCost of\nhaulage and\nconveyance,\ncarriages, per ton\nper ton\nRate of speed in\nmiles per hour.\nResistance, per\nton in lbs.\nCost of\nCost of\nCharges of\nhaulage and\nconveyance,\nconveyance,\ncarriages, per ton\nper ton\nper ton\nper mile.\nper mile.\nper mile.\nper mile.\nper mile.\nper mile.\nCARRIAGE.\n*\n21\n0.5d.\n1.36d.\n8.5\n0.565d.\n1.065d.\n{\n1.065d.\n2.73\n21\n0.75d.\n1.65d.\n8\n8.5\n1.565d.\n4\n7.07\n1.16d.\n3.5d.\n4\n8.5\n1.127d.\n3.627d.\n12\n8.5\n0.727d.\n2.138d.\n3.5d.\nHaulage.\n0.275d. per\n1.08d per\n0.25d. per\n1 to 1.5d.\n0.25d.\n0.675d. per\n1d. to 14d.\nDigitized by Google\n10\n56.8\npassenger,\npassenger,\n10\n8.5\npassenger,\nper pas-\nper\npassenger,\nper pas-\n3.5d. per\n13.25d. per\n2.24d. per\nsenger,\n20\n8.5\nsenger,\nsenger,\nton.\nton.\nton.\n15d.perton\n0.73d.\n2.855d. per\n12.37d.\nper ton.\nton.\nper ton.\nSee Lock, Lock-gates, Clough, and Elbow.\nCARRIAGE-CEMENT.\n51\nCARRIAGE (railway). The carriages employed on railways are\nbuilt in a variety of styles, and are usually mounted on wooden\nframes situated above the wheels, the bearing of the axles being\non the outside of the same; high wheels are, therefore, very in-\nconvenient: they are connected together by a draw-link, or\nchain. The patent draw-link, by Mr. H. Booth, is now much\nemployed; the carriages are also protected from the effects of\nshocks that might result from their striking against each other\nby the buffing apparatus.\nThe employment of low-bodied carriages is a great preven-\ntative of serious accidents, as they preserve their equilibrium\nbetter than high ones; they are, therefore, particularly suitable\nto viaduct lines, as the Greenwich Railway, where they are\nupon Curtis's improved plan, the bodies being suspended from\nthe springs, instead of being placed on them a less draught is\nalso produced upon the engine by them, as a train of low-bodied\ncarriages will approach nearer the line of traction, which is situ-\nated at the level of the rails.\nThe first-class railway carriages are extremely convenient, and\ncostly: perhaps those on the Great Western are the most perfect,\nbeing from 18 to 21 feet long, and 8 feet wide, and of sufficient\nheight for a person to walk about in; the second class are not so\nwell fitted up and the third class, when employed, are generally\nopen at the top and sides.-See Axle, Bearings, Buffing Apparatus,\nWheel, &c.\nCATANARIAN CURVE, the curved line, described by a chain,\ncord, or other flexible body, when hanging freely from two fixed\npoints, whether they be horizontal or not; which form of curve\nis considered by some mathematicians to be the best for arches\ngenerally.\nCATCHWATER DRAINS, drains laid along the side slopes of\ncuttings, the which generally run in an oblique direction, and\nconvey the water into a culvert or cross drain.\nCAUSEWAY.-See Road.\nCEMENT, a composition of several mineral substances, natu-\nDigitized by Google\n52\nCENTRES.\nrally combined or artificially prepared, which become hard upon\nmixture with lime and a small portion of water. Every kind of\nstone-lime, when well burnt, becomes a very durable cement ;\nand none other was used in this country until the introduction of\nroman cement, which is now very extensively employed.-See\nLime, Hydraulic or Water-lime, and Roman Cement\nCENTRES (of arches), the wooden frames or moulds used in\nthe construction of arches, for the support of the voussoirs or\narch-stones, during the course of execution.\nThe construction of the centres of bridges over rivers is of\ngreat importance. In cases where a communication is not re-\nquired under the arches during the execution of the works, the\ncentres may be constructed with a level tie-beam, which lessens\nthe difficulties attending the same exceedingly ; but it is gene-\nrally necessary to form them in such a manner that the navigation\nshall not be impeded : where head-room is left above the spring-\ning of the arches, such centres are termed cocket-centres.\nThe following cut represents the form of centre used in the\nconstruction of Blackfriar's Bridge :-\nElevation of one of the ribs, forming the centre of Blackfriar's Bridge.\nThe centres used in the construction of bridges were formerly\nremoved piece by piece upon the completion of the arches: the\npractice of \"striking them\" (as technically termed) by driving\nwedging-pieces between two striking-plates fixed in each side, is\nemployed at the present time, which has the effect of lowering\nthe centre, whereby the arch is left standing without support ;\nDigitized by\nGoogle\nCHAIN.\n53\nthus it may be gradually eased in every direction simultaneously,\nwhich prevents any unequal pressure or strain. The best way of\nsupporting the striking-plates, upon which the whole of the\nframing rests, is by struting, or raking-pieces resting upon sills\nlaid upon the top of the footings.\nThe system of supporting centres by rows of piles driven in\nthe bed of the river should not be resorted to, unless the span of\nthe arch is of such extent as to prevent any other mode of ex-\necution, or the foundation is particularly safe ; but even then\nthe work is likely to suffer, unless the framing is exceedingly\nwell balanced and secured together.\nMr. M. I. Brunel has recently succeeded in erecting an arch\nwithout centres of any kind.-Upon the piers being built, the\nribs, by his method, must be carried forward from each side at\nthe same time, whereby the equipoise is preserved; and when\nthose of opposite abutments arrive sufficiently near to each other,\nthe key-stones must be fixed ; the bricks, of course, to be set in\ncement, and iron hooping or lathing is intended to be laid\nbetween the courses.-The experimental arch above alluded to\nwas carried out a distance of 60 feet, it would, therefore, have\nformed a segmental arch, 120 feet span, the rise being no more\nthan 11 feet ; and the whole was ,built from above by hanging\nscaffold.\nThe angle of friction of ordinary cut stone is about 30° with\nthe horizon; when laid in thin tempered mortar it is from about\n34° to 36° ; and with very porous stones laid in full mortar it is\nnearly 45° ; therefore a centre is unnecessary for those voussoirs\nlaid at a less inclination than the above respectively, while\nthose exceeding it must be duly supported until the key-stones\nare set.\nCHAIN, or LAND, CHAIN, a measure used in measuring land,\nDigitized by\nGoogle\n54\nCHAIR.\nconsisting of a number of links connected together by rings.\nGunter's chain, which is that generally used, is composed of 100\nlinks, and is equal to 66 feet or 4 poles in length : one square\nchain is 10,000 links, or 16 poles; and 10 square chains 100,000\nlinks, or 160 poles make one 1 acre.\nThe chain should invariably be stretched out on level\nground and measured, previous to commencing operations, by a\n10 feet rod, and if found too long, corrected by removing some\nof the rings or shortening the links, the corrections being made\nequally from each end, and from the centre: if any considerable\nerror exists it should be distributed equally over the ten divisions\nof the chain. It is also customary with some surveyors to mark\nout a chain correctly on some convenient spot, as a standard to\nrefer to from time to time. Chains, double the length of\nGunter's, are also used, and preferred by some, on account of\ntheir expediting the work and 50 feet, also 100 feet chains,\nmay be advantageously employed in a survey, as for streets, roads,\ncanals, and railways, where the superficial contents are not the\nimmediate motive for the survey, it being necessary to return to\nthe 66 feet chain in reducing the quantities to acres.\nCHAIR (railway), a pedestal or socket, of cast-iron, used upon\nrailways for receiving and securing the rails, and generally\nweighing from 12 to 20 lb. each.\nThe chair for receiving the ends of two\nrails is termed a joint, or double chair; and\nthese are of larger size than the others,\nwhich are called single, or intermediate chairs.\nThe chairs are fastened to the blocks by oak\ntrenails and iron pins : a hole, 2 inches in\ndiameter, being first drilled in the block, into\nChair on the Birmingham Railway\nwhich the oak trenails are driven a 1 inch hole is then bored in\nthe latter by an auger, and the iron pin passed through the seat of\nthe chair and drove securely into the trenail, a piece of felt being\nintroduced between the seat of the chair and the block, to ensure\na firm bearing. When sleepers are employed, the chairs are\nsecured to the sleepers by means of iron spikes.\nDigitized by\nGoogle\nCHAIR.\n55\nIt is very desirable to get such a form of chair as will adapt\nitself to any settlement of the block without deranging the rail,\nby either forcing it up or down. Mr. Nicholas Wood, in his\nPractical Work on Railways, states, that none of the many\nchairs at present in use, which receive the ends of the rails in\ntheir sockets bodily, effect this. A rail which merely rests on\nthe chair at a single point, partly obviates it but a mere pin,\npassing transversely from one cheek of the chair to the other,\nand through the rail, will best accomplish it. This formed an\nexcellent mode of securing cast-iron rails, as they were made\nin lengths equal to the bearing between each chair only; but\nit is unnecessary with wrought-iron rails, except at joint chairs,\nin which case the rails must be halved and lapped at the ends,\nto allow of the passing of the pin through each of them; although\nsquare jointing is employed on most lines of railways, being the\ncheapest.\nThe chairs should be formed as little wider than the rails as\npossible, by which they would be more likely to escape the wheels\nin the event of an engine running off, and consequently concussion:\nand the means adopted to confine the rails within the chairs should\nbe as simple as possible: the most general plan of securing\nthem at the present time, is by driving a key, in a horizontal\ndirection, within the space between the cheek and the rail an\nSection.\nElevation.\nPlan.\niron key was originally used, but\none of oak has been found to answer\nthe purpose best; although there are\nmany other varieties of chairs and\nView of chair.\nfastenings.\nMr. Robert Stephenson took out a patent, in 1833, for the\nfollowing chair, the principal improvement in which consisted in\nDigitized by\nGoogle\n56\nCHALK.\nthe self-adjusting seat for the rails to rest on, and the mode of\nfastening the same ,-\nFig. 1.\nFigure 1 is a plan of the chair, &c., a a\nz\nbeing the rail.\nFigure 2 is an end elevation.\na\nFigure 3 represents a transverse sec-\ntion of the chair, b b being the pins\nthrough which the cottars are passed to\nsecure them ; and c the segmental bear-\nPlan.\ning-piece, which lays loose in a socket prepared for it in the\nbottom of the chair.\nFigure 4 is a perspective view of a joining, showing the halving\nof the rails.\nFig. 2.\nFig. 3.\nCross Section.\nElevation.\nFlg. 4.\nView of joining of rail.\nCHALK, a calcareous earth, of very soft substance and of a fine\nwhite colour, with a yellowish tint when mixed with iron. It is\ngenerally found in thick beds, nearly horizontal, with thin layers\nof flints intervening, and containing a great quantity of dis-\norganized matter. Mr. Kinman gives the following analysis of\nchalk when in a pure state :-\n3 of water.\n53 \" lime.\n42 \" carbonic acid.\n2,, alum.\n100 total.\nDigitized by Google\nCHEEKS-CHIMNEY\n57\nThe Tring cutting, on the London\nand Birmingham Railway, is taken\nthrough this material, in which many\nElevation of top.\nfossils were discovered.\nChalk will stand at a very steep in-\nclination, if executed in steps or ledges.\nLime prepared from chalk is very\nserviceable for building purposes, al-\nthough it is not generally considered\nequal to stone lime; but Dorking, and\nother excellent limes, are obtained from\nchalk quarries\nCHEEKS, those parts of machinery\nwhich are double, and enclose other\nparts.\nCHIMNEY, a long funnel or aper-\nture, erected for the purpose of draw-\ning off the smoke from a furnace, and\nthe like, which operates as follows, viz.\nas the column of air in the chimney\nbecomes heated, and consequently\nrarified, its specific gravity or weight\nis thereby reduced, when it effects an\nescape at the top of the chimney, cre\nating a draught up it from the furnace\nand the higher the chimney the greater\nwill be the power of draught. The dense\nblack smoke, so often seen escaping\nfrom chimneys, is composed of a quan-\ntity of unconsumed fuel; it is, there-\nfore, a great object to prevent this waste,\nA\nby consuming the smoke in the furnace,\nthe pernicious effects of it upon the at-\nmosphere is also thereby removed.\nIn erecting chimneys, from 70 to 90\nI\nA, A, Level of the Rails.\nDigitized by Google\n58\nCHIPPING-PIECES-CLACK-VALVE\nfeet high, it is a common rule to make them 20 inches square at\nthe top for each horse power of the boiler, giving an area of 400\nsquare inches and the draught is not improved by increasing\nthe height much beyond 40 or 50 yards, unless the width be\nincreased in a similar ratio.\nThe two chimneys connected with the stationary engines that\nwork the Euston-square plane, on the London and Birmingham\nRailway, are 132 feet 4 inches high, and have a very elegant\neffect; they are nearly 13 feet in diameter at the base, and about\n5 feet 6 inches at the top, and the greater part of each is carried\nup in 1½ and 2 bricks only, the bases being rather more (see cuts).\nCHIPPING-PIECES, the projecting pieces of iron cast on the\nfaces of iron framing, when intended be rested against each\nother ; the chipping-pieces, therefore, become the points of\ncontact.\nCHOCK, a filling in piece, or loose block of iron or wood, in\nany machine or contrivance.\nCIRCUMVERENTER, an instrument, used in surveying, for\ntaking angles by means of the magnetic needle, and employed\nwhere great accuracy is not required, excepting in the line of the\npermanent direction of the needle.\nThe magnetic needle is enclosed in a compass-box, which is\nmounted on a pivot in the head of a three-legged stand, the cir-\ncumference of the box being divided into 360 parts, or degrees,\nand the latter is furnished with two sights on opposite ends of\nthe meridian line, or 180°.\nIn taking the angle between two objects with it, the box is\nturned until one of them is seen through the sights the number\nof degrees to which the south end of the needle points is then\nnoted, and the box is again turned until the second object is seen,\nwhen the degrees pointed to by the needle are again noted, and\nthe difference between the two numbers is the quantity of the\nangle.\nCLACK-VALVE, a valve much employed in hydraulics, con-\nsisting of a circular piece of leather covering the bore of the tube\nDigitized by\nGoogle\nCLAYING-COAL-MINE.\n59\nin which it is fixed, and moving by a hinge,\nsometimes consisting of metal, at other times\nof leather. When two semi-circular valves of\nthis description are employed, and attached to a\nbar placed across the tube, it is called a butter-\nfly valve, which is considered an improvement on the common\nclack-valve.\nCLAYING, the operation of puddling.-See Puddle.\nCLINOMETER, or BATTER-LEVEL, an instrument employed in\nmeasuring the slopes of cuttings and embankments; it consists\nof a quadrant graduated to degrees, and fixed at the end of a flat\nbar which is laid along the slopes, and an index turns upon the\ncentre of the quadrant to which a spirit level is attached; there-\nfore, upon the bar being laid lengthways across the slope, and\nthe level set horizontally, the angle of the same will be indicated\non the quadrant, as the latter partakes of the motion of the rod.-\nSee Slope.\nCOAL-MINE. The working of coal-mines differs from stone\nquarries, inasmuch as the latter are generally laid open to the\nlight, and worked from pits at the surface; while those of the\nformer are worked by means of shafts, which are sometimes of\nvery great depth, the coals being drawn up to the surface of the\nground by a steam-engine. There are no instances in this country\nof coal-measures, or beds, lying sufficiently near the surface to\nbe laid bare and worked in open day ; nor are they met with in\nthe sides of hills, where the mines could be pushed forward in a\nhorizontal direction.\nThe method of working coal-mines differs throughout the king-\ndom, being regulated by the various local circumstances and\ncustoms; and that class of civil engineers, who devote their atten-\ntion exclusively to the subject of coal-mines, are designated\ncoal or colliery viewers.\nIn the Newcastle coal-field the amount of capital necessary to\nwork a mine varies from £10,000 to £15,000; they are gene-\nrally leased from the proprietors, the lessees being termed\n12\nDigitized by Google\n60\nCOAL-MINE.\nadventurers the extent of the mine is marked out on the surface\nof the ground, the coal has then to be won, i. e. obtained pos-\nsession of. The risk attending the winning of a field of coal is\nvery great quicksands are frequently encountered in sinking the\nshaft, and great quantities of water occur at certain parts of the\nstratification, generally at about 250 or 300 feet, which is\ndammed back by tubes, or iron pipes.\nThe shafts vary in depth from 40 or 50 to 1,000 or 1,200 feet\nbesides the working shaft, another is also required to draw up\nthe water and ventilate the mine, and these are independent of\nventilating-shafts, which are required at every 100 yards distance.\nThe weight of water drawn up is frequently ten times greater\nthan that of the coal. A steam-engine is fixed at the pit's mouth\nto draw up the coals, and they are also employed below in deep\nmines with very great advantage, in which case the shaft goes\nonly a part of the way down, when inclined planes are made to\nthe bottom, the which are worked by another steam-engine, fixed\nat the top of the plane. The coal is worked in galleries laterally,\nor in the direction of the seams; pillars being left to support\nthe top strata, forming the roof. In Staffordshire the whole of\nthe coal is removed, and the roof allowed to fall in, precautions\nbeing taken for the safety of the miners : sometimes the roof does\nnot give way, in which case immense vacant spaces or voids are\nleft, which, in course of time, become filled with water, to the\nimminent danger of the adjoining mines, as they may acciden-\ntally open into one : mines have frequently been drowned by this\ncircumstance.\nThe presence of fire-damp is another fearful occurrence to\nwhich coal-mines are subjected; the coal, in its natural bed,\ncontains a great quantity of free uncombined gas, which is dis-\nengaged by the action of the air occupying the place of the\nstrata excavated, and on account of its being relieved from the\ngreat pressure exerted upon it by the latter the lower the strata\nthe greater will be the quantity of gas evacuated, as it partly\nescapes from the upper beds by means of the fissures a great\nDigitized by\nGoogle\nCOCK-COFFER-DAM.\n61\nescape of gas takes place under ordinary circumstances, as it is\nin continual process of distillation from the lower coal-measures,\nand it accumulates in all the fissures of the stone where it\nacquires a highly condensed state; these fissures are frequently\nmany miles in extent; and if the miners cut across one of these,\nor approach sufficiently near, the elastic force of the compressed\ngas causes an eruption, when it rushes out with immense force,\nand in vast quantities: these currents are termed blowers, and\nhave been known to continue in action from two to three years.\nNaked lights in mines are wholly inadmissible, as, upon the\napproach of a candle, the gas instantly explodes with a report\nlike gunpowder, often causing lamentable accidents. Light was\nformerly obtained in mines by steel mills; a small steel wheel,\nabout 6 or 7 inches diameter, was moved with great velocity, and\na piece of flint was presented to it, when a stream of sparks was\nemitted; the light thus obtained was very feeble, and not alto-\ngether free from accidents with certain gases. The safety lamp\nof Sir Humphry Davy is now universally employed, which\nconsists of a vessel for the reception of the oil, and a cover of\nfine wire gauze enclosing the wick, which is generally locked on\nto prevent its removal; upright frame wires surround the cover,\nterminating at the top by a sort of cap, in which there is a ring\nfor carrying it. The principle of the davy, as it is called by the\nminers, consists in the circumstance of fire-damp not exploding,\nunder any degree of heat, provided flame is not present; and the\nfact discovered by Sir Humphry, that flame could not pass\nthrough short tubes of very fine bore, which the gauze may be\nsaid to represent. The lamp subsequently received some im-\nprovement in the shape of reflectors placed above it, whereby the\nlight was concentrated.-See Mine.\nCock, a sort of revolving valve, fixed in a pipe, for the pur-\npose of stopping the passage of any fluid through it when\nrequired.\nCOFFER-DAM, a water-tight enclosure, used in putting in the\nfoundations of bridges, sea and river walls, &c. (which are en-\nDigitized by\nGoogle\n62\nCOFFER-DAM.\ncircled by the same) when the work cannot be done between the\ntides, on account of the water constantly covering the site.\nCoffer-dams are\neither of a cir-\ncular, oval, or\noblong form, and\nconsist of one or\nmore close rows\nof sheet piling,\nrising above high\nwater-mark, and\nbolted transversely toge-\nPlan of the Coffer-Dam used for the Piers of Staines' Bridge.\nther, having a large body\nof clay well punned be-\ntween each row, with\nstays, raking-piles, and\nbraces, at the back of the\nsame, to support the\npressure of the water on\nthe outer side. Upon the\ncompletion of the dam,\nthe water enclosed by it\nis pumped out, and the\nPortion of the Coffer-Dam used for the Piers of London Bridge.\nfoundations carried up.-See Piles.\nSection of the Coffer-Dam and Wall of the New Houses of Parliament.\nDigitized by Google\nCOGS-CONICAL WHEELS.\n63\nCoGs, the teeth employed on wheels and racks in machinery,\nconstituting their means of action.\nCoG-Wheel, a wheel having a number of cogs placed round\nits circumference.\nCOKE, a mineral charcoal, a fuel much employed for steam-\nengines; it is obtained by burning coal to a red heat, in heaps,\nproperly covered, to prevent exposure to the air: the bitumen,\nand other gaseous substances, are thus drawn off, leaving a\ncinder behind, such as is left in the retorts employed in gas-\nworks.-See Fuel.\nCOLLAR, or GLAND, a term applied generally to a circular\npiece fitting into another, for the purpose of holding it in its\nplace, as a metal plate screwed down upon the stuffing-box of a\ncylinder to keep the former in its place.\nCOMPASS, an instrument for determining the angle of any\nparticular object with the meridian, which is effected by looking\nthrough sights placed on the margin of the instrument, and then\nreading off the degrees and minutes pointed to by the needle,\nthe which gives the angle formed with the magnetic meridian;\nthe variation of the same at London, with the true meridian,\nbeing about 231 degrees westward of north at the present time.\nCONCENTRIC ENGINE.-See Rotatory-Engine.\nCONCRETE, an artificial cement, principally employed in the\nfoundations of structures: it is composed of good lime, gravel,\nand sand, in the proportion of about 1th to }th of lime, and it\nshould be laid in about 12 inch layers or courses, and pitched\ndown by barrows from a height of 10 or 12 feet, and it should\nnot be disturbed until properly concreted and set, when it may\nbe levelled, the footings laid upon it, and the walls carried up.-\nSee Foundations.\nCONDENSING ENGINE.-See Low-pressure Engine.\nCONDUIT, a passage, pipe, or canal, for conveying water, or\nany other fluid.\nCONICAL VALVE.-See Safety-Valve.\nCONICAL WHEELS.-See Bevel Gear.\nDigitized by\nGoogle\n64\nCONSTANT-CONTINUOUS BEARINGS.\nCONSTANT (railway). The term constant is applied to certain\nfixed quantities, both in nature and art, the which are supposed\nto be conclusive, as the height which a body falls in a second of\ntime, the ratio of the circumference of a circle to its diameter,\nand as applied to railways; it refers amongst others to the pro-\nportion which the tractive power necessary to move a train\nbears to the weight of the latter, which is stated at 280 to yoo,\nvarying according to the perfection of the carriage and railway\nexperimented upon.-See Railway, Adhesion, and Angle of\nRepose.\nCONTINUOUS BEARINGS, the method originally employed of\nlaying rails, in this country, consisting of longitudinal sleepers\nsecured to transoms.\nThe system of continuous timber bearings has been con-\nsiderably improved, and much used in America, where it has\nbeen found very suitable, on account of the abundance of timber\nin that country, and the scarcity of iron.\nThe plan of forming the line of the Great Western Railway\nmay also be described as a return to this system. The longi-\ntudinal or continuous bearings being from 5 to 7 inches in depth,\nand 12 to 14 inches in breadth, and laid down in about 30 feet\nlengths, securely bolted to cross transoms, 6 inches broad by\n9 inches deep. There is a double transom at the joinings of the\nlongitudinal beams, and a single one between them, thus they\nare single and double alternately. Piles of beech are driven\nwithin each tract at nearly midway between the rails, 10 inches\ndiameter, and 12 feet long, to which the transoms are secured\nby horizontal bolts; and there are, therefore, two piles to the\ndouble transoms (which are situated between them), and the same\nnumber to the single ones. When the piles and timbers are\nproperly fixed and secured together, sand, or fine screened\ngravel, is beat or packed underneath the longitudinal bearers,\nuntil the spaces between the piles are forced upwards, and a firm\nbed is obtained; and the rails, weighing about 44tb. per yard,\nare then laid. Mr Nicholas Wood, in his excellent Work upon\nDigitized by\nGoogle\nCONVOY.\n65\nMode of forming the Great Western Railway.\nLongitudinal Section.\nPlan.\nTransverse Section.\nRailways, states, that the whole\nstability or superiority of this rail-\nway over other wooden railways,\ndepends entirely \"upon the retain-\ning power of these piles.\"\nCONVOY (to railway carriages).- -\nSee Brake.\nDetails of Rail.\nK\nDigitized by Google\n66\nCOPPER MINE-COUNTERBALANCE\nCOPPER MINE. The principal copper mines in this country\nare those of Cornwall, some of which are of prodigious extent,\nand the metal is contained in veins, termed lodes, which are gene-\nrally inclined, sometimes considerably so; they are generally\nfrom 3 to 6 feet wide, but occasionally much more. After a\nvein has reached a certain depth, generally somewhat considerable,\nit gradually diminishes in size, and is not pursued any farther\nby the miners.\nThe consolidated mines of Cornwall are by far the most ex-\ntensive in Europe, and are of wonderful extent and depth, being\n1,652 feet from the surface, which is the deepest excavation in\nthe kingdom; the amount of the several shafts exceeds 20 miles\nof perpendicular excavation, and the various levels, or ways\ndriven from them, amount to about 47 miles; the machinery con-\nsequently required for drainage and other purposes exceeds any\nsimilar combination in the world.-See Mine.\nCORE, the internal mould or body upon which a tube or pipe is\ncast, by which the hollow or hole within is formed.\nCORNICE, a collection of mouldings, used in bridges and other\nworks, being plain or enriched, according to circumstances\nthey are sometimes executed with projecting blocks in the lower\npart, when they are called blocked cornices.\nCOTTAR.-See Key.\nCOUNTER, a contrivance connected with a steam-engine, for\nthe purpose of showing the number of strokes that are made in a\ngiven time: it consists of a train of wheel works, resembling that\nof a clock, and so contrived that at each stroke of the piston-rod\na small detent is moved one tooth; it is very useful for regu-\nlating the consumption of fuel.\nCOUNTERBALANCE, or COUNTERBALANCING WEIGHT, a weight\nemployed to counterbalance the vibrating parts of machinery\nupon their axes, causing them to turn freely, by which a very\nlittle power is required to put them in motion, as the counter-\nbalancing weight of a drawbridge, &c. A lever, acted upon by\nany force, is also frequently returned to its position by a counter-\nDigitized by\nGoogle\nCOUNTERFORT-COWL.\n67\nbalancing weight, as in the case of the beam of a single acting\nsteam-engine, &c.\nCOUNTERFORT, a pier or buttress, generally applied at the\nback of retaining walls in modern civil engineering, for the sup-\nport of the same, and likewise for the purpose of forming a tie to\nthe material at the back of the wall. Counterforts are also some-\ntimes carried up upon the face of a wall.\nCOUNTERSUNK, the term applied to a screw, or other con-\ntrivance, when the bead is let in flush with the surface of another\nbody in which it is secured the head is bevelled round on the\nunderside, and the hole is similarly cut to suit it.\nCOUPLINGS, the means employed of communicating the action\nof one machine to another; thus, where several machines are put\ninto operation by the same steam-engine, the means of stopping\nany one of them, and of again restoring its motion without inter-\nfering with the others, is effected by couplings, of which there\nare many descriptions. The couplings mostly used are sliding-\nboxes, which move longitudinally upon shafts or axles, and\nengage or lock a shaft which is at rest with one in motion some-\ntimes they are provided with projecting teeth, called clutches, or\nglands, which catch on other teeth or levers, and thus lock the\nshaft together; at other times they have bayonets or pins, adapted\nto enter holes, and the connection is sometimes produced by the\nforce of adhesion only, the surfaces being flat, or conical : the fast\nand loose pulley is, perhaps, the most simple plan, which consists of\ntwo parallel band-wheels on the same axle, one of which is fast\nupon it, and the other loose. A common band may also admit of\neither motion or rest, accordingly as it is rendered tense or loose.\nThe force of the steam in a locomotive engine usually acts\nupon two wheels only; when all four are influenced by it, it is\ndone by coupling the other two to the driving-wheels.\nCowL, a wire cap, covering the top of a locomotive engine\nchimney, and intended to prevent the escape of lighted flakes of\nfuel, &c., being made of various shapes, although not employed\nupon all railways.\nDigitized by\nGoogle\n68\nCRAB-CRANE.\nCRAB, a small portable crane, used for raising materials, &c.,\nas the ram of a pile-driving machine, &c.\nCRADLE, or COFFER, the frame-work employed in perpen-\ndicular lifts, for holding the boats, and conveying them from one\npond to the other.-See Perpendicular Lift.\nCRAMP, a metal tie, used for securing the several stones of\na wall together. Cramps. are not much used in engineering\nworks, as the masonry is generally solid, and the blocks laid in\nlarge sizes, which, therefore, do not require them. Copper is the\nbest material for them, particularly when occurring externally\nbut iron is generally employed. A vertical cramp is termed a\ndowel, or plug; and each description of cramp should be well run,\nand covered with lead.\nCRANE, a machine employed at wharfs, warehouses, &c., for\nraising and lowering goods, materials, &c., consisting of a long\nprojecting arm, called the jib, having a pulley at the extremity\nof the same, over which the rope or chain passes, by which the\ngoods are raised, the other end being taken round a barrel\nattached to the foot of the jib. The great desideratum is the\nturning of the barrel with the least degree of power; and there\nhave been various plans for effecting the same. The handle of a\ncrane, called the vinch, should not be less than 2 feet 11 inches,\nor 3 feet from the\nground; and the\njib should have an\nangle given to it\nof about 45 de-\ngrees.\nThe annexed\na\nf\nf\ncut represents an\nelevation of one\nof the cranes em-\nployed on the\nk\ng\ng\nE\nRegent's Canal\nwharf:-\nDigitized by Google\nCRANK-CROSSING-POINT.\n69\na is an upright pillar of cast-iron, firmly fixed in a foundation\nof masonry, in the head of which there is a pin which supports\nthe jib b, and forms a pivot, round which it turns. d, d, are two\nstruts supporting the extremity of the jib, the lower ends resting\non a collar, which is suspended from the jib by iron rods, f,f,\nand passes all round the pillar. The barrel is supported by side\nframes, g; and k is the toothed wheel, whereby the barrel is\nput in action, which is turned by a winch and pinion. The\ncrane is turned round on its pivot by the winch m, which ope-\nrates on an intermediate wheel and pinion, and thereby turns the\nlower pinion n, which works in a wheel o, fixed in the base of\nthe pillar.\nCRANK, a short arm or lever, fixed to the shaft of any machine,\nand set in motion by a connecting rod proceeding from some\nother part of the engine, which has a reciprocating motion to and\nfro, by which it is conyerted into a rotatory one. Large fly-wheels\nare required to be fixed to the shaft where one cylinder is used,\nand a continuous motion is required, as they carry the crank\nround the dead points by reason of their greater weight and\nleverage. A crank usually con-\nsists of two limbs joined together\nby a pin, termed the crank-pin.\nAs the cranks of locomotives\nare very liable to fracture, straight axles are sometimes employed,\nand the wheels are turned by a connecting rod fixed to them on\nthe outside. Some manufacturers cut the entire crank and axle\nout of a solid piece of iron, which reduces the liability of acci-\ndents much.-See Steam-Engine and Steam-Boat.\nCROSSING (on a double line of railway), the necessary arrange-\nment of rails to form a communication from one line to the other.\nThey are similar in construction to sidings, having switches and\ncrossing-points.-See Siding.\nCROSSING (level).-See Level-Crossing.\nCROSSING-POINT, or FIXED POINT or POINT-PLATE (in rail-\nway sidings), the points where one rail crosses another, which\nDigitized by Google\n70\nCROSS-STAFF-CULVERT.\nare fixed or immoveable, suitable grooves being left for the pas-\nsage of the flanges of the carriage wheels on either trackway.-\nSee Siding.\nPlan and Sections of the Fixed Points used on parts of the London and Birmingham Railway.\nCROSS-STAFF (in surveying), a rod shod with iron, upon the\ntop of which a rectangular cross is fixed, for the purpose of\nsetting off offset-lines square with the principal ones, and similar\npurposes. It is also frequently divided into ten links, and used\nfor a rod for measuring the offsets, instead of the chain.\nCROWN, or CONTRATE WHEELS, a wheel employed for con-\nnecting the motion of one axis to another,\nsituated at right angles to it, thus—\nConical wheels are more frequently em-\nployed for the same purpose, on account\nof their possessing less friction.\nCUDDY, a three-legged stand, forming a fulcrum, upon which\na long pole is placed, which is used as a spring lever, and\nemployed to lay railway blocks.-See Block (stone as applied to\nrailways).\nCULVERT, a drain carried under a road, railway, &c., and\ngenerally constructed of either stone or brickwork.\nDigitized by Google\nCURVE.\n71\nCulverts are sometimes used for conveying the water of brooks\nfrom the high side of a road to the lower. It is necessary, after\nfixing the best situation for a culvert, to ascertain the quantity of\nwater that is likely to run in the direction of its course, previous\nto determining the\nsize of the bore.\nFigure 1, repre-\nsents a cross sec-\ntion through a cul-\n2\nvert.\nFigure 2, the\nhalf plan.\nFigure 3, eleva-\n3\ntion of mouth.\nFigure 4, the\nlongitudinal sec-\ntion.\nCURVE, a term applied to a bend in a line of road, canal,\nor railway.\nTurnpike roads should be formed as straight and direct as\ncircumstances will allow, and without any sudden bends; but\nthey are frequently obliged to wind round a hill in order to get\nup it, and a similar expedient is employed in the construction of\ncanals, to preserve the low level.\nSharp curves on a line of railway are highly objectionable, as\nthe centrifugal force arising upon them has a tendency to throw\nthe train off the rails: they should never be laid down with less\nthan 4ths of a mile radius; notwithstanding, many expedients are\nresorted to of obviating the difficulties attending them : the fric-\ntion is also increased, on account of the flanges of the carriage\nwheels rubbing upon the sides of the rails. The peripberies of\nthe wheels of railway-carriages are always enlarged in diameter\nnext the flanges, being made slightly conical, which compensates,\nio a certain extent, for the extra length of the curve of the\nouter rail. The tires of the wheels are usually made about\nDigitized by\nGoogle\n72\nCUTTING-D SLIDE-VALVE.\n1 inch more in diameter on the outside than on the inside, the\nbreadth of the same being 31 inches; and 1 inch is allowed upon\neach side of the rails, in fixing the wheels to the axles for play,\nby which they are not strained in passing along the curves.\nAn engine, with wheels 3 feet diameter, and of the above de-\nscription, will turn a curve 1th of a mile radius, provided the\nouter rail is elevated sufficiently to counteract the centrifugal force,\nby causing a gravitating power towards the centre of the curve\nThe degree of elevation necessary to balance the load depends\nupon the velocity with which the train is moving; upon a curve\n4ths of a mile radius, and traversed at a rate of 10 miles an hour,\nit should be .07 of an inch; and at 15 miles an hour .20 of an\ninch ; at 20 miles .36 of an inch ; but they are frequently elevated\nmuch more in practice. The least objectionable situation for\ncurves on a railway is at the extremities of the line, and the foot\nof an inclined plane is the most dangerous, more particularly if\nany portion of it should be in tunneling the objection also\nincreases with the speed of the train.\nA rise of 16 feet per mile upon a curve of 4ths of a mile\nradius, reduces the speed of a locomotive to nearly one-half; yet,\nthere is a curve of 4ᵗʰ of a mile radius on the Bolton and Leigh\nRailway, which is daily passed at a speed of 30 miles an hour,\nand with perfect safety.\nCUTTING, a name applied to excavations.-See Excavation.\nCUTWATER, the lower portion of a pier separating two arches\nof a bridge crossing a river; they are usually formed of stone,\nand pointed in front, for the purpose of dividing the stream,\nwhereby it is carried away from the foundations, and of cutting\nthe ice in frosty weather.\nD SLIDE-VALVE (in steam-engines), a valve\nb\nmuch employed for opening and shutting the com-\nmunications with the steam cylinder, particularly\nE\nin locomotive engines : its action will be readily\nunderstood by the cut. a is the steam-pipe;\nC\nb, the upper passage; and c, the lower passage to\nDigitized by\nGoogle\nDAM.\n73\nthe cylinder; d being the passage to the condenser or chimney,\nas the case may be; and E represents the slide-valve.See Four-\nway Cock.\nDam, or WEIR, a water-tight contrivance, for the purpose of\nsupporting a body of water, and preventing filtration.\nA dam usually consists of a wall, or mole, erected across a\nriver or stream, for the purpose of raising the level of the water\nby confining it, and which is employed for various purposes, as\nfor irrigation and for ornamental purposes; also for impelling\nmachinery, as water-wheels, in which case the wheel is not\nplaced in the current, but is mostly situated upon one side of the\nstream, the water being conveyed to it by a channel from the\nupper level, and after having passed over the wheel it finds its\nway to the lower level of the river by another channel, and the\nrequisite head of water is constantly kept up by means of the\ndam, which is furnished with proper means of passing off all\nsurplus water when the supply is greater than required.\nDams should be erected at the broadest parts of rivers, in order\nto secure a sufficient reservoir of water, as some mills, when at\nwork, require more water than the ordinary run of the stream can\nafford ; by means of these basins the supply is thus rendered\nregular, and the intermitting nature of the current obviated: the\nwater that accumulates in the night is also preserved by them.\nThe reservoir of a mill is called the mill, or dam-head: and the\nlarger the surface the better will it operate, but*a great depth is\nunnecessary; the water should run freely over the dam when not\nrequired, or in the event of floods, the channel to the mill being\nprovided with side walls and sluices.\nTimber framing is very frequently employed in the construc-\ntion of dams; but masonry is better, and, of course, the requisite\nprecautions must be taken to prevent any\nleakage of water from above. A thick bed\nof puddle should be laid next the upper side\nof the water, protected by a layer of gravel.\nLower Level.\nUpper Level.\nDams are usually made in the form of a\nL\nDigitized by Google\n74\nDAM.\nsegment of an arch on the plan, and the face of the dam wall\nshould be plumb, or battered down very gradually, and the\nlower level, or foot, being properly paved or planked. In cases\nwhere the fall is considerable, it is frequently divided into more\nthan one dam: they are also sometimes constructed upon a\nmoveable principle, and are removed in flood seasons.\nThe following is a representation of a dam, as generally con-\nstructed:-\nElevation of a portion of the front of\nDam Wall.\nPlan of Superstructure.\nUpper Level.\nLower Level.\nSection of Wing Wall.\nDigitized by Google\nDATUM-LINE.\n75\nTransverse Section through Dam, showing Wall, &c.\nSection of another method of forming the Dam Wall.\nDATUM-LINE, the base or horizontal line of a section, from\nwhich all heights and depths are calculated, and which is de-\ntermined by the level, and bears reference to some fixed point\nin the line.\nThe level of Trinity high water mark, as fixed in the year 1800,\nis usually taken as a datum in the vicinity of the metropolis; and it\nis often observed by engineers, that the adoption of one general\ndatum for England and Wales would be very advantageous.\nHigh water spring-tides form a good datum, as giving an idea of\nthe possibility of draining the line of country, marked on the\nsection. In extensive operations the mean level of the sea may\nbe taken, which, according to M. De la Laude's method, and\nadopted in the Trigonometrical Survey of England, may be\nobtained by taking the level of low water, and deducting there-\nfrom 3rd of the height the tide rises.\" The section may be made\nto refer to any other datum-line that may be required, differing\nfrom that to which a drawing may be plotted, by ruling a line\nabove or below it, of the requisite difference in level; and by the\nsame rule it is much easier to plot each portion of a section to a\nL 2\nDigitized by\nGoogle\n76\nDEFLECTION.\ndatum-line of its own, and afterwards rule the proper datum-line\nof the entire survey parallel to it, and in its proper situation.\nDEFLECTION, a term applied to the degree of bending of any\nmaterial when exposed to a transverse strain. If a body be sup-\nported at both ends, and loaded in the centre, a certain deflection\nalways takes place, which is proportionate to the weight. When\nthe elastic force of the material exceeds the straining force of the\nmaterial, the amount of deflection is directly proportionate to the\npressure, and will remain only as long as the weight is upon it,\nand the body experimented upon will instantly regain its original\nposition, upon the removal of the weight; but when the load is\nthe greater power, the deflection gradually increases, until a per-\nmanent alteration of form ensues, and at length a fracture occurs,\nif the load be very great, or in the event of its being increased.\nMr. Tredgold gives 6.83 tons as the degree of elasticity, or\namount of strain, which a square inch of cast iron will bear,\nwithout permanent alteration and Professor Barlow assumes the\ntension of wrought-iron, or power to resist tension of wrought-iron\nbars, at 10 tons per square inch.\nThe deflection, and consequently the strain, of railway bars,\nor rails, are considered by Professor Barlow as nearly the\nsame, whether the load be in motion or at rest when every\nthing is well fixed and secure (as demonstrated by some\nexperiments of his on the strength of iron made at Wool-\nwich, and some experiments on rails made on the Liverpool\nand Manchester Railway): but as strains are frequently thrown\non the rails, which produce a strain equal to double that which\nbelongs to the load in question-in other words, a waggon will\nsometimes lurch, and throw all the weight on one side-he\ntherefore considers, that until greater perfection is obtained in\nrailways, a strength of bar, more than double that required for\nthe mere strain, must be provided; and the above experiments\nshow that it must be 10 or 20 per cent. beyond the double; thus,\nfor a 12 ton engine, a strength of rails equal to 7 tons would be\nnecessary, according to the present distribution of the weight,\nDigitized by\nGoogle\nDEGREE-DIVING BELL.\n77\nbut with greater accuracy of construction, a heavier engine\nmight pass over the same rails-say an engine of 14 or 16 tons.\nIt was found, in prosecuting the experiments, that the blocks\nalso yielded at the time of a train passing over them, which de-\npression, or disturbance of the block, amounted to from .019 to\n.021 of an inch when securely fixed ; and with hanging and loose\nblocks it was double, or even triple. And taking one-half of\nthis as resolvable to the middle of the rails brings the deflection\nof bars, with weights moving over them, to about that of rails\nwith equal weights resting upon them.\nDEGREE (in geometry), the 360th part of the circumference\nof a circle, all circles being supposed to be divided into that\nnumber; it is denoted by a small near the top of a figure,\nthus, 36°; each degree is again subdivided into sixty parts, called\nminutes, and denoted by a mark, thus, 25'; and those are again\nsubdivided into sixty parts, called seconds, denoted thus there-\nfore, 36°, 25', 20\", means thirty-six degrees, twenty-five minutes,\nand twenty seconds.\nDEPÔT, or STATION (on railways, &c.). This term is applied\nto the commencement and termination of a railway, &c.; also to\nstations for the taking up and setting down of passengers or\ngoods. The additional quantity of rails required for the stations,\nsidings, &c., of a railway, is very great; it amounted, on the\nLondon and Birmingham Railway, to of the total quantity\nrequired.\nThe receptacles for tools and materials on the side of a rail-\nway, or road, are also termed depóts.\nDIAGONAL, a term applied generally to a right line drawn\nacross any figure, from the vertex of one angle to the vertex of\nanother, or across from one corner to the other.\nDIVING BELL, an apparatus employed for under water works,\nsomewhat resembling a large barrel without a bottom, or a bell, as\nthe name implies, and is usually of about 5 feet in height, and\nthe same in width, in the clear.\nDiving bells are mostly formed of very thick cast iron, and in\nDigitized by Google\n78\nDOCK.\none piece, whereby they are air-tight the weight of metal causes\nthe bell to sink readily, and its substance protects it from acci-\ndents; the top has an opening disposed for the reception of a\nsupply of air: thick lenses are also fixed in the upper part to\nadmit light. It has been thought that many under water works,\nat present executed by means of coffer-dams, and other con-\ntrivances, may be effected by the help of diving bells, by which\na great saving would be made and there have been instances of\ntheir being employed for such purposes. The piers of the Lary\nBridge were carried up by means of wooden diving bells, under\nthe direction of Mr. Rendel, although the stream was very\nrapid.\nDock, an artificial enclosed basin, formed for the reception\nof shipping, of which there are three descriptions, viz. wet docks,\nor docks for the reception of ships at all states of the tide\ndry docks, so called from their being left dry when the tide is\nout; and graving docks for the repairing of vessels.\nWet docks consist of very extensive basins, communicating\nwith some large river or harbour, by means of locks, and a\nproper depth of water is always kept up in them, so that vessels\nare afloat at all times of the tide. The entrance to wet docks is\nby a basin, with lock and pier-head at its entrance; and this\nentrance basin is generally connected by locks with two different\ndocks, viz. an import, or one appropriated for ships in loading\nand an export dock, for vessels going out, the quays of which are\ngenerally surrounded by warehouses, for the reception of goods.\nThe wet docks, at Eiverpool, were commenced in the year\n1708, and they extend, at the present time, to a distance of above\ntwo miles along the banks of the River Mersey, and in front of\nthe town, presenting a most striking effect. The Hull docks were\ncommenced in 1774; and docks were also commenced at Bristol,\nand at Leith : but there was no dock in the metropolis, or accom-\nmodation on the Thames, until nearly half a century after a wet\ndock had been constructed at Liverpool, which is partly ac-\ncounted for by the superiority of the port of London as a natural\nDigitized by\nGoogle\nDOCK.\n79\nharbour when compared with that of Liverpool. The West India\nDocks, which were the earliest in London, were commenced in\nthe year 1800, in which the import dock is about 2,600 feet in\nlength, and 400 in breadth, covering an area of nearly 25 acres ;\nand the export dock is of the same length, by 500 feet in breadth,\ncomprising nearly 30 acres. There are, also, other wet docks\nconnected with the establishment their depth of water is 25 feet,\nat spring tides, and the whole will contain 600 vessels, from\n250 to 500 tons burthen the warehouses are noble buildings\nthe tobacco warehouse is the most spacious erection of the kind\nin the world, being capable of containing 2,500 hogsheads, and\nthe vaults underneath will hold the same quantity of wine it is\nsaid to occupy a space of 4 acres, and is all under one roof.\nThe London, East-India, and other metropolitan docks, are also\nvery fine docks. St. Katherine's Docks were opened in 1828,\nand are convenient, on account of their close connection with\nthe centre of the city. The machinery employed at the several\ndocks, consisting of cranes, railways, &c., is also very ingenious\nand perfect. The depredations carried on upon the River Thames\nprevious to the construction of the docks, was immense, they\nmay, therefore, be said to have been of considerable benefit : the\nships, also, now lie in perfect security from the effects of storms,\nwhile their cargoes are being shipped or unshipped, and the river\nis kept clear of obstructions, comparatively speaking.\n, Graving docks are prepared for the reception of vessels that\nrequire repairing; they are also known by the name of repairing\ndocks, and are formed of dimensions merely sufficient to admit of\none vessel, although sometimes large enough for two ; they are\nfurnished with a pair of gates next the river or entrance, to keep\nthe water out, the vessel being floated in at high water, when the\nwater is withdrawn by the tide, and the sluices connected with it\nare shut, and any that may be left within it, is pumped out proper\nshores or props having been previously placed against the sides\nof the vessel to support it.\nA description of floating graving dock is employed in the\nDigitized by\nGoogle\n80\nDOUBLE-ACTING INCLINED PLANE-DRAINAGE.\nUnited States of America, consisting of a hollow vessel or\nbox of framed work, upon which the vessel to be repaired is\nfloated, the water is then pumped out from the interior of the\nhollow vessel, when it gradually rises, lifting the former out\nof the water, and leaving the bottom exposed to view. There\nare, also, other methods for effecting the same end practised\nthere.\nDOUBLE-ACTING INCLINED PLANE (on railways).-See Self-\nacting Inclined Plane.\nDOUBLE-RAILED INCLINED PLANE, an inclined plane having\ntwo lines of rails upon it.\nDRAIN, or DITCH, a trough for receiving the water drained\nfrom a road, or railway.-See Ballasting, Culvert, Embankment,\nExcavation, Fencing, and Railway.\nDRAINAGE (for agricultural purposes), the process of diverting\nand drainingthe water off from bogs, marshes, and lands, subject\nto be flooded from heavy rains; also for recovering land from the\nsea. It is recorded, that the drainage of the extensive marsh,\nwhich reached from the Thames to Camberwell hills, was con-\ntinued by the Romans, until, by drains and embankments,\"\nthey recovered all the low land in Southwark and its vicinity\nand the general method resorted to at the present time is some-\nwhat similar, viz. by cutting trenches to a certain depth below\nthe surface, to carry the water to the lower levels, forming em-\nbankments to support it, &c.\nAccording to Dr. Anderson, of Edinburgh, swamps and\nmorasses arise in consequence of the water attracted from the\natmosphere, by the summits of hills and mountains, which pene-\ntrate through the porous strata, of which they are formed, until\nits course is arrested by a stratum of clay, or other impervious\nmaterial, where the water accumulates and stagnates, and at\nlength forces its way upwards through the soil, forming bogs and\nmarshes in the valleys at the foot of the hill. And he recom-\nmends that a trench be cut along the base of the hill, extending\nto the substratum of clay, or other body, which impedes the escape\nDigitized by\nGoogle\nDRAINAGE.\n81\nof the water, and it can then be conveyed away by another drain :\nfaggots or stones may be piled over the trenches, so that the run\nof water is not disturbed. In cases where the top soil is of very\ngreat depth, and the water does not rise in the ditch, he recom-\nmends boring for the clay until it is reached, when the water will\nrise into the ditch. He is supported in this opinion by Mr.\nElkinton, who bestowed great attention to the subject about the\nsame time.\nIn every level country where there is not sufficient fall to carry\noff the water, mechanical means are obliged to be resorted to, as\npumps, syphons, and the like : pumps driven by windmills were\nvery extensively used for this purpose in Lincolnshire formerly\nbut steam-engines are now substituted, and with considerable\nadvantage. The amount of mechanical power necessary to drain\nfen land is not so great as commonly imagined, as there are not,\ngenerally speaking, any natural springs to' encounter; therefore,\nupon the upland water being enclosed by embankments, and carried\ninto the rivers in their vicinities by catch-water drains, nothing\nmore remains to be removed but the water that descends from\nthe clouds, which has to be raised to the higher level, where it\nis run off; the lift varies according to the height of water in\nthe river, which is influenced by the tides, floods, &c., but it\nseldom exceeds 3 or 4 feet, to which about 18 inches must be\nadded, on account of the water lying in drains, and consequently\nbelow the level of the ground. The land recovered is generally\nof a rich and fertile nature; it also possesses the advantage of\nirrigation; thus, when the country is dry, the sluices from the\nrivers may be opened, and the earth moistened. The effect\nproduced by windmills would be quite sufficient if they could be\ndepended upon : but steam is preferable, as it generally happens\nthat in cases of much rain there is but little wind the latter are\nalso always ready, and have been found to be the cheapest,\ntaking all things into consideration.\nMr. Joseph Glynn, C.E., has demonstrated the comparative\nfacility of recovering fenny lands, by drainage, in a very satis-\nM\nDigitized by\nGoogle\n82\nDRAINAGE OF MINES.\nfactory manner : he employs cast-iron wheels to raise the water\nfrom the lower levels, which are termed scoop-wheels, and are\nsituated in the ditches; these carry the water upwards, being\nturned by a steam-engine.\nIn reference to marine drainage, it may be stated, that mere\nlands reclaimed at once from the sea can seldom be of much\nvalue for agricultural purposes, sand materials being naturally\nthe general deposit; but the finer and lighter soils, which are\nconstantly driven down from the alluvial tracts by the tidal pro-\ncess, should be first arrested, the which forms a fruitful supersoil.\nThere are instances existing of portions of a country being now\ncovered by the sea, which was once dry land and a vast quantity\nof vegetable matter may be allowed to have accumulated upon such\nground, provided the action of the shingle has not reached it ;\nand cases of this kind may be considered as forming exceptions\nto the above rule.-See Sewerage, Scoop-wheel, &c.\nDRAINAGE OF MINES, the getting rid of the water within the\nbowels of the earth, arising from springs, and other natural\ncauses; and for the purpose of facilitating mining operations.\nThe drainage of mines forms a subject of immense importance,\nthe power employed to accomplish the same being frequently\nten times greater than that required in conveying the minerals up\nthe pit the system pursued is regulated by local circumstances.\nIn mountainous countries, and wherever practicable, the method\nof draining by means of a day-level, or subterraneous channel,\nis adopted, extending from the lowest part of the mine to the\nadjacent valley; in other cases, an adit is used as far as possible,\nand steam-engines employed to pump the water up the remaining\nportion; and in flat countries steam power is obliged to be used\nfor conveying it the whole of the beight up to the surface. The\ndepth of the pump shaft is usually divided into lifts, which, if\npossible, should not exceed 25 or 30 fathoms, a cistern being\nplaced at each, and the water is raised alternately from one to\nanother; the diameter of the pump is regulated by the power\nrequired, and varies from 8 to 16 inches, or 18 at most, and the\nDigitized by\nGoogle\nDRAINING TILES-DRAW-LINK.\n83\nlength of the stroke is from about 6 to 8 feet, which it should\nnever exceed.-See Adit and Mine.\nDRAINING TILES, the hollow tiles employed in the formation\nof embankments, to carry off the water to the side drains, being\nlet into the earth, or placed one upon another down the slopes:\nthey require frequent attention, owing to the settling of the soil,\nA row of drain tiles should be carried through the mounds of\nfencing at about every 100 yards distance, to convey the water\ninto the side ditches.\nDRAUGHT (in masonry) the chisel-dressing at the angles of\nstones, which are generally made as a guide for the regular\nlevelling of the several surfaces.\nDRAUGHT (in mechanics), the power or force required to put\nany machine in motion-as a horse-mill, or a coach, waggon,\nboat, or other vessel.\nThe depth of water necessary to float a ship, or other vessel,\nis likewise termed the draught.\nDRAW-LINK (railway), a contrivance for securing the several\ncarriages of a train together. The patent railway draw-link, in-\nvented by Mr. Henry Booth, of the Liverpool and Manchester\nRailway, is now very extensively used; it consists of a double-\nworking screw, a a,\nwhich is attached\nto the hooks at the\nends of the car-\nc\nriages by two long\nMr. Booth's Patent Draw-Link.\nlinks, b b, which are spirally threaded, to receive the screws;\nand the carriages are screwed up close together until the buffer-\nheads, d d, touch each other, by means of a lever, c c, fixed in\nthe middle of the screw ; the springs of the several carriages are\nthus brought into constant play, and an equal elastic pressure is\nproduced at starting, in lieu of the sudden shocks, of such\nfrequent occurrence previous to its introduction. There is a\nweight at the end of the lever which keeps the cottar constantly\nsuspended, by which the screws are maintained in their proper\nplaces.-See Buffing Apparatus.\nM 2\nDigitized by Google\n84\nDRAW-BRIDGE.\nDRAW-BRIDGE, or LEAF-BRIDGE, a certain description of bridge\nthrown across a cut or ravine, and constructed in such a manner\nas to be capable of being raised up and down when required ;\nthey were much employed in ancient military engineering, being\nused for crossing the moats surrounding fortifications : one of the\nends of the platform of the bridge answered as an axis, upon\nwhich the other part turned, strong chains being fixed to the\nsame, by which it was raised; and a kind of balance, termed\nplyers, was employed in effecting the same, which consisted of\ntwo long timber levers, about twice the length of the bridge,\nand joined together by other diagonal pieces, and they acted as\na counterpoise, and swung on the jambs on each side.\nDrawbridges are not much used at the present time, having\nbeen superseded by swing, or swivel bridges, in civil engineering\nworks.\nThe drawbridge over the Ravensbourne, upon the London\nand Greenwich Railway, is one of the most recent instances of\nDrawbridge on the Greenwich Railway.\nits application, where it was erected for the purpose of allowing\ncraft to pass through the creek, and it consists of two framed\nleaves meeting in the centre, upon which the rails are laid ; these\nleaves are lifted by the aid of chains, fixed at the point of junc-\ntion, and carried over piers at each end, with counterbalancing\nDigitized by\nGoogle\nDREDGER-DROUGHT.\n85\nweights fixed at their other extremities. There is also a small\nfoot drawbridge built on one side of it, for passengers. Another\nbridge is also lately erected at Selby, over the River Ouse, on\nthis principle, for the passage of the Hull and Selby Railway.\nDREDGER.-See Ballast Lighter.\nDREDGING, the operation of removing the sand, silt, and the\nlike, from the beds of rivers, harbours, docks, &c., which is\neffected by means of a dredger, or ballast-lighter. See Ballast\nLighter.\nThe constant dredging of large rivers, for the purposes of\nnavigation, is a very expensive process, and should be applied in\nconfined positions only, or where it is imperatively necessary,\nin order to secure a certain depth of water against the inroads of\nthe sea; but it is employed to great advantage in the removal\nof shoals intercepting the beds of rivers.\nDRIFT, DRIFTWAY, or HEADING (in mining, and excavating),\na square horizontal passage, or boring in the earth, between the\nshifts or turns, sufficiently large to allow of a man passing through,\nthey are generally employed in forming tunnels, and driven\nthrough from one shaft to the other, to ascertain the nature of the\nsoil, and for other purposes. A driftway is sometimes made on\nthe top or back of a tunnel, from one shaft to another, to assist\nthe ventilation.\nDROP, a machine employed for lowering coals from railway\nstraiths into the vessels below; they are of a similar principle to\nperpendicular lifts, and are much adopted in the north of Eng-\nland, the waggon being placed upon a moveable cradle, to which\ncounterbalancing weights are attached; and the balance is so\ncontrived that scarce any force is required to effect its ascent or\ndescent, although a brake is attached to conduct the waggons:\nthe cradle is suspended from a falling frame or leaf, which is\nprojected forwards as may be found necessary, by which it is\nbrought directly the vessel.\nDROUGHT, a scarcity of water on canals, &c., for the purposes\nof navigation, and other uses; the term is also used as the op-\nposite to flood, and signifies a dry season, or a want of rain, &c.\nDigitized by\nGoogle\n86\nDROVE-DIKE.\nDROVE, a narrow channel or drain, much used in the irriga-\ntion of land.\nThe term, drove, also refers to a description of tooling applied\non the faces of hard stones.\nDRUM, or ROPE ROLL, a hollow cylinder or barrel fixed on an\naxle, around which either single or endless ropes or bands are\npassed, for the purpose of communicating motion to other parts\nof the machine. The drums used on the inclined planes of rail-\nways are generally formed of cast-iron, the rope being wound\nround their peripheries, by which movement the trains are con-\nveyed along the line.\nDrums are also frequently connected with machinery, being\nfixed on the main shaft, and leather belts are usually passed\nround them.-See Inclined Plane.\nDRY ROT, a term applied to that rapid decay in the interior\nof timber, by which its substance is converted into a dry powder,\nwhich issues from minute circular cavities, resembling the borings\nof worms. Timber once affected can never be restored there\nremains no choice but to cut away such parts. It is supposed\nto arise principally from the timber being used before the interior\nis perfectly dry; and it also occurs from being placed in con-\nfined and close situations where there is not a sufficient current\nof air.\nThere have been many attempts to prevent the occurrence of\nthe dry rot, but Kyan's patent preparation is considered the\nmost successful, and it is very generally employed as a preven-\ntative for the same.\nDRY Dock.-See Dock.\nDIKE, a term sometimes used in the same sense as embank-\nment, with this difference, that a hydraulic embankment, and\none impervious to water, is alluded to; thus, a considerable por-\ntion of Holland is preserved, by works called dikes, which is\nrendered necessary by such parts of the cou being below the\nlevel of the sea; the consist of a mound, properly sloped on\neach side, on the top of which there is a road, and a sort of reed\nis planted on the banks next the sea, which serves to strengthen\nDigitized by\nGoogle\nDIKE-EARTHWORK.\n87\nthem, and the continual deposit of sea warp that takes place\nfurther assists them : a second dike is sometimes formed behind\nthe first, as an additional security, the space between them\nserving as a canal to carry off extraordinary floods.\nDIKE (mining), a name applied to a kind of faulty vein when\noccurring of some extent, and which are generally found in a ver-\ntical position, intercepting and disturbing the regular strata of\nthe earth; they sometimes consist of clefts or fissures, and extend\na considerable distance, being called, according to their ele-\nments, as whin dikes, basaltic dikes, &c. ; at other times they\nare merely filled with clay, having foreign substances imbedded\ntherein.\nThe occurrence of dikes frequently occasions great difficulty\nand expense in mining operations, both on account of the trouble\nof working them out, and their sometimes containing water, when\nthe works are frequently inundated.\nDYNANOMETER, an instrument invented by Mr. Macneill, and\nused for measuring the amount of force required to draw either\ncarriages or boats.\nThis instrument has received various improvements; but even\nnow it answers very indifferently upon railways, and it gives no\ntest whatever of the amount of atmospheric resistance (which is\nsupposed to be considerable at high velocities) on account of\nbeing situated between the engine and train, as the locomotive\nreceives the force of the air, but does not communicate it to the\ndynanometer.\nEARTHWORK, a term applied to cuttings, embankments, &c.\nThe several methods employed in executing earthwork at dif-\nferent parts of the country are very similar. The earth, after\nbeing dug, is conveyed by wheelbarrows at the commencement;\nand waggons, running upon rails, (usually from 30 to 50tb. per\nyard) are employed as the work proceeds; six teaming-places\nmay be made where the slope equals 2 to 1, which greatly ex-\npedites the work ; if less, four only can be made : a flat slope\ncan, therefore, be executed, in a certain proportion, quicker than\nDigitized by\nGoogle\n88\nEARTHWORK.\na steep one. If time is an object, the tip end of an embankment\nshould be made wider than it is intended to be finished, to admit\nof more roads upon it; and as the work proceeds it may be re-\nduced to the required width, and the soil from it thrown down\nthe slopes: a certain width may, in fact, be allowed for it at the\nbottom of the embankment. The time of executing an extensive\nembankment may be reduced one-half, by forming it in two\nstages, as the works of each may proceed at the same time; and\nthe difference in level is got over by inclined planes on each side,\nfor the use of the waggons the teaming is thus progressing on the\nupper and lower one at the same time. 800 to 1000 cubic yards\nis said to be the utmost that can be excavated and led to em-\nbankment, or teamed, in one day, under ordinary circumstances ;\nalthough this amount has been exceeded upon some occasions :\nthus, 1,600 have been moved per day at a steep cutting, on the\nManchester and Leeds Railway, and that for many weeks to-\ngether. The waggons hold about 2 cubic yards : 2½ or 3 yards\nis the utmost they can hold, even by piling up.\nThe most rapid method of executing earthwork on railways, and\nthe like, is by throwing a part of the excavation to spoil, taking\nit out from the higher side all throughout the length, by means of\nbarrows worked by horse gins, instead of removing it from the\nends, the embankments being constructed from side cuttings\nthis, of course, forms the most expensive process of procedure,\nalthough land may sometimes be found suitable for it, which is\ntermed sideling ground. The prices of earthwork vary according\nto the nature of the soil, locality, and extent of the work; the\nprice with an average material may be stated at 9d. per cubic\nyard, which includes excavating, and teaming a distance of\n1 mile to the embankment with a lead of about 2 miles, it is about\n11d. ; and 3 miles 1s. 1d. When the lead exceeds 1½ miles, a\nlocomotive may be advantageously substituted for horses in the\nteaming.\nIt is generally desirable to lay down the cuttings and embank-\nments on a line of railway, canal, &c., equal or similar in cubic\nDigitized by\nGoogle\nEARTHWORK.\n89\ncontents. There are about 16,000,000 cubic yards of excavation\nupon the London and Birmingham Railway, I°σths of which are\nused for the embankments, and 11ᵗʰ laid as spoil banks, or spread\nover the country.\nThe amount of earthwork of an engineering undertaking is\nobtained from the section, the height of the embankment and\ndepth of the cuttings being marked thereon; and the contents\nare calculated on the supposition, that \" the area of any cross\nsection in sideling ground does not differ from the area of a\nsimilar section on level ground;\" therefore the section, being\ntaken along the centre of the line, affords a true criterion of it.\nThe contents are usually found, by Mr. Macneill's tables, which\nhe calculated upon the prismoidal formula, viz., that the cubic\ncontents of a solid figure (such as an embankment) is equal to\nthe areas of each end added\nto four times the mean area,\nand the sum multiplied by\nthe length of the prismoidal\ndivided by 6,\" thus: sup-\nLongitudinal Section of Embankment.\npose the number of cubic\nyards in the embankment,\nrepresented in the cut,\nwere required (and the cut-\ntings are obtained in a\nTransverse Section of Embankment.\nsimilar manner), enter the dimensions in the book, thus :\nBase 30 feet, slope 21 to 1.\nHeight in\nTabular\nDistance in\nContents.\nfeet.\nnumbers.\nyards.\n0\n=23.46\nx 200\n=4692\n20\n86.42\n200\n17284\n30\n44.44\n200\n8888\n0\n30864\nArea of embankment 30864 cubic yards.\nN\nDigitized by Google\n90\nEARTHWORK.\nThe column, headed \"Tabular numbers,\" is that derived from\nthe tables; but they may be calculated without them, as fol-\nlows :-\nHeight of end 20 multiplied\n20 height of highest end\nSlope\n2.5 ] together.\n0 ditto of other\n100\n2) 20\n40\nMean height 10\n50.0\nSlope 2.5 multiplied together\nBase\n30 added\n50\n80.0\n20\nMultiplied by 20 height\n25.0\nArea of end = 1600.0\n30 base added\n55.0\nMultiplied by 10 mean height\n550. middle area\n4\n2200 = 4 times middle area\n1600 = area of end\n6) 3800 feet\n3) 633.33\n9) 211.11\n23.456 yards\nDistance 200.\nin yards\nArea of A 4691.200 cubic yards\nDigitized by Google\nEARTHWORK.\n91\nHeight of lower end 20 feet : the area consequently same as\nlast = 1600.\nHeight 30\n30 height of highest end\nSlope 2.5\n20 ditto of lower ditto\n150\n2) 50\n-\n60\n25 mean height\n75.0\n2.5\nBase 30\n125\n105.0\n50\n30\n62.5\nArea of higher end 3150\n30 base\n92.5\n25\n462.5\n1550\n2312.5 middle area\n4\n9250.0\n3150.0 area of higher end\n1600.0 ditto of lower ditto\n6) 14000\n3) 2333.33\n9) 777.77\n86.418\n200.\nArea of B 17283.600 cubic yards\nN 2\nDigitized by Google\n92\nEARTHWORK.\nHeight of end 30 feet: the area consequently the same as\nlast = 3150.\n30\n0\n3) 30\n15 mean height\n2.5\n75\n30\n37.5\n30 base\n67.5\n15\n337.5\n675\n1012.5\n4\n4050.0\n3150\n6) 7200\n3) 1200\n9) 400\n44.444\n200.\nArea of C 8888.800 cubic yds.\nSummary of Contents.\nA\n4691.200\nB\n17283.600\nC\n8888.800\nArea of embankment 30863.600 cubic yds.\nDigitized by Google\nECCENTRIC WHEEL-EDGE RAILWAY.\n93\nECCENTRIC, or ECCENTRIC WHEEL, a contrivance employed\nin mechanics, and in very general use, for working the valves of\nsteam-engines, consisting of a wheel situated upon the main\nshaft, but fixed out of its centre; it is placed in a brass ring,\nwhich fits it loosely, and rods are connected with the ring, and\nsecured to a lever at the other end; an alternating motion is,\ntherefore, given to the rods as the eccentric wheel turns round\nwith the shaft, by which the valves are opened and closed.\nEDGE RAILWAY, a certain description of roadway, consisting\nof a succession of iron bars or girders, properly supported, upon\nwhich the peripheries of the carriage wheels revolve; a flange,\nprojecting 1 inch, being formed on the inner edge of the wheels,\nto prevent their getting off the rails.\nEdge-rails succeeded plate-rails, having been first used in\n1785; the inconvenience arising from the dust laying on the\nlatter probably led to their introduction originally, although the\nmany other advantages possessed by them might not have been\ncontemplated at the time, as the form of edge-rails is certainly\nvery superior, combining the least expenditure of material with\nthe greatest possible strength, and the friction upon them is less\nthan upon tram-rails.\nThe first public railway laid with edge rails was constructed\nby Mr. Jessop, at Loughborough, in 1789; and they were origi-\nnally made of cast-iron, in 3 or 4 feet lengths, with a flat base at\neach end, in which holes were left for the insertion of pins,\nby which they were secured to the sleepers, and cast-iron\nchairs were ultimately adopted for this purpose; they were\nalso bowed on the under side, technically termed fish-bellied,\nwhich form edge-rails retained until very recently, the head\nbeing made about 21 inches wide, and rounded; a cross section\ntaken through the centre of a rail showed a greater thickness of\nmetal at the upper than at the lower part. The rails were after-\nDigitized by\nGoogle\n94\nEDGE RAILWAY.\nwards formed of wrought-iron, consisting at first of merely flat\nbars of iron, from 1 to 2 inches square, or bars 1 or 2 inches by\n3 inches, which were found to damage the peripheries of the\nwheels of the carriages considerably, from their narrow shape and\nwant of an upper table or head (neither case hardening the wheels,\nnor wrought-iron tires being invented at that time) and they\ncontinued to labour under this disadvantage until 1820, when\nMr. Birkenshaw, of the Bedlington iron-works, invented a way of\nrolling and manufacturing iron rails of a fish-bellied form, and\nwith heads complete, similar to the most approved cast-iron rails.\nThe increased velocity of the trains upon public railways have\nrendered wrought-iron rails absolutely necessary, and they are\nalmost invariably employed at the present time. Cast-iron rails\nare also becoming less used every day upon private railways, as\nthey are brittle, and apt to snap upon a sudden shock, and the\nwear is greater upon them, the interior of the rail not being so\nhard as the surface, arising from the more rapid cooling of the\nmetal of the exterior: thus, when the surface of a cast-iron rail is\nworn through by the wheels of the carriages, the decay increases\nconsiderably. Wrought-iron rails can also be manufactured in\nlonger lengths, by which a less number of joinings are required.\nThe wear and tear of the surface of the rails upon the Liverpool\nand Manchester Railway, were stated by Mr. Dixon, the resident\nElevation showing a Parallel Edge Rail. A, Section of same.\nB\nElevation showing a Fish-bellied Edge Rail. B, Section of same.\nengineer, at 1σth of a tb. per yard per annum; and it is remark-\nable, that good malleable rails do not oxydize when in use upon\nDigitized by Google\nEDUCTION PIPE-ELBOW JOINTS.\n95\na line of railway, although similar rails, thrown down at random\nby the side of the line, will lose weight continually.\nThe rails originally laid down upon railways were very light,\nviz., about 35 lb. to the yard, but experience has shown the ad-\nvantages of heavy rails : parallel rails, or rails having the top and\nbottom webs parallel, are almost universally adopted at the\npresent time, in preference to the fish-bellied, although there are\n10 miles of the latter on the London and Birmingham Railway;\nthere are also 25 miles of 65 lb. parallel rails, and the remainder\nis laid with 75tb. parallel rails, the tables or webs being usually\nof similar size, and about 21 inches in width, and rounded off;\nand they are made in 15 feet lengths. The meeting of the\nseveral lengths of the rails in edge railways are usually formed\nwith butt joints, or, in other words, with square joints, being the\ncheapest: half-lap joints are sometimes used, but diagonal joints\nmay be considered the best. There are several\ndescriptions of edge-rails in use, some of which\nmay be found at different parts of this work.\nThe side cut represents the \"Croydon rail,\"\nwhich is screwed down on a timber beam, and therefore has a\ncontinuous bearing throughout.- - See Railway, Tram Railway,\nChair, &c.\nEDUCTION PIPE (in steam engines), the pipe through which\nhe steam escapes after fulfilling its duty.\nELBOW, the name given to an abrupt turn in a river, frequently\ncaused from the action of the current upon one of the banks,\nwhich thereby becomes washed away, when the silt is thrown to\nthe other side, where it forms an elbow. They are usually re-\nmedied by erecting a rough stone dike across the concave side\nof the river, whereby the current is turned; or by a wing dam,\nas it is termed, built to the requisite height, which diverts the\nwater into the proper course.\nELBOW JOINTS, those voussoirs of an arch which\nform part of a horizontal course; as A, A, in the\ncut.\nA\nDigitized by Google\n96\nEMBANKMENT.\nEMBANKMENT (sometimes termed filling), artificial banks, or\nmounds of earth.\nThe employment of embankments\nfor the protection of low country from\nencroachments of the sea, and the\noverflowing of rivers, is of great anti-\nquity, having been constructed by the\nBabylonians and Egyptians for the\npreservation of their cities, the which\nwere mostly built on level plains; the\nwater also afforded a means of irri-\ngation, which the nature of the soil\nrequired; and the utility of embank-\nments was not lost sight of by the\nRomans: but very little attention ap-\npears to have been bestowed upon them\nSection of a Railway Embankment, a Culvert being shown beneath it.\nduring the middle ages, in common\nwith roads and canals, and their re-\nvival may be dated at about the same\nperiod as the latter. The embankments\nof the River Thames are supposed to\nbe of great antiquity.\nThe embankment on any engineering\nwork should be carried up with great\ncare, and in regular concave layers\nin other words, it should be gradually\nfilled in towards the centre, which will\ngive the sides an inclination to lean\ninwards and prevent their slipping:\nthe water being properly run off, a\nhigh embankment is best formed by a\nsuccession of lifts, or stages, at least\ntwo in number, as the soil is more\nliable to slip when carried up to the\nintended height at once.\nDigitized by Google\nENGINE.\n97\nA large drain is required to be made at the top of all cuttings, on\nthe high side of the ground, to cut off the land springs, and prevent\nthe water running down the side slopes, and a smaller one is dug\non the lower side, which should be continued along the foot of\nthe embankment, communications being made from one side to\nthe other under the latter, by means of culverts, as circumstances\nmay direct. An embankment of moderate height, and formed of\ngood materials, as chalk or gravel, will consolidate in about two\nor three years; but one formed of slippery clay, and of lofty pro-\nportions, will require ten years to elapse before it is thoroughly\nsettled, up to which period wooden sleepers should be employed\nupon it, and the line may afterwards be relaid with stone blocks.\nThe embankments of roads and approaches to bridges, &c., are\nsometimes formed with a layer of fagots, or brushwood, at the top,\nto receive the ballasting.-See Earth-work, Dike, Slope and Slip.\nENGINE, the name given to all machines and mechanical con-\ntrivances for producing, increasing, or regulating the power\nrequired for the accomplishment of any purpose. Most engines\nmay be described as consisting of three parts: 1st, the starting\npower, by which the whole is put into motion, which bears\nno analogy whatever to the end attained, which is termed the\nprime mover; animal power, also water, steam, and even air, gas,\nand gunpowder, have been applied as prime movers; it would\nbe represented in a steam-engine by the boiler and contingent\nworks, by which the steam is produced. 2nd, That portion con-\nstituting what is commonly called the engine, and to which the\ningenuity of man is most frequently directed : thus, steam may\nbe the motive power in two different machines, but one may be a\nreciprocating, and the other shall be a rotatory engine. And 3rd,\nthe machinery which absolutely performs the operation required,\nby which the object is attained, the motion being conveyed to it by\nthat division of the engine last described : thus, in a steam-engine\nfor pumping water, the pumping apparatus would represent it.\nMr. Murdoch, Mr. D. Gordon, and others, have made various\nexperiments with highly compressed air, with a view of making\n0\nDigitized by\nGoogle\n98\nENGINE-HOUSE-EXCAVATION.\nits power of expansion available, and using it as a prime mover\ninstead of steam. Mr. M. I. Brunel also obtained a patent for\ncertain mechanical arrangements for obtaining power from certain\nfluids, and for applying the same to\nvarious useful purposes, and he gave\nthe preference to carbonic acid gas;\nbut the high pressure at which his en-\ngine was obliged to work, viz., 30 at-\nmospheres, formed a great difficulty,\nand he could not keep it sound and free\nfrom leakage. It has also been ima-\ngined by some, that electro-magnetism\nwill some day compete with steam as a\nmotive power.\nENGINE-HOUSE, the house or shed\nerected over and about a steam-engine,\nwhich is constructed to suit the pur-\nposes of same.\nSection of a Railway Excavation.\nENROCKMENT, a term applied to the\nstone filling upon breakwaters, and the\nbanks of rivers, underneath quays or\nharbours, &c. It consists of large mas-\nses of broken stones thrown in at ran-\ndom, and of sufficient size to resist the\ncurrent.\nESTUARY, an arm of the sea.\nEXCAVATION, a term referring to a\ncutting through the earth, when con-\nstructed on the surface. The method\nformerly adopted of forming an exca-\nvation, was by working at the face, and\nbringing the soil out in lifts, but it is\nnot followed at the present time in\nextensive works, particularly where\ntime is an object, the plan of running\nDigitized by Google\nEXPANSIVE ENGINE-FANNER.\n99\na gullet through at once being mostly practised, and the soil is\nthrown down into the waggons from above : in removing the earth\nit is frequently dug out from beneath, when wedges and spikes are\nemployed in falling it from above.\nA line of railway. or canal, should be laid out in such a manner\nthat the cubic contents of the cuttings should be of similar amount\nto the earth required for the embankments.-See Earth-work and\nEmbankment.\nEXPANSIVE ENGINE, a steam-engine in which the expansive\npower of the steam is taken advantage of and employed, instead\nof being dismissed at full power into the air or condenser, as\nthe case may be. Mr. Watt availed himself of it, by cutting off\nthe steam before the end of the stroke, which was finished by the\npower of expansion of the steam that was let into the cylinder.\nThere are also engines in which two steam cylinders and pistons\nare employed, both of these being connected to the same beam;\nin one the steam works at full force, and is afterwards discharged\ninto the other, which is of a larger size, where it acts a second\ntime by its expansive force this plan was first practised by Mr.\nHornblower, and it succeeded very well; but the engine was\nrendered more complex and expensive. Mr. Woolf also em-\nployed the same plan, but with high pressure steam, together with\na condenser; and engines of this description are yet used in some\nparts of the kingdom.\nFACE OF A STONE, that part of a stone forming the front or\nvertical face.\nFACING (in hydraulic earth-work), a layer of common mate-\nrial or soil, laid over the lining or puddle, and upon the\nbottom and sloping sides of a canal or reservoir. The facing is\nuseful at the period of execution, as it retains the puddle in its\nproper position during the working in ; and it also affords a\nprotection from the pole hooks of the bargemen after the works\nare completed.\nFANNER, a contrivance of vanes or flat discs revolving round a\ncentre for the purpose of creating a draught, by producing. a\n0 2\nSIN25\nDigitized by\nGoogle\n100\nFALLING SLUICES-FELT.\ncurrent of air. This principle has been applied to some loco-\nmotives in place of the blast-pipe; as to the Novelty,\" by\nMessrs. Braithwaite and Erickson, which competed for the pre-\nmium at the opening of the Liverpool and Manchester Railway,\nand to Mr. Hancock's patent road locomotive.\nFALLING SLUICES, a certain description of flood-gates in\nconnection with mill-dams, rivers, canals, &c., and which are\nself-acting, or contrived to fall down of themselves, in the event\nof a flood, whereby the water-way is enlarged.\nFATHOM, a measure of vertical distances, and employed in\nmarine and mining operations, comprising a depth of 6 feet.\nFEATHER-EDGED, a term referring to any wrought substance,\nin which the work is materially reduced in thickness towards\nthe edge.\nFEEDER (sometimes called a carriage or catch drain), a term\napplied to a small canal, cut, or channel, by which a stream or\nsupply of water is conveyed for the use of a canal; feeders\neither convey the water into the reaches, or take it direct\nto the reservoir at the summit level, and are usually furnished\nwith sluices and waste weirs, like ordinary canals.\nFEED PIPE (of a steam-engine), the pipe employed for con-\nveying the water to the boiler. The feed pipes of land engines are\nusually supplied by a cistern situated above the boiler, operating\nby the weight of the water, but in locomotive and other high\npressure engines, the boiler is supplied by a force pump worked\nby the engine, and acting against the force of the steam.\nFEED PUMP, the force pump employed in supplying the boilers\nof steam-engines with water.-See Feed Pipe.\nFELLOES, the covered pieces of wood forming the circum-\nference of the wheel of a carriage, which is generally made in six\nor eight pieces, placed end to end, into which the spokes are in-\nserted-See Wheels, &c.\nFELT, a fabric of hair and wool worked into a firm texture, and\nmuch employed upon railways; a piece of it is cut into the\nsame shape as the seat of the chairs, and introduced between the\nDigitized by\nGoogle\nFENCING-FENDER.\n101\nunder side of the same and the upper surface of the blocks, to\nsecure a firm hold, being previously well soaked in tar.\nFENCING, a system of enclosure for the protection of roads,\nrailways, and other works. The fencing upon railways should be\nsituated upon the top of the mound formed from the excavation\nof the ditches, and the water collected in the latter should be\nproperly diverted into the adjacent water-courses, and it should\nconsist of good oak or larch posts, placed about 9 feet apart, and\n3½ feet from the surface of the bank, with a scantling of 5 inches\nby 31 inches, the posts which go below the ground being well\ncharred; the rails should have a scantling of 31 inches by 11\ninches or 2 inches, with a prick-post or stay, to support them\nbetween the posts, 5 feet long and 3 inches by 1½ inches; the\njoining of the rails and posts should be secured by iron hooping,\nsome strong iron wires should be filled in next the ground in\ngrazing lands, and quicks may be planted on the slopes of the\nmound. The total cost of fencing of this description will gene-\nrally be about four or five shillings per running yard, including both\nsides of the line. Stone is also sometimes employed as fencing\nin localities where it is plentiful and adjacent to the line. The\naccompanying cut represents the fencing used on the London and\nBirmingham Railway.\nB\nElevation.\nSection.\nA, shows the slope when in Embankment. B, shows the slope when in Exeavation.\nFENDER, or FENDER PILES, the timbers placed in front of a\nquay wall, or other work, to protect it from injuries by vessels.-\nSee Quay.\nDigitized by\nGoogle\n102\nFERRY-FLOATING BRIDGE.\nFERRY, the method commonly employed of crossing rivers\nprevious to the general introduction of bridges; the sites of most\nof the river bridges of the present time were formerly occupied\nby ferries.\nFIELD-BOOK (levelling).-See Levelling.\nFIELD-BOOK (surveying).-See Surveying.\nFILLING, or FILLING IN.See Embankment.\nFISHED BEAM, a beam bellying on the underside.\nFIXED ENGINE (railway).-See Stationary Engine.\nFLANCHE, or FLANGE, a projecting piece, or table,\nforming part of an iron girder or framework; ; the flanges\nof one casting are generally placed flat against those of\nanother, and holes are drilled through each for the pas-\nsage of bolts, whereby they are secured together.\nFLANK WALLS, the wing or return walls of a bridge or lock.\nFLASHES (upon navigable rivers), a description of sluice,\nerected for the purpose of raising the water over any shoals while\ncraft are passing.\nFLOAT, or WATER GAUGE, a body partially suspended and\npartly floating upon the surface of the water in steam boilers,\nbeing usually a piece of Yorkshire paving-stone; and employed\nto regulate the supply of water to the boiler by operating upon\nthe valve at the top of the feed-pipe, and the water is kept at\nthe same constant height through its agency. The height of\nwater in the boilers of locomotives and marine engines, is ascer-\ntained by means of gauge-cocks and glass tubes, as floats will only\nact with stationary boilers. Gauge-cocks are also becoming\nmuch used for land engines.-See Boiler.\nFLOAT-BOARDS, the boards fixed to undershot water-wheels to\nreceive the falling stream, and to paddle-wheels, being the means\nwhereby they act.\nFLOATING BRIDGE, a certain description of steam-vessel, em-\nployed for ferrying passengers and goods across rivers, and the\nlike.\nThe Torpoint Floating Bridge, by Mr. Rendell, is one of the\nDigitized by Google\nFLOATING CLOUGH-FLY WHEEL.\n103\nlast built, and consists of a large flat-bottomed vessel, of a width\nnearly equal to its length, the engines being situated in the centre.\nDrawbridges are fixed at each end, by which carriages may be run\non board by the horses, and the leaves are slightly raised during\nthe passage, forming a sort of barrier. The bridge is guided by\ntwo chains laid across the bottom of the river, and secured upon\neach side to counterbalancing weights placed in deep wells, and\nthey rise and fall according to the strain upon the chains, which\nare, therefore, never so tight as to interrupt the navigation, or\nso loose as to allow the bridge to make leeway and miss the\nlanding-place: they also pass over guide-wheels fixed at each\nend of the vessel. The scheme has been found to answer well,\nthere being two bridges employed at the same site, running\nalternately each for the space of one month.\nFLOATING CLOUGH, a moveable dam, or machine, used for\nscouring out channels or inlets. It is constructed of timber,\nand upon being floated to the required spot, is sunk, the flaps\nconnected with it are then let down upon the banks on each\nside, an iron scraper being fixed thereto; its action is effected\nby the force of the tide, which pushes it along, when it clears\naway all obstructions in its course, and the action of the tide is\nafterwards employed to bring it up again.\nFLOATING HARBOUR, a breakwater, composed of large masses\nof timber, anchored and chained together in certain positions,\nwhich rise and fall with the tide. The same principle has also\nbeen applied to the piers of marine erections.\nFLOOD, or TIDE-GATES, or SLUICES, the gates employed in\nthe admission of water from the sea or from a river, as the\ntide rises, &c.\nFLY, or FLY WHEEL, a heavy wheel employed in machines\nfor equalizing the motion and increasing the effect, revolving\nupon an axle, after the same principle as a counterbalancing\nweight.\nThe fly-wheels of steam-engines are of large diameter, and are\nused to conduct the motion round the dead points, or such parts\nDigitized by\nGoogle\n104\nFOOTINGS-FOUNDATION.\nwhere the crank has the least effect; and they are only suitable\nin stationary engines, on account of the inconvenience that would\narise from their great size and\nweight: it is therefore customary,\nin motive engines, both those of\nland and of water, to employ two\nengines, or rather cylinders, as they\nare each supplied from the same\nboiler, and one piston is employed\nin full force while the other is pass-\ning the centre, whereby they mutu-\nally assist each other : thus, when\nFly Wheel.\none has finished its upward motion and is upon the turn\ndownwards, the crank connected with it has a tendency to\nstick on the top, and just at that moment the crank of the other\nis in full play upwards, so that a continuous and nearly uniform\nmotion is consequently attained; and engines so constructed are\ncalled reciprocating engines, the cylinders being placed in a ver-\ntical position in marine engines, and laid horizontally in modern\nlocomotives. A rotatory engine is the only one that can give\na uniform rotatory motion, as the course of the cranks in the\nformer kind occasions an unequal motion, which may be readily\nperceived and sensibly felt, particularly in motive engines.\nFOOTINGS (of walls), the projecting courses of stones or bricks\nat the bottom of all walls, which are laid for the purpose of resting\nthe buildings firmly upon its base, and as a precaution against\npartial settling or sinking.\nFORESHORE.-See Breakwater.\nFOUNDATION, the superstructure upon which all erections rest,\ndepending entirely upon the nature of the bottom, or subsoil. In\nthe case of good firm ground, as rock, hard clay, or gravel, very\nlittle attention is required, except to rest the structure upon it square\nand regular throughout; when the soil is of a loose or yielding\nnature-as soft clay, common earth, or boggy earth-recourse\nmust be had to artificial means of consolidating it. York land-\nDigitized by\nGoogle\nFOUR-WAY COCK.\n105\nings, also timber sleepers and planking,\nPlan.\nwere formerly very generally employed\nfor the foundations of large buildings,\ntogether with strong chain-bond laid\nin the footings of the walls; but con-\ncrete is the favourite expedient re-\nsorted to in the present day, upon\nPiles.\nSleepers.\nwhich the footings are laid, and the\nwalls carried up.\nIt is generally necessary to drive a\nrow of sheep piles next the foundations\nof walls adjoining the sea, or rivers,\nand marshy soils, &c., to keep the\nwater off, and prevent any lateral\nPier.\nyielding of the soil below the foun-\ndations, the space between the piles\nbeing well puddled in; and in very\nmarshy, or watery ground, the whole\nsuperstructure is obliged to be con-\nstructed on a timber platform, supported\nby piles and sleepers. The accompa-\nnying cut represents the foundation of\none of the piers of Staines Bridge.\nFOUR-WAY Cock (in steam-engines),\na description of valve much used for\npassing the steam to the cylinder; it\nwas invented by Leopold in about the\nyear 1720. The accompanying sketch\nshows a vertical section of it. A, is the\ncommunication with the steam-pipe;\nB, the passage to the upper end of the\ncylinder; and C, that to the lower end\nSection.\nD being the passage to the condenser,\nor the escape into the air, as the case may be. By merely\nturning the plug or centre a quarter of a revolution, the action\nP\nDigitized by Google\n106\nFREE-STONE-FRICTION.\nis reversed, and the steam, instead of\nentering the lower part of the cylinder,\nwill be on its passage to the upper one,\nand that last received into it will be\nA\nescaping at D.\nFREE-STONE.-See Sandstone.\nFRICTION, the obstruction or resistance\noffered by the rubbing of the several parts\nof an engine or machine against each other, upon the appli-\ncation of the force necessary to put the same into action, by\nreason of which a great part of their power is lost, and the several\nparts of the machinery become worn and defective.\nIt arises from various causes, such as the roughness, inequality,\nor imperfection of the opposing surfaces, and from the interposi-\ntion of dust, moisture, &c., between them; also from the action of\ngravity, and the adhesion of the several parts together : the\ndegree of friction is also regulated by the amount of rubbing sur-\nfaces in contact.\nAs it is highly necessary to reduce the friction of engines to as\nsmall an amount as possible, they should therefore be constructed\nwith as little rubbing surface as practicable, and oils or other\nunctious substances introduced between the parts in contact.\nThe resistance arising from the surface of roads has been con-\nsiderably reduced of late years ; the substitution of a rolling mo-\ntion, as the motion of carriage wheels, for a sliding one, as that of\na sledge, was found to reduce the friction very considerably at the\nperiod of its introduction; but the foremost plan for effecting the\nsame is by means of iron railways, laid along a road prepared to\nreceive them; tramways and pavedways may also be mentioned,\nand the many excellent common roads recently constructed\nthroughout the kingdom; the carriages employed respectively\nupon each, have also received many important modifications.\nThe friction or resistance of the wheels of carriages arises, first,\nfrom the friction of attrition, or the pressure of the bearings upon\nthe axles supporting them, as in roadway carriages, or that of the\nDigitized by\nGoogle\nFRICTION.\n107\naxles against the bearings resting upon them, which support the\ncarriage, as in railway carriages ; and, secondly, from the rolling\nfriction, or the resistance offered to the revolution of the wheels\nby the roadway, the amount of which depends principally upon\nthe degree of smoothness and hardness of the surface over which\nthe wheels are run ; and the resistance of the road being so much\nreduced on railways, that presented by the axle of the carriage\nconsequently forms by far the greater portion : it is, therefore,\nvery important to keep up a constant supply of lubricating matter,\nin order to reduce it as much as possible, as before described.\nOil unguents are best for light weights, a thicker composition\nbeing used for heavy machinery.\nThe resistance of a good level railway to the peripheries of the\ncarriage wheels does not exceed 1000th part of the insistent\nweight, while upon common roads the average is about the 25th\npart of the same, or 40 times that of the railway; but the friction\nof the axle is much the same with both roadway and railway car-\nriages, depending upon the degree of accuracy of the model.\nThe following shows the result of Mr. Macneill's experiments\nto determine the proportion of friction due to the road, and to the\naxles of roading carriages :-\nWeight of\nPower required\nwaggon and load\nto draw the\nResistance of the\nResistance of the\naxles.\nsurface.\nin pounds.\nwaggon.\n13.0\n2240\n31.0\n23.6\n7.4\n10.6\n16.2\n2800\n52.0\n29.5\n22.5\n13.3\n19.5\n3360\n70.0\n35.4\n34.6\n15.9\n2.7\n3920\n91.0\n41.3\n49.7\n8.6\nAt an early stage of railroad communication, the chairs, or\nbearings resting upon the axles, were made very narrow, under an\nerroneous idea of reducing the friction, being only 1 ₫ inches in\n2 P\nDigitized by\nGoogle\n108\nFRICTION.\nlength, and less than the diameter of the axles in breadth but\nthey are now made 3 inches long and upwards. Brass bearings\npresent the least friction ; but as they are usually formed narrower,\nnothing is gained in this respect by them. The bearings were\nalso formerly situated upon the inner side of the wheels but they\nare now placed on the outside, and the stage or frame-work of\nthe waggon is elevated above the wheels, projecting beyond them\non each side: the wheels are thus protected by the bearings,\nwhich are also made very strong and, as the ends of the axles are\nnot required to be as large in diameter as the middle portion, the\nfriction is consequently reduced, compared with bearings on the\ninner side of the wheels—(an axle 3₫ inches diameter need not be\nabove 2 inches on the outside of the wheels). The various im-\nprovements in carriages and carriage wheels have also tended\nto reduce the amount of friction.\nMr. Wood, after numerous experiments on the friction of\ncarriages,\" comes to the following conclusion, viz. :-\n\" That in practice we may consider the friction of carriages,\nmoved along railways, as an uniform and constantly retarding\nforce, both with respect to velocity and weight.\n\" That there is a certain area of bearing-surface compared with\nthe insistent weight, and the friction is in strict ratio with that\nweight.\"\nThe area of bearing-surface in the axles of carriages, cal-\nculated to give the minimum of friction, he found to be 1 inch to\nevery 98 tb. of the insistent weight. Mr. Peter Lecount, in his\nwork on Railways, states, that this should not exceed 90 tb. per\nsquare inch, nor the length of bearing much less than twice the\ndiameter of the axles.\nThe total amount of friction upon a railway depends upon the\nweight of the carriages, or the weight contained within them, and\nis in the same proportion that the amount of rubbing action bears\nto the weight ; and, taking all contingencies, it may be generally\nconsidered to average about 2}₀th part of the weight of the load,\nor 9 lb. per ton ; i. e. a weight of 9 lb., hung over a pulley, will\nDigitized by Google,\nFRICTION.\n109\ndraw one ton: thus a train, weighing 55 tons, will require a\npower of draught equal to 495 tb. to convey the same upon a\nlevel; but, it varies according to circumstances. The friction is\nmuch increased where ropes, attached to a fixed engine, are used\nto conduct the trains, when it bears different proportions to the\nload, according to the diameter of the axles and peripheries of\nthe running sheaves or friction-rollers on which the ropes runs.\nMr. Walker, C.E., in his Report to the Directors of the Liverpool\nand Manchester Railway, in 1829, takes the friction of the ropes\nat 2ⁿᵈⁿᵈ part of their weight; but it is considerably increased by\nbad weather. Messrs. R. Stephenson and J. Locke, in their reply\nto same, state it at 1½ᵗʰ.\nThe comparative resistance upon different descriptions of roads,\nmay be classed as follows: :-\nPer ton.\nPart of the load.\nOn the best wrought-iron edge rails\n81 to 9tb\n284 to 2to\nOn common ditto, in bad repair\n14\n1\n100\nOn the best cast-iron tram-rails, when\nnewly laid down and swept clean\n12\n1\n187\nOn common ditto, in a dusty state\n25\n1\n90\nOn the old wooden railways\n30\n1\n75\nOn well made pavement\n33\n1\n08\nOn a broken stone road, upon a rough\npavement bottom\n46\n1\nTo\nOn a broken stone surface upon a bot-\ntoming of concrete, formed of Parker's\ncement and gravel\n46\n*\n1\n49\nOn a broken stone surface, laid on an\nold flint road\n65 * 35 1\nOn a gravel road\n147\n*\n1\n15\n* These are according to Mr. Macneill's experiments; but\nthe carriage employed not having been of good construction they\nmay be taken at much less, particularly the friction of pavement\nindeed it is questionable whether a pavedway, newly laid and\nswept clean, would amount to above half that stated.\nDigitized by Google\n110\nFRICTION.\nIt is singular that while the surface fric-\ntion has been so much reduced, scarce any\nattempts have been made to reduce the fric-\ntion of the axles of the carriages. Mr. Coles'\npatent anti-friction railway carriages cer-\ntainly form an exception, and are worthy the\nconsideration of the profession. The run-\nning wheels have anti-friction wheels bearing\nupon their axles, and these wheels again\nMr. Cole's Patent Anti-Friction Railway Carriages.\nhave smaller anti-friction wheels bearing\nupon them in a similar manner; the axles of\nthe upper ones are fixed, and do not revolve\nwith the wheels, but the middle and lower\naxles, with their boxes, or collars, work up\nand down in a groove of the framework of\nthe carriage, and the whole weight of the\nload and frame is borne off by the upper\nfriction wheels. Mr. Coles states, that they\nwould reduce the friction at least 1°0ths, and\nconsequently effect an immense saving of\npropelling power, also wear and tear, and\nlubricating matter.\nFRICTION ROLLER.-See Sheave.\nFUEL (in reference to steam-engines), the\nmaterial employed in converting water into\nsteam. Those substances which receive\nand retain heat until wholly or partially\nconsumed, are the most suitable for steam-\nElevation.\nengines, provided they emit neither smoke\nnor deleterious effluvia. Coal is the fuel\nDetails of Wheels.\nmostly used for ordinary engines; but coke is\ngenerally employed in locomotives at the\npresent time, as it is particularly well\nSection.\nadapted for them, it is preferable to coal in\nmany respects; although the latter is yet\nDigitized by Google\nGABLE-GAS-WORKS.\n111\nemployed upon some of the colliery lines in the North of\nEngland, as the Leicester and Swanington Railway. Coke also\npacks well, and, being of a light substance, the air from the\nfire-grate passes through it freely ; neither does any smoke\narise from its combustion, which forms so great an objection\nwith coal.\nThe coke used upon the London and Birmingham Railway is\nmade upon the works, and consists nearly of pure carbon. The\ncoke obtained from gas-works is objectionable, as it contains but\na very small portion of carbon, and a considerable quantity of\nsulphur, which is very destructive to the metal of the boiler ; coal\nalso possesses the same injurious property, and this likewise forms\na considerable objection with peat fuel : anthracite coal, or stone\ncoal, although it is composed of nearly pure carbon, and produces\nneither flame nor smoke, is not well adapted for locomotives\non account of its density, the draught of air through the fire-box\nbeing of the utmost importance to the power of the engine.-\nSee Locomotive-Engine and Steam-Engine.\nGABLE.-See Roof.\nGALLERY, the term given to a certain description of under-\nground excavation; thus coal-mines are worked in galleries or\nlevels, and tunnels are sometimes worked by horizontal shafts,\nwhich are called galleries (the vertical being generally em-\nployed). A tunnel is projected through the cliffs at Dover,\nupon the South Eastern Railway, which is being formed by this\nmethod, and the galleries are intended to be left open for light\nand ventilation.\nGASOMETER.-See Gas-works.\nGAS-WORKS, the buildings in which gas is manufactured.\nThe introduction of coal gas for the lighting of towns and\ncities is of very modern date, although it is probable that the\ndiscovery was known for some considerable time previous. Mr.\nMurdock was the first who conceived the use of coal gas as a\nmeans of affording light by night; and he accordingly fitted up\nhis house and offices, at Redruth, Cornwall, with it, in the year\nDigitized by\nGoogle\n112\nGAS-WORKS.\n1792 and, subsequently, his residence in Ayrshire: he also par-\ntially lighted the manufactory of Messrs. Boulton and Watt, near\nBirmingham, in the year 1798 and upon a public illumination,\nin 1802, it was exhibited at the Soho, and succeeded so well\nthat public attention was drawn to the subject; and a company\nwas formed, in 1804, for the purpose of manufacturing it, called\nthe National Light and Heat Company.\" Their first essay\nwas made in Pall-mall, in the year 1807 which was for some\nyears the only street lighted with it. But while gas was struggling\nwith public prejudice in the metropolis, it was making great way\nin the provinces; and at length, in consequence of the success\nattending it, the old oil lights became abolished as public lights\nthroughout most parts of the kingdom.\nThe manufacture of gas is conducted in large buildings erected\nfor that purpose the coal from which the gas is to be obtained\nbeing placed in iron vessels, termed retorts, of which a great number\nare employed; and a large building is appropriated for them, called\nthe retort house. The retorts are usually of a shape, thus—\nCylindrical retorts were originally used, and are at\nthe present time in some manufactories; they are laid horizon-\ntally in ovens, in groups of 5, 6, or 7 together, the furnaces being\nplaced beneath ; the mouth of each projects out from the oven,\nand a cover is screwed over it, air-tight, after the introduction of\nthe coals : the gas is conducted by pipes from the retorts to the\nhydraulic main situated above them; the latter is also placed\nhorizontally, and is generally half-full of the tar and water eva-\ncuated from the gas: the pipes from the retorts dip a few inches\ninto the tar, by which all return of gas is cut off; the gas then\npasses through condensers, which consists of a quantity of iron\ntubes, placed vertically and bent in a serpentine form, and at the\nlower part of each turn syphon-pipes are fixed, by which the\ndeposited matter is drawn off: these pipes are sometimes placed\nin cold water to cause a more rapid evacuation, whence the name\ncondenser was given to them. Upon the gas being cleansed from\nall palpable and visible impurities, those of a more latent nature\nDigitized by\nGoogle\nGAS-WORKS.\n113\nhave to be removed, viz. the sulphureted hydrogen, which is\nproduced from the sulphureous substances contained in the coal,\nwhich is of a most injurious nature; this is effected by the inter-\nposition of lime, which possesses the property of abstracting it\nfrom such a combination, and it is performed in vessels termed\npurifiers, in which there is a quantity of lime mixed with water,\nto a sort of semifluid state, through which the gas is driven, and\nthence passes out, thoroughly purified; the lime is kept in a\nproper state of mixture, and prevented settling by an agitator, of\nsomewhat the shape of a roller, placed horizontally and kept\nturning round by a steam-engine, or other power : and several\npurifiers are employed, through all of which the gas passes in suc-\ncession. The renewal of lime takes place continually, as a certain\nquantity of lime will only purify a certain quantity of gas; the\ngas from common coal requires a quantity of lime equal in weight\nto Toth that of the coal from which it is produced, and with the\nbest coal 3rd of the quantity is sufficient.\nThe gas is from thence passed into a large vessel, termed a\ngasometer, from whence the main pipes are supplied; it is of a\ncylindrical form, covered at the top and open at the bottom, and\nis placed in a pit, or tank, filled with water; friction-rollers are\nfixed upon the top edge, upon the inner sides of which the gaso-\nmeter slides up and down, being suspended by a chain fixed at\nthe top, where a pulley is situated; the chain then passes over\nanother pulley at the side, and the lower end is attached to a\nweight. These chains are unnecessary in large gasometers, as\ntheir weight is not increased in the same proportion as their\ncapacities; thus a large gasometer will remain suspended of\nitself; if very large, it will require a weight to keep it down.\nThere are two pipes at the bottom of the tank, through one of\nwhich the gas enters, and through the other departs, for the sup-\nply of the main pipes. There are gasometers capable of holding\nthe immense quantity of 60,000 cubic feet of gas; and there are\nsometimes as many as twenty of them connected with a gas-work.\nUpon the gas being turned on into the pipe for the supply of the\nQ\nDigitized by\nGoogle\n114\nGATES.-GAUGE OF WAY.\ncity, the gasometer begins to sink, and the pressure exerted is felt\nat the same moment throughout an extent of many miles.\nIt is customary, in most works, to measure the gas as it passes\ninto the gasometer, which is effected by a very ingenious instru-\nment, termed a meter. The flow of gas in the pipes is required\nto be steady and regular, and proportioned to the number of\nlamps burning; and accordingly as that number is increased or\ndiminished at certain times of the night, so must the supply be\nadapted. There are men employed at the works during the\nnight to regulate it, and who are informed of the state of the\nconsumption, by pressure gauges connected with the main.\nA self-regulator, called a governor, is employed at some esta-\nblishments for a similar purpose.\nThe pipes are of various sizes, and are formed of cast-\niron, and generally made with a socket at one end only, the\nsmall end of one pipe being inserted into the socket end of\nanother, and the joints are finished by molten lead. The mains\nconnected with the gasometers are about 18 inches diameter, the\npipes are laid as nearly straight as circumstances will admit of,\nwith a slight fall, and all deposits are collected from time to\ntime, and removed. A pipe, 1 inch in diameter, affords a light\nequal to 100 mould candles of six to the pound.\nA gas obtained from oil has also been employed for the pur-\npose of lighting towns, &c., which affords a stronger light than coal\ngas, but it is considered more expensive, and therefore not much\nused; the necessary process, however, is much less complicated.\nGATES (of locks and sluices).- - See Lock-gates.\nGAUGE-COCKS, the cocks usually connected with the boilers\nof steam-engines, for the purpose of ascertaining the height of\nwater in the boilers, and which are always used with motive-\nengines: Eglass tubes are also sometimes employed for the same\npurpose, and floats are commonly used for regulating the supply\nof water to the boilers of fixed engines.\nGAUGE of WAY (as applied to railways), the width in the clear\nbetween the top flanches or rounded rims of the rails. It is very\nDigitized by Google\nGEARING-GIRDER.\n115\nnecessary, in the practical working of railways, to keep standard\niron gauges, from which all those employed on the line should be\nmade ; viz., one of the width between the rails, and another of the\nspace between them.\nThe gauge of way generally employed and that adopted on the\nLondon and Birmingham, Grand Junction, and other great lines of\nrailway, is 4 feet 81 inches; but it is made 7 feet on the Great\nWestern. The Irish Railway Commissioners recommend 6 feet\n2 inches; and some of the Scotch railways are laid at 5 feet\n6 inches.\nGEARING, a series of toothed wheels for conducting motions in\nmachinery generally. There are two sorts of gearing in common\nuse, viz. spur gear, and bevelled gear\n(sometimes called conical wheels).\nThe former consists of teeth ar-\nranged round either the concave or\nconvex surface of a cylinder, in the\nSpur Gear.\ndirection of radii from the\ncentre of the wheel, and are of\nequal depth throughout ; but\nin bevelled gear the teeth are\nplaced upon the exterior peri-\nphery of a conical wheel, and\nconvex towards the apex of the\ncone, in which direction they\nBevelled Gear,\nare gradually diminished.\nGIBS, pieces of iron used\nin connection with keys.-See\nKey, Cottar, or Cottrel.\nGIRDER, the name given to both timber and iron beams when\nresting upon walls or piers at each end, and employed for the\npurpose of supporting a superstructure or any superincumbent\nweight, as a wall, floor, or the roadway of a bridge, &c. A gir-\nder, employed to carry the superincumbent part of an external\nwall, is also known by the name of a bressummer, and is gene-\nrally rested upon oak posts.\nDigitized by\nGoogle\n116\nGIRDER.\nWhen a beam is loaded beyond its proper limits, it continually\nyields to the load, although slowly, until at length it breaks; and\nif the load approaches very near to the breaking weight, the time\noccupied will not be very considerable. Buffon states, that a\nbeam should not be loaded with more than 3rd of the weight\nwhich would be required to break it. The strength of beams is\nas the square of their depths, as proved by some experiments by\nMr. Fairburn, who placed three cast-iron beams, of No. 2, Carron\niron, upon supports, having bearings of 4 feet 6 inches; they\nwere each 1 inch broad, and 1, 3, and 5 inches deep respectively,\nand which broke with 452 tb., 3,843 lb., and 10,050 tb weight\nrespectively, which is very nearly in the proportion of 1, 9, and 25.\nA girder will bear 31 times more weight when placed with the\ntable downwards, as 1, than when it is placed upwards, thus, T.\nAs girders of sufficient scantling to span lengths of from 24 to\n30feet, and upwards, are difficult to be procured, it is customary\nto apply trusses to such, when they are called trussed girders. It\nis supposed by some engineers, that merely sawing a beam in two,\nlengthways, and bolting the pieces together in a different relative\nsituation to what they were previously, adds much to its strength ;\nin other cases wrought-iron truss bolts are placed between them,\nby which either iron or oak struts are made available to strengthen\nthe beam, and prevent its sagging, or bending in the middle.-\nSee Cuts.\nTrussed Girder.\nSection.\nPlan.\nThe term built beam is applied by some writers to a beam com-\nposed of several pieces-as the one represented below.\nBuilt Beam.\nDigitized by Google\nGLAND-GRADIENT.\n117\nGLAND, or COLLAR.-See Collar.\nGNEISS.-See Granite.\nGOVERNOR, or CONICAL PENDULUM, the contrivance connected\nwith some machines for regulating their\nmotion.\nThe steam governor consists of an upright\nspindle, which is put in motion by the en-\ngine, and from which two balls are sus-\npended by rods; these partake of the motion\nof the spindle, and the balls fly off from it,\naccordingly as it is rapid or slow, by reason\nof the centrifugal force, in consequence of\nwhich the upper portion of the contrivance\nis either elevated or depressed, which operates\nupon the throttle-valve, and regulates the\nsupply of steam to the cylinders; thus, if the\nengine is going too fast, the governor checks\nThe Steam Governor.\nit, by partly closing the throttle-valve; but if too slow they fall\ndown, and allow more steam to pass.\nThe governor was first applied to the steam-engine by Mr.\nWatt, although it had been in use for other machines sometime\nprevious; as to water-mills and wind-mills, the governors of\nwhich may be described generally as acting upon a similar prin-\nciple.-See Steam-Engine.\nGRADIENT, a term indicative of the proportionate ascent or\ndescent of the several planes upon a railway; thus, an inclined\nplane, 4 miles long, with a total fall of 36 feet, is described as\nhaving a gradient of 1 in 5863rds, or 9 feet per mile. These\nslopes are also called by the general name of gradients; although\nthe difference between a gradient and an inclined plane is not\nvery clear; the former is, however, understood to allude to a\nslope of small inclination only, while the latter refers to a\nsteep one.\nClivity is a more appropriate term than gradient, as suggested\nby Mr. Macneill and its derivations, acclivity and declivity, are\nvery comprehensive and significant.\nDigitized by\nGoogle\n118\nGRANITE-GRAVITY.\nThe following Table of Gradients, by Mr. C. Bourne, C.E.,\nmay be found useful :-\nPer Mile.\nPer Chain.\nPer Mile.\nPer Chain.\n1\nft.\nII\n1\nin\n5280\n=\n.15 of an in.\n31\nft.\n=\n1\nin\n170.3\n=\n4.65 of an in.\n2\n=\n\"\n2640\n=\n.30\n32\n=\n\"\n\"\n165.0\n=\n4.80\n\"\n3\n=\n1760\n=\n.45\n33\n=\n\"\n160.0\n=\n4.95\n\"\n\"\n\"\n4\nA\n\"\n1320\n=\n.60\n\"\n34\n=\n\"\n155.3\n=\n5.10\n\"\n5\n=\n1056\n=\n\"\n.75\n\"\n35\n=\n150.8\n=\n5.25\n\"\n\"\n6\n=\n\"\n880\n= .90\n\"\n36\n=\n146.6\n=\n5.40\n\"\n\"\n7\n754.2\n= 1.05\n37\n\"\n142.7\n=\n\"\n5.55\n\"\n\"\n8\n=\n660.0\n= 1.20\n38\n=\n5.70\n\"\n138.9\n=\n\"\n\"\n\"\n9\n=\n\"\n586.6\n= 1.35\n39\n=\n\"\n135.4\n=\n\"\n5.85\n\"\n10\n=\n528.0\n= 1.50\n40\n=\n132.0\n=\n6.00\n\"\n\"\n\"\n\"\n11\n=\n\"\n480.0\n= 1.65\n41\n=\n128.8\n=\n6.15\n\"\n\"\n\"\n12\n440.0\n= 1.80\n42\n=\n125.7\n=\n6.30\n\"\n\"\n\"\n\"\n13\n\"\n406.1\n= 1.95\n\"\n43\n=\n\"\n122.8\n=\n6.45\n\"\n14\n=\n377.1\n=\n\"\n2.10\n44\n=\n\"\n120.0\n=\n6.60\n\"\n\"\n15\n=\n352.0\n=\n2.25\n45\n=\n\"\n117.3\n=\n\"\n\"\n6.75\n\"\n16\n=\n330.0\n=\n\"\n2.40\n114.8\n\"\n46\n=\n=\n6.90\n\"\n\"\n17\n=\n\"\n310.6\n= 2.55\n47\n=\n112.3\n=\n\"\n7.05\n\"\n\"\n18\n=\n\"\n293.3\n= 2.70\n48\n=\n\"\n110.0\n=\n7.20\n\"\n\"\n19\n277.9\n=\n2.85\n49\n=\n107.7\n=\n\"\n\"\n\"\n7.35\n\"\n20\nH\n264.0\n=\n\"\n3.00\n105.6\n\"\n50\n=\n=\n\"\n7.50\n\"\n21\n=\n\"\n251.4\n= 3.15\n51\n=\n\"\n103.5\n=\n\"\n7.65\n\"\n22\n=\n\"\n240.0\n= 3.30\n52\n=\n\"\n\"\n101.5\n=\n7.80\n\"\n23\n=\n229.5\n=\n3.45\n53\n=\n\"\n99.6\n=\n\"\n\"\n7.95\n\"\n24\n=\n\"\n220.0\n= 3.60\n\"\n54\n=\n97.8\n=\n\"\n8.10\n\"\n25\n=\n\"\n211.2\n= 3.75\n55\n=\n\"\n96.0\n=\n\"\n8.25\n\"\n26\n=\n\"\n203.1 = 3.90\n56\n=\n\"\n\"\n94.3\n=\n8.40\n\"\n27\n=\n\"\n195.5\n= 4.05\n\"\n57\n=\n92.6\n=\n\"\n8.55\n\"\n28\n=\n\"\n188.6\n= 4.20\n\"\n58\n=\n91.0\n=\n\"\n8.70\n\"\n29\n=\n\"\n182.1\n=\n4.35\n\"\n59\n=\n89.5\n=\n\"\n8.85\n\"\n30\n=\n\"\n176.0\n= 4.50\n\"\n60\n=\n\"\n88.0\n=\n9.00\n\"\nGRANITE, a very hard durable silecious stone, and one much\nused for engineering purposes; the essential ingredients of which are\nfelspar, quartz, and mica, which are scattered irregularly through-\nout it: gneiss is composed of similar particles, but disposed in\nbeds. Grey granite is more generally employed than red, on ac-\ncount of the difficulty of working the latter, from its excessive\nhardness. Aberdeen granite is considered superior to that of\nCornwall, as it abounds more with quartz; the latter has more\nfelspar in its composition.\nGRAVING Dock.-See Dock.\nGRAVITY (as applied to railways), a term referring to the\nextra weight acquired by a train of carriages when upon planes not\nperfectly level or horizontal; or, in other words, to the downward\npressure, which force is in proportion to the clivity of the plane.\nIf the train is proceeding up the plane, great additional power\nis necessary to overcome the gravity compared with that required\nDigitized by Google\nGRILLAGE-GROUTING.\n119\nupon the level portions of the line, particularly if the same degree\nof velocity is to be maintained. Upon a plane 1 in 50, the re-\nsistance by gravity is 44.80tb per ton; and upon 1 in 90 it is\n24.83 lb. per ton, which, on a train of 60 tons gross, amounts to\n1493 lb., and is sufficient force to propel a train amounting to 186\ntons upon a level if, on the contrary, the train is descending\nthe plane, the gravity assists them.\nIt is customary to shut off the steam of an engine in descending\nsteep planes, the gravity being sufficient to propel the train, and\nit is moreover checked by the brake accordingly as may be\nrequired.-See Inclined Plane.\nGRILLAGE, a term applied to the sleepers and cross beams\nsupporting a platform, upon which some erections are carried up,\nas piers, in the case of marshy or watery soils, whereby an equal\nbearing is given to the foundation. In the event of clay being\nemployed as a grillage, instead of timber, it should be 4 or 5 feet\nin substance, and spread in layers, and well rammed in between\nthe heads of the piles.\nGROIN, a frame-work usually of wood, and constructed across\na beach between high and low water-mark, and perpendicular to\nthe general line of same, for the purpose of retaining the shingle\nalready accumulated on the spot, or to obtain more from the sea :\nthey usually consist of piles and planking, land-ties, &c.\nGROINED ARCH, an arch cutting across another arch in a\ntransverse direction; the point of juncture being termed a groin.\nIt has been said that the groined arch is the most stable of all\narches, and, therefore, capable of being executed with a very\nsmall rise, provided the abutments are sufficiently strong to sup-\nport it; yet groined arches are but seldom used in modern works,\nwhilst the cylindrical appear to have been carried almost to as\ngreat an extent as practicable.-See Arch.\nGROUTING, a description of mortar used in brick and storie-\nwork, composed of quick lime and a portion of fine sand, em-\nployed in a thin liquid state; it is poured into the upper beds\nand internal joints of the work.\nBrickwork should be well grouted every four courses.\nDigitized by\nGoogle\n120\nGUDGEON-HARBOUR\nGUDGEON, the term applied to the extremity of a horizontal\nshaft or axle, when it turns in a collar. It is customary to\nmake the gudgeons of smaller diameter than the other portions\nof the shaft, for the purpose of reducing the friction as much as\npossible.\nGULLIES, a term sometimes applied to iron tram-plates or rails.\nGUTTER, a trough for carrying off the water from any works.\nThe trenches dug for the reception of puddling are also termed\ngutters, which are usually formed about 2 or 3 feet in thickness,\nand wider at the bottom than at the top.-See Canal.\nHACKING (in walling), an objectionable plan, practised by\nworkmen, when one of the courses of a wall can-\nnot be carried up of equal depth throughout its\nlength for the want of stones sufficiently large for\nA\nsame. The hacking consists in dividing the remain-\ning portion into two courses ; the end stones (A, in\ncut), being frequently notched to receive the stones of the lesser\ncourses.\nHALF-TIDE Dock, a basin connecting two or more docks, and\ncommunicating with the entrance basin.\nHARBOUR, or HAVEN, the name applied generally, to a port,\nor to the entrance of a port, where vessels may lay at anchor,\nsheltered from storms.\nIt is highly necessary that harbours should possess a good en-\ntrance, consisting of firm ground, free from rocks, so that a ship\nmay not be liable to founder, also of width and depth of water\nsufficient to float the largest vessels; if surrounded by lofty hills\nand mountains, it is an advantage, as they are then screened from\nthe effects of high winds, and when their situation is far inland,\nthey are secure of bombardment from the sea.\nThe entrances to some ports are formed with good harbours na-\nturally, but artificial means are obliged to be resorted to, in some\ncases, to render them safe, by enclosing a certain space from the sea,\nin such a manner as to form a shelter to the shipping. The works\nconsist of two curved arms, called piers or jetties, which are built\nin a suitable position to counteract the peculiar local effects of the\nDigitized by Google\nHARD.\n121\nwinds, and afford a free ingress and egress to vessels at the mouth.\nThey are also sometimes formed by the building of isolated walls,\ncalled breakwaters, instead of jetties, and likewise by the fixture\nof large masses of floating timbers, called floating breakwaters,\nwhich rise and fall with the tide.\nHarbours are generally furnished with a lighthouse, to direct\nships at night, also with numerous buoys, moorings, posts, &c.\nA backwater, or scouring power, is usually connected with the\nentrance of a harbour, and which should be so situated that the\nforce may act in the direction of the tidal wave, forming a small\nangle with it, and it should on no account approach a right angle,\nwhich has the effect of impeding the shingle, as may be frequently\nobserved, when a bar is soon formed and, by the same rule, the\nmouth of a river, crossing a tide wave at right angles, will also\ncause a bar ; this principle of action, therefore, should not be over-\nlooked in the construction of harbours and sea embankments and\nit may be further remarked, that in carrying the necessary works\ninto execution, the commencement should never be opposed to\nthe tidal wave, but if possible run in the same direction and the\ngreatest care should be taken that the motion of the shingle\nbe not opposed, but rather diverted, as depositions of it are sure\nto occur unless efficient remedies are adopted. Shingle has been\nknown to acquire an extent of area equal to nearly 20 square\nmiles in the course of two years, the same being from 5 to 8 feet\ndeep, even where there has been a powerful stream of backwater.\nA close investigation of local circumstances is of the utmost\nimportance, previous to determining the precise site of a harbour\n-comprising the peculiar features of the coast, the effect and ge-\nneral action of the tides, and nature of the deposits-since the\nerection of piers and other works must influence the movements\nof the shingle on the beach in some way.-See Backwater and\nIsolated Harbour.\nHARD, a term signifying a ford or passable place in a river, or\nfen, consisting of a hard bottom of gravel, which is supposed, in\nsome cases, to have been brought there for the purpose of forming\nR\nDigitized by\nGoogle\n122\nHATCH-HIGH-PRESSURE.\na passage across : they are not often met with now, having been\nremoved on account of their impeding the navigation in dry sea-\nsons, and increasing the floods in wet ones.\nHATCH.-See Lock Gates.\nHEAD OF WATER, a term signifying a regular height of water\nin any stream or basin, and intended for the supply of mills, foun-\ntains, and the like they are usually supported by banks of earth,\nin a similar manner to dams.\nHEADING.-See Drift.\nHEADING COURSE (in masonry and brickwork), a course con-\nsisting of all headers, or stones, bricks, or the like, laid length-\nways across the whole thickness of a wall-See Bond and Stretch-\ning Course.\nHEADWAY, a name sometimes applied to the clear height under\nthe arches of bridges, tunnels, &c.-See Arch.\nHEDGEHOG, a machine for removing mud, silt, &c., from\nrivers and streams.\nIt is in shape somewhat similar to a road or garden roller,\nconsisting of a wheel revolving on an axle, to which drawing shafts\nare fixed. Timber stocks are projected from the cylinder with\niron spades bolted thereto, which act upon the bottom of the\nriver, clearing away all obstructions.\nIt is generally attached to the stern of a barge which is drawn\nby horses; sometimes the barge is moored, and the machine\nmoved backwards and forwards by means of leading blocks and\nchains; mechanical purchase being obtained by means of the\nbarge.\nHEWN STONE, a term applied to stone when reduced to the\nrequired form, by means of a mallet and chisel only.\nHIGH-PRESSURE, or Non-Condensing ENGINE, an engine\nin which the cylinders are worked by the elastic force of the\nsteam alone, without the aid of a vacuum-it is consequently of\nvery great power; and the engine is also light, compact, and\ncheap, compared with others, from the circumstance of the whole\nof the condensing apparatus being dispensed with. The loco-\nDigitized by\nGoogle\nHIP-HORSE POWER.\n123\nmotive engines in general use are all constructed upon this\nprinciple.\nFrom the circumstance of the steam of non-condensing engines\nbeing of such very high pressure, and their great evaporating sur-\nface, the fire is required to be kept at a greater heat than usual\nwith other engines; the repairs, therefore, become exceedingly\nheavy, and their durability comparatively short in comparison\nwith the latter.-See Steam-Engine and Locomotive Engine.\nHIP.-See Roof.\nHOARDING, the name given to the wooden boarding enclosing-\nany building operations.\nHOLLOW QUOIN (in lock-gates), the re-\ncess made in the walls of locks at each end\nfor receiving the gates, which are properly\nhollowed out to fit the shape of the quoin-\nposts.-See Lock-Gates.\nHORSE PATH, or TRACK, the name some-\ntimes given to the towing-path by the side\nof a canal, or river, where horses are used for towing ; they were\nformerly made only on one side of canals, but are now frequently\non both, and about 8 or 10 feet wide.\nHORSE POWER, the power or force which a horse generally\nexerts, which is compounded of his weight and muscular strength;\nthe weaker and heavier horse will overcome a resistance which\nthe stronger and lighter horse cannot, provided the excess of his\nweight exceed, in the smallest degree, his deficiency in strength.\nA horse drawing in a mill, or machine of any kind, should be\nallowed a track of sufficient diameter to exert his power to the\ngreatest advantage ; it ought not to be less than 40 feet for full-\nsized horses; and where such an extent cannot be obtained,\nhorses of reduced size should be employed, in order to corre-\nspond with the contraction of the track : it has been ascertained\nthat a horse loses grds of his effective strength when removed\nfrom a 40 feet track-circle to one of 19 feet; and a horse works\nto the greatest advantage when the line of draught inclines a\nDigitized by\nGoogle\n124\nHORSE POWER.\nlittle upward to his breast, making a small angle to the horizontal\nplane.\nThe amount of force exerted by a horse is generally reckoned,\nin mechanical calculations, equal to 33,000±., raised 1 foot high\nper minute; and if continued throughout the whole day of 8\nhours, amounts' to 150tb. conveyed a distance of 20 miles, at a\nspeed of 21 miles an hour : but some engineers consider 125tb. a\nsufficient load for an ordinary horse, although, according to Mr.\nBevan's calculations (deduced from the effects produced by\nhorses in several different ploughing matches) 160lb., raised at a\nvelocity of 2½ miles per hour, is the average of their power; but\nmuch depends upon the size and muscular strength of the horses\nemployed, and the mode of shoeing, fitting of the collar, line of\ndraught, and other circumstances.\nThe power of horses decreases with the velocity of their speed\nthus, taking 125tb., moved twenty miles a day, at a rate of 2½\nmiles an hour, or 2,500±b., conveyed 1 mile, as the daily perform-\nance of a horse (which is the power assigned to a horse by Mr.\nNicholas Wood), and allowing for the friction of railway car-\nriages at 8½tb. per ton, gives nearly 300 tons, conveyed 1 mile, as\nthe power of a horse upon a railway. And as the friction of a\nstage upon a turnpike road, when loaded, amounts to 83tb. per\nton (according to Mr. Macneill's experiments), and calculating\nit to weigh 2 tons, would give 42tb. as the share of each of the\n4 horses, the rate of travelling being about 10 miles an hour ; and\nsupposing they average 13 miles per day, which is taking the\nutmost, the total force exerted by each horse, per day, is equal\nto 546tb., conveyed 1 mile : now, applying this force upon a rail-\nway, as in the former instance, reckoning the friction again at\n8½tb. per ton, gives 64 tons moved 1 mile; their relative efforts at\n21 miles, and 10 miles, an hour, are, therefore, in the proportion\nof 300 to 64.\nThe belief that locomotives will one day compete with horses\nupon common roads is becoming very general in the scientific\nworld: how far this is correct time will show ; but the superiority\nDigitized by\nGoogle\nHORSE RUN.\n125\nof locomotives over horses, upon railways, is very evident : yet as\nit is necessary that the trains upon a railway should start at cer-\ntain fixed periods, whether they have full loads or not, they\nconsequently become expensive with light ones.\nThe following Table S hows the comparative expense of locomo-\ntives and horses as a motive power upon railways :-\nHORSES.\nLOCOMOTIVE ENGINE.\nRate of\nCharges of\nRate of\nCharges of\nspeed,\nCost of\nconveying goods\nspeed,\nCost of\nconveying goods\nin miles\nhaulage, per ton\nand\nin miles\nhaulage, per ton\nand\nper\nper mile.\npassengers.\nper\nper mile.\npassengers.\nhour.\nhour.\nd.\nd.\nd.\nd.\n21\n0.56\n1.65 per ton\n8\n0.375\n1.065 per ton\nper mile.\nper mile.\n4\n0.9\n3.627 per ton\n12\n0.5\n3.5 per ton\nper mile.\nper mile.\n4d. per pas-\n1d. to 11 per\n0.25 per\n1d. to 13d.\nsenger.\npassenger.\npassenger.\nper passenger.\n10\n20\n2.24 per ton\n18. 3d. per ton\n0.73 per ton\n12.37 per ton\nper mile.\nper mile.\nper mile.\nper mile.\nThe expense of conveying goods by horses, at 2½ miles an hour,\nis about the same as by locomotives at 12 miles, therefore, where\nspeed is of no consequence, horses may be preferred ; as a horse\nrailway can be executed for a much less sum than a locomotive\nline. There are many railways, in the North of England, where\nhorses still continue to be used.-See Canal.\nHORSE RUN (in earthwork), a contrivance for drawing up the\nloaded wheelbarrows from the bottom of deep cuttings for rail-\nways, docks, &c., by the assistance of a horse, which walks to and\nfro, instead of round, as in a horse gin. The horse runs, em-\nployed at the deep chalk cutting at Tring, on the London and\nBirmingham Railway, were worked by two horses, the which\npulled a loaded wheelbarrow from the bottom, a man guiding it\nup the plank by means of the handles ; and, in descending, he\nDigitized by\nGoogle\n126\nHORSING BLOCK-INCLINED PLANE.\nmerely attached the rope to the barrow, and the friction of the\ntackle offered sufficient resistance to let him down the plank with\nsafety.\nHORSING BLOCK, a square timber framing, used in forming\nexcavations for raising the ends of the wheeling planks.\nHUB, a block of wood employed to stop the wheels of car-\nriages, and prevent their progress by gravity, or any acquired\nmomentum: they are used upon railways with great advantage.\nHURRIES, a term sometimes applied to a timber framing, or\nstage, erected on the quays of harbours, and navigable rivers, and\nat the extremity of railways connected with coal-pits, spouts\nbeing fixed at the end of the hurries, down which the coals are\ndischarged and shot at once into the hold of the ships.\nHYDRAULIC ENGINE, the term applied to all machines which\nreceive motion from the weight or impulse of water, and to\nengines employed in raising water, &c.\nThe term, however, bears more immediate reference to a\nmachine, somewhat resembling the steam-engine, in which the\npiston is impelled by a column or head of water, instead of by\nthe force of steam.-See Pump, Water-wheel, &c.\nHYDRAULIC, or WATER LIME, lime which possesses the pro-\nperty of hardening, when used in water operations. A small\nmixture of burnt clay, with the lime, during the process of\nburning, will give it this quality ; also brick, or tile dust, or poz-\nzolano, the latter being very valuable for hydraulic works.\nICE-BOAT.-A boat employed on canals to break the ice in\nfrosty weather; it is usually heavily laden, and protected by iron\nbows and keel. The improved ice-boat, which forms an inclined\nplane under the ice, and rents it upwards instead of thrusting\ndownwards, as in the ordinary boats, has been found very effica-\ncious in practice. A man steers the ice-boat from the towing-path,\nby means of a long shaft attached to a pole projecting over the\nstern. Ice-boats are, however, only applicable when the ice is of\nbut little thickness, or to clear it away after a thaw.\nINCLINED PLANE, one of the mechanical powers or con-\nDigitized by\nGoogle\nINJECTION ENGINES-INTERMEDIATE SPACE.\n127\ntrivances by which the raising of heavy bodies is much facilitated,\nas a plane inclined to the horizon sustains but a portion of the\nweight of any load that may be resting on it ; thus, if the\nplane be 6 feet long, with a rise of 1 foot, and a load of 6 tb. be\nplaced upon it, and a cord passed from the same over a pulley\nat the top of the plane, and parallel thereto, then a weight of\n1tb. fixed at this end will balance the load: if the height is\n2 feet, 1 lb. will balance 3 tb. ; but the total amount of power\nrequired to move a body up a hill is the same that is required\nto lift it up a height equal to the degree of altitude that it is\nmoved up the hill; thus, the power to run a carriage, weighing\n2 tons, a distance of 12 yards up a rise of 1 in 12, is similar to\nthat which would be required to lift it up 1 yard.\nThe term is indicative of all planes not perfectly horizontal\n(of a higher level at one end than the other) ; but when ap-\nplied to railways, it is generally understood to refer to steep\ninclinations only, as the Euston-square inclined plane, of 1 in 86,\non the London and Birmingham Railway, and the Box inclined\nplane, of 1 in 107, on the Great Western Railway, at Bath.\nInclined planes should not have an uniform slope or clivity,\nbut they should be laid with a greater fall at the higher than at\nthe lower end, towards which it should gradually diminish. The\nvelocity acquired at commencing the descent will thereby be\ncounterbalanced by the gravity increasing as the carriages ap-\nproach the extremity of the plane.-See Steam and Self-acting\nInclined Plane.\nINJECTION ENGINES, those steam-engines in which the steam\nis condensed by an injection of cold water into the cylinder, as\nmost condensing engines at present in use. Mr. Samuel Hall's\npatent engines effect the condensation without any injection,\nwhich system is considered to be the most perfect; the presence\nof air into the condenser is also prevented by it.\nINLET, a term applied to an opening into a drain or culvert.\nINTERMEDIATE SPACE, the centre space or distance between\neach line of rails, on double lines of railway, which varies on\ndifferent lines. It is frequently made the same as the width\nDigitized by\nGoogle\n128\nINVERT-IRON.\nbetween the rails, or 4 feet 81 inches ; although it is increased to\n6 feet on the London and Birmingham and other Railways.-\nSee Railway, &c.\nINVERT, or INVERTED ARCH, a term applied to an arch when\nplaced in an inverted position, the intradoes or soffit of the arch\nbeing below the axis or springing-line they are much employed\nin the foundations of buildings, and are turned between piers and\nthe like, to connect the whole together, whereby the bearing of\nthe foundations is rendered regular and even throughout : they\nare also used for the purpose of excluding water.\nIRON, a very hard and durable metal of a bluish white colour,\nvery malleable and elastic.\nIron is considered to be the most important of the mineral trea-\nsures of the United Kingdom after coal ; but it is not often found\nin a natural state, as the ore is generally diffused in immense\nbeds, and is converted, by chemical means, into pure metal.\nSweedish and Russian iron have long been held in high esti-\nmation on account of their being smelted by charcoal furnaces.\nPit coal is obliged to be used in this country for that purpose,\nowing to the scarcity of wood (the period of its first application\nwas in the year 1619) : notwithstanding, the best English chain\ncable iron is very little inferior to foreign iron.\nIron is of two kinds, viz., the cast, or moulded, and the wrought,\nor forged; the latter is employed for all purposes where strength\nand stiffness to resist a pull or stråin laterally is principally\nrequired cast-iron, on the contrary, is mostly used in a vertical\nposition, and is not to be depended upon as a tie, unless cast of\nvery large proportions; it is also much used for engineering pur-\nposes, in such situations where it would be difficult to apply\nwrought iron, as for the ribs of bridges, &c. ; also for ornamental\npurposes, arising from the facilities which it presents, being capa-\nble of taking almost any shape.\nThe manufacture of iron received a vast impulse at the period\nof Watt's great improvements in the steam-engine, on account of\nthe increased demand thereby occasioned: this new power was\nalso employed in improving the blast in the furnace.\nDigitized by\nGoogle\nIRON.\n129\nThere is nothing particular to distinguish common iron ore\nfrom common stone, excepting its greater weight and it is worthy\nof remark, that the fuel required for its reduction generally\naccompanies it the ore is principally found in coal measures, and\nin connection with limestone, both of which are used in the ope-\nration. The metal is obtained from the ore, by a process termed\nsmelting. It is first broken into moderate-sized pieces, and roasted,\nor baked by a method very similar to the burning of bricks by\nclumps, being formed into heaps about 30 feet long, 15 feet\nbroad, and 5 feet high, with sloping tops: a thick layer of coal is\nplaced at the bottom, and intervening layers are also laid within ;\nthe whole is then ignited, and left to burn for four or five days,\nand when cool, the ore is taken to the smelting furnace, which is\na brick or stone building, in the form of a tower, from 40 to\n50 feet high it is filled with ore, and a mixture of coke and\nlimestone, in the proportions of about 3 of ore to 4 of coke, and\n1 of limestone.\nThe accompanying sketch represents a blast furnace upon the\nmost simple and approved principle. The interior portion, marked\nA, is built of fire-bricks; it is fed at\nthe top, through the hole B; the fire,\nsituated at the bottom is forced in\nby the powerful aid of the blast-\npipe, which is worked by a steam-\nengine; an opening is left at the\nbottom, for the escape of the metal\ninto a receiver, C, upon its acquir-\ning a state of fusion; and it is con-\nducted into sand-moulds, laid upon\nthe ground, of the pattern required, or into furrows made in\nsand: the large mass, which sets in the main one, being called by\nthe workmen a sow, and the lesser ones, pigs-this sort being\nknown by the general name of pig, or crude iron. The furnace is\nnever allowed to cool, but fresh ore is continually poured in at\nthe top, as may be found necessary ; in the event of repairs being\nS\nDigitized by Google\n130\nIRON BRIDGE.\nrequired, it is blown out : the coke not only serves as fuel, but it\nattracts the oxygen from the ore, and enters into combination with\nthe iron in a state of pure carbon : the limestone assists the smelting\nas a flux upon the earths in connection with the ore, as flint and\nclay ; the which rise and float upon the surface, and are termed\nscoria, or slag.\nThe hot air blast is now used in preference to the cold air blast,\nas a great saving is effected by it; a large portion of the heat being\nabsorbed by the cold air, which occasions an unnecessary con-\nsumption of fuel : coal has also been successfully employed in\nsome instances, in place of coke.\nWrought iron is prepared from the cast, the pigs being again\nsubjected to the furnace, melted, and run into moulds, by which\nthe remaining extraneous matter, as earth and oxydized iron, is\ngot rid of; this process being repeated until the iron clots to-\ngether upon being stirred, forming soft pasty lumps, when it is\ntaken out and beaten by the large forge hammer, which is worked\nby a steam-engine ; and when the metal is compressed into cakes\nof about 1 inch in thickness, they are placed in another furnace,\nand softened and shaped into bars, the ends being welded together\nand the operation is completed by the entire bars being again\nplaced in the furnace, softened, and beat under the forge hammer :\nby this process, the metal is freed from all carbon, oxygen, and\nearthy ingredients; and instead of being brittle and easily fusible,\nit is now possessed of great tenacity, ductility, and malleability.\nIRON BRIDGE, a description of bridge formed of cast iron, and\nemployed in situations where the width or span is very great,\ncompared with the rise being preferable, in such cases, to those\nof stone.\nIron bridges consist, generally, of ribs thrown across, having\niron plates filled in between them, as described under the general\nhead of Bridge.\"\nThe first iron bridge was constructed in the year 1779, and\nerected over the Severn, a little below Colebrook Dale, at a\npart of the river where the stream was narrow, and, consequently,\nDigitized by\nGoogle\nIRRIGATION OF LAND.\n131\nrapid: the span of the ribs is 100 feet 6 inches, the spandrels\nbeing filled in with metal rings; but owing to the piers not\nhaving been sunk sufficiently deep to ensure a firm foundation,\nnor strong enough to resist the internal pressure of the ground,\nwhich was of a slipping nature, the masonry became thrown out\nof the perpendicular, and, consequently, much damaged; and the\nform of the ribs being nearly semi-circular, they did not offer much\nresistance to this pressure; whereas, had they been segments,\ntheir power of withstanding it would have been much greater.\nThe success of this experiment was, however, fully acknowledged\nand appreciated, although the ribs are now mostly executed in\nflat segments.-See Bridge.\nIRRIGATION OF LAND, the operation of applying water to\nland, for the purpose of agriculture.\nIrrigation is a process but little practised in this country,\nowing to the soil not requiring it; although it generally forms a\npart of the system of drainage in low lands, the requisite works\nfor enclosing the water serving the purposes of both; and by\nstoring it up in dry seasons, the sluices have only to be opened to\nflood the whole of the lower level.-See Drainage for Agricultural\nPurposes.\nThe irrigation of land may be described, generally, as being of\nthree kinds first, simple flooding, usually termed flooding and\nwarping; secondly, surface irrigation ; and, thirdly, subterraneous\nirrigation. The first has long been practised, being an evident\nimitation of nature in the overflowing of rivers; it consists in the\nfloating of a quantity of water over the land, and is generally\npractised with grass land; and when it is charged with soil, or\nany alluvial matter, it is called flooding and warping ; the warp is\nvery serviceable, and increases the fertility of the land consider-\nably; it also tends to raise the surface of the soil. The second\ndescription, or surface irrigation, is executed by open cuts or\nchannels traversing the surface of the land, by which the water\nis conveyed to the roots of the grass. This system, also, is of\ngreat antiquity, and, being simple, it has continued in use up to\nS 2\nDigitized by\nGoogle\n132\nISOLATED HARBOUR.\nthe present period. The meadows around Salisbury have been\nwatered in this way from time immemorial, where these nume-\nrous cuts also assist the drainage, there being much water in the\nneighbourhood. The third kind, or subterraneous irrigation, is of\nmore modern date, and constitutes the most approved plan, being\nmore convenient, and requiring the least quantity of water of any.\nIt is effected by a system of main drains, having covered gutters\nconnected with them, and placed in the sub-soil, the former\ncommunicating with a main conduit, or feeder, proper sluices being\nattached, by which the water is discharged when required.\nIrrigation by Liquid Manure is a subject well deserving the at-\ntention of the profession, no practical plan of effecting the same\nhaving yet been devised, although it is much adopted on the\nContinent, and there are occasional instances of it in this country,\nas in the neighbourhood of Edinburgh, where it is employed on\ngrass land, and succeeds exceedingly well.\nISOLATED HARBOUR, a harbour of refuge, built independent\nof the coast, and con-\nnected to it by a bridge,\nunder which the shin-\ngle is allowed to pass ;\nthe inclination of the\nshingle to travel on-\nwards, even through a\nvery contracted chan-\nnel, gave the idea of\nthis plan of construc-\ntion; and by keeping\nthe mouth of the har-\nbour in sufficiently\ndeep water, no cause\nwill operate to diminish the depth, impede the silt, or stop it up.\nThe above is a plan of an isolated harbour upon the system of\nMr. William Tait, C.E., who has devoted considerable attention\nto the possibility and expediency of constructing them; the arrow\nDigitized by\nGoogle\nJIB-KEY.\n133\nrepresent the direction of the tidal current and the dotted line,\nthe course of the prevailing south-west wind.\nJIB, the projecting frame of a crane, from which the weight or\ngoods are suspended.\nJOGGLE, a term applied to a particular\ndescription of joint; thus, to the joint\nconnecting two stones, or other bodies, in\nsuch a manner that they cannot slip away\nfrom each other without tearing the joggle\nor joint asunder. A separate piece of\nhard stone, called a joggle, is sometimes\nintroduced at joints of stones exposed to\ngreat strains, thus-See Cuts.\nJOINT, the connection or juncture of separate bodies, but\napplying more particularly to vertical joinings, as in stone-work\nthose situated horizontally being termed beds.\nJOINT CHAIR, the chair which secures the jointure of two\nrailway bars together. They are generally made larger than\nother chairs.-See Chair.\nJOISTS, the timbers employed in supporting the flooring of\nwarehouses, and other buildings.\nJOURNAL, the name given to that portion of a shaft which re-\nvolves on a support situated between the power applied and the\nresistance.\nKEY, COTTAR, or COTTREL, a wedge-shaped or taper-\ning piece of iron or wood, which\nis driven firmly into a mortice\nprepared to receive the same, to\nB\nA\ntighten and secure the several parts\n1\nB\n18\nof any framing or contrivance toge-\nther, as a rail to a chair, &c., thereby\nforming a fastening. When a key is\nA, A, the Keys. B, B, B, B, the Gibs.\npassed through a timber beam, or two or more pieces of metal\nplaced side by side, it is customary to clasp them together by\nirons, termed gibs, previous to inserting the keys.\nDigitized by Google\n134\nKEY STONE-LEVEL.\nKEY STONE.-See Arch.\nKING, or CROWN Post.-See Roof.\nKYAN'S PATENT PREPARATION, a process of preserving timber\nfrom the dry rot, recently invented by Mr. Kyan, consisting of a\nsolution of corrosive sublimate, in which the timber is immersed,\nwhereby the primary element of fermentation is neutralized, and\nthe fibre of the wood rendered indestructible. It also effectually\nseasons the timber, occupying a space of only two or three\nmonths instead of from two to six years, which is usually con-\nsumed in laying it to dry, by the common method; and it also\nprotects it from the ravages of insects.\nThe preparation has become generally employed for railway\nsleepers, and for all timbering employed in engineering works,\nwhich, from their exposure to the weather, are very liable to pre-\nmature decay.\nLAND SLIP.-See Slip.\nLEAF-BRIDGE, or HOIST-BRIDGE, a certain description of bridge,\nconsisting of two opening leaves, and much used formerly, although\nvery seldom employed at the present time.-See Drawbridge.\nLEAT, an artificial channel for conducting water for the work-\ning of water wheels, and for other purposes.\nLEGGERS, the name given to the men employed in conveying a\nbarge through a canal tunnel, by means of pushing with their legs\nagainst the side walls.\nLEVEL, the name given to a tract of low marshy land, or\nmorass, as the Bedford Level, which is the receiver of the waters\nof nine counties, and which extends into six counties; viz., Nor-\nthamptonshire, Huntingdonshire, Cambridgeshire, Lincolnshire,\nNorfolk, and Suffolk and comprises about 400,000 acres of\nlow land, encompassed in all directions: it therefore becomes\nvery difficult to provide a sufficient outlet to the sea to carry\nthe water off. The works connected with levels are of great im-\nportance, and frequently possess extensive embankments and\nsluices.-A canal, or any particular portion of one, is also termed\na level-See Drainage for Agricultural Purposes.\nDigitized by Google\nLEVEL.\n135\nLEVEL, or GALLERY (in mining). This term is much used in\nreference to coal mines, and the levels are usually distinguished\nfrom each other by their depth, and are designated 40 fathom, or\n50 fathom levels, accordingly.\nLEVEL (spirit). The spirit level is an instrument for mea-\nsuring the rise and fall of the surface of the ground, and used in\ntaking the section of a hill, or proposed line of road, canal, or\nrailway, consisting of a spirit level fixed to a telescope, with\nscrews to adjust it horizontally. The eye of the observer is\ndirected to the object-glass of the telescope, when he observes the\nheight at which the horizontal wire crosses the staff. It is necessary\nto employ great care in adjusting the instrument, as every thing\ndepends upon the accuracy with which it is performed. Sup-\nposing the primary adjustment of the telescope and level together\nto be correct, the rendering the whole horizontal is easily accom-\nplished by bringing the bubble to the centre of the glass tube.\nThe eye-piece of the telescope must be drawn out until the cross\nwires appear perfectly distinct, and the screw, acting upon the\ndiaphram containing the wires, must be turned until the smallest\ngradations are perfectly visible; when any wavering motion\nappears in either the wires or the staff, parallax is said to exist,\nwhich must be removed before any observations are taken.\nThe Y level\" is the oldest instrument used for this purpose;\nbut Troughton's Improved\" forms a great improvement upon\nsame. Gravatt's Level,\" so named from the inventor Mr. Wm.\nGravatt, C.E., is at present the favourite instrument among engi-\nneers, as it possesses very important advantages over others.\nThe term level is also applied to a perfectly horizontal plane, or\nline, i. e. a line drawn between any two points which are equidistant\nfrom the centre of the earth.-See Levelling and Levelling Staff.\nLEVEL, or PAVED CROSSING (on a railway). Level crossings\noccur where a railway crosses roads upon the same level ; in which\ncase the rails are protected by iron frames and paving.\nLevel crossings, although of frequent occurrence formerly, are\nvery seldom made at the present time, on account of their prohi-\nDigitized by\nGoogle\n136\nLEVELLING.\nbition upon highways and turnpike roads, and the accidents\nsometimes occasioned by them ; also the expense of gate-keepers,\nto attend them.\nLEVELLING, the operation of finding a line parallel with the\nhorizon, from which the rise and fall of the ground may be duly\nmeasured, the which is attained by the aid of instruments, on the\nprinciple of it being perpendicular to the direction of gravity ;\nbut although the horizon is apparently a right line, and level, yet,\nin point of fact, it is not so, but is a segment of the earth. The\nglobe is an oblate spheroid, flattened at the poles; the polar\ndiameter being 7,808, and the equatorial, 7,924 miles; and a\ndistance of 1 mile upon its surface, gives a depression of 8 inches\nbelow the visible horizon due to curvature; at 2 miles, it is\n4 times that quantity, or 32 inches; and at 3 miles, 9 times, or\n73 inches, and so on, increasing in proportion to the square of\nthe distance ; but this fall is slightly reduced by the effects of the\nrefraction of the atmosphere, which incurvates the rays of light\nproceeding from objects near the horizon in the direction of dis-\ntant parts, raising them upwards; in other words, the points of\nobservation appear higher than they really are ; this rise may be\ntaken at 1th of the curvature, and therefore deducted from it. In\nordinary levelling operations, the influence of both curvature and\nrefraction are counteracted by taking observations at equal dis-\ntances from each side the instrument, when they are each simi-\nlarly affected, and thereby nullified, their influence in extensive\ntrigonometrical surveys only being calculated and allowed for.\nLevelling is usually performed by means of an instrument\ntermed a level, and with levelling staffs, the operation being com-\nmenced by the staff-man setting up the staff at the starting point\nof the proposed line of section ; the observer then fixes his level at\na suitable distance beyond it, either upon the line, or on one side\nof it, whichever is most convenient; he then adjusts his instru-\nment, and takes a sight at the staff, noting the same in his field-\nbook, the staff-man now proceeds forward, and upon arriving at a\nsuitable point in the line, the observer turns his level, and takes\nDigitized by\nGoogle\nLEVELLING.\n137\nanother observation, noting it as before; and the former sight is\ndenominated the back sight, and the latter the fore sight ; and they\nare placed in the book, thus—\nB.S.\nF.S.\n7.32\n5.20\nSometimes several successive fore sights are taken without altering\nthe position of the level, in which case the fore sights become\nalternately back sights to the succeeding observations, as-\nB.S.\nF.S.\n7.32\n5.20\n5.20\n2.30\n2.30\n9.22\nIt may be remarked that the position and height of the level is\nimmaterial, and any trifling error in the adjustment is also rec-\ntified by placing it about midway between the stations. If the sec-\ntion be required for an especial purpose, it is necessary to number\nthe stations, and chain the distances; which are entered in chains\nand links miles are marked in the book thus-\nCH. LKS.\n40.00\n60.00\n70.00\n85.00 = 1 Mile\n12.00\nthe surplus 5 chains being carried on to the next length of\n7 chains, making it 12 chains.\nIt is essential to hold the chain as nearly horizontal as possi-\nble, and not along the surface of the ground. Of course, in run-\nning check levels for the purpose of merely ascertaining the\ngeneral correctness of a section, it is unnecessary to go over the\nground in the same line, or to measure it; the comparative level\nof the several bench marks only being regarded; they may run\ndown a turnpike road, if considered the most convenient.\nT\nDigitized by Google\n138\nLEVELLING.\nThe following is a good specimen of a field-book, and will ex-\nplain the method of proceeding:-\nNumber of\nStation.\nDistance.\nTotal\nDistance.\nBack Station.\nFore Station.\nRise.\nDepression.\nTotal Rise.\nTotal\nDepression\nObservations.\nch.lks.\nch. lks.\nch.lks.\nft.\nft.\nft.\nft.\n1\n23.60\n{\nAbove Trinity Datum.\nNo. 1, (B. M.) centre of\n1to2\n3.50\n3.50\n6.26\n5.30\n.96\n24.56\nnew road to (width\n2-3\n4.60\n8.10\n7.50\n8.35\n.85\n23.71\n40 ft.)\n3-4\n7.55\n15.65\n9.10\n4.25\n4.85\n28.56\n4-5\n2.30\n17.95\n7.69\n5.40\n2.29\n30.85\nNo. 5, corner of planta-\n5-6\n9.16\n27.11\n2.17\n4.30\n2.13\n28.72\ntion.\n6-7\n7.45\n34.56\n7.50\n8.96\n1.46\n27.26\n7-8\n4.18\n38.74\n9.28\n7.49\n1.79\n29.05\nThe following cut represents the section of the above, the hori-\nzontal scale being 4 inches to the mile, and the vertical 100 feet\nto the inch :-\nCentre of new road.\nCorner of plantation.\n24.56\n23.77\n28.56\n30.85\n22\n2726\n29.05\nDatum.\nLine.\nNo. 1\n2\n3\n4\n5\n6\n7\n8\nThe 1st column gives the number of the station; the 2nd, the\nlength or distance between the sights; the 3rd, the total distance\nfrom the first station ; the 4th, the height of the back sight; the\n5th, the height of the fore sight; the 6th and 7th gives the\ndifference between the height of the sights, the rises being\nplaced in the 6th, and the falls in the 7th column; the 8th and-\n9th gives the reduced or total level above or below the first\nstation or datum line, the total rises being reduced in the 8th,\nand the falls in the 9th column; the 10th, or last column, is left\nfor notes of the crossing of roads, rivers, &c., and to enter the\nbearing of the line of levels; also any necessary observations upon\nthe local nature of the country, soils, &c., may be advantageously\nDigitized by Google\nLEVELLING.\n139\nplaced therein. It is occupied in the diagram by memoranda of\nthe situations of the stations.\nThe line parallel with the horizon, mentioned at the commence-\nment of this article, is called the datum line, and is generally on a\nlevel with the high water spring tides (Trinity datum), or low\nwater spring tides, or some other fixed mark, or at the level of the\nfirst station, or 50 feet, or 100 feet, below it.-See Datum Line.\nIt may be remarked, that in common with all surveying opera-\ntions, the correctness of the instrument should be proved by expe-\nriment, and the chain should also be measured previous to com-\nmencing; a strong stand is also desirable for the level, with legs\nformed out of whole pieces, instead of being joined in the centre,\nas frequently made. When the instrument is adjusted, and the\nobservations are proceeding, the movements around it should be\nvery few, and carefully made, particularly when situated on boggy\nground, as they are very likely to throw the whole out of adjust-\nment; and, for the same reason, the telescope should be capable\nof turning upon the application of a very small degree of force.\nIn plotting out the work and drawing the section, it is cus-\ntomary to adopt a larger vertical scale, compared with the hori-\nzontal, in order to show the inequalities of the ground plainer.-\nSee Section.\nA section is always commenced and finished at a bench mark,\nconsisting of some fixed object, (See Bench Marks). If none should\nexist on the line of survey, it is necessary to make some, for the pur-\npose of reference at any future time, and for continuing, checking,\nor deviating from the line of levels, if found necessary therefore,\nupon the spirit level being fixed, the difference between the\nbench mark and the first station forms the commencement, the\nlevel of the bench mark being entered first, in the column of total\nrises, or total falls, as the case may be (although the first station\nshould be situated at a bench mark if possible): if, at the close of\na day's levelling a good bench mark cannot be found, a stake\nmay be driven into the ground as a temporary bench mark, of\nwhich no notice need be taken in the field-book.\nT 2\nDigitized by\nGoogle\n140\nLEVELLING STAFF-LIGHT-HOUSE.\nIn the event of meeting with obstructions in the line, as woods,\nlakes, forbidden property, &c., the levels must be taken round them:\nif the distance should extend far, and the opposite side cannot be\nseen, the plan must first be taken, then plotted, and the proper di-\nrection of the line marked upon it, also measured and set off on the\nground, by which the levels may be readily carried round; and\nupon arriving at the ultimate point, the original bearing of the\nline must be taken, which will give the true direction of the line\nof section. Lakes, ponds, woods, and buildings, may be readily\npassed, by setting off a right angle, and continuing the line until\nit clears the obstruction; next set off another right angle, and\nagain another, which carries it into the line of section; the length\nof the second line must, of course, be equal to that of the first line\nset off.See Level (Spirit).\nLEVELLING STAFF, a graduated rod or staff, which is advanced\nalternately with the spirit level, denoting by the graduations\nbisected by the latter the rise or fall between any two points.\nThe improved levelling staff with inverted figures, which ac-\ncommodates itself to the inverting telescope, whereby the figures\nmay be read off by the observer in their proper position, tends\nmuch to prevent errors, and facilitates the operation. Two staffs\nare sometimes used which are moved on alternately, one being\napplied for the back, and the other for the fore observation.\nLIFT-WALL, the cross wall of a lock chamber.\nLIGHT-HOUSE, a certain erection, generally in the form of a\ntower, built upon or adjacent to dangerous rocks, for the purpose\nof warning ships of their situation or along the sea coast, as land-\nmarks, lights of various descriptions being introduced upon the\ntop at night : a gallery, or balcony, usually runs round the lantern\non the outside. Light-houses, of a similar description, are also\nfrequently erected at the extremity of one of the arms forming\nthe entrance to harbours, for the purpose of guiding the vessels\nin and out during the night, &c., which are generally called\n\" harbour lights.\"\nThe present Eddystone Light-house, which is situated at the\nDigitized by\nGoogle\nLIGHT-HOUSE.\n141\nentrance to Plymouth Sound, and was commenced in 1756, by\nMr. Smeaton, is one of the most celebrated, presenting a fine\nspecimen of scientific construction, being situated upon an exten-\nsive reef of rocks, known by the name of the \"Eddystone,\" the\nscene of many shipwrecks, about 91 miles from the Ram-head, or\nnearest point of land.\nElevation of the Eddystone Light-house.\nIt is built upon an inclined piece of rock, upon which the\nfoundation stones are stepped down. The height to the top of the\ncupola is about 86 feet at the highest level of the rock or head-\nDigitized by Google\n142\nLIGHT-HOUSE.\nland point, and about 94 feet at the lowest level ; the building\nis carried up solid as high as there was any reason to suppose\nit was exposed to the heavy stroke of the sea, viz. to 35 feet\n4 inches above its level, and 27 feet above the top of the rock, or\ncommon spring tide high water-mark the entrance is about\nhalf-way up the latter, and the ascent is made by a well stair-\ncase in the centre; the sides of the stones forming the courses of\nthis portion are worked into one añother, thus\nPlan of the 14th Course.\noak vertical wedges were introduced into grooves\nprepared to receive them in the masonry,\nwhereby the stones were secured from the effects\nof the sea, during the intervals the works were\nobliged to be left; each course was likewise\nsecured to the one below it by oak trenails,\nwhich were driven through the upper course, entering 9 or 10\ninches into the one beneath it, and these trenails were again split\nand wedged to secure their safe purchase, as the violence of the\nwaves was such, that the mortar from the beds and joints of the\nstones forming the upper courses were washed away when the works\nwere left during the intervals of stormy weather; these courses\nwere further secured together by marble joggles or plugs, which\nwere introduced between the beds of the stones, and well wedged\nand flushed with mortar. The next portion, extending to the cap\nof the pillar, forming the surface of the balcony, or gallery, round\nthe base of the lantern, is carried up in stone walling, varying in\nthickness from 2 feet 4 inches at the bottom to 1 foot 6 inches at\nthe top, which is arched over in masonry, and there are three in-\ntermediate floors between them, a well-hole being left in the centre\nof each for communication, which is effected by means of ladders\nand 2 tier of strong chain-bond is laid in each floor in the middle\nof the walls, the several joints of the stones of this portion of the\nbuilding have grooves worked into them, into which thin pieces\nof marble are joggled they are also well cramped together,\nand a wall, about 6 feet 6 inches high, and 1 foot 2 inches thick,\nis carried up above the capping, upon which the lantern rests.\nDigitized\nby\nGoogle\nLIME.\n143\nThe Bell-rock Light-house, erected also on a dangerous reef in\nthe Frith of Forth, by Mr. Stevenson, and finished in the year\n1811, is another excellent specimen. It is 42 feet in diameter at\nthe base, and 13 feet at the top, the total height being upwards of\n100 feet.\nSection of the Eddystone Light-house.\nLIME, a valuable substance much used in building, and for\nother purposes, being the most essential ingredient in all ce-\nments; it forms one of the primitive earths, although never found\nnative, or in a state of purity, but is always combined with acids,\nDigitized by Google\n144\nLIME STONE-LINING.\nparticularly carbonic, in which it exists in prodigious quantities:\nmarble, limestone, and chalk, are all carbonates of lime, and gypsum\nis sulphate of lime. Lime may be prepared from any carbonate\nof lime, as limestone, or chalk, calcined or well burnt in kilns for\nsome time to a white heat, by which the carbonic acid and acid\ncontained in those substances are expelled, and the earth is left\nin a fragile mass, having very little coherence, and is therefore\neasily reduced to powder, when it is called quick lime, in which\nstate it shows a great disposition for water; upon applying which\nit instantly swells and cracks, producing a considerable degree of\nheat (it will absorb one quarter of its weight of that fluid, and\nyet appear dry), it then falls into a fine white powder, when it\nis called slack lime.\nStone lime is generally used for engineering works, and the\nharder the stone the better is the lime produced from it. Brown\nstone lime is said to be the best for all kinds of cements, although\nblue lias lime is considered by some to be superior, as it\nstands the action of water exceedingly well it was used by Mr.\nSmeaton in building the Eddystone Lighthouse, where it has suc-\nceeded after all other limes had failed. Good chalk lime, although\nsaid to be inferior to stone, is yet much esteemed. Lime should\nalways be kept under an enclosed shed, particularly chalk lime, as\nit suffers considerably from exposure to the air: the efficacy of\nlime also depends materially upon being well burnt, after which\nprocess it should be used as soon as possible.-See Hydraulic Lime.\nLIME STONE, or CALCAREOUS STONE, the stone from which\nlime is produced.-See Stone and Lime.\nLINING (in canal and other hydraulic works), a term applied\nto puddle laid along the bottom and upon the sloping sides of\ncanals, whereby it prevents the water from escaping; it is usually\nlaid about 2 feet in thickness. A small portion of water will\nalways percolate through the banks of canals immediately after\ntheir formation, but it gradually subsides as the soil consolidates.-\nSee Canal.\nLINK, a certain portion of a chain. Gunter's chain, which is\nDigitized by Google\nLOCK.\n145\nthat usually employed in surveying, contains 100 links, each\nmeasuring, with the connecting rings, 72 1922 inches.\nLock, or HYDRAULIC Lock, a small lock of modern inven-\ntion, and of frequent occurrence in the line of a canal; also at\nthe entrance of docks, basins, &c., constituting a contrivance for\npassing boats from one level to another.\nLocks are provided with gates at each end, and are made suffi-\nciently large to receive the largest boats navigating the canal\nupon which they are constructed. The upper portion of the canal\nis generally called the upper pond, and the other the lower pond,\nthe difference between the levels being termed the lift of the lock\n(which varies from about 3 to 12 feet-the greater the lift the\nmore water is consumed) ; that portion of the lock enclosed by\nthe gates is called the lock chamber, the size of which is regulated\nby the boats employed upon the canal. A (in the sections) repre-\nsents the level of the upper pond, and B that of the lower ; C is\nthe lift wall, and D, D the side culverts. The lock chamber\nshould be rather wider than the boats used upon the canal, and\nthe utmost care is necessary to prevent the water from the upper\nlevel making its way below, and rising up through the bottom of\nthe lock, and undermining the works; the bottom is constructed\nwith an inverted arch, to counteract any defect of this kind, the\nwhich also excludes any humidity in the soil, and diffuses the\nweight of water equally throughout. The recess into which each\nleaf of the gate turns is termed the gate chamber the gate post,\nhung in the hollow quoin, is called the quoin or heel post, and the\nother the mitre post. The bottom framings, against which the\ngates are shut, are called mitre sills, and are distinguished as\nupper mitre sill and lower mitre sill.\nThe portions of a lock at each extremity of the lock chamber\nare termed bays, and are either fore or tail bays accordingly, they\nare usually finished with circular wing walls, extending to the\nfull width of the canal, and carried down below the bottom of the\nsame ; and bumping apparatus is sometimes formed against the\nlatter, by which they are protected from any shock of the boats\nU\nDigitized by\nGoogle\nLongitudinal Section of a Lock.\n146\nA\nB\nE\nPlan of a Lock.\nA\nLOCK.\nLower Pond.\nLOCK CHAMBER\nUpper Pond.\nDigitized by Google\nLOCK GATES.\n147\nor boat-hooks grooves are generally\nA\nmade in the head and tail bay walls,\nfor the insertion of stop planks, to\nB\nshut off the water when repairs are\nnecessary.\nWhen a boat is required to be\nTransverse Section.\npassed from the higher to the lower\nlevel, it is first floated into the lock chamber, and the upper\ngates closed; the water is then allowed to escape from the lock\nchamber to the lower level, which is effected either by paddles\nformed in the gates, or by side culverts; the boat being thus\nsunk to the lower level, the lower gates are opened, and it is\ntaken through : and the boats are passed up by a similar process,\nonly reversed. Some locks are constructed sufficiently large\nto allow of two boats being passed up or down at the same time\nand others effect the same by two distinct chambers.\nLOCK-GATES, or HATCHES, the framed gates employed on\nrivers and canals, for penning back the water, which consist of\ntwo leaves, and are opened either by means of balance-beams,\nsituated on the top of the gates, or by boat-hooks a large gate\nrunning upon wheels is opened by means of a windlass and\nchain.\nThe gates of a lock are termed either upper or lower gates,\naccording to their situation; they are generally formed of strong\noak framing, the upright frame, or posts, at each side being called\nquoin or heel posts, and the others mitre posts, according to their\nsituation, and horizontal pieces are framed into them, termed\nrails; their tops are finished by long heavy beams, termed balance-\nbeams, which are for the purpose of opening and shutting the\ngates, these rest upon the quoin posts, and are morticed into the\nmitre posts; strong planking is nailed or trenailed on to the leaf\nframing, which is sometimes laid in a diagonal direction, and\na slight foot bridge is usually formed on the top of the gates.\nThe quoin posts rest upon an iron pin, which turns in a socket\nsecured to the platform, and the upper part is enclosed by an\nU 2\nDigitized by\nGoogle\n148\nLOCK GATES.\niron collar, connected with irons fastened to the stone curb, and\nusually denominated anchor irons.\nIt has been found by experience, that lock gates, in common\nwith all timber framing, stand better when secured together\nwithout the aid of irons, by means of dove-tailed tenons, wedges,\nand pins, as iron soon affects those parts in immediate contact\nwith it.-See Anchor Irons, and Paddle or Clough, &c.\nElevation of Inner Side of a Lock Gate.\nG\nPlan of Gates, showing Platform, &c.\nA, A, the balance-beams, by which the gates are opened\nand shut.\nDigitized by Google\nLOCK SILL-LOCOMOTIVE ENGINE.\n149\nB, B, the clap-cill and frame.\nC, C, the cross bearers, resting upon plates, and upon which\nthe planking is laid.\nD, D, the rails or framing of gates, to which the leaf planking\nis secured.\nE, the upper diagonal planking.\nF, the bottom planking.\nG, the elm sheet-piling, for protecting the platform.\nH, H, the quoin, or heel posts.\nI, I, the mitre, or meeting posts.\nLock SILL, or CILL, the bottom framing against which the\ngates are shut.-See Lock.\nLock-WEIR, a weir furnished with a lock, for the transport of\nboats from one level to the other.\nLOCOMOTIVE ENGINE, a motive steam-engine constructed on\nthe high-pressure principle, and adapted to run on roads and\nrailroads, being employed in conveying passengers and merchan-\ndise along the line.\nLocomotive engines differ considerably from other steam-\nengines in their mode of construction, as numerous modifications\nfrom the latter became necessary to render the machine suitable\nfor a rapid transit; the foremost of which is the combining of the\nengine and boiler together, the boiler is also formed of much less\ndimensions in proportion to its power, and the size of the cylinders\nare reduced; the several parts of the framing is also secured\ntogether in a stronger manner than usual, whereby the whole is\nrendered proof against the sudden shocks and strains to which it\nis subjected; the motion of the piston-rod is transferred to the\nwheels, either by connecting rods fixed upon one of the spokes of\nthe wheels, or it is effected by cranks fixed upon the axles, which\nthereby cause the wheels to revolve: the latter system is the\nmost convenient and direct, and is in almost general use ; although\nthe crank, being subjected to very great strains, is rather liable\nto fracture, the former may consequently be considered to be the\nstrongest method.\nDigitized by Google\n150\nLOCOMOTIVE ENGINE.\nThe honour attached to the inventor of the locomotive engine\nis undoubtedly due to Mr. Trevithick (although Mr. G. Stephenson\nhas the credit of perfecting it) ; the first one having been con-\nstructed by Trevithick and Vivian in about the year 1802, which\nwas tried upon the common roads. It was supposed at the time,\nbut erroneously, as experience has since shown, that the wheels\ndid not possess sufficient power of adhesion to the road to impel\nthe engine forward; and various contrivances were consequently\nattempted in other engines to increase the same by the aid of\npropellers or levers, whereby it was pushed along, and which acted\nupon the ground somewhat similar to the feet of horses: among\nthe foremost of these was Mr. Gurney's common road locomo-\ntive, as originally constructed; the propellers being afterwards\nfound useless, were removed, although they have been described\nas forming the chief peculiarity of his patent. Mr. Gurney's car-\nriages obtained a very great share of public patronage and con-\nsideration : indeed they have been the most successful of any.\nTrevithick and Vivian also constructed another modification of\ntheir patent steam-engine, and applied it upon a very indifferent\ntramway, where it realised all that could be reasonably expected ;\nit was worked by only one cylinder, which was placed vertically ;\nand it got over the centres or dead points by the momentum of\nthe carriage when in motion.\nThe first public railway, worked by locomotives, was the\nStockton and Darlington, by Mr. G. Stephenson, which was\nopened in 1825 the locomotives were worked by vertical cylin-\nders, the motion being communicated to the wheels similar to\nthe last-mentioned engine, and all four wheels acted upon it by\nmeans of an endless chain running round cog-wheels fixed on the\naxles. Although far from perfect, these continued to be the\nmost effective engines at work, until the opening of the Liverpool\nand Manchester Railway ; and all engines, up to this period, may\nbe described, generally, as being of very poor construction,\nhaving one flue passing through the boiler, and returned again to\nthe fire-box (the Trevithick plan of boiler), at which end the\nDigitized by Google\nLOCOMOTIVE ENGINE.\n151\nchimney was situated; and a greater velocity than 8 miles an\nhour could never be attained by them, owing to their small extent\nof evaporating surface : they did not possess 14ᵗʰ the power of\nthe present locomotives.\nThe directors of the latter railway having, in the year 1829,\noffered a premium of £500 for the best locomotive engine, gave\nthe first stimulus to the subject, the stipulations and conditions\nbeing as follows:-viz., \" To consume its own smoke; to be\ncapable of drawing three times its own weight at 10 miles an hour,\nwith a pressure on the boiler not exceeding 50tb. upon the square\ninch; the whole to be proved to bear three times its working\npressure-a pressure gauge to be provided; to have two safety-\nvalves, one locked up : the engine and boiler to be supported on\nsprings, and rested on six wheels, if the weight should exceed\n41 tons; height, to the top of the chimney, not to exceed 15 feet;\nweight, including water in boiler, not to exceed 6 tons, or less, if\npossible: the cost of engine not to exceed £550.\" The Rocket\"\nengine, by Messrs. Booth and Stephenson, proved the successful\none, in the boiler of which tubes were introduced for the first\nb\nb\n00000000\n0000000\n000000\n0000\nElevation and Section of the \"Rocket\" Locomotive Engine.\nDigitized by Google\n152\nLOCOMOTIVE ENGINE.\ntime, which greatly increased the evaporating powers of the\nengine, and formed a considerable improvement.\na, the fire-box, which is surrounded with water on every side,\nexcept that perforated for the reception of the fire tubes.\nb, the boiler in which the steam is generated, containing 25 fire\ntubes.\nc, one of the side pipes for conducting the water from the\nboiler to the casing round the fire-box.\nd, one of the steam cylinders.\ne, the chimney by which the smoke and condensed steam\nescapes.\nf, one of the connecting rods for communicating the motion of\nthe piston-rod to the driving wheels.\ng, one of the eduction pipes, through which the steam escapes\ninto the chimney, after performing its office in the cylinders.\nh and i, the safety-valves.\nThe boiler of the 'Rocket\" locomotive was 3 feet 4 inches\ndiameter, and 6 feet long, having flat ends; the lower half was\nkept constantly filled with water, and 25 copper tubes, of 3 inches\ndiameter, were passed along its whole length, and fixed water-\ntight, the further ends of which were open to the chimney, and, at\nthe other ends, to the furnace (the tubes employed in locomotives\nat the present time are of much smaller diameter, but three or four\ntimes the number of the Rocket\"). The upper half of the boiler\nwas appropriated as a reservoir for steam : the square furnace-box,\nwas 3 feet long by 2 feet broad, and 3 feet deep, the fire bars laying\nat the bottom of it; the surface exposed to heated air, or flame,\nfrom the furnace 117.8 square feet ; the whole of the furnace was\nenclosed in a casing, except the bottom and the side next the\nboiler; and the space between the furnace and the casing was\n3 inches in the clear, and kept constantly filled with water: there\nwas also a pipe from the side of same, which communicated with\nthe underside of boiler, and another pipe was fixed at the top of\nit, which conducted the steam from it into the boiler. The cylin-\nders had a stroke of 16½ inches, and were placed in a diagonal\nDigitized by Google\nLOCOMOTIVE ENGINES.\n153\ndirection upon each side at the extremity of the boiler, each\nworking a wheel of 4 feet 81 inches diameter. The principle of\ngenerating steam was by the exhausting power of the chimney,\nassisted by the impulse of the steam from the cylinders, which\nescaped from them into the chimney by two pipes, one on each\nside, called the ejection pipes.\nTons.\ncwt.\nqrs.\nlbs.\nThe engine weighed\n4\n5\n0\n0\nTender, with water and coke\n3\n4\n0\n2\nTwo loaded carriages attached\n9\n10\n3\n26\nTotal weight in motion\n17\n0\n0\n0\nThe evaporating surface of the boiler was three times the extent of\nthe former engines, which weighed upwards of 71/2 tons, to which\nits success is mainly attributable; it evaporated 114 gallons of\nwater an hour, and consumed 217tb. of coke in that time, and it\nattained a speed of 29 miles an hour, and an average velocity of\n141 miles an hour.\nAlthough locomotives have since been considerably modified,\nyet the above engine has formed the basis of all the many great\nimprovements which have taken place in them. The cylinders\nhave been removed from the outside of the boiler to the inside,\nand the piston rods placed underneath, instead of on the outside\nof the wheels; they are also connected with the latter by means of\ncranks placed upon the axles of the driving-wheels at right angles\nwith the same; a warm air chamber has also been made at the\nupper end, and a blast-pipe introduced in the chimney, whereby\nthe draught of the furnace is considerably increased.\nIt was soon after found, that by constructing engines of greater\nsize, the increased evaporating powers would make ample amends\nfor the additional weight, and a strong desire was accordingly\nmanifested of having heavier engines on the Liverpool and Man-\nchester Railway, but owing to the rails not being sufficiently\nstrong to carry them, they were found objectionable; and there\nX\nDigitized by Google\n154\nLOCOMOTIVE ENGINES.\nwas accordingly a constant struggle between light and heavy en-\ngines for some time, but the line being now relaid with heavier\nrails, they are exclusively used. The locomotives in general use\nat the present time, upon public lines of railway, weigh from 9 to\n13 tons, and are mounted on six wheels, which are frequently\ncoupled to increase their power of adhesion. The framing of the\nengine is usually placed on the outside of the wheels, but Mr.\nBury places the framing of his engines on the inside, by which he\nreduces the length of the axle, and consequently increases its\nstrength. The slide-valves are shifted by the engineer by means\nof the connecting rod, or hand-gear, at starting and stopping an\nengine only when at work, the engine performs it. A larger pro-\nportionate passage is required for the entrance of the steam in\nlocomotives than in stationary condensing engines; the usual\nvelocity of the piston being about 440 feet per minute, or double\nthat of the latter, when running at a rate of 25 or 26 miles an\nhour: they move at 700 feet per minute, when moving at 40\nmiles an hour; a proportion of 14th the area of the cylinders is\nconsidered the best for the area of the steam port.\nThe power of a locomotive engine varies according to the\nvelocity with which it is propelled, and it cannot be estimated in\nthe same manner, as other engines, viz., taking the actual force\nupon the piston and the velocity of its motion, as it is very diffi-\ncult to ascertain the effective pressure of the steam upon the\npiston, in consequence of its often differing very considerably from\nthat in the boiler, and on account of the large amount of resistance\nof the waste steam, owing to the great velocity with which the\npiston moves. The only true method of determining the power of\na locomotive is, therefore, by experiment.\nThe extent of power of a modern locomotive engine, having\n12 inch cylinders, and an 18 inch stroke of piston, has been stated\nat about 38 or 40 horse power at high velocities upon a level\nplane, and 70 to 80 horse power at a slow rate of speed and their\ngeneral performance has also been estimated by other engineers at\nfrom 30 to 40 tons, moved at the rate of 15 miles an hour; accord-\nDigitized by\nGoogle\nLOCOMOTIVE ENGINES.\n155\ning to which the following Table shows the load it will have at\ndifferent inclinations at plane:-\nGross load in Tons, which a Locomotive Engine,\nGross load in Tons, which a Locomotive\nInclination\nEngine, capable of taking 40 tons\nof\ncapable of taking 30 tons at 15 miles per hour,\nwill drag at the under-mentioned Velocities,\nat 15 miles per hour, will drag\nin miles in an hour.\nat the under-mentioned Velocities,\nPlanes.\nin miles in an hour.\nMiles.\nMilea.\nMiles.\nMiles.\nMiles.\nMiles.\nMiles.\nMiles.\nMiles.\nMiles.\n10.\nF2.\n14.\n16.\n18.\n12.\n14.\n16.\n18.\n20.\nLevel\n53.4\n45.\n34.28\n26.25\n20.\n60.\n45.70\n35.\n26.66\n20.\n1 in 4480\n50.85\n42.57\n32.62\n24.97\n18.97\n57.1\n43.5\n33.3\n25.3\n19.\n1 in 2240\n48.51\n40.87\n31.12\n23.85\n18.15\n54.5\n41.5\n31.8\n24.2\n18.1\n1 in 1120\n46.5\n39.07\n29.77\n22.8\n17.32\n52.1\n39.7\n30.4\n23.1\n17.3\n1 in 1000\n43.56\n36.75\n27.97\n21.45\n16.27\n49.\n37.3\n28.6\n21.7\n16.3\n1 in 900\n42.9\n36.3\n27.6\n21.15\n16.12\n48.4\n36.8\n28.2\n21.5\n16.1\n1 in 800\n41.7\n35.15\n26.77\n20.47\n15.6\n46.9\n35.7\n27.3\n20.8\n15.6\n1 in 700\n41.25\n34.05\n25.95\n19.87\n15.07\n45.4\n34.6\n26.5\n20.1\n15.1\n1 in 600\n39.\n32.85\n24.97\n19.05\n14.55\n43.8\n33.3\n25.4\n19.4\n14.6\n1 in 500\n37.05\n31.2\n23.77\n18.22\n13 87\n41.6\n31.7\n24.3\n18.5\n13.9\n1 in 448\n35.61\n30.0\n22.87\n17.47\n13.27\n40.\n30.5\n23.3\n17.7\n13.3\n1 in 400\n33.75\n28.8\n21.97\n16.8\n12.75\n38.4\n29.3\n22.4\n17.\n12.8\n1 in 350\n32.7\n27.37\n20.85\n15.97\n12.15\n36.5\n27.8\n21.3\n16.2\n12.1\n1 in 300\n31.44\n25.8\n19.65\n15.07\n11.47\n34.4\n26.2\n20.1\n15.3\n11.4\n1 in 250\n28.2\n23.77\n18.57\n13.87\n10.57\n31.7\n24.1\n18.5\n14.1\n10.6\n1 in 200\n25.11\n21.22\n16.12\n12.37\n9.37\n28.3\n21.5\n16.5\n12.5\n9.46\n1 in 150\n21.36\n18.\n13.65\n10.5\n7.95\n24.\n18.2\n14.\n10.6\n8.\n1 in 100\n17.55\n14.77\n11.25\n8.62\n6.58\n19.7\n15.\n11.5\n8.78\n6.58\nIt is generally considered injudicious to work an engine regu-\nlarly to the utmost of its power; the load should, therefore, be\nalways a-little less than it is capable of drawing, to allow for the\nvariation of level in the line, and other contingencies; and extra\npower may yet be obtained, if required, for the inclined planes, by\npartially stopping the flow of water into the boiler at the time of\npassing up, which increases the power of the steam, although not\nto much extent. The water lost by the steam blown away in a\nlocomotive and other steam engines is replaced by an equal\nquantity of water at each stroke of the piston, being supplied by\nsmall force-pumps from the tender, and worked by the engine.\nEngines are generally oiled by means of syphon wicks, or by\ncocks and tubes; and the engine-man should carefully examine the\noil cups and syphon wicks previous to starting, also the water-\ngauge and the other parts of the engine; and, as he sets her\nx 2\nDigitized by Google\n156\nLOCOMOTIVE ENGINES.\nagoing, should try the hand-gear and force pumps; the condensed\nsteam-cock should be kept open as long as possible, and not\nshut until just before the train starts. During running, the water-\ngauge should be tested by the gauge-cocks, if considered neces-\nsary, and the cocks should always be turned before the supply\npumps are used.\nThe locomotives may be frequently observed running up and\ndown a line of railway for a short distance in the vicinities of the\nengine-house and depôts; this is for the purpose of pumping the\nwater from the tender into the boiler, the supply pumps, as before\nstated, being worked by the engine ; it is obviated, in some cases,\nby the locomotive being placed upon the circumference of large\nwheels situated beneath the line, instead of upon the rails, when\nthe only effect produced is the turning of these friction wheels, the\nlocomotives remaining stationary.\nThe boiler forms the limit to the power and speed of a locomo-\ntive, as each stroke of the piston consumes two cylinders-full of\nsteam, the same causing one revolution of the wheels; a certain\nquantity of steam, may, therefore, be said to represent a certain\nnumber of feet travelled over; and the cylinders are generally\ncapable of more work if a greater quantity of steam could be sup-\nplied to them the diameter of the pump and feed-pipes are also\nnot sufficiently large to feed the boiler at very high velocities,\nwhich consequently causes a lack of steam the boilers of station-\nary engines, on the contrary, may be enlarged without difficulty,\nif the engine requires it.\nNearly one-third of the power of locomotive engines is absorbed\nin preparing to move a load, and it is the same for great as for small\nloads; the wear and tear of the engine also bears the same ratio\nand the current expenses, as that of the stations, the sum for\ndirection, wages of engineers, attendants, &c. ; it is, therefore, of\nthe utmost importance that the goods and passengers upon a rail-\nway should be conveyed in large masses.\nThe consumption of fuel of locomotives is regulated by the\nload; with a full load it amounts to about 1ᵗʰ of coke per ton\nDigitized by\nGoogle\nLOCOMOTIVE ENGINES.\n157\nper mile, taking the gross weight (the quantity of water evapo-\nrated is rather less than 1 of a gallon per ton), and the consumption\nof it is nearly double with a light load.\nThe following cuts represent Mr. Robert Stephenson's Patent\nLocomotive Engine :-\nno\nN\n23\nE\nD\nnum\no\nEnd Elevation. Scale @ of an inch to the foot.\nDigitized by Google\nDigitized by Google\n09600\non\n3\no\no\n000000\n0\n000000000\n00\n0 o c 0 or a 0 - c o o 0 o c 0 0 0\nD\no\n©\n0\no\no\nD\n00 DO o o o 0 D D D 0 c 2 C D o c o © 0 000\n0 o 0\n3\no\n0\none\n00000090000 0 0000m 0\n00\no\n0\nSide Elevation, with the Tender attached. Scale I of an inch to the funt.\n0\no\nD\n0\n0\nD\n4\n0\npood\nD\n0\n0\no\n3\n0\n0200\n.\n$\n3\n:\n,\nMr. Robert Stephenson's Patent Locomotive\na\no\n0\n0\n0\n0\no\n0\no\n0\nD\nc\n0\n©\n©\n0\nor\n©\no\no\n0\n0\na\n.\ne\n0\n0\no\n-\n0\n0\nM\na\n.\nname .\n0\n00000000 000\ne\n0\n0\na\n$\nLOCOMOTIVE ENGINES.\n1388\nDigitized by Google\nLION\n11\nN\nA\nInternal Fire Box\nSteam Entrance\nExternal FireBox\nLongitudinal Section, showing Construction. Scale i of an inch to the foot.\nP\nSafety Valve\nBoiler\nSteam : Pipe\n-\nF\nBoiler\nMan Hole\nSteam Prpe\nDamper\nSmoke box\nBlast Prps\nChimney\nlind\nY\n05\n1599\nLOCOMOTIVE ENGINES.\n-\n160\nLOCOMOTIVE ENGINES.\nMr. Robert Stephenson's Patent Locomotive.\nSteam Entrance\nH\nW\nR\nR\n0\nInternal Pine Barn\nC\nTransverse Section taken through Smoke-box. Scale I of an inch to the foot.\nA, the fire-grate, which is situated at the bottom of the internal\nfurnace-box.\nB,B, the feed-pumps which supply water to the boiler, which\nare worked by an arm attached to the piston-rod.\nDigitized by Google\nLOCOMOTIVE ENGINES.\n161\nChimngy\nDamper\n/\nBlast Pipe\nDUE\nCYLINDER\nCYLINDER\nTransverse Section taken through Smoke-box.\nC, C, the suction-pipes to same.\nD, the gauge for regulating the height of water in the boiler.\nE, E, the gauge-cocks for trying the same.\nF, the lock-up safety-valve, over which the engineer has no\ncontroul.\nY\nDigitized by Google\n162\nLOCOMOTIVE ENGINES.\nG, G, the blow-off cocks, through which the water is blown\nwhen the boiler undergoes cleansing.\nH, the regulator, which is fitted to the steam-pipe, by which\nthe engineer regulates the supply of steam to the cylinders as\nmay be required.\nI, I, the slide-valves forming the communication between the\nsteam-pipe and the cylinders.\nK, K, the steam-chests in which the same work.\nL, one of the cylinder covers, which are fixed air-tight.\nM, one of the piston-rods.\nO, the steam-dome or cover, being placed over the steam-pipe.\nP, one of the connecting-rods, which is attached to the last by\nmeans of cross-heads.\nQ, Q, the cranked axle.\nR, R, the driving-wheels.\nS, S, the eccentrics and accompanying gear for reversing the\nmotion of the engine.\nU, U, the principal or outside framing, upon which the springs\nW, W, are fixed, the framing employed within it being termed\nthe inside framing.\nX, X, the pet-cocks, for ascertaining the flow of water in\nthe suction-pipes.\nY, Y, the cocks to let off the priming water from the cylinders;\nanother cock is also connected with the blast-pipe for a like\npurpose.\nZ, the steam-whistle, for giving signals as occasion may\nrequire.\nThe modern locomotives take about 8tb. of fuel to evaporate\n1 cubic foot of water (which is nearly the same that is required by\nstationary engines) ; as much as 18tb. were consumed by the old\nlocomotives to accomplish the same, owing to their evaporating\nsurface being considerably less. The cost of a locomotive engine\nand tender is about £1,200, and the annual repairs are stated\nat £800.\nThere have been several locomotives constructed, with a view\nDigitized by\nGoogle\nLOCOMOTIVE ENGINES.\n163\nto their running on common roads, as before stated, which are\nnecessarily of much less weight than those employed on rail-\nways, and they usually possess a greater degree of power in pro-\nportion to their weight. Mr. Gurney was among the foremost in\nMr. Gurney's Patent Road Locomotive, with a Carriage attached to it.\nintroducing them he proposed having the carriage containing the\npassengers attached to the propelling carriage, or engine, and he\nconsidered that if his conveyance was employed instead of horses\nthe total weight upon the road would be about the same in either\ncase thus, supposing the average weight of 1 horse to be 10 cwt.\nit would give 2 tons as the weight of 4, which is about that of his\npropelling engine, and the passenger-carriage (containing 18 per-\nsons) would be of the same weight as the stage-coach drawn by\nthe horses; but as horses cannot work above 1 or 11 hours per\nday, from 25 to 32 horses are constantly required to work 8 hours,\nor the length of time a locomotive may be readily run per day,\nwhich number of horses it may therefore be said to be equal to ;\nalthough his engine is calculated to be of only 12 nominal steam-\nengine horse power : notwithstanding, where a speed of 4 miles an\nhour only is required, horses are the cheapest. If the engine is\nemployed to draw carriages, as represented in the above cut, they\nshould not exceed 3 tons, nor the engine 2, or 21 tons. An engine,\nwith a carriage, can turn a circle of 10 feet inner diameter, and be\nstopped within 6 or 7 yards. The ordinary pressure on Mr.\nGurney's boiler is 70tb per square inch; it consequently blows\nwith that pressure, and generally lifts the valve: when the carriages\nstop, it is sometimes increased to 100, and 130 is the greatest\nY 2\nDigitized by\nGoogle\n164\nLOCOMOTIVE ENGINES.\npressure it is liable to be subjected to ; 20tb. is also the utmost pres-\nsure on the piston : the danger of the boiler of a road locomotive\nbursting is not so great as that of the horses running away. Mr.\nGurney has thrown out an idea of adopting a locomotive, both for\nhigh and slow velocities, by a very simple contrivance; viz., by\nusing wheels 5 feet diameter, when the load is light, and a great\ndegree of speed is required, and substituting smaller ones, when\nthe load is heavy, say 2 feet 6 inches diameter, and a slow velocity\nonly is necessary ; the power with the latter would be double that\nof the former, but they would travel at only half their velocity.\nAn advantage is gained by quick travelling, as the momentum\nassists in overcoming the inequalities of the road, in a similar\nmanner to the action of a fly wheel. One of Mr. Gurney's loco-\nmotives, weighing 2 tons, drew 11 tons, inclusive of the engine, the\nroad being hard and good, although it undulated. The width of\nthe tires of the wheels were originally 2 inches, but he has\nfound 31 inches a more advantageous width, particularly for the\nroads.\nMr. Hancock's common road locomotive was the first publicly\nrun upon a road for hire, which occurred in the year 1831 ; in\nwhich case the engine was adapted for the reception of passengers,\nand was capable of containing 16 persons, independent of the\nengineer and guide; the machinery being situated behind the car-\nriage, and the weight was about 31/2 tons, without passengers,\nand exclusive of the engines, boilers, coke, water, &c. The\ninventor states, that it requires about 20 minutes to get up the\nMr. Hancock's Patent Road Locomotive.\nsteam, the same consuming\n1 bushel of coke, taking in\nwater according to circum-\nstances-say every 8, miles,\nand about 7 or 8 cwt. at a\ntime ; the carriage can be\nturned in little more than 10\nfeet, and stopped in a much\nshorter space than a coach; the pressure of the steam in the\nDigitized by\nGoogle\nLOCOMOTIVE ENGINES.\n165\nboiler is much the same as in Mr. Gurney's, but he has worked it\nat a greater pressure. The fire is blown by a rapid current of\nair produced by a fanner, which is turned rapidly round by the\nengine, instead of the draught being effected by a high chimney.\nOne driving wheel is generally found sufficient; but, on slippery\nroads and steep hills, both hind wheels are connected with the\nengine; he has accomplished 1 mile up hill, at a rate of 17 miles\nan hour.\nIt may be very fairly stated, that the several unsuccessful\nattempts that have been made to introduce locomotives upon\ncommon roads, have not been caused by any imperfection in their\nmode of construction, neither are there any practical difficulties\nconnected with them that could not be surmounted their failure\nis wholly attributable to the obstacles which beset them, both\npublic and private; and until these are removed, it is in vain to\nexpect perfection, or even a partial fulfilment of the duties required\nfrom engines for such purposes.\nA select committee of the House of Commons were appointed\nto investigate and report upon the subject of steam carriages,\n(road locomotives) in the year 1831, and, after examining several\neminent engineers, came to the following conclusion :-\n\" That sufficient evidence has been adduced to convince your\nCommittee,-\n\" 1. That carriages can be propelled by steam on common\nroads at an average rate of 10 miles per hour.\n2. That, at this rate, they have conveyed upwards of 14\npassengers.\n\" 3. That their weight, including engine, fuel, water, and at-\ntendants, may be under 3 tons.\n\" 4. That they can ascend and descend hills of considerable\ninclination with facility and safety.\n\" 5. That they are perfectly safe for passengers.\n\" 6. That they are not (or need not be, if properly constructed)\nnuisances to the public.\n\" 7. That they will become a speedier and cheaper mode of\nconveyance than carriages drawn by horses.\nDigitized by Google\n166\nLODE-MASONRY.\n8. That, as they admit of greater breadth of tire than other\ncarriages, and as the roads are not acted on so injuriously as by\nthe feet of horses in common draught, such carriages will cause\nless wear of roads than coaches drawn by horses.\n9. That rates of toll have been imposed on steam carriages,\nwhich would prohibit their being used on several lines of road,\nwere such charges permitted to remain unaltered.\"\nLODE (in mining), a vein containing metal.-See Mine and\nCopper-mine.\nLow PRESSURE, or CONDENSING ENGINE, a steam-engine, in\nthe cylinder of which a vacuum is formed, whereby the pistons are\nworked; they are considered to be the most economic for ordi-\nnary purposes, and are, therefore, in very general use.-See\nSteam-Engine.\nMACHINE, an instrument employed to regulate motion, or to\nincrease either its velocity, or its force, the term is, therefore,\nmore particularly significant of the contrivance interposing be-\ntween the natural force and that employed in fulfilling the end\ndesired, as to a water-wheel which is situated between the\nwater and the apparatus for grinding corn, or for pumping water,\nas the case may be. The tackle connected with most contrivances\nare also known by the general name of machinery. It is a general\naxiom in mechanics, that whatever a machine may gain in velo-\ncity, it loses in force; and, vice versa, no instrument effecting a\nsaving in both time and force.-See Mechanical Powers.\nMARINE ENGINE.-See Steam-Engine.\nMASONRY, a term applied to all works, either prepared or ex-\necuted in stone.\nIt may be classified generally under three heads; viz., 1st,\nplane ashlar, or cut masonry 2nd, hammer-dressed masonry;\nand, 3rd, rubble or rough masonry; and there are several va-\nrieties of each practised in different parts of the country. Ashlar\nmasonry consists of fair cut stones, and is mostly used for the faces\nof buildings, when it is well bonded and crumped together; but\nashlar for engineering purposes is generally laid solid throughout,\nparticularly where great strength is required.\nDigitized by\nGoogle\nMECHANICAL POWER-MILL.\n167\nThe cutting or working upon the several faces and beds of\nstones is called dressing, and such stones are described as wrought.\nThe term hammer-dressed is applied to masonry, when merely\nsquared and picked by the hammer, and this is more particularly\nadapted for hard stones. Tooled, or droved, is another very gene-\nral description of dressing for hard stones, the surfaces being\nworked in parallel perpendicular flutes: when the tooling is\nworked irregularly, it is described as random tooled; when on the\ncontrary, they are worked by a chisel or narrow tool, it is called\nboasted, or chiseled; the surface is also sometimes nicked or cut\nwith a small tool, when it is said to be pointed.\nRubble masonry is composed of stones merely axed on the face,\nand laid according to circumstances; thorough stones being occa-\nsionally introduced.\nBrickwork is sometimes brought under this head, being de-\nscribed as brick masonry.-See Ashlar, Rubble-work, and Pinning-in.\nMECHANICAL POWER, the term applied to the force produced\nby any machine for the accomplishment of any particular purpose.\nIt may be said to form the measure of all other forces, as it bears\nreference to the degree of power exerted or required; thus,\nsteam, water, man, and horse power, are all represented by cer-\ntain amounts of \"mechanical power.\"-See Animal Power and\nHorse Power.\nMECHANICAL POWERS, the simple agents employed in pro-\nducing mechanical power, of which all machines are composed;\nthe application of them constituting the science of \" Mecha-\nnics.\"\nThe mechanical powers are usually divided into six classes\nViz., the lever, the wheel and axle, the pulley, the inclined plane,\nthe wedge, and the screw.\nMETALLING.-See Ballasting.\nMILE, a land measure of distance, extending 1760 yards: 80\nchains also make one mile.\nMILL, a machine employed in pulverizing any substance, as\nthat of grain, whereby it is formed into flour, which is usually\nDigitized by\nGoogle\n168\nMINE.\naccomplished by rubbing it between two hard substances, consist-\ning generally of stone, and termed mill-stones; the operation being\neffected by the aid of machinery.\nAll descriptions of wheel-work at the present time are known\nby the general name of mill-work, originating, no doubt, from the\ncircumstance of this being one of its first applications.\nMINE, a term applied generally to underground works, or ex-\ncavations, when made for the purpose of obtaining metallic ores,\nand other minerals.\nThe body of the earth, as far as investigated, consists of\nnumerous strata, or beds, of various substances, differing exceed\ningly from each other in their appearance, specific gravity, che-\nmical qualities, &c., and the strata of the same district frequently\nvaries considerably at very short distances the same description\nof stratum also sometimes occurs in countries far apart. The\nstrata are traversed in all directions by cracks, or fissures, which\nare supposed to have been originally open chasms, but which\nare now mostly filled by substances differing from that of the\naccompanying rocks: when they contain minerals, or any kind\nof metal, they are called metallic veins, lodes, or courses, which are\nonly met with in what are denominated primitive rocks, as granite\nand slate, and they are usually found in a slanting position,\nrunning from east to west, and of various thicknesses and extent.\nWhen a vein runs of an uniform thickness, and in a straight line,\nit is called a rake; if its course is extended and swelled out in\nsome places, and contracted in others, it is termed a pipe vein,\nthe wider parts of the vein being termed floors the vein is some-\ntimes divided into branches, when it is said to take horse : in some\ncases a cross grain occurs, throwing it 10 or 20 feet out of its\ncourse, by lifting or heaving a portion of it up; and a vein is\nsometimes run to a mere thread, and at length completely lost,\nappearing again at a distance. When a vein falls, it is said to\ndip, the reverse being called the rise. The miners apply the name\nof passable metals to any soft easy materials, as free-stone, and\nthe like; and when a stratum lies in an inclined position, and ulti-\nDigitized by\nGoogle\nMINE.\n169\nmately terminates at the surface, it is said to crop out. It is\nrather remarkable, that a less quantity of water is encountered in\nmines under the sea than in ordinary excavations. There are\ncoal-mines extending for miles under the sea along the coast,\nwhich are perfectly dry.\nTransverse Section.\nLongitudinal Section of a Metal Mine.\nThe perpendicular line shows the shaft, and the inclined lines\n(in transverse section) the metallic lode; the several horizontal\nlines being the galleries. The adit is represented by the level line\nat the upper part of the cuts.\nMines are entered by three different methods, viz.-1st, by\nvertical shafts or pits, similar to wells; 2ndly, by day-levels, or\nadits, which are galleries carried from the side of a valley into\nthe mine; and, 3rdly, by inclined planes, or rather inclined tun-\nnels, from the natural surface into the mine, which is a medium\nbetween the two former : they are generally laid with rails, and\nare sometimes very steep, being worked by water-wheels, or\nsteam-engines. The working of mines was conducted originally\nin a very simple manner; and only such of the ore that could\nbe easily removed was regarded. Tin is the first metal recorded\nby historians as having been worked in this country, which pro-\nbably occurred from its near connection with the surface of the\nearth. The ore is seldom found pure, although gold, silver, cop-\nper, and other comparatively soft metals are frequently met with in\na state of purity; it is therefore probable that they were sought for\nand discovered before iron. Doubtless, but iron, which is a very\nZ\nDigitized by Google\n170\nMITRE-MORTICE.\nplentiful metal, was also worked very early, although it very rarely\noccurs in a pure state. The vast mountains of metallic ashes and\ncinders in the neighbourhood of Ashton, near Birmingham, and\nother places, are supposed to be of very ancient origin, and to have\nbeen deposited from the earliest period of civilization in this coun-\ntry. Lead was also early discovered from its striking appearance,\nand its laying near the surface. Copper is comparatively of modern\ndiscovery in this country, not having been worked longer than a\ncentury, owing to its generally laying at a greater depth than tin,\nwhich rendered it difficult to reach without the aid of proper\nmachinery and tackle, which was not obtained until a compara-\ntively recent period.\nStrata, or beds of coal, of the best quality, are extremely\nplentiful in this country, more so than in any other part of the\nglobe; and it is to this circumstance, that our great advance over\nother countries in the manufacturing arts is to be traced and\nascribed.-See Coal Mine, Copper Mine, &c.\nMITRE, the diagonal juncture of two substances, as of wood,\nstone, &c.\nMITRE DRAINS, or CROSS MITRE DRAINS, the drains laid\nwithin the metalling of roads to convey the water to the side\ndrains; they are usually placed about 60 feet apart, and filled up\nloosely with flints.\nMITRE SILL -See Lock.\nMOLE.-See Breakwater.\nMORTAR, a cement used for building purposes, composed of\nlime, sharp coarse sand, and the hair of cattle, which should\nbe thoroughly mixed together in a pug-mill, with a small portion\nof water, in the proportion of 1 of lime to 2 of sand, and well\nchafed: the lime ought to be used as fresh as possible, and\nshould be kept under an enclosed shed ; it should also be employed\nas stiff as practicable, and the bricks or stones well saturated\nwith water, if possible, particularly in hot weather.-See Lime,\nBrick, &.\nMORTICE AND TENON, a description of joint used in wood-\nDigitized by Google\nNATURAL BEDS-OBLIQUE ARCH.\n171\nwork. The extremity of\none piece of timber is let\ninto the face of another\npiece, a tongue being formed\nat the end of the piece to\nbe let in, which is called a\ntenon, and the hole cut in\nthe face of the other is\ntermed a mortice.\nNATURAL or QUARRY BEDS (of stone), the position in which\nthe laminæ lays in the quarries. It is highly necessary that all\nstone, particularly soft freestone, should be laid upon the walls\nin its natural, or quarry bed, parallel with the horizon; when a\nstone is enclosed on each side, it may be set with its laminæ\nperpendicular to the face of the wall, as it cannot then flake off\nthrough exposure to the atmosphere or frost.\nNAVIGATORS, the name given to men working upon canals, rail-\nways, &c. A tall man is considered to be worth more wages than\na short one, inasmuch as he possesses a greater length of leverage.\nNON-CONDENSING ENGINE-See High Pressure Engine.\nNUT (of a screw), a piece of iron used in connection with a\nbolt, which is pierced with a cylindrical hollow, throughout which\na spiral groove is formed, corresponding with the worm onthe end\nof the bolt.\nThe nut is screwed upon the end of the bolt, upon the latter\nbeing passed through the bodies to be held together.-See Bolt.\nOBLIQUE ARCH (commonly called skew arch), a brick in which\nthe arch is formed aslant.\nIt is necessary, in some situations, for one line of communica-\ntion to cross another in an oblique direction, on account of cir-\ncumstances preventing the diversion of either, or of their being\nset at right angles with each other; the arch of the bridge is\ntherefore obliged to be formed askew, according to the angle of\nthe crossing. The beds of the courses of an oblique arch con-\nsist of spiral lines, wound round a cylinder, every part of which\nZ 2\nDigitized by\nGoogle\n172\nOFFSET-OFFSETS.\ncuts the axis at a different angle, the angle being greatest at the\nkey-stone and least at the springing; and when so placed, and\nviewed from beneath, they present the appearance of straight\nlines.\nMr. G. W. Buck, C.E., was among the first who overcame the\ndifficulties attending them in a satisfactory manner. The skew\narch, constructed by him, over the turnpike road, at Watford, on\nthe London and Birmingham Railway, is an excellent model.\nIn bridges of very great obliquity Mr. Buck cuts off the acute\nquoins of the abutments, gradually diminishing the edges of the\narch to the obtuse angles on the opposite sides, which is advan-\ntageous both in point of appearance and stability.\nElliptical arches are the least suitable for an oblique plan, as\nthe spiral courses render them insecure and difficult to construct;\nthey are also more expensive than the cylindrical. The difficulty\nof turning skew arches also increases from 90° to 45°, which is\nsupposed to be the most unsafe angle for a semicircular arch; the\ndanger is less from 45° downwards, and they may be safely built\nat an angle of 25° nearly.\nThe following cut represents a bridge with an oblique arch\nformed with spiral courses :-\nOFFSET, a ledge left at the junction of two different thick-\nnesses of a wall, being the upper surface of the lower portion;\nthe upper part of a wall being always less in thickness than the\nlower.\nOFFSETS (in surveying), the several distances set off from an\nDigitized by Google\nOFFSET STAFF-PADDLE-WHEELS.\n173\nimaginary right line, or otherwise, and run along\nthe side of a fence or boundary, for the purpose of\nmeasuring the situation of the bends; thus, in the\nannexed sketch, a b c d are the offsets required,\n15\na\nwhich are plotted perpendicular to the principal\nline, and are usually taken with an offset staff or\n18\n6\ncross.\nOFFSET STAFF, a rod employed in surveying, for\nmeasuring short distances ; the most convenient\n10\ne\nlength for which is 10 links of the chain, or 6 feet\n7.2 inches.\n26\na\nOPTICAL SQUARE, an instrument used in sur-\nveying, for laying out perpendicular lines. It is\nmade of brass, in the shape of a circular box,\nand contains the two principal glasses of the sex-\ntant, viz., the index and horizon glasses, fixed at an angle of 45°;\ntherefore, while viewing an object by direct vision, any other\nforming a right angle with it, will appear, by reflection, at the\nspot where the observer is situated. This contrivance has almost\ncompletely superseded the use of the surveying cross.\nPADDLE or CLOUGH a panel made to fit the openings left in\nlock gates and sluices, for the purpose of letting the water in or\nout, as may be desired.\nPADDLE HOLES (sometimes called clough arches). The small\nculverts or drains connected with canal work-as the small pas-\nsages through which the water passes from the upper pond of a\ncanal into the lock chamber during the process of filling, and\nthrough which it again escapes-which vary according to the\nconstruction of the locks.-See Lock.\nPADDLE-WHEELS, the wheels employed in the propulsion of\nsteam-boats.\nCommon paddle-wheels mostly consist of iron framing, sup-\nporting paddle-boards or floats fixed at equal distances around\nthe rim, and radiating from the centre; they are placed one upon\neach side of the vessel, and are secured to a strong shaft pass-\nDigitized by\nGoogle\n.174\nPADDLE-WHEELS.\ning across it, which is turned round by the engines, each engine\nworking a crank fixed upon it; and are placed at right angles to\neach other. The accompanying cut represents the common pad-\ndle-wheel:\nThere is a loss of power\nCommon Paddle-Wheel.\nattending this description of\nwheel, on account of only one\nof the floats striking the water\nin a vertical position at the\nsame time, the action of the\nothers being oblique; some of\nthem, in fact, backwater, or\npartially oppose the motion of\nthe vessel. Attempts have\nbeen made to obviate these\ndefects by constructing im-\nproved wheels, the paddles of which maintain a vertical position\nin their passage through the water, when in front of the wheel,\nby having feathering floats, and these are called vertical paddle-\nwheels; and have been found to answer very well for sea-going\nVertical Wheel of the \"Medea.\"\nSection.\nElevation.\npackets, where the paddle-wheels are deeply immersed in the\nwater; but they are more liable to derangement than the ordi-\nDigitized by Google\nPADDLE-WHEELS.\n175\nnary wheels the floats may be made to leave the water at any\nrequired angle. Mr. P. W.\nCycloidal Wheel.\nBarlow, C. E., states the pro-\nportion of the power ex-\npended on Morgan's vertical\nwheels at 546, and of the\nformer at 151 to 197.\nThe Cycloidal paddle-\nwheel forms the most recent\nimprovement, and is said to\npossess the advantages of\neach of the former, being\neffective and strong, yet\nPaddle-Wheel of the Great Western.\"\nsimple, in point of construction. It was patented by Mr. Gallo-\nway in the year 1835, although first used by Mr. Field in 1833.\nThe floats are divided into a number of parts, which are placed\nupon the wheel in the curve of a cycloid, so that they enter the\nwater at the same spot, and follow one another so rapidly as to\ncause little resistance to the engine; in passing the centre, there\nis full scope to their action, and in coming out they allow the\nwater to escape readily from them. The Great Western steam\nship is fitted with wheels of this description, by Messrs. Maudsley\nand Field.\nThe draught of the vessel is necessarily greatest at the\ncommencement of a voyage, particularly if it should be a\nlong one, on account of the full quantity of coals for the whole\nvoyage increasing the amount of tonnage, and other similar\ncontingencies; the wheels are, therefore, immersed very deep\nin the water, which has the effect of increasing the resistance;\nbut this loss of power diminishes as the vessel proceeds. The\nadjusting of the floats of paddle-wheels to the requisite depth of\nimmersion is called reefing the floats, and there is some difficulty\nconnected with it; but this defect may be partly rectified with\nthe cycloidal wheels, as the outer floats need not be fixed at\nstarting, but fitted on as the voyage proceeds; and the larger the\nDigitized by\nGoogle\n176\nPARALLEL MOTION-PAVED WAYS.\nwheel, the less will the vessel be affected by this defect, as the\ndiameter of the wheel increases in a greater proportion than the\nvariation of immersion of the vessel, the latter is consequently\nproportionately less than other vessels, when each are laden.\nPARALLEL MOTION, an arrangement of parallel rods connected\nwith the piston-rod of a steam-engine and the working beam, by\nwhich the motion of the piston is transmitted to the latter this\nsystem is employed in all double acting steam-engines; but a\nchain was used to pull down the beam in single acting engines.\nThe parallel motions of marine engines are situated below the\ncylinders, the beams being at the bottom part of the engine.-\nSee Steam-Engine and Steam-Boat.\nPARALLEL RAIL.-See Edge Rail.\nPARAPET, a slight wall carried up on the outer faces of bridges,\nquays, &c., and generally built breast high (or from about 3 feet\n3 inches to 4 feet), to prevent accidents to passengers and to the\nvehicles, by falling off; cast-iron railing and wooden fencing are\nsometimes substituted for parapet walls.\nPASSING PLACE.-See Siding.\nPAVED CROSSING.-See Level Crossing.\nPAVED-WAYS, a certain description of tramway, but formed of\nstone instead of iron; it may be described as a medium between a\nroad and a railway.\nPaved-ways possess great advantages over roads-the employ-\nment of separate bodies for the wheels of the carriages to run upon,\nconstituting a great improvement a rough surface is thus obtained\nfor the horsepath, and a smooth hard surface for the carriage-wheels,\nthey are therefore very suitable for ordinary purposes; they also\nafford a great benefit from their surface being even with the road,\nand unencumbered with ledges of any kind, by which they are\navailable for carriages of any gauge, or width, between the wheels,\nwhich advantage is not possessed by either tramways or railways.\nThe friction upon paved-ways is certainly much greater than\nwith the former; but the resistance operates beneficially in other\nrespects, by offering a greater amount of adhesion to the wheels\nDigitized by\nGoogle\nPAVED-WAYS.\n177\nof the carriages. A locomotive cannot work usefully on a railway\nof very steep inclinations; thus, upon 1 in 15, or 20, it can\nbarely propel itself, supposing it worked in the usual manner, or\nby the adhesion of the wheels only, whereas it could work very\neasily at these inclinations on a paved-way. Mr. Wood, in his\nPractical Treatise on Railroads, states, that an engine, drawing\n67.25 tons on a level, will only draw 15.21 tons up a rise of 1 in\n100 even with the adhesion of all four wheels. Therefore, as steep\ninclinations are not very objectionable upon paved-ways, it be.\ncomes a question whether the present turnpike roads might not be\nconverted into paved-ways, by having blocks of stone laid along\nthem, which would be a ready plan of forming them, and they\nmight be used by both locomotives and horses; or a portion could\nbe railed off, for the exclusive use of the former, by which all\ndanger of coalition, and the like, would be avoided; and this\npart of the road would not sustain any injury from the feet of\nhorses and other cattle.\nThe expense of forming a paved-way has been estimated as\nfollows:-\n£ N. d.\nFirst cost, per superficial yard\n0 13 0\nTen years' repair, at 4d. per ditto\n0 3 4\nTen years' cleansing, at 3d. per ditto\n0 2 6\n0 18 10\nDeduct value of old stone\n0 8 0\nPer yard, in ten years\n0 10 10\nMost of the London pavement appears to be laid down at an\nexpense of 7s. to 10s. per yard.\nThe paved-way along the Commercial-road, London, is formed\nof blocks of granite, 16 inches wide, and 12 inches thick, which\nare laid in 5 and 6 feet lengths, the space between them being\nfilled in with stone paving. The friction upon this road, when\nfirst opened, in good order and free from dust, (as dust increases\n2 A\nDigitized by Google\n178\nPAVING.\nthe friction upon tram-ways and paved-ways considerably, viz., from\n¹ᵗʰ to ¹th) did not amount to more than per ton, or the\n1190th part of the load; but the waggons having since created ruts\non the surface of the blocks, it has consequently increased. Mr.\nWalker, under whose direction the way was formed, states the\nannual maintenance and repair of it at £5 per annum, taking a\nperiod of five years, and the cost was 1°0th cheaper than that of\nany railway. It must not be forgotten that the above calculation\nof the friction was made when the stones were newly laid, free\nfrom dust, and in a high state of perfection, which it has since lost—\nthe wear of a paved-way being very irregular; and in reference\nto the repairs upon same, it may also be remarked, that the line\nhas merely been kept in order, not restored to its original state, as\nis usually the case with railway repairs.\nPAVING, a covering of stones laid or spread over roads; the flat\npaving laid down on the footpaths being generally termed flagging,\nor pavement, and a curb is placed between them, which keeps\neach in its place.\nThe paving in common use consists of square cut stones, mostly\ngranite, and they are set in rows running across the road ; and the\nsystem of laying them down in diagonal lines, as lately practised,\nis considered an improvement. There are two descriptions of\nstone paving employed for causeways 1st, rubble causeway, which\nis the cheapest, the stones being only slightly hammer-dressed\n2nd, aisler causeway, the stones of which are properly jointed and\nfitted, and are from 8 to 12 inches long, 5 to 7 inches wide, and\n12 inches in depth. A paved-way may also be described as a\ndescription of aisler causeway.\nThe experiment of wooden pavement has been lately tried in\nthis country, and with various success, but it is impossible to\njudge of its merits, at present, any more than in a general way ;\nthe wear, however, may be reasonably expected to be less than\nthat of stone, although it is the dearest, in the first instance: the\nblocks are formed polygonal, and laid upon a bed of concrete, or\nasphaltum. The system is said to have succeeded very well abroad,\nDigitized by Google\nPENSTOCK.-PERPENDICULAR LIFT.\n179\nand there is one great advantage connected with it, viz., the ab-\nsence of all noise. The blocks laid down in the Old Bailey, Lon-\ndon, are hexagonal prisms, varying from 81 to 93 inches long.\nPENSTOCK, a sluice or floodgate employed to retain the water\nof a mill-pond, water-trough of a water-wheel, &c., and to let it\noff when required.\nPENTAGRAPH, an instrument used for reducing or for enlarging\nplans.\nPERBEND, or THOROUGH, the term applied to the heading\nstones forming a wall, when they are carried through the whole\nthickness: if the stones only reach a part of the way through,\nthey are termed binders.\nPERPENDICULAR LIFT (on canals), a contrivance for passing\nthe boats from one level to another.\nThe perpendicular lifts on the Grand Western Canal, by Mr.\nJames Green, C.E., have deservedly attracted much attention;\nthey are intended to remedy the scarcity of water on that canal,\nby overcoming a great height at one spot, one of them having a\n46 feet lift : this lift consists of parallel chambers, somewhat\nsimilar to those of the common lock, a pier of masonry being\ncarried up between them; and a wooden water-tight cradle or\ncistern, is fitted into each chamber, for the reception of the\nboats; the boats carry about 8 tons, and are 26 feet long and\n61 wide, drawing 2 feet 3 inches of water (whereby a canal 3 feet\ndeep is sufficient for them), and the water is kept in both the\nupper and lower ponds by lift-up or stop-gates. Upon one of\nthe cradles reaching the upper gate, it is secured to it water-\ntight, by a bolt and staple, and the doors of both the canal\nand cradle are drawn up together by a winch gear fixed on the\nside of the chamber: after sufficient water has escaped into the\ncradle, to cause its descent, the doors are let down, and the cradle\nis allowed to descend to the lower level, where it rests upon cross-\nbeams, when, by a contrivance, it is forced close to the lower\nstop-gate of the canal, and rendered water-tight as before; the\nlower gates are then raised, and the boat floated out: three\n2 A 2\nDigitized by Google\n180\nPERMANENT WAY.\nsheaves, each 16 feet diameter, are fixed at the top of the\nchamber, for the purpose of raising and lowering the cradle, the\nshaft attached to same being supported by iron framing and\ncolumns; the two outer sheaves simply support the chains, but\nthe centre one has a spur gear, in segments, fixed to it, which\nworks on pinions on each side, thereby giving motion to bevel\ngear, and diagonal shafts, by which a communication is effected\nwith hand winches fixed on each side of the chamber, when re-\nquired; thus, the machinery may be put in motion by these\nwinches, as well as by the gravity of the cradles; and a brake is\nalso attached to each of them, for regulating the descent of the\ncradles: a strong iron bar is fixed at the top of each cradle to\nwhich the suspending chains are attached; which latter pass over\nthe sheaves, and the cradles are kept in a horizontal position, by\nmeans of an adjusting rod placed above them, in a horizontal\nposition, to which they are screwed up, as may be required. The\nlength of the suspending chains are so arranged, that when one\ncradle is at its proper level at the bottom of the lift, the other is\nin a suitable position at the top and no more force is required\nto put the machinery in motion than the power to overcome the\nvis inertice and friction of the apparatus, which is obtained by\nmaking the length of the chain a trifle shorter than the height of\nthe lift, say about 2 inches, which produces a preponderate\nweight in the descending cradle of about 1 ton ; a sufficient space\nIS left at the bottom of the chamber to allow of the coil of the\nbalance-chains, which are fixed beneath them, by which the\ncradles are equipoised at whatever height they may be, and a\ndrain is laid from each the side and cross walls of the chambers\nare pierced by arches, which give light below, and afford access\nto the several parts. The quantity of water consumed is about\n2 tons for about 8 tons of cargo ; whereas, in common locks, it is\nabout 3 tons of water to 1 ton of cargo.\nPERMANENT Way, the finished road of a railway. The term\nis applied in contradistinction to the temporary way laid down for\nthe purpose of forming the line : the term is usually understood\nDigitized by\nGoogle\nPIER.\n181\nto refer to the rails, ballasting, spiking down of the chairs to the\nblocks, and fastening of the rails to same; also adjusting the\ngauge of way to the proper level and curve. The permanent\nrails are elevated above the surface of the ballasting rather more\nthan an inch.-See Railway and Ballasting.\nTransverse Section, showing one side only.\nE\nEl\nC\na\nX\nE\nR\n5.\nF\nThe annexed cut re-\nC\nR\nE\npresents the permanent\nway of the London and\n15\nBirmingham Railway, both\nEL\nil\nE\n1\nwith blocks and with\nsleepers.\nE\n-\nE\nR\nE\nRETE\nET\nX\n15\nE\n2\nB\nPlan, showing one side only.\nPIER, a strong marine erection, commencing from the shore a\nrocky point being preferred) and jutting into the sea, extending\nDigitized by Google\n182\nPIER-PILES.\neither in a curved or in a straight line, constituting a harbour for\nthe protection of shipping and other craft. Piers are generally\nconstructed of strong masonry, with fender piles and framing : iron\nis also adopted in some cases, after the suspension principle, such\nbeing called chain piers and timber piers of slight construction,\ntermed jetties, are sometimes erected, which are employed merely\nfor the purpose of landing goods and passengers.-See Harbour\nand Breakwater.\nPIER (of a bridge), the impost or wall from which the arches\nspring or abut. The thickness of the upper part of the piers of\nbridges, appears, from the examination of some of the most cele-\nbrated works, to vary from 1th to ¹ᵗʰ of the span of the arch ; the\npiers of Neuilly Bridge are 1/th of the span.\nThe piers of wooden bridges were formerly built upon piles,\ntermed stilts, in situations where they could not be laid dry, at\nthe bottom of the river, and the stilts were cut off at the level of\nlow water-mark, the piers being carried up upon them; they were\nalso surrounded by a row of piles which were placed a few feet\nfrom them, and the place enclosed was called a starling, or jetty,\nand was filled in with loose stones, or rough rubble work the\narches were mostly commenced on the paving laid on the top of\nthe piles. This method of erecting a pier was afterwards super-\nseded by caissons; and, lastly, by the adoption of coffer-dams.-\nSee Caisson and Coffer-dam.\nPIER (in buildings generally), a flat buttress projecting from\nthe face of a wall; the term is also applied to any wall situated\nbetween two openings.\nPIG IRON, also known by the name of cast-iron and crude-iron.\nSee Pig Iron.\nPILES, or PILE TIMBERS, the timbers driven into the earth for\nthe support of structures and other works, when built upon a loose\nsoil, whereby the foundation is rendered firm and stable.\nBuildings erected on marshy soils are frequently rested upon\npiles, which are mostly of round timber, and from 9 to 18 inches\ndiameter, and placed about 2 feet apart, which are driven home\nDigitized by\nGoogle\nPILE-DRIVING MACHINE.\n183\ninto some solid stratum, passing completely through the loose\nearth, or upper stratum. The feet of the piles are generally\nprovided with wrought-iron shoes, weighing from about 8 to 25th.\neach, and the heads are enclosed by strong iron hooping, to pre-\nvent their splitting in driving; although they are sometimes\ndriven without any but a flat piece of wood, or a plate of iron, is\nplaced on the head of the pile which receives the ram at the end\nofeac h stroke, instead of the pile. Amsterdam and other cities\nare built wholly upon piles\nThe stoppage of Dagenham Breach, on the River Thames, by\nCaptain Perry, about the year 1720 was accomplished by piles\nmorticed into one another by a dovetailed joint.\nThe foundations of walls are sometimes enclosed by square,\nor edge piles, termed sheet piling, which are driven close to-\ngether: they are more especially employed in works adjacent\nto the sea, and to rivers, marshes, &c., whereby the soil is pre-\nvented sinking by forcing But in a lateral direction.\nPILE-DRIVING MACHINE, a machine used for driving piles\ninto the ground, consisting of a strong framework.\nThe pile-driving machine usually employed at the present\ntime is composed of two pieces of wood, about 30 or 35 feet\nlong, which are placed in an upright position, and rested upon sill-\npieces, the space between them forming a slide or gauge for the\niron ram to be drawn up and run down the slides are edged with\niron, a strong shoring-piece is secured upon each side, and\na ladder is also connected with them, in the opposite direction,\nwith horizontal ties at different heights; and the whole is further\nsecured by stays and chains at different parts. There are two\ncross-pieces laid across the sills, upon which a crab is placed,\nby which the ram is drawn up; there is, an apparatus situ-\nated immediately above the latter, usually called a monkey, for\ndisengaging and again securing the ram after each fall, a chain\nbeing attached to it, which is carried over a pulley ! fixed at\nthe top of the framing, and passed down again on the other\nside to the crab. The length of the fall of the ram is regulated\nDigitized by\nGoogle\n184\nPINION-PINNING.\nat pleasure by a rope fastened to the monkey, which allows of its\nmoving upwards to a certain extent, when its disengagement\nfrom the ram is effected: a pair of forceps, or tongs, have also\nbeen extensively used for detaching the ram.\nThe accompanying cut represents one of the pile-driving ma-\nchines used in building the embankment of the New Houses of\nParliament:-\nSide Elevation.\nFront Elevation.\nPINION (in mechanics), a small toothed wheel, which drives, or\nis driven, by a larger one.\nPINNING or PINNING IN (in masonry), a system of wedging or\nunderpinning the bed of a stone, and employed when it is not\nproperly squared, to supply any deficiences, and which is conse-\nquently a very objectionable practice.\nDigitized by Google\nPIPES-PLANE.\n185\nPIPES, the name applied generally to the vessels employed for\nthe conveyance of any fluid, and which are usually of a cylindrical\nshape.\nThe pipes used at the present time for water, gas, &c., are\nmostly formed of cast-iron. Water pipes are cast in lengths of\n9 feet, the principal ones being called mains, and the others ser-\nvices-See Water Works and Gas Works.\nPISTON, a thin cylindrical body adapted to move within a cy-\nlinder, and employed in steam-engines and pumps, being the body\nacted upon by the steam or air, as the case may be; it is there-\nfore necessary that it should run up and down as nearly air-tight\nas possible; they are sometimes formed of wood, with leather\nbelts nailed round the edges, but metal is the material in general\nuse at the present time. Metallic packing is almost exclusively\nemployed for the pistons of steam-engines, instead of leather or\nhemp coiling; the packing consists of rings possessing a tendency\nto spring outwards, and they are further kept so by springs within\nthe body or substance of the piston; the metallic packing also\npresents the least friction, and is the most durable.-See Steam-\nEngine and Locomotive Engine.\nPISTON RoD, the rod connected with a piston, being passed\nthrough the centre of it, and secured by means of a screw or a\nkey; the other end of the piston rod of an ordinary steam-engine\nis attached by a joint to the parallel motion, whereby its action is\ncommunicated to the working beam. In marine engines it is\nsecured to a cross head at the top, and in locomotive engines to\nthe connecting rod.\nPLAN, the name applied to a plot of land, or to a horizontal\nsection of any engineering work.\nAccording to the standing orders of the House of Commons,\nall plans for railways, &c., are required to be drawn to a scale of\nnot less than 4 inches to a mile, and the enlarged parts to a scale\nof not less than 4th of an inch to 100 feet.\nPLANE, this term, as applied to railways, refers to each length\nof a line of railway at the same gradient or inclination. They are\n2 B\nDigitized by\nGoogle\n186\nPLANE TABLE-PLOTTING.\nof two kinds, level and inclined.-See Gradient, Inclined Plane, Self-\nacting Inclined Plane, and Stationary Plane.\nPLANE TABLE, an instrument formerly much used in surveying,\nfor taking angles and laying down the work in the field as it was\nmeasured. The plane table consists of a board, upon which the\npaper is laid, and enclosed by a frame, graduated into degrees from\nthe centre, by which the lines can be easily plotted, and a compass\nis also connected to it.\nPLANKING, a term applied to a layer of planks, or to any other\ntimber (excepting fir), when exceeding 11 inches in thickness.\nPLATE RAILWAY.-See Tram Railway.\nPLOT, a plan, or horizontal section of any land, country, or\nworks-See Plan.\nPLOTTING, the operation of laying down the lines of a survey,\nby admeasurement, from the field-book.\nIn plotting a survey, it is generally customary to have the\nnorth upwards, the writing running from east to west. Upon the\nfirst line being drawn in the required direction, the length of the\nsecond line is taken as a radius, and a curve described from the\nsecond station; another curve is then described from the other\nend of the first line, after the same system, by which the apex of\nthe survey is found; the adoption of beam\ncompasses for this part of the operation is\nfound very convenient, particularly if the\nsurvey is extensive: the tie lines across the\nsurvey (see Surveying) have next to be tried,\nand if found correct, the offsets may be laid\noff (see Offsets), the same system being followed out in the re-\nmaining portion of the plan. In plotting a field taken by chain\nangles, it is usual to set out the angles to a much larger scale\nthan that of the survey, by which a greater degree of accuracy\nis obtained. All angles taken by angular instruments, as theo-\ndolites and sextants, are laid down by circular or semicircular\nprotractors. The whole of the main lines of a survey should be\nset off before plotting the offsets.\nDigitized by\nGoogle\nPLUNGER-PROTRACTOR.\n187\nPLUNGER, a long solid brass cylinder, and sometimes employed\nas the forcer in force pumps.-See Pump.\nPLUMBER BLOCK, a carriage fastened on to any contrivance,\nand adapted to support a shaft or axle.\nPOINTING, a term applied to the finishing of the external face\nof the several courses of a wall. The common mortar is first\nscraped out, and the joints and courses cleaned, when they are\nfilled up with fine mortar or Roman cement.\nPOLINGS, the small boards supporting the earth during the for-\nmation of a tunnel.\nPOST, any piece of timber, when used in an upright position, as\na king post, story post, &c.\nPORTLAND STONE, a hard white sandstone procured from\nquarries in the Isle of Portland, and formerly in general use in the\nmetropolis for both engineering and architectural works; but its\nuse in engineering has been much superseded by granite, and in\narchitecture by Gloucestershire stone.\nThe merchantable beds of this stone are usually covered with a\nstratum called the cap, which is harder than the beds beneath it,\nand which is generally removed by gunpowder.\nPRIMING (in steam-engines), the hot water carried along with\nthe steam from the boiler into the cylinders, which is very objec-\ntionable: various methods have therefore been resorted to of get-\nting rid of it.\nPRINCIPAL.-See Roof.\nPRISMATIC SQUARE, an instrument used in surveying for mea-\nsuring horizontal angles only, and which are taken from the mag-\nnetic meridian ; a graduated floating card being attached to the\nneedle. This instrument is very well adapted for filling in the\ndetail of a map, being very portable; but all the principal points\nshould be fixed by a theodolite.\nPROTRACTOR, a mathematical instrument used for daying down\non paper the angles of any figure. The protractors mostly used\nconsists of a small brass semicircle, the ends of the arch being\nconnected by a straight rule, the outside edge of which consti-\n2 B 2\nDigitized by Google\n188\nPUDDLE-PUMP.\ntutes the diameter of the outer circle; the semicircle is divided\ninto 180 parts, termed degrees, and represented thus °, as 10°,\nand there is a small point in the diameter which marks the centre;\ncircular protractors are also much employed, the divisions being\nnumbered from °, 10°, 20°, &c., quite round to 360°, the same as\nthe theodolite, which the protractor represents. Protractors are also\nmade in the form of a parallelogram, and graduated from a centre\non the lower edge, which represents the diameter of the circle, to\ndivisions marked off for the degrees.\nPUDDLE, a mixture of good tempered- clay and sand reduced\nto a semifluid state, and rendered impervious to water by manual\nlabour, as working and chopping it about with spades. It is used\nfor the purpose of retaining the water in any particular situation,\nor for excluding it from any works : and it is usually spread in\nlayers of about 12 inches in thickness.\nPUNNING.-See Claying.\nPUMP, a machine for raising fluids, by means of pistons, or\nbuckets, working in tubes, valves being also placed within\nthem.\nPumps may be described generally as being of two kinds:\n1st, those which operate upon the lifting principle, and termed\nlifting pumps; 2ndly, those of the forcing description, termed\nforce pumps. Lifting pumps are applied to wells where the height\ndoes not exceed 33 feet, or 30 inches in practice, as in the case of\nthe pump in common use, and known by the name of the suction\npump, which consists of two tubes; the end of the lower one,\ntermed the suction pipe, being placed in the water to be lifted\nand the higher tube, called the barrel, is furnished with a spout\nat the top, for the escape of the water, a valve opening upwards\nbeing placed at their junction; ; a piston or bucket is moved up\nand down the barrel, perfectly air-tight, by means of a lever\nhandle fixed at the top, a valve is also placed in it, opening\nupwards. Now, as the bucket is moved upwards by the handle,\nthe air below escapes by means of the stop valve, but it cannot\nagain return: the whole of the air is thus removed from the\nDigitized by Google\nPUMP.\n189\nsuction pipe, on the same system as in the air-pump. The\nlength at which the water will rise is proportionate to the length\nof the stroke of the piston, and it continues to\nrise higher at each stroke until at length it\npasses out at the spout.\nThis description of pump consequently ope-\nrates by the pressure of the atmosphere from\nwithout, which forces the water upwards, by\nreason of the vacuum formed within it, the air\nbeing equal to a column of water 33 feet high.\nThe water may be carried higher by fixing ad-\nditional tubing at the top of the barrel, and\nshifting the spout to the upper part of it, and\nthis may be extended to whatever height the\nThe Suction Pump.\nforce and strength of the pump will admit of; the handle, or\nprime mover, must also be fixed at the upper end of the delivery\npipe, and the piston rod proportionately extended; but this\narrangement is unfit for very great depths, in consequence of the\nbending of the rod, unless cast-iron pipes are employed, when\nsmall pieces with projecting arms may be fixed at each joint of\nthe pipe, about 10 or 12 feet apart, to touch the inside of the\npipe.\nThe force pump acts by compression, instead of by exhaus-\ntion; and it is mostly employed for great depths, as for mines,\nalso for supplying boilers against the force of steam, &c. ; it does\nnot differ much in construction from the former; but\nno feed or suction-pipe is required, as the barrel\nextends below the water. The piston works in a\nframe, a, a, or some other convenient contrivance\nand the water moves upwards at each upstroke\nthrough the valve in the top of the piston; the rising\npipe b, which delivers it, may be continued to any\nThe Force Pump.\nheight; the barrel c, c, is also filled again at each stroke.\nForce pumps, which take advantage of the pressure of the at-\nmosphere (and most of them do), are called lift and force\npumps.\nDigitized by Google\n190\nPURLINE-QUARRY.\nThe accompanying cut represents a lift and force\npump, as generally constructed. The feed pipe\ndips into the water to be raised, and may of course\nbe of any height not exceeding 33 feet; the supply\nupwards is rendered continuous and regular, by\nmeans of an air-chamber o, o, the elasticity of the\nair within it acting upon the surface of the water\n(see Air-chamber) ; the barrel is sometimes covered\nover, a stuffing-box being fixed in it for the piston\nThe Lift and Force\nPump.\nto slide in.\nThe length and leverage of a pump is termed the stroke; and\nMr. Tredgold states, in reference to the pumps employed in\ndraining mines, that the stroke should not exceed 8 feet, and\nthat the velocity of the piston should be no more than 98 times\nthe square root of the length of the stroke. There have also\nbeen several attempts made recently to introduce pumps worked\nby a continuous rotative motion, and with considerable success.-\nSee Drainage of Mines.\nPURLINE.-See Roof.\nPUZZOLANA, or Pozzolana, a celebrated natural cement, formed\nof volcanic ashes, and of great service in hydraulic works, as a\nsmall portion of lime hardens it very quickly, even when applied\nunder water.\nQUARRY, an artificial excavation formed in rocks or in rocky\nground, for the purpose of obtaining marble, stone, slate, and the\nlike. Blocks of freestone are usually drawn from the quarries as\nfollows, the ground is first uncaped by removing the soil, and\nthe grain is examined ; the direction of the beds of laminæ is\ncalled the cleaving grain, and those in the contrary direction the\nbreaking grain; the quarrymen then drive wedges into the stone in\nthe direction of the cleaving grain, until they loosen the block,\nthey then proceed with the other side, and afterwards with the\nends of the blocks; the wedges are driven about 6 or 8 inches\napart, and the whole of the wedges on one side are driven at the\nsame moment, the strokes being delivered with exact regularity.\nHard stones are quarried in a somewhat similar manner, viz.,\nDigitized by\nGoogle\nQUEEN-QUAY.\n191\nby means of channels, in which wedges are driven, but stronger\nimplements are obliged to be used ; iron bars are sometimes em-\nployed for confining the wedges in their proper position during\nthe operation. The blocks are also sometimes separated by the\naid of gunpowder, the operation being called blasting, but a great\nwaste of stone is caused by this plan in consequence of its irregu-\nlarity.- In some quarries the blocks may be obtained of almost\nany dimensions, while others only furnish blocks of a limited size,\nowing to the peculiarities of their formation quarries situated\nclose to the sea, or to rivers and canals, possess great advantages\nover others, an easy communication thereto being of great import-\nance. The stones quarried for the purposes of building are\nusually raised and squared out roughly into an even shape, and\nthe builders afterwards cut them to the forms required.\nQUEEN, or QUEEN-POST.-See Roof.\nQUICK LIME.-See Lime.\nQuay, or KEY, the name applied to a long wharf by the side\nof a harbour, river, or canal, for the purpose of landing and ship-\nping goods and passengers, being furnished with cranes and cap-\nstans, also mooring posts, rings, &c.\nA, A, side piles.\nTransverse Section of a Timber-Quay.\nB, B, side wales.\nC, C, cross beams.\nD, D, top beams.\nE, E, side braces.\nF, F, fender piles.\nA\nThe quays of harbours\nare generally formed by\nretaining walls being pro-\nperly supported by coun-\nterforts, and backing fen-\nder piles are also fixed in\nthe front to protect them\nfrom injury.\nc\nD-F\nTimber is also much\nc\nF\nemployed for this pur-\nPlan showing Construction.\nDigitized by Google\n192\nQUOIN-RAILROAD.\npose on the banks of rivers; the accompanying sketch (see Cut on\nlast page) represents a portion of a timber-quay; no other kind\nof material is used in America for this purpose, it being very plen-\ntiful. The piling in general need not go further into the ground\nthan is sufficient to take a firm hold.\nCast-iron piling has also been very successfully employed for\nthe protection of wharfs, as those recently constructed at Black-\nwall and Deptford, the main piles being formed with rebates on\neach side, into which the sheets are driven, and the former are\nsecured at the back by stays and a thick bed of concrete; great\ncare is necessary in driving iron piles on account of their greater\nliability to fracture, compared with those of timber.\nS, P, stay piles.\nDetails of Deptford Pier.\nM, G, main piles.\nG, P, guide piles.\nL, T, land ties.\nQUOIN, the name\ngiven to the corners\nConcrete\nof stone and brick\nwalls, but referring\nmore particularly to\nthe stone edging\nsometimes employ-\ned in brickwork; if\nElevation.\nTransverse Section.\nthe stones project\nbefore the face of\nthe wall, and have\nMP\nS.P\nchamfered edges,\nConcrete\nthey are termed rus-\ntic quoins.\nPlan enlarged.\nRACE, or RACE COURSE, the cut or canal along which the\nwater is conveyed to and from a water-wheel.\nRACK, a straight bar, having teeth or cogs similar to those on a\ntoothed wheel.\nRAILROAD, or RAILWAY, an improved description of roadway,\nof modern invention, having been used from about the year 1600;\nDigitized by\nGoogle\nRAILROAD.\n193\nrailways or tram-ways, as they were first called, were originally\nformed of wood, this plan becoming perfected in the double way.-\n(See Cuts in Tram-way.)\nCast-iron tram-plates were next employed, then wrought-iron,\nand at length wrought-iron edge rails were adopted these several\ndescription of rails are detailed under the heads of Tram Railway\nand Edge Railway.\nRailways were first used in the collieries, particularly in those\nof the north of England, and horses were exclusively employed\nupon them for many years, and very little attention was bestowed\nupon the gradients or inclinations of the road the horse was con-\nsequently obliged to exert himself according to the utmost of his\npower for a short distance, after which he might not be required\nfor some time, and it was customary for the men to unhook him\nand allow him to follow after the waggons, at very rapid descents,\nwhere the gravity was sufficient to propel the waggons. Acci-\ndents were very common upon these runs or inclines, although a\nbrake or convoy was employed to check the waggons, but they\nwere frequently prevented acting in wet or damp weather, owing\nto their imperfect construction and the steepness of the planes ;\nashes were sometimes strewed over the rails, to assist the working\nof the brake, notwithstanding which the works were often stop-\nped; thus, if a sudden shower occurred when a train was descend-\ning a very steep plane, it let them down at a fearful velocity, and,\ndespite of ropes which were drawn across the railway to stop\nthem, fatal results sometimes ensued, as the ropes were frequently\nbroken. These early railways generally descended in the direc-\ntion of the delivery of the goods conveyed upon them; the wag-\ngons were, therefore, easily drawn back when emptied. The gross\nload upon the wooden rails was about 2 or 3 tons, but upon the\nintroduction of iron tram-rails, a horse took nearly double, whereby\nthe velocity of the train down the inclined planes was much in-\ncreased, which is supposed to have originated the idea of self-\nacting inclined planes.\n2 C\nDigitized by\nGoogle\n194\nRAILROAD.\nThere have been many different descriptions of rails pro-\nposed at various periods, amongst others was the oval rail,\nexecuted on the Penrhyn Railway, by Mr. Wyatt, in the\nyear 1800.\nIt was about 4 inches deep, and cast in lengths of 4 feet 6\ninches, with a plug at each end, which was let into the stone sills,\neach length weighing 36tbs. ; and the wheels run upon these rails\nhad concave rims : but it was found in practice that these rails had\na tendency to wear out very quickly, when others were conse-\nquently substituted.\nMr. Woodhouse's 'Patent Rails,\" dated 1803, are very inge-\nnious :-(See Cuts.)\n1\n2\n6\n3\nDetails of Woodhouse's \" Patent Rails.\"\nFig. 1, Plan of the rails and sleepers, which are formed of cast-\niron.\nFig. 2, Side elevation.\nFig. 3, Plan of a rail inverted.\nFig. 4, Transverse section, showing the mode of securing the\nrails, the sleepers being bedded in gravel.\nDigitized by Google\nRAILROAD.\n195\nFig. 5, Transverse section, in which both the rails and sleepers\nare worked in stone paving.\nFig. 6, Section of the rail enlarged.\nIt may be briefly stated, that wrought-iron parallel edge rails,\nset on chairs, are now very generally adopted, the weight being\nabout 65 lbs. to the running yard. The system of continuous bear-\nings is also employed on some lines of railway. The steam-engine\nwas applied to railways, shortly after its application to mechanical\npurposes generally, or about the year 1808, (at which period\nit was employed in drawing the minerals from the pits); its action\nwas at first applied upon the ascents only, a rope being extended\nfrom the steam-engine, and made fast to the waggons, whereby\nthey were drawn up-which system was afterwards introduced upon\nthe remaining portions of the line; and it continued in use until\nthe invention of locomotive engines, which were then run upon\nthe level portions, and the fixed engines were confined to the\ninclined planes. Horses may be described as preferable to loco-\nmotives when the amount of goods to be conveyed is small, and\nthe distance short, particularly if coal is scarce upon the line;\nand there is another great advantage attending animal power over\nmechanical, viz., that the degree of force may be varied accor-\ndingly as may be required, but, of course, within certain limits.\nLocomotives are the most suitable where dispatch is required, and\nthe goods to be conveyed are light and valuable also, where many\npassengers are expected, and the line is of some length and pretty\nlevel; and the system of fixed engines is the best for a hilly country,\nwhere the levels do not admit of sufficient adhesion for the wheels\nof locomotives. The practice of putting two engines to a train is\nnot considered so advantageous as dividing the train into two, and\nputting an engine to each, as that engine travelling the fastest\ndoes the largest proportion of work.\nThe American railways were originally formed of timber beams,\nupon which flat iron bars were laid; upon these being found ob-\njectionable, on account of their premature decay, stone was used\nin place of the timber rails; next came heavy iron rails, laid upon\n2 C 2\nDigitized by Google\n196\nRAILROAD.\nstone blocks, but the great variations of the weather soon de-\nranged this plan a foundation of timber was then substituted ;\nwhich is the plan now mostly adopted. The Alleghany Postage\nRailway, constructed by Mr. Roberts, C.E., in the year 1835, is\nformed of white oak longitudinal pieces, 10 inches by 10 inches,\nimbedded in the ground; cross transoms of locust tree, 8 inches by\n6 inches. and 7feet 6 inches long, are laid athwart them, notched\nand trenailed, and upon these the chairs are bolted the rails are\nlaid about 3 inches to 34 inches high, and from 34 inches to\n44 inches on the base.\nThe resistance to the motion of a carriage upon a railway arises\nfrom two causes,-1st, from the friction of the several parts of the\nmachine, as described under the head of Friction; and, 2ndly,\nfrom the resistance offered by the air and wind : the atmosphere\nequally opposes the passage of the stage coach, the track-boat,\nand the steam-boat but the motion of these vehicles being com-\nparatively slow, and the power required to overcome the friction\nencountered being very great, the resistance of the air is disre-\ngarded in their construction, but a very large proportion of the\nresistance upon railways is attributable to it, as the atmospheric\nresistance is supposed to vary in the square of the velocity; a\nhigher velocity on a railway than 35 miles an hour has therefore\nbeen deemed inexpedient with the present engine powers: the\nexpense attending any further increase of speed would also be\nvery great. The average speed of the first class passenger trains\nupon public lines of railway varies from 20 to 30 miles an hour\nthere has been a few instances of an engine, with its tender, ac-\nquiring a very high velocity-as 15 miles in 15 minutes. The\neffects of high winds upon a railway train is very considerable,\nparticularly side winds, as they press the flanges of the wheels\nagainst the rails, thereby impeding their progress, and increasing\nthe wear and tear much. Public lines of railway, (as the London\nand Birmingham,) are generally made 33 feet wide in excavations\n(see Excavation), and 30 feet on embankments (see Embankment), the\ndifference being caused by two drains, each 18 inches wide,\nDigitized by Google\nRAILROAD.\n197\nwhich are required at the bottom of cuttings, one upon each side\nthe line : the surface of the ballasting or road is laid a little con-\nvex, to carry off the water; and two or three yards should be\nallowed on each side for fencing and ditching. The width between\nthe rails is 4 feet 8} inches upon the principal railways through-\nout the kingdom, (as the London and Birmingham and Grand Junc-\ntion Railways-although it is made 7 feet upon the Great Western),\nand the intermediate space in the centre between the trackways\nis usually about 6 feet, and it is of similar width as the space be-\ntween the rails upon some lines-as upon the Newcastle and Car-\nlisle, and the Leeds and Selby Railways; and the side space, or\nthe distance on the outside of the rails, is generally about 5 feet—\nas upon the London and Birmingham and Grand Junction Rail-\nways.\nThe following table shows the average expense of working the\nLiverpool and Manchester Railway, from the year 1831 to 1834 :-\nMerchandize, per ton\nPassengers.\nAggregate cost,\nper m.e.\nper ton per mile.\nHEADS OF CHARGE.\nUseful\nGross\nPer pas-\nPer ton\nUseful\nload or of\nload.\nsenger per\nper mile\nload or of\nGross\nload.\ngoods.\nmile.\ngross.\ngoods.\nd.\nd.\nd.\nd.\nd.\nd.\n* Locomotive power\n0.55\n0.36\n0.27\n0.73\n0.73\n0.51\nMaintenance of railway\n0.307\n0.233\n0.085\n0.233\n0.307\n0.233\nUpholding carriages\n-\n-\n0.054\n0.146\n0.082\n0.058\nCoaching\n{\nConducting coaching\n-\n-\n0.104\n0.282\n0.158\n0.111\nDuty on passengers\n-\n-\n0.071\n0.216\nCarrying\nUpholding waggons\n0.227\n0.159\n-\n-\n0.09 4\n0.067\ngoods\nConducting traffic\n1.08\n0.76\n-\n-\n0.463\n0.324\nGeneral expenses\n0.354\n0.248\n0.091\n0.248\n0.354\n0.248\nTotal cost\n2.518\n1.760\n0.675\n1.855\n2.188\n1.551\nThe preceding Table does not include the cost incurred in laying\n*\nThe cost of locomotive power differs according to the locality of the rail-\nway. The London and Birmingham Railway Company have contracted for\ntheir motive power at 0.05d. per ton per mile for goods, and 0.25d. per mile for\npassengers.\nThe average expense of maintenance was £422. 13s. 6d. per mile.\nDigitized by Google\n198\nRAILROAD.\ndown new rails where required, as such contingencies would not\nbe likely to occur on another line, neither the interest paid for\ncapital, or the cost of carriage at each end of the line.\nThe annual cost of private railways is much less, as will be seen\nby the following Table-which shows the expense of working a line\nadapted for the conveyance of heavy goods, or for a mixed traffic,\nwhere the latter is such that a maximum effect can be produced in\nthe conveyance of heavy goods, without interruption to the gene-\nral traffic of the line, and where the goods are generally carried in\none direction only, the carriages having to be brought back empty\nin the other direction-deduced from the cost upon the Stockton\nand Darlington, the Seaham and Clarence, and other railways :-\nCost, per ton per mile.\nHEADS OF CHARGE.\nUseful load.\nGross load\nd\nd.\nLocomotive power or haulage\n0.380\n0.191\nMaintenance of railway\n0.208\n0.104\nUpholding waggons, including loading and unloading coals\n3.265\n0.133\nGeneral expenses\n0.100\n0.051\nTotal cost\n0.953\n0.479\nThe following Table gives the comparative average cost of con-\nveying goods and passengers by locomotive engines on railroads:-\nRate of\nResist-\nCost of\nCost of\nCost of\nCharges\nspeed,\nin miles\nance, per\nhaulage, per ton\ncarriages,\nconveyance,\nfor conveyance,\nRemarks.\nton in lbs.\nper hour.\nper mile.\nper ton\nper mile.\nper ton per mile.\nper ton per mile.\nd.\nd.\nd.\nd.\n1.065\nExport coals.\n8\n8.5\n0.375\n0.19\n1.065\nLansdale\n1.566\ncoals.\nGeneral mer-\n12\n8.5\n0.5\n0.227\n2.138\n3.5\nchandize.\n0.25 per\n0.675 per\n1d. to 1}d per\n20\n8.5\npassenger.\n0.206\npassenger.\npassenger.\n1.73 per ton\n2.855 per ton\n12.37 per ton\nDr. Lardner has lately made some interesting discoveries re-\nDigitized by\nGoogle\nRAILROAD.\n199\ngarding railway constants, which he communicated to the last\nSessions of the British Association, held at Birmingham, and\nwhich confirmed the opinion that he had given in 1835, before a\nCommittee of the House of Lords, viz., that a railway laid down\nwith gradients from 16 to 20 feet per mile, would be for all practical\npurposes nearly, if not altogether, as good as a railway laid down\nfrom terminus to terminus upon a dead level,\" as he considered\nthat a compensating effect would \" be produced in descending\nand ascending the several gradients, and that a variation of speed\nin the train would be the whole amount of inconvenience which\nwould arise ; that the time of performing the journey, and the ex-\npenditure of power and maintenance of way would be the same in\nboth cases : and he therefore advised that no considerable capital\nshould be expended in obtaining gradients lower than those\nabovementioned.\"\nHe stated to the meeting, that he had since proved this theory\nupon the Grand Junction Railway, where he found that the mean\nspeed in ascending and descending to be the same as the usual\nrate of the same engine upon a level, the difference amounting to\nno more than the casual variations constantly occurring in the\nmoving power, the surface of the rails, commonly regarded as level,\nbeing in reality subject to continual variations of inclinations for\nshort distances. He also stated, that the form of the front of the\nwaggons had no influence upon atmospheric resistance, but by\nincreasing the whole volume of the train a material increase was\nproduced in the resistance of the atmosphere.\nThe motion of a train down an inclined plane has been generally\nconsidered to be uniformly accelerated ; i. e. an increase of velo-\ncity takes place every second of time, being the speed due to the\ngravity of the plane, and the resistance due to the friction of the\ncarriages only was calculated as being the sole check to the velo-\ncity : the effect of the atmosphere, or anything else which might\nproduce a retardation, increasing with the speed, was wholly neg-\nlected, being considered of comparatively trifling amount; but\nthe learned Doctor proved by these experiments, that the degree\nDigitized by\nGoogle\n200\nRAILROAD.\nof acceleration was gradually diminished as it run down the plane,\ninstead of increased. The former theory would certainly hold good\nif there was no other resistance but that arising from the friction,\nand the speed would then be diminished by the amount of velo-\ncity destroyed by the friction of the train only. Now, as the force\nof gravity is well known, (also the effect produced by an inclined\nplane, of given inclination, in diminishing the intensity of same),\nfinding the amount of resistance occasioned by the friction, is\nconsequently an easy calculation, all other resistance being disre-\ngarded, or the acceleration due to gravity could be calculated,\nand the actual acceleration moving down the plane observed, the\ndifference being supposed to give the retarding force due to the\nresistance.\nAccording to this new theory of Dr. Lardner, if an inclined\nplane of sufficient length could be attained, the motion of a train\nwould continue to be accelerated until a velocity was acquired,\nwhich would produce \" a resistance from the air, such as com-\nbined with friction, would be equal to the gravitation down the\nplane upon such velocity being obtained, the moving weight\nbeing equal to the resisting force, no further acceleration would\ntake place.*\nAs it was thought that inclined planes of sufficient lengths\nwere not accessible to try the accuracy of this theory, it occurred\nto the Doctor that the end would be equally attained by starting\nthe train from the top of an inclined plane, at a considerable\nspeed, as the acceleration it would receive while descending,\nadded to the speed with which it started, might be expected to\ngive that velocity at which all increase of speed would cease, and\nan uniform motion be maintained to the bottom of the plane; and\nthis anticipation was realized by experiments, and an uniform\ngravitation or velocity was produced, which was regulated by the\nload; when the latter was increased the velocity was increased,\n*\nThe angle of repose upon a railway may be cited as a comparative con-\nstant to this, occurring when the gravity of the plane and friction of the load\nare equal.\nDigitized by Google\nRAILROAD.\n201\nits motion being accelerated for a short distance from starting,\nbut at length becoming uniform in every case, the velocity dimi-\nnishing with the steepness of the plane. It was found that the\nsame general principle applied to trains of whatever magnitude;\nhe also ascertained by these experiments that the common esti-\nmate of the resistance upon inclines is erroneous, being taken at\nthe same as the resistance upon the level portions, or about 2'50th\nof the load; whereas it was found that the actual resistance at high\nspeeds very considerably increased, compared with it when the\nmotion was slow. The motion of a train for about 100, 200, or 300\nyards was found to give a very small degree of resistance, when\nstarted with little velocity, viz., from τ}σth to r}σth of the load,\nthereby showing that the atmosphere was but slightly affected by\nthe same, although it amounted to from 010 to 100ᵗʰ of the load,\nwhen the initial motion was very great, the state of the weather\nand the direction of the wind were also found to influence the mo-\ntion of the train very considerably ; a great portion of the force of\nthe engine is also absorbed by the wheels of the carriages, owing\nto their velocity and their great number, they may be said to\nact against the atmosphere, and the air for some distance round\nthem is also affected, and which forms part of the resistance op-\nposed to the moving power. The uniform velocity above described\nwas precisely the same upon the curves as upon the straight parts\nof the line, the former being of 1 mile radius: the Doctor therefore\nconcludes, that curves of that radius have no perceptible effect\nupon the resistance. Dr. Lardner described his conclusions to be\nas follows, reserving to himself the power of modifying them when\nhis experiments shall be all reduced.\n1. That the resistance to a railway train, other things being the\nsame, depends on the speed.\n2. That at the same speed, the resistance will be in the ratio of\nthe load, if the carriages remain unaltered.\n3. That if the number of carriages be increased, the resistance\nis increased, but not in so great a ratio as the load.\n4. That, therefore, the resistance does not, as has been hitherto\n2 D\nDigitized by Google\n202\nRAILROAD.\nsupposed, bear an invariable ratio to the load, and ought not to be\nexpressed at so much per ton.\n5. That the amount of the resistance of ordinary loads carried\non railways at the ordinary speeds, more especially of passenger\ntrains, is very much greater than engineers have hitherto sup-\nposed.\n6. That a considerable, but not exactly ascertained, proportion\nof this resistance is due to the air.\n7. That the shape of the front or hind part of the train has no\nobservable effect on the resistance.\n8. That the spaces between the carriages of the train have no\nobservable effect on the resistance.\n9. That the train, with the same width of front, suffers increased\nresistance with the increased bulk or volume of the coaches.\n10. That mathematical formulæ, deduced from the supposition\nthat the resistance of railway trains consists of two parts, one-\nproportioned to the load, but independent of the speed, and the\nother proportional to the square of the speed, have been applied\nto a limited number of experiments, and have given results in\nvery near accordance, but that the experiment must be further\nmultiplied and varied before safe, exact, and general conclusions\ncan be drawn.\n11. That the amount of resistance being so much greater than\nhas been hitherto supposed, and the resistance produced by curves\nof a mile radius being inappreciable, railways laid down with\ngradients of from 16 to 20 feet a mile have practically but\nlittle disadvantage compared with a dead level ; and that curves\nmay be safely made with radii less than a mile; but that further\nexperiments must be made to determine a safe minor limit for the\nradii of such curves, this principle being understood to be limited\nin its application to railways intended chiefly for rapid traffic.\nAttempts have also been made to introduce a Pneumatic rail-\nway. Mr. John Vallence was the first who thought of employing\nthe natural pressure of the atmosphere operating upon a partial\nvacuum, for the purpose of transporting passengers and goods\nDigitized by\nGoogle\nRAILWAY-RAFTER.\n203\nfrom place to place; he proposed having cast-iron cylinders suffi-\nciently large to allow the carriages and passengers to pass through\nthem, which latter were intended to act similar to pistons; he\ncaused a model to be constructed with which very satisfactory\nexperiments were made, but Mr. Henry Pinkus subsequently im-\nproved the above plan, by transferring the action of the piston\nfrom the inside to the outside of the tubes, a model of which has\nbeen lately exhibited, and a company also formed for carrying\nout the scheme; a guide-carriage is connected with the piston on\nthe outside, and termed the governor, which drags the train of\ncarriages along the top of the tube, similar to a locomotive, the\ntube being from 3 feet to 3 feet 6 inches diameter, with ledges on\neach side, on which the wheels of the carriages revolve; if the\ncarriages are proposed to be run on rails already laid down, or the\npower be employed to draw barges, the tubes need not be above\n2 feet 10 inches to 2 feet 4 inches diameter, and they would be\ncast in lengths with regular socket joints. The pistons are in-\ntended to be worked and the cylinders exhausted by stationary\nair-pumps worked by steam-engines, and the distance between the\nstations would be regulated according to circumstances.-See\nContinuous Bearings, Edge-railway, Tram-railway &c.\nRAILWAY.-See Railroad.\nRAILWAY LINK.-See Draw Link.\nRAILWAY SLIDE, a contrivance employed on railways, for the\npurpose of shifting a carriage from one line of rails to another,\nconsisting of a platform running upon wheels, upon which there\nare two or more pair of rails of similar gauge to those employed\non the line; the slide is generally placed at the extremity of the\nmain rails of the line, and it runs transversely across it upon a\ncarriage being wheeled on to the slide, the latter is moved in the\ndirection of the line of rails to which it is required to be transferred,\nwhen it is run off.\nRAFTERS, the beams employed in supporting roofing. Rafters\nar of two kinds, viz., principal rafters, and common rafters; the\nfirst are employed to carry the purlines, and the latter lay above the\n2 D 2\nDigitized by Google\n204\nRATCH-RESERVOIR.\npurlines, and support the slating or tiling, as the case may be.-\nSee Roof.\nRATCH, a bar containing angular teeth, into which a paul is\ndropped to prevent machines from running back.\nRATCHET WHEEL, a circular ratch.\nRECIPROCATING ENGINE, any steam-engine worked by an alter-\nnate rectiliniar motion, and which is effected by means of pistons\nmoving in cylinders.-See Fly-wheel.\nRECIPROCATING SYSTEM (on a railway,) the reciprocating plan\nof working railways was introduced by Mr. Benjamin Thompson,\nin the year 1821, who applied it very successfully. It consists of\na succession of stationary steam-engines along the whole line,\nwhich are fixed about 11 miles apart, having ropes from one to\nthe other, rollers are fixed along the line to receive the latter.\nWhen a train of carriages leaves a station, it is secured to the\nrope, and is thereby drawn along the line, in which case the rope\nis termed the head rope, and another is secured to the last waggon,\nwhich is called the tail rope, which is thus pulled along by the\ntrain, upon returning it becomes the head rope, and the former\nthe tail rope, thus alternating to and fro. A railway may be\nworked by stationary engines, but it does not necessarily follow\nthat it should be upon the reciprocating system; thus the Brun-\nton and Shields Railway has five continuous planes worked by\nthem, but only one can be said to be upon the reciprocating prin-\nciple; as the loaded waggons run of themselves upon three of the\nplanes by the effect of gravity, the rope being used merely to\ndraw the empty ones back, and upon the remaining plane the rope\ndraws up the loaded waggons, the empty ones returning of them-\nselves; it will therefore be perceived that on the last four places\none rope only is used, and the plan pursued appears to be very\nadvantageous.\nRESERVOIR, a large pond containing a body of water, and em-\nployed as a means of supply for hydraulic works, as for the sum-\nmit levels of canals, water-wheels, &c.; they are usually formed by\nmeans of dams or embankments.\nDigitized by\nGoogle\nRETAINING WALL-RIVER.\n205\nRETAINING Wall, a wall used for the support and mainte-\nnance of a body of earth, when circumstances render it inexpe-\ndient to slope the same gradually down.\nRetaining walls are sometimes used where land\nis valuable, and are battered on the outside face\nfrom 1 inch to 1½ inches to the foot ; the greatest\ndegree of batter (which is usually curved) being\ngiven to the foot of the wall.\nCounterforts are generally carried up at the back\nof the wall, and piers are placed sometimes on\nthe face of it.-See Batter.\nRETORT.-See Gasworks.\nRIB, a term applied generally to a girder, but\nmore particularly to an arched beam, as to the\nRetaining Wall, Loud.\nand Birm. Railway.\nsegments of a cast-iron bridge.\nRIGGER.-See Sheave.\nRIVER, a natural water-channel communicating with the sea.\nRivers are formed by the union of springs, brooks, rills, &c., and are\nthe natural channels by which the surplus water of a country is con-\nveyed to the ocean, fertilizing the land, and affording a means of\ntransport by navigation throughout their course they usually take\ntheir rise in elevated situations, at the top of high mountains, where\nthe spring rises, and they receive numerous tributaries in the\ncourse of their descent, and at length after numerous meanderings\nthey acquire a considerable width ; these springs are generally\nsupposed to arise from the condensation of atmospheric vapours,\nthawing of ice, snow, &c., and some other natural causes. Altera-\ntions frequently occur in the courses of rivers, particularly near\ntheir mouths, arising from the force of the current, some parts\nbecoming depressed and others raised. The velocity of a stream\nis usually greatest at about the middle, both as regards breadth\nand depth; it is consequently least at the sides and bottom.\nIn order to insure a proper depth of water for the barges navi-\ngating rivers, it is found necessary to preserve them by artificial\nmeans, such as by sustaining the banks on each side, (which also\nDigitized by\nGoogle\n206\nRIVER.\nprotects the adjacent country from inundation) by removing all\nshoals and obstructions, and by various other works. If the width\nof a river be increased beyond its natural limits, or that required\nfor carrying off the various land streams and floods, a reduc-\ntion in depth will be the natural consequence; if on the contrary,\nthe river is contracted or narrowed, it will acquire in depth what\nhas been taken from it in width ; a constant expense is therefore\nnecessary in preserving its navigation. Rivers are sometimes\nwidened for the purpose of facilitating the trade upon them, when\nevery means should be taken to secure sufficient depth, and the\nnature of the soil, of the bottom and sides, duly considered; also\nthe velocity of the current, and every obstacle interfering with the\nfree tidal flow of the sea-water upwards should be removed, all\nbanks, shoals, and obstructions being cleared away : the current\nshould be carried to the utmost point, by deepening and widen-\ning the entrance channel, the water will thus rise higher, and the\nvelocity of the flow and ebb will be increased, whereby the scour-\ning power is made greater, and all the numerous impurities from\nthe sewerage will be carried away the water will likewise be ren-\ndered more pure and wholesome. There is less chance of the\nbanks of a large river being overflowed than those of a small one,\nas the former may be made with a less slope at the bottom, longi-\ntudinally, than the latter, owing to the greater inclination of the\nwater to run off by reason of its increased body.\nMr. Nimmo gives the following data on the subject of the rela-\ntive inclination of streams necessary to insure the discharge of\ntheir waters :-\nLarge and deep rivers run sufficiently swift, with a fall of about\n1 foot per mile, or 1 in 5,000.\nSmaller rivers and brooks, ditto, ditto, 2 feet per mile, or 1\nin 2,500.\nSmall brooks hardly keep an open course under 4 feet per mile,\nor 1 in 1,200.\nDitches and covered drains require at least 8 feet per mile, or 1\nin 600; and furroughs of ridges and filled drains require much more.\nDigitized by\nGoogle\nRIVER WALL-ROAD.\n207\nRIVER WALL.-See Quay.\nRIVET, an iron pin used for the purpose of joining two\nplates of iron together, as in the formation of boilers ; they\nare put on in a red hot state, whereby a very great degree\nof closeness is obtained in the joint by their contraction\nin cooling a double row of rivets is generally employed\nin particular work.\nROAD, or COMMON ROAD, an expedient for effecting the con-\nnection of districts, cities, or towns, forming the most general\nmeans of communication.\nThe formation of roads was most probably commenced at a very\nearly period, being a subject of immense importance. The Ro-\nmans appear to have been quite aware of the advantages of good\nroads, some portions of the ancient Roman roads remaining at the\npresent time ; but they were entirely neglected during the\nmiddle ages, and it was not until the middle of the last century\nthat any very great improvement was made in them.\nThe ancient Roman military roads generally run in direct lines,\nand hilly ground appears to have been selected in preference to\nthe level, for the purpose of commanding the country ; towers of\ndefence being erected on the several summits. The great desi-\nderatum in laying out of modern roads is to obtain the most level,\ntogether with the shortest line of route ; some attention being paid\nto the materials afforded by the country for the proposed works.\nHighways, or national roads, are roads of the first class, and\ncomprise the great communications throughout the country ; they\nare conducted under the direction of the Government or of the\nseveral county authorities, and are maintained by tolls levied upon\nthe horses and carriages using them; hence the term \" turnpike\nroads.\" Parish roads rank next to highways, and are sustained at\nthe expense of the various parishes in which they are situated.\nPrivate roads, or the roads belonging to an estate, may be in-\nstanced as the next in point of importance; and, lastly, lanes,\nwhich may belong to either of the last stated classes.\nA road should be raised 3 or 4 feet above the surface of the\nDigitized by\nGoogle\n208\nROAD.\nground, in order that it\nmay have the benefit of\nthe sun and wind, also as\nan allowance for drain-\nage ; and it should al-\nways have an inclina-\ntion, longitudinally, from\nabout 1 in 60 to 1 in 100,\nby which the water will\nbe got rid of; but steep\ninclinations upon a road\nimpede the passage of\nthe coaches, and are like-\nwise exceedingly danger-\nous; alternate rises and\nfalls also increase the\ndistance : the inclination\nof highways should not\nbe less than 1 in 30 in\nder any circumstances,\nTransverse section of a Road on Mr. Telford's plan of construction.\nDitto, ditto, a culvert being shown beneath it.\nthe vicinities of towns un-\nand that of parish roads\n1 in 20 to 24. The sur-\nface of a road should be\nformed as smooth as pos-\nsible, provided it remains\nhard, as it then offers the\nleast resistance ; thus a\npaved - way forms the\nnearest approximation to\na railway. A road should\nalso be of uniform width\nthroughout, say about 30\nfeet for highways, although\n10, 50, or even 60 feet is not too much for the leading thoroughfares\nDigitized by Google\nROADS.\n209.\nto cities; the surface should also be made of a convex shape, for\nthe purpose of carrying the water off into the side drains at the\njunction of the footway with the road, and it should be conveyed\nfrom thence to the ditches upon each side, by means of culverts;\nproper mitre drains should also be constructed under the road,\n(see Mitre Drains), and filled in loosely with large flints or pebbles\nto carry off the water that percolates through it into the side drains;\nthe latter require to be kept perfectly clear of obstructions, and\npassed into the natural water-courses of the country.\nThe centre part of a road is generally metalled, the sides being\nmerely gravelled on the natural subsoil, these portions being\nsometimes called summer roads; the method of paving the centre\npart is of great importance, the system practised by the late Mr.\nTelford on the Holyhead road is generally admitted to be the\nmost correct plan of formation, viz., the laying down of a regu-\nlar close-set pavement, as a foundation for the road, having the\nbroad part of the stones securely placed on the bottom of *the\nexcavation upon which the ballasting was laid, consisting of a\ncoating of broken stones, with a binding gravel covering, the\nthickness of the whole being from about 6 to 9 inches; the old\nRoman roads may be described as specimens of this principle of\nconstruction, as they were formed upon a bottoming of stone and\ncement, which is frequently discovered almost as hard as iron,\nand of very great substance. Gravel concrete is employed for\nthe same purpose, in cases where stone is difficult to obtain, as in\nthe case of the Highgate Archway road, the proportions of which\nwere 10th Roman cement, 1σᵗʰ sand, and To ths stones, with a co-\nvering of broken stone, 3 inches thick; the cost of this road\namounted to from 12s. to 15s. per running yard, the portion of road\ncovered with it being 18. feet wide. Concrete, composed of 4\nparts of gravel to 1 of lime, has also been successfully used by\nMr. C. Penfold, C.E. ; for instance, on the Brixton road, where\nit is laid 6 inches thick, and extends over one half the width\nof the road, comprising the centre part, and good hard gravel,\nor broken stone, is spread over afterwards, in two courses; the\n2 E\nDigitized by\nGoogle\n210\nROADS.\nfirst being laid a few hours after the concrete has been placed on\nthe road. The metalling of a road requires to be removed as it is\nworn down, and on no account should the vehicles be suffered to\nbe in immediate contact with the concrete; the paths on each side\nof the road may also be much improved by a similar foundation\nlaid about 2 inches thick.\nA macadamised road is generally understood to refer simply to\na broken stone road, and which are inferior to roads of the above\ndescription, unless the subsoil is of a perfectly unyielding nature ;\nthey are probably the cheapest to lay down, but their repairs are\nfar the heaviest.\nThe following are the principles laid down by Mr. M'Adam for\nconstructing roads :-\nThat a foundation or bottoming of large stones is unnecessary\nand injurious to any kind of subsoil.\n\" That the maximum strength or depth of metal required for\nany'road is only 10 inches.\n\" That the duration only, and not the condition of a road, de-\npends upon the quality and nature of the material used.\n\" That freestone will make as good a road as any other kind\nof stone.\n\" That it is no matter whether the substratum be soft or hard.\"\nThe expence of a Macadamised road has been estimated as\nfollows :-\n£ 8. d.\nThe first cost per superficial yard\n0 7 6\nTwo coatings, at 1s.9d. each per yard per annum, for\n3 years\n1 15 0\nCleansing, at 10d. per yard per annum, for 10 years\n0\n8\n4\n2 10 10\nIt is now pretty well known that roads so constructed are not\nfit for situations where there is much traffic, as the expence of\nkeeping them in repair is very great; the continual attrition of\nthe angles of the several stones, from their constantly changing\nDigitized by Google\nROADS.\n211\ntheir position, having nothing to support them, is, in fact, much\ngreater than the wear occasioned by the traffic of the road, it is\nthus rendered dusty in summer, and muddy in winter ; hollows\nare also soon formed by the partial settling of the ground for want\nof a foundation, whereby the surface is rendered irregular and\nbad for the passage of carriages.\nThe following cut represents the method of forming a road on\nwhat is termed sideling ground :-\nRoad on sideling-ground.\nRoads are sometimes constructed along rocky ridges, when re-\ntaining walls are mostly adopted-thus,\nRoads across bogs or moss\nare formed by first thoroughly\ndraining the ground ; longitu-\ndinal drains must, of course,\nextend on each side with other\ndrains parallel to them, also\ncross drains to carry the wa-\nter into the side drains; and\nas this work can only be ex-\necuted in fine weather, it oc-\ncupies some time, probably\nthree or four years would\nelapse before perfectly conso-\nRoad on the side of a precipice.\nlidated ; the turf, when thoroughly dried, may be used in forming\n2 E 2\nDigitized by Google\n212\nROADS.\nthe roads and embankments connected with it, being carefully\nworked in regular layers, and well rolled with a heavy cylinder\nprevious to the gravelling and metalling being laid. The drain-\nage of Chat Moss and Parr Moss on the Liverpool and Manchester\nrailway may be cited as specimens in this class of engineering.\nChat Moss is composed of an extensive bed of peat or turf,\nabout 5 miles in length, and 2 or 3 in breadth (containing about\n12 square miles altogether), about 41 miles of which is crossed by\nthe railway. It consists of a very soft spongy substance, from 10\nto 35 feet deep, the bottom being clay and sand. The works for\nthe railway were commenced by cutting longitudinal drains on\neach side of the line, also cross drains : the moss between these\ncuts was thus drained,\nand became partly con-\nsolidated : hurdles, 9 by\n4 feet, and wattled with\nheath, were then placed\nacross the line in one or\nA, the Hurdles.\ntwo layers, according to the tenacity of the moss, and a bed\nof ballasting, 2 feet thick, was laid upon them, upon which\nlongitudinal beams were laid, the timber sleepers being next in-\ntroduced in the usual manner, and another set of longitudinal\nones, upon which the rails were fixed by means of chairs.\nWhere the railway is elevated the embankment was formed of\ndried moss, and it took four times the quantity of material that an\nembankment of similar height would require, upon sound ground,\nowing to the sinking nature of the foundation; and where the\nline was in cutting, it was effected by draining, in a similar manner\nto the level portions, but by successive lifts or layers, 12 inches\nthick, the longitudinal ditches becoming deeper every lift. The\nroad is therefore entirely floating upon the moss, and depends\nwholly upon the tenacity of the materials.\nParr Moss is crossed in embankment, the moss being about\n20 feet deep, and the material of an adjoining excavation was used\nin forming it, consisting of clay and gravel, which gradually sunk\nDigitized by\nGoogle\nThe following table shows the cost of conveying goods and passengers on turnpike roads, with\nthe comparative expence of the same upon railways, both with horses and with locomotive\nengines.\nTurnpike roads (with Horses).\nRailways (with Horses).\nRailways (with Locomotives.)\nDescription of\ntraffic.\nRate of travelling, in\nmiles per hour.\nForce of traction,\nin lbs. per ton.\nCost of haulage,\nCost of\nForce of\nCost of haulage,\nCost of\nper ton per\nconveyance,\ntraction,\nper ton per\nconveyance,\nmile.\nper mile.\nin lbs.\nmile.\nper mile.\nper ton.\nRate of travelling,\nin miles per hour.\nForce of traction,\nin lbs. per ton.\nCost of haulage,\nCost of\nper ton per\nconveyance,\nmile.\nper mile.\nHeavy goods\n~\n21\n73\n3d.\n8d. per ton.\n8.5\n0.56d.\n1.65d. per\n8\n81\n0.375d.\n1.065d. per\nwas only 4 or 5 feet high, at the completion it was found to have\nas it was thrown upon the moss and, although the embankment\nROADS.\n(stage vans)\ntom.\nton\nLight goods\n(vans or light\n4\n73\n4.5d.\n12d.perton.\n8.5\n0.9d.\n3,srd. per\n12\n81\n0.5d.\n3.5d. per\ncarts)\nton.\nton.\n1d. to 11d.\nPassengers\n0.7d. per\n3d. per\n0.25d. per\n0.25d. per\nld.to 11d.\nper pas-\nper pas-\nand parcels\n9\n83\n8.5\npassenger,\npassenger,\npassenger,\nsenger,\n20\n81\npassenger,\n(stage coach)\n10d.perton.\n3s. per ton.\n2.24d. per\n0.73d. per\nsenger,\n1s.3d.per\n12.37d.\nton.\nton.\nton.\nDigitized by Google\nper ton\n* Arranged from Wood's Practical Treatise on Railways.\n213\n214\nROCK.-ROOF.\ntaken a sufficient quantity of earth to have formed one 24 or\n25 feet high, on ordinary ground; therefore the portion of\nthe line across Chat Moss could not have been made with such\nmaterials.\nMr. Macneill stated, in his evidence before a Committee of the\nHouse of Commons, in the year 1830, that the expence of im-\nproving the present turnpike roads, altering all the slopes to within\n1 in 40, would cost from £600 to £2,000 per mile, according to\ncircumstances.\nRoads are also sometimes paved, particularly in cities and\ntowns.-See Paving and Paved Way.\nRock.-See Stone.\nROLLEY, the name formerly applied to a tram-wheel.\nROMAN CEMENT, a cement in very general use for building\npurposes, and forming an excellent water cement; being mostly\nemployed with an equal portion of good sharp sand, it also forms\na perfect preventive against corrosion, and may therefore be\nserviceable in covering joints in iron-work, and for similar pur-\nposes; the stone is of a dark brown colour, and is principally\nbrought from the Isle of Sheppy.\nROOF, the covering to any building or shed.\nRoofs may be described generally as being of two kinds, viz.,\n1st, those with their outer surfaces or tops nearly level, such being\nusually covered with lead-2ndly, those which have their tops\ninclined, as the common roof, gutters being formed at their lower\nedges, and slates employed for the external covering.\nIn the first description of roof the lead is supported by means\nof horizontal joists or bearers, proper boarding being interposed\nbetween them; and in the second kind, long timbers, called raf-\nters, are employed to carry the slates, and either boarding or thin\npieces of wood, termed fillets, are nailed on them to secure the\nslates to ; when the rafters are long, they are supported by purlines,\nas may be required, and these rest on framed trusses, termed\nprincipals, which are placed at regular intervals, usually about 10\nfeet distance; and it is in the construction of these principals\nDigitized by\nGoogle\nROOF.\n215\nthat the stability of the roof mainly depends: such roofs are also\ndescribed as trussed roofs. Roofs of small dimensions are con-\nstructed without either principals or purlines. The width between\nthe walls, or supports, is called the span of the roof, and the height\nin the centre the rise, the slope of the rafters being termed the\npitch.\nRoofs of from 20 to 30 feet span may be supported by princi-\npals, composed of a king-post, principal, rafters, and struts, thus,\nand of the following scantlings :-\nG\nE\nE\nc\nE\nH\nH\nI\nSpan in feet.\nTie-beams.\nKing-post.\nPrincipals.\nStruts.\nIns.\nIns.\nIns.\nIns.\nIns.\nIns.\nIns.\nIns.\n20\n9 X 4\n4 X 4\n4 X 4\n4 X 3\n25\n10 X 5\n5 X 5\n5 X 4\n5 X 3\n30\n11 X 6\n6 X 6\n6 X 4\n6 X 3\nThis and the following Tables are according to Mr. Gwilt, with\nthe exception of the line marked *:-\nA, the tie-beam, which is notched to receive the feet of the\nprincipal rafters; it is also notched on the wall-plate.\nB, the king-post; the head is prepared to receive the upper\nends of the principal rafters, and at the feet for the reception of\nthe struts.\nC, C, the principal rafters or principals; these are laid to the\nrequired pitch of the roof, the feet are joggled into the tie-beam,\nand the upper ends abut against the king, and are secured by\nstraps and bolts.\nD, D, the struts for supporting the principal rafters, &c.\nDigitized by Google\n216\nROOF.\nE, E, the purlines which are secured to the principal and to\nthe common rafters.\nF, F, the common rafters for receiving the outer covering.\nG, the ridge-piece, against which the common rafters abut.\nH, H, the pole-plates for receiving the feet of the common\nrafters, which are secured to the tie-beam.\nRoofs of from 30 to 40 feet span may be supported with prin-\ncipals framed with two queen-posts, and one straining-beam be-\ntween them, &c., thus, and of the following scantlings :-\nH\nF\nF\nX\nG\nG\nF\n-\n1\nI\nA\nK\nK\nSpan in feet.\nTie-beams.\nQueen-posts.\nPrincipals.\nStraining-piece.\nStruts.\nIns.\nIns.\nIns.\nIns.\nIns.\nIns.\nIns.\nIns.\nIns.\nIns.\n35\n11 x 4\n4 X 4\n5 X 4\n7 X 4\n4 X 2 *\n40\n12 X 5\n5 X 5\n5 X 5\n7 x 5\n5 X 21\nA, tie-beam.\nF, F, Purlines.\nB, B, queen-posts.\nG, G, common rafters.\nC, C, principal rafters.\nH, ridge-piece.\nD, D, struts.\nI, I, pole-plates.\nE, straining-piece.\nK, K, Wall-plates.\nRoofs of from 40 to 60 feet span may be framed with two\nqueen-posts, and two straining-beams between them, and struts\nfrom the queen-posts to other smaller queens and struts.\nThe principals are much improved by trussing the upper strain-\ning-beam, as shown on cut. The scantlings being of the follow-\ning dimensions :-\nDigitized by Google\nROOF.\n217\n1\nF\nG\n02\nc\nG\nF\nc\nH\nH\nB\nG\nB\nc\nWALL\nM\nM\nc\nM\nK\n>\nK\nN\nA\nL\nL\nSpan\nin feet.\nTie-beams.\nQueen-posts.\nSmall Queens.\nPrincipals.\nStraining-piece.\nStruts.\nIns.\nIns.\nIns.\nIns.\nIns.\nIns.\nIns.\nIns.\nIns.\nIns.\nIns. Ins.\n45\n12 X 7\n7 X 7\n7 X 4\n7 X 4\n8 x 5\n413\n50\n13 X 8\n8 X 8\n8 X 4\n8 X 6\n9 x 6\n5 X 3\n55\n14 X 9\n9 x 8\n9 X 4\n8 X 7\n10 X 6\n5] x 3\n60\n15 x 10\n10 X 8\n10 X 4\n8 X 8\n11 X 6\n6 X 3\nA, tie-beam.\nH, H, common rafters.\nB, B, large queens.\nI, ridge-piece,\nC, C, small queens.\nK, K, pole-plate.\nD, D, principal rafters.\nL, L, wall-plate.\nE, straining-piece, or collar.\nM, M, M, M, struts.\nF, king-post.\nN, Lower straining-piece.\nG, G, purlines.\nThe following Tables show the scantlings of purlines and com-\nmon rafters, also according to Mr. Gwilt :-\nPURLINES.\nCOMMON RAFTERS.\nBearing in feet.\nScantlings.\nBearings in feet.\nScantlings.\nIns.\n11.s.\nIns.\nIns.\n6\n6 X 4\n8\n4 X 21\n8\n7 X. 5\n10\n5 x 21\n10\n8 x 6\n12\n6 x 21\n12\n9 X 7\nThe whole of the several joinings of the timbers must be well\n2 F\nDigitized by Google\n218\nROPE-ROLL-ROTARY ENGINE.\ntied together; the feet of the principal rafters are commonly jog-\ngled into the beam, and further secured by bolts or by straps, and\nthey are fastened at their upper ends by being let into the heads\nof the posts, or by irons; and the tie-beam is supported by the\nposts, by means of stirrup-irons fixed at the extremity of the\nlatter.\nThe height of the rise or pitch of a roof is generally between\n4th and 1th of the span, the former being considered the true pitch\nfor strength and security.\nWhen the end of a roof is sloped off similar to the sides, it is\nsaid to be hipped, but if the ridge runs out straight with the face\nof the end walls or supports, such mode of termination is described\nas a gable-end.\nStruts are understood to be upright pieces of wood, and are\nemployed to resist vertical compression; braces are diagonal pieces\nused to prevent any flexure in a framing, or to stiffen a truss; and\nthose timbers exposed to the force of extension are termed ties ;\nthe term collar is applied to a tie extending from about the middle\nof a rafter to the corresponding one on the other side of a roof.\nROPE-ROLL.-See Drum.\nROTARY, ROTATORY, or CONCENTRIC ENGINE (sometimes\ncalled a steam-wheel), an engine worked by the elastic force of\nthe steam acting upon pistons fixed to an axis, whereby the latter\nis put into motion instead of being turned by means of pistons\nworking in tubular cylinders, and communicated by the crank\nmotion. The construction of an efficient engine after this system\nhas been considered the grand desideratum with steam power,\nalthough some engineers assert, that it would not be able to exert\nmore force than other engines with a similar quantity of steam.\nNotwithstanding various modifications may be made in steam-\nengines, to suit the purposes to which they are applied, yet it is\nvery questionable whether much more will be accomplished than\nlessening the friction of the several parts by greater simplicity of\nconstruction: There have been two or three rotary engines spoken\nvery highly of lately, as \"Avery's Rotary Engine,\" and the \" Pa-\nDigitized by Google\nRUBBLE-WORK-SAFETY-VALVE.\n219\ntent Rotative Disc-Engine,\" also \" Bunnett and Corpe's Concen-\ntric Engine.\"\nRUBBLE-WORK, a rough description of masonry, the stones\nbeing merely axed on the face, and laid in as regular courses as\nsuits the convenience of the mason, and well flushed with mor-\ntar, occasional bonders being inserted (which are more required\nin this description of walling than in any other), running through\nthe whole thickness of the wall, to tie the whole together: chain-\nbond may also be used in rubble walls with great advantage, if\nmany openings are required to be left. In good work the stones\nshould be as large as the workmen can conveniently lift.\nIf the stones are laid in regular courses, the work is described\nas regular coursed; if otherwise, irregular coursed work: and when\nthey are not laid in courses, but merely piled, or laid one upon\nanother, according to the sizes of the several stones, it is termed\nuncoursed rubble walling.\nThe filling-in work at the back of arches, and the like, is also\ncalled by this name, although not so properly speaking, as it con-\nsists of chippings and pieces of stones, of all shapes, thrown in\nwithout any attention to position.\nSAFETY-VALVE, the valve usually employed in the boilers of\nsteam-engines, to prevent explosions, which are constructed in\nsuch a manner that the power of the steam opens them when it is\nof a higher pressure than the boiler is calculated to bear, whereby\nthe surplus power escapes, upon which the valve instantly closes\nagain.\nThe conical or button-valve, is that\nmost frequently employed, which is\nkept shut by a lever with a sliding\nweight.\nThe safety-valves of locomotive engines usually have a series of\nspiral elliptical springs instead of a weight, with an index to show\nthe pressure of the steam upon the valve. It is sometimes found\nin practice, that valves of this description stick, and consequently\noffer a far greater resistance to the steam than intended, which has\n2 F 2\nDigitized by Google\n220\nSAND-SAND-STONE.\nled to the use of spherical valves;\nthese supersede the necessity of any\nweight, and afford very little fric-\ntion; they are, therefore, very suit-\nable for the lock-up valves of an\nengine, as upon the top being\nscrewed down, it is not very easy to tamper with them, and on\naccount of their freedom from derangement (a lock-up valve is\nalways attached to a boiler, in case the ordinary one should fail).\nThe fusible valve is also used by some engineers, which consists\nof a safety-plate or plug, made of a certain mixture of metals,\nwhich becomes fusible before the steam attains a dangerous pres-\nsure. The safety-valves employed in France are required by\ngovernment to partake of this prin-\nciple; it is appended to the usual\nsafety-valve. a, a, is the extra\nsafety-plate, made of zinc, tin, and\nbismuth, being kept down by an\niron grating. The only objection\nto this valve is, that it not only lets off the superabundant power,\nbut the whole of the steam from the boiler with it, whereby the\nengine becomes stopped, although a safety-valve should be con-\nstructed of sufficient size to pass all the steam that the boiler can\ngenerate in an ordinary state of work. The steam blown off at the\nsafety-valve often amounts to 4ᵗʰ of the steam generated in the\nboiler.\nSAND, a granular mineral substance insoluble in water. Pit-\nsand is superior to river-sand for all building purposes.\nSAND-STONE, also termed Free-stone, a very serviceable and\ndurable stone, when of good quality, being composed of grains\nof sand adhering together without any visible cement; it varies\nin its component parts, being at different places siliceous, argilla-\nceous, and calcareous.\nSand-stone is generally found stratified, each strata varying in\nthickness from about that of a slate to many feet, as the enormous\nDigitized by\nGoogle\nSCAFFOLD-SCOURING POWER.\n221\nblocks sometimes drawn from the Portland quarries: it is much\nused for building purposes, as it can be readily cut into any form.\nSCAFFOLD, a temporary erection, formed of poles, for the pur-\npose of building. In stone erections the poles are obliged to be\nused double, when it is termed a double scaffold.\nSCANTLING, a term used in reference to timber, in the same\nsense as size, but with respect to breadth and thickness only; thus,\na piece of timber 12 inches wide, and 6 inches thick, is said to\nhave a scantling of 12\" X 6\".\nSCARFING (of timber), the joining together of two wooden\nbeams endways, which operation is resorted to when timber is re-\nquired of longer lengths than can be procured in single pieces.\nThe length of all scarfings should be at least twice the width of\nthe face of the beam (although not always made so), well notched\nand wedged together. An iron plate, fixed beneath the scarfing,\nmaterially strengthens it, when the beams are not laying on a wall,\nor otherwise supported on the under side.\nScoop-Wheel, a certain description of wheel which is formed\nof cast-iron, and employed in conveying a stream of water up-\nwards, from one pond, to another situated above it; they are there-\nfore employed in a contrary manner to water-wheels, since, instead\nof being acted upon by the impulse of the water, they operate\nupon it, being turned by the aid of a steam-engine.\nScoop-wheels are much employed in the drainage of fenny land\nand levels. Mr. Joseph Glynn, C. E., who has had much experience\nin using them, usually makes the dip of the float-boards extend 5\nfeet below the water, where powerful engines are used such a wheel\nbeing described as having a 10-feet head and dip, and the axis of\nthe wheel should be 4 or 5 feet above the level of the river or\noutfall drain. Mr. Glynn states, that the best velocity for the\nwheel is 6 feet per second at the circumference, which gives it a\ncentrifugal force quite sufficient to hold the water up against the\nbreast of the stone trough or wheel-track, yet not enough to carry\nit beyond the point of delivery.\nSCOURING-POWER.-See Backwater.\nDigitized by\nGoogle\n222\nSEA-WALL-SECTIO PLANOGRAPHY.\nSEA-WALL, or REVETMENT, a retaining wall erected along the\nline of a coast adjoining the sea.\n-See Harbour and Quay Wall.\nSECTION, a drawing of any ob-\nject, representing it cut or divided\ninto two parts.\nSections are either vertical,\nhorizontal, or oblique, and generally\nrepresent plain surfaces.\nA section of a line of country\nis a vertical section, made for the\npurpose of explaining the nature\nof the ground, as the soil within,\nand the level of the surface; and\nif intended for parliamentary pur-\nposes, it must be drawn according\nto the standing orders of the\nHouse of Commons, or 4. inches\nper mile for the horizontal scale,\nand 100 feet to an inch for the\nvertical scale.-See Levelling:\nSECTIO PLANOGRAPHY, a me-\nthod of laying down the section\nof engineering works upon the\nplan, and recently introduced by\nMr. Macneill, and required, by\nthe standing orders of the House\nof Commons, for all proposed rail-\nways, &c. It is performed by\nusing the line of direction laid\ndown on the plan as a datum-line;\nthe cuttings being plotted on the\nupper part, and the embankments\nupon the lower part of the line;\nthus.\nDigitized by\nGoogle\nSELF-ACTING INCLINED PLANE-SEWERAGE.\n223\nBy this plan the nature of the undertaking may be readily un-\nderstood, and the owners of property on the line will see how\ntheir land is crossed, whether in cutting or embankment, and the\ndepth of same. If the former be coloured red, and the latter\nblue, it will further assist ; or the cuttings may be represented by\nvertical lines ruled over them, and the embankment by horizontal\nones. The regular section is required for the practical purposes\nof the engineer the same as usual.\nSELF-ACTING INCLINED PLANE (upon railways, canals, &c.),\nan inclined plane, worked by the gravity of the load conveyed\nwe first read of their being used in the year 1788, on which occa-\nsion a loaded boat was placed on a cradle and run down upon\nframe-work to the lower level, by the action of which some empty\nboats were also drawn up to the higher level. They are occa-\nsionally employed upon canals in America at the present time.\nInclined planes were formerly much employed upon colliery\nrailways, having been applied soon after the introduction of iron\nrails and wheels, when they were adopted to counteract the in-\ncreased velocity occasioned by them on the runs: the surplus\ngravity of the loaded waggons drawing up the empty ones, which\nat the same time served as a brake to them; each train of waggons\nwas connected together by a rope, which is passed round a\ndrum fixed at the top of the plane. Inclined planes are not\napplicable unless there is a preponderance of goods to be con-\nveyed one way, sufficient to counterbalance the gravity of the\nempty carriages coming in the opposite direction.\nMuch advantage is derived from the adoption of self-acting in-\nclined planes during the execution of railway works.-See Inclined\nPlanes and Double-acting Inclined Planes.\nSEWER, an arched covering, similar in shape to a tunnel, used\nfor the conveyance of water.-See Culvert and Drain.\nSEWERAGE. This term was formerly synonymous with drain-\nage, but its signification at the present time is very different;\ndrainage bearing more immediate reference to the recovering of\nmarsh land, for the purposes of agriculture, whereas the former\nDigitized by\nGoogle\n224\nSEXTANT-SHAFT.\nimplies the draining of a city or town of all superfluous water,\nand ridding it of all filth, whether accumulated by natural or by\nartificial causes ; and this branch of internal convenience has not\nyet received that attention and consideration which it undoubtedly\ndemands, it being very essential to the health of the people.\nThe drainage of open country is not a very difficult operation,\nwhere there are ample means provided to effect the undertaking,\nbut the drainage of a large city or town is frequently a work of\nconsiderable difficulty, on account of the difference in the levels\nof the several streets, and the comparative lowness of some of\nthem; hence all new shores required to be made in a city are\nobliged to bear reference to those already laid down.\nSEXTANT, Box SEXTANT, or POCKET SEXTANT, an instrument\nmuch used in surveying, for measuring horizontal angles only ; it\nis sufficiently accurate for all general purposes, although a theo-\ndolite should always be used in laying out large triangles. A\nsmall telescope is sometimes attached to the sextant, to assist the\nsight, but it is not always used.\nSHAFT, a vertical sinking or well, excavated and dry, for the\npurpose of working and ventilating mines, also tunnels, and for\nascertaining the nature of the ground before commencing any en-\ngineering operations. The principal shaft of a mine is usually\ncalled the engine-shaft.\nThe brickwork of the shaft sunk for the working of the Thames\nTunnel was first built up from the ground to the required height\n(40 feet), and then sunk to the proper level by loosening the\nground from beneath it; proper precautions were, of course,\ntaken to prevent any irregular settlement during the course of ex-\necution, by tying it well together; it was carried up upon piles,\non which an iron curb was laid, wrought-iron rods, 2 inches dia-\nmeter, were taken from thence to the intended height of the shaft,\nand secured into a top curb; the bricks were laid in cement, and\nfurther bound by timber hoops, half an inch thick. Upon the\ncompletion of the brickwork, the piles were removed from the\nbottom, and it was left standing upon the gravel; a thirty-horse\nDigitized by\nGoogle\nSHAFT-SHEAVE.\n225\npower high pressure-engine and raising gear were then fixed upon\nit, and after being kept a proper time to dry, the excavating was\ncommenced from within it.\nSection of the Working Shaft employed at the Thames Tunnel.\nThe shaft is 50 feet in diameter, 42 feet deep, and the brick-\nwork is 3 feet in thickness. The two large ventilating shafts of\nthe Kilsby Tunnel on the Lendon and Birmiugham Railway were\nalso constructed by the same method ; the ordinary shafts commu-\nnicating with the tunnels on this railway are 9 feet in diameter,\ncarried up in 9-inch brickwork, and supported below by a cast-\niron curb, fixed in the crown of the tunnel.\nSHAFT (in machinery), the term applied to a large axle. The\nshaft is one of the most essential parts for the conveying of motion\nin all machines; the action of the primary power causing it to re-\nvolve upon its axis, when any wheels fixed upon it are also carried\nround by it, as the shaft of a fly-wheel.\nA small shaft is termed a spindle; shafts placed in a horizon-\ntal position are described as lying, and those situated vertically\nare called upright. The cylindrical form of shaft is considered\nsuperior to both square or feathered, but for large shafts hollow\ncylinders are best.\nSHEAVE, FRICTION ROLLER, or PULLEY, a description of wheel\nmuch used in connection with inclined planes and fixed engines,\nbeing formed for the purpose of receiving the rope, whereby the\nfriction of it is considerably reduced.\n2 G\nDigitized by\nGoogle\n226\nSHEAVE.\nSheaves are generally formed of cast-iron on railway or canar\nworks, and are constructed of various sizes. The large wheels\nsituated at the top and bottom of a plane, and employed for re-\ntaining the rope, and for communicating the action of the steam-\nengine to the train, are termed sheaves, and the small wheels fixed\nalong the surface of the ground are generally called running\nsheaves, or friction rollers.\nAn inclined plane in a double line of railway is usually worked\nby an endless rope, and a large metal sheave is fixed at the end to\npass the rope back ; the rope runs between flanges formed on each\nedge of the peripheries of the wheels. This method is applied\non the Euston-square Plane, the terminal sheave and tackle being\nfixed beneath the level of the rails, and set in a diagonal direction\nwith masonry and brickwork; it therefore does not form any ob-\nstruction, being entirely concealed from view ; the rope is received\nat the top of the plane upon a sheave placed vertically, and is\nthen passed to another in a horizontal position, termed the tight-\nening sheave, from thence it turns back, passing round another\nvertical sheave, and an additional smaller one is employed on\nthis side of the tightening sheave, when a very great degree of\nfriction is required; the rope is thus taken again to the surface of\nthe rails, and runs down the other line of rails, constituting an\nendless rope; the tightening sheave is fixed on a moveable stage\nplaced on a railway, and a counterbalancing weight is connected\nto it, in order to keep the rope in a proper state of tension, what-\never weight the load may be : the counterbalance is situated in a\nwell, and acts upon the rope like a spring.\nThe accompanying cut represents the plan adopted by Mr. Ste-\nphenson in the working of the stationary plane on the Liverpool\nand Manchester Railway :-\nFig. 1.\nFig. 2.\nFig. 1, is the horizontal wheel at one end of the lines of rails.\nDigitized by Google\nSHEET-PILING.\n227\nFig. 2, is the working wheel, with its pit and tightening sheaves,\nand which is worked by a stationary engine.\nThe running sheaves used upon inclined planes are from 10 to\n15 inches diameter, having their peripheries hollowed out to re-\nceive the rope, and are usually fixed about 8 or 10 yards apart,\nthe axles resting upon a metal box or socket, which is well bed-\nded in the ballasting, they are also sometimes fixed upon stone\nblocks. In cases where a plane is curved laterally, as parts of\nthe Euston-square plane, the running sheaves are fixed in a slant-\ning position, and at different degrees of inclination, according to\ntheir situation in the curve, a strong stay-bar being attached at\nthe back of each, which enables them to support the pressure of\nthe rope without altering their position. The proper angle for\nthe same, is that which allows of neither an upward or a down-\nward stress of the rope, but which presents the wheel in such a\nposition that the strain shall be in a line at right angles with\nthe axis; there is a double or endless rope to each set of rails,\nor each double line (there being four lines of rails laid down),\neach rope is 7 inches in circumference, and 4,000 yards long,\nand weighs 10 tons. Wooden friction rollers and frames are\nused on the Whitby and Pickering Railway.\nThe humming noise attendant on this method of working a rail-\nway, arising from the velocity with which the friction rollers\nrevolve, is considered objectionable by some individuals, (more\nespecially if occurring in crowded neighbourhoods) ; it has,\nhowever, been proposed to cover their edges with netting, as a\npreventive, although rather a doubtful remedy.\nSHEET-PILING, a row of timbers driven firmly side by side into\nthe earth. When the piling consists of planks, it is termed pile-\nplanking, and which is sometimes joggled together. Sheet-piling\nis used for protecting foundation walls from the effects of water,\nalso in the construction of coffer-dams, sluices, &c., and it is usu-\nally supported and secured to guide-piles and to waling-pieces\nsituated along the top, by iron bolts.\nSheet-piling is always employed to support walls and other\n2 G 2\nDigitized by Google\n228\nSHIFT-SIDING:\nworks next rivers, canals, &c., and good clay should be well pun-\nned in at the back of the piles next the wall. Cast-iron sheet-\npiling has been recently adopted, and with considerable success.-\nSee Quay and Piles.\nSHIFT, a name employed in reference to the gangs of men em-\nployed in excavating upon railways, &c.; for instance, when two\ndifferent sets of men are employed alternately, they are described\nas working double shifts, which is found more expensive than\nsingle shifts, although occasionally resorted to during the long\ndays, where great speed is necessary. Night-work is also consi-\nderably more expensive than that performed in the usual working\nhours.\nSHORE, or SHOAR, the name given to the pieces of timber\nplaced diagonally against the sides of walls, or otherwise, as a\nprop or support to them; timber plates are usually placed at each\nend of shores, and the junctions are further tightened by wedges\ndriven in between them.\nSIDE CUTTING, a term applied to a cutting made along the side\nof a line of railway or canal, for the purpose of obtaining mate-\nrial for the embankment, when there is not sufficient excavation\nupon the line to form it.\nSIDE-FORMING, a term applied to an embankment when made\nby a side cutting, and which constitutes the quickest way of\nforming an embankment, as the whole can be commenced at the\nsame time from one side, and filled in at once towards the other,\nin which case the embankment is usually supported by steps cut\nat the bottom of it.-See Road.\nSIDE SPACE (on railways), the distance on the outside of each\nline of rails, which is generally about 3 feet 6 on private, and\n5 feet on public lines, as the London and Birmingham and Great\nWestern Railways.\nSIDELING GROUND, a line of country whose cross-section is\ninclined or sloping.-See Earthwork, Side-forming, and Road.\nSIDING, PASSING PLACE, or TURN-OUT (on railways), a short\nlength of additional trackway laid by the side of a line of rail-\nDigitized by\nGoogle\nSILT-SKEW-BACK.\n229\nway, and connected therewith at each extremity by suitable\ncurves, the rails being constructed and disposed in such a manner\nthat the carriages can either proceed along the main line, or turn\ninto the siding, as may be required; to accomplish which, the\nportion of rails forming the junction of the siding with the main\nline is made moveable to suit either trackway, and is termed a\nswitch, and the points where one railway crosses another are\ntermed crossing points, which are generally fixed or immoveable;\nsuitable grooves being left on the surface of them for the passage\nof the flanges of the carriage-wheels on either trackway.\nThe switches are mostly worked by an eccentric movement,\nwhich is enclosed in a cast-iron box, and it is effected on some\nrailways by a vertical lever, which draws backwards and forwards,\nmeans being taken to secure it in the proper position.\nThe occurrence of sidings is most frequent in the vicinities of\ndepôts and stations. Mr. R. Stephenson allowed one in every\nfive miles in his estimate of the London and Birmingham Railway.\n-See Switch and Crossing-point.\nSILT, the alluvial soil washed down, and deposited upon the\nbottoms and sides of rivers by the action of the tides; the term\nis also indicative of any soft light description of soil.\nSKEW-BACK, or ASKEW-BACK, the course of\nmasonry forming the abutments to a segmental\narch, or to the cast-iron ribs employed in bridges.\nIt is necessary, in the latter case, to lay a plate\nof cast-iron upon the stone skew-backs, which\nis generally run through the entire width of the\nbridge, thereby forming a tie ; but-the iron ribs\nshould not be fixed to this plate, particularly if they are of great\nspan, on account of the alternate contraction and expansion of the\nmetal, and a sufficient space should always be allowed for this\nvariation.\nThe ribs of the Southwark Bridge, London, were originally\nsecured by bolts to the masonry ; but it was found necessary,\nduring the execution of the work, to remove them in consequence\nof the injuries threatened.\nDigitized by\nGoogle\n230\nSLACKED LIME-SLIP.\nSLACKED LIME.-See Lime.\nSLEEPERS, the name applied generally to beams of wood laid\nhorizontal in any works.\nIt\nD\nIN\nEX\nThe sleepers used upon railways, upon which the railway chairs\nare fixed, are generally of oak, or larch timber, and about 5 by 9\ninches scantling, 9 feet long, and 3 feet from centre to centre ; the\ncost of the former may be stated at 7s. 6d. each, and the latter 6s.\nto 6s. 6d. A line of railway, formed of wooden sleepers, is much\nmore elastic than one laid on stone blocks, and consequently easier\nfor the passengers, and the process of kyanizing the wood sleep-\ners, as generally practised, is expected to render them very dura-\nble.-See Kyanize.\nSLEETCH, the thick mud laying at the bottom of rivers.\nSLIP, or LAND-SLIP, a slipping of the earth of a cutting, or\nembankment, which most frequently occurs in the case of deep\ncuttings and high embankments; they generally arise from the\nwant of stability of the soil, and general badness of foundation,\nalso from the side-slopes being formed too steep; but clayey soil\nwill slip at almost any slope, good drainage is, therefore, import-\nant in earth-work. During the formation of the Colne embank-\nment, on the London and Birmingham Railway, the level fre-\nquently sank several feet in the course of a few hours, the base\nextending out to an enormous width, owing to the badness of the\nfoundation. The only plan of procedure, in some cases, is by\nthat of loading the slip itself with a sufficient quantity of earth,\nto enable it to bear the embankment above ; slips are likewise\ncaused by heavy rains : high embankments should always be ex-\nposed to the wet season of the year, and the succeeding winter,\nprevious to the opening of the railway, as it tends much to conso-\nlidate and render them less liable to give way. Alternate beds of\nDigitized by\nGoogle\nSLOPE.\n231\nclay, sand, or other soil, are very liable to slip, particularly if the\nclay should be easily acted upon by water, and if the strata dips,\nor inclines to the horizon; but it may be sometimes obviated, by\ndriving piles into the faces of the side slopes, and laying binders\nacross them, by which the earth is supported.\nSLOPE, the name given to any inclination, but applied more\nparticularly to those of excavations and embankments; the term\ngradient being adopted for the inclinations of the rails upon rail-\nways. The slopes of cuttings and embankments are usually mea-\nsured by an instrument termed a clinometer, (see Clinometer) which\nindicates the angle of the slope ; but their proportion of slope is\nusually expressed by comparing the horizontal dimension with\nthe perpendicular, as an embankment, with a slope of 2 to 1, sig-\nnifres a fall of 2 feet horizontally to 1 foot vertically.\nThe ratio of the slope to the perpendicular, is represented by\nthe natural cotangent of the angle thus measured :-\nTABLE OF SLOPES.\nSlope.\nSlope.\nAngle.\nAngle.\nTo one\nTo one\nPerpendicular.\nPerpendicular.\no\n,\no\n,\n75.58\nt\n17.6\n34\n63.28\n1\n15.56\n31\n53.8\n4\n14.55\n34\n45.0\n1\n14.2\n4\n38.40\n11\n13.15\n44\n33.42\nIf\n12.32\n41\n29.44\n14\n11.53\n44\n26.34\n2\n11.19\n5\n23.58\n21\n10.47\n54\n21.48\n21\n10.18\n51\n19.59\n24\n9.52\n54\n18.26\n3\n9.27\n6\nThe proper slope for each description of soil can only be\ndetermined by observation, and the state of the slopes of any\nadjacent works forms a good criterion\nIt is generally understood, that whatever angle the soil of a\nDigitized by Google\n232\nSLUICE, OR SLUICE-GATE.\ncutting takes, without slipping, immediately after being teamed\n(the angle of repose), is sufficient for the embankment formed\nfrom it, but much depends upon the dryness of the soil at the\ntime it is tipped into the embankment.\nOxford clay will stand with a slope in the proportion of 2 to 1,\nbut London clay, whereof any height requires to be made, 3 to 1,\nalthough a less slope is sufficient for light works. Gravel or sand\nwill stand at 1½, or 2 to 1; coal measures at 1½ to 1; chalk or\nchalk marl varies from to to 1, and good sandstone will stand at\n1 to 1; but much depends upon the height of the work, and other\ncircumstances.\nThe vegetable soil upon the surface of the ground should\nalways be carefully removed, and afterwards relaid upon the finished\nsurface of the banks; and sown with grass seed, or covered with\nturf, for the purpose of strengthening them, also to carry the rain\noff; and this should be done as soon as possible, that the works\nmay be protected from the effects of the weather.\nThe banks are also sometimes planted with shrubs;\nand in situations where stone is plentiful, it may be\nadvantageously employed in covering the side\nslopes, more especially the lower part or feet of the\nslopes.-See Angle of Repose, Excavation, and Em-\nbankment.\nSLUICE, or SLUICE-GATE, a description of slid-\ning-valve, worked by a rack and pinion, and much\nused in connection with hydraulic works, which\neither retains the water, or allows it to pass through\nas may be required. It is set in a frame of timber\nor stone, by which the water is collected and raised\nfor the purpose required.\nThe following cuts represent a sluice with a dou-\nble valve, which, together with the slides, is formed\nof cast-iron, and the whole is supported by an oak\nframe and side walls, the foundation being protect-\ned by sheet-piling : both valves are opened by the\nTransverse Section, show-\ning Paddle opening.\nDigitized by\nGoogle\nSLUICE.\n233\nsame movement, being connected together by means of wrought-\niron rods, the upper one terminating with a rack, in which a pinion\nworks:-\nElevation of Sluice taken on the outside face.\nPlan of Sluice.\n2 H\nDigitized by Google\n234\nSMELTING-STATIONARY ENGINE.\nWhen a number of sluices are placed side by side, the erection\nis denominated a weir.-See Lock-gate and Weir.\nSMELTING (of iron).-See Iron.\nSOFITE, the underside of any overhanging erection, as the in-\ntrados of an arch, the underside of a cornice, &c.\nSOUGH, a small drain, situated at the top of an embankment,\nfor the purpose of conveying the surface water from it into the\nside drain. The term is also applied to an adit in some parts of\nthe country.\nSPANDREL WALL, the walls built on the back of an arch ; the\nterm, properly speaking, does not apply to any other than such as\nrest upon the extrados, and not to those situated upon the back-\ning of the arch, although frequently applied to them.-See Arch.\nSPHERICAL VALVE.-See Safety-Valve.\nSPINDLE, the term applied to a small shaft, as to that of a pinion.\nSPIRIT LEVEL-See Level (Spirit).\nSPOIL, or SPOIL BANK, the surplus excavation, which is laid\nby the side of a line of railway, canal, or other work, to save the\nexpense of removal, and which occurs when the amount of cutting\nupon the line exceeds that of the embankments.-See Earthwork.\nSTAITH, the line of rails forming the extremity of a railway,\nand generally occurring next rivers, being laid down upon high\nplatforms, for the purpose of discharging coals, &c., into the holds\nof the vessels or receptacles prepared for them. The staiths pro-\nject over the banks of the river, and shoots usually lead from them\nto the vessels below.\nSTARLING.-See Cutwater.\nSTATIONARY, or FIXED ENGINE, any steam-engine of a fixed or\npermanent nature; but one connected with a railway is more im-\nmediately alluded to. Stationary engines are usually employed\nupon inclined planes, to convey the carriages along, and are\nconstructed on the low-pressure system; they are also sometimes\nused upon the other parts of the line. Recourse is had to a fixed\nsteam-engine where an incline is too great to be overcome by the\ngravity of the meeting trains, owing to the traffic being equal in\nDigitized by\nGoogle\nSTATIONARY PLANE-STATIONARY SYSTEM.\n235\neach direction; and where it is necessary to pass a steep hill, in-\nclined planes are sometimes made on each side up to the summit,\nupon which an engine is fixed. In all such cases of inclined\nplanes worked by fixed engines, their inclination should be suffi-\ncient to enable the empty waggons to descend by gravity alone,\npulling the rope after them, which would thus be in readiness to\nreturn with the train passing up.\nThe principal objections to the adoption of fixed engines is, the\ngreat friction arising from the rope, also the inconvenience of\nsame where passenger trains are conveyed along the line but\nthey are not so objectionable when situated at the termination of a\nrailway.\nThere is not much difference in the expense between the adop-\ntion of fixed and of locomotive engines-for instance, the Durham\nand Sunderland Railway is entirely worked by fixed engines, upon\nwhich the charge for conveying coals is precisely similar to that\nupon the Stanhope and Tyne line, where locomotives are used,\nviz. 1.13d. per ton per mile, but the charges for the same upon the\nSeaham and Clarence Railway, which is worked by locomotives,\nis only 0.75d. per ton per mile.-See Friction, Inclined Planes, and\nStationary System.\nSTATIONARY PLANE, a plane worked by a stationary engine\nand rope, as the Euston-square Plane, at Camden Town, on the\nLondon and Birmingham Railway.\nSTATIONARY SYSTEM, a method of facilitating the conveyance\nof carriages along railways, &c., by the action of two or more\nfixed steam-engines, according to the inclination and length of the\nroad.\nSome of the private railways in the north are worked by sta-\ntionary-engines throughout, which are fixed at certain distances,\nin regular succession, reciprocating with each other. This plan\nwas partially recommended by Mr. J. Walker and Mr. J. U.\nRastrick, Civil Engineers, in their celebrated Report to the Direc-\ntors of the Liverpool and Manchester Railway, in 1829, on the\nsubject of the best motive power to be employed on that line ;\n2 H 2\nDigitized by Google\n236\nSTEAM.\nbut locomotive engines at that period may be described as being\nin their infancy.\nThe destruction of ropes by the stationary system is very great,\nwhich is mainly attributable to the sudden straining to which they\nare subjected at the time of the train's starting; the bottom of a\nplane should therefore be level, or even slightly inclined in the\nopposite direction, to assist the start which plan is successfully\npractised on the Brussleton Plane, on the Stockton and Darlington\nRailway.-See Stationary or Fixed Engine, and Reciprocating System.\nSTEAM, the vapour arising from any liquid when heated to the\nboiling point, which possesses very great force or power. It is\ngenerally allowed, that of all known fluids water is the best\nadapted for producing steam. The fluid is composed of a vast\nquantity of separate bodies, or atoms, having a great natural at-\ntraction for each other, and cold has the effect of increasing this\nattraction: heat, on the contrary, decreases it; in other words,\nheat possesses the power of separating these atoms, and repulsive\nforce is imparted to them, equal to the degree of heat.\nThe following Table, by Dr. Dalton, will be found very useful :-\nTABLE of the Expansive force of Steam when contained in a closed vessel,\ntaken at every 10° of Temperature from 212° Fahrenheit (the boiling point)\nup to 320°.\nPressure of the Steam against the atmos-\nPressure of Steam, or the force which\nphere, when the barumeter is at 30\nit will exert to enter into a vacuous space.\ninches, or the force it will exert to\nescape from the closed vessel into the\nTemp.\nopen air.\nFahr.\nColumn of\nColumn of\nPressure, per\nColumn of\nColumn of\nPressure, per\nMercury.\nWater.\nsquare inch.\nMercury.\nWater.\nsquare inch\nInches.\nFt. In.\nLbs. Oz.\nInches.\nFt. In.\nLbs. Oz.\n212\n30.\n33 11\n14 11\nThe Steam\nequal to the\natmosph.\n220\n35.\n39 6\n17 1\n5.\n5 7\n2 7\n230\n41.75\n47 2\n20 7\n11.75\n13 4\n5 13\n240\n49.67\n56 1\n24 4\n19.67\n22 3\n9 10\n250\n58.21\n65 9\n28 8\n28.21\n31 11\n13 14\n260\n67.73\n76 6\n33 2\n37.73\n42 8\n18 8\n270\n77.85\n87 11\n38 1\n47.85\n54 1\n23 7\n280\n88.75\n100 3\n43 7\n58.75\n66 5\n28 13\n290\n100.12\n113 1\n49 0\n70.12\n79 3\n34 6\n300\n111.81\n126 4\n54 12\n81.81\n92 6\n40 2\n310\n123.53\n139 6\n60 8\n93.53\n105 8\n45 14\n320\n135.\n152 6\n66 1\n105.\n116 5\n51 7\nDigitized by\nGoogle\nSTEAM-BOAT.\n237\nSteam is produced upon the water being heated to 212° Fah-\nrenheit's thermometer, or the boiling point. It is perfectly colour-\nless when pure, or unmixed with other ærial matter, but is white\nand cloudy when mixed with air, as it thereby becomes partly\ncondensed, or reduced to a temperature below the boiling point,\nwhen it again becomes water.\nSTEAM-BOAT, or STEAM-VESSEL, a vessel propelled by the\nforce of steam.\nPerhaps of all the innumerable advantages derived from the\napplication of steam, its utility for the purposes of navigation\nis the most beneficial and important to mankind. The idea of\npropelling vessels by steam was, in all probability, coeval with\nthe introduction of that power; as, on referring to the period of\nits application, or about the year 1700, we find many individuals\nfamous for their ingenuity in mechanics endeavouring to adopt it\nfor the purpose of propelling boats; among whom was the cele-\nbrated Savery, who was the first to introduce the steam-engine\nin a practicable shape, and his contemporary Dr. Papin, the in-\nventor of the safety-valve; also Mr. Hulls, the inventor of the\ncrank motion (in the year 1737), so essential to the rotary motion\nof the paddles.\nThere have been many ways tried of employing steam for the\npropulsion of boats on water : in the usual mode adopted, it is\nmade to turn a shaft situated athwart the vessel, by means of\ncranks, and large cast-iron wheels are fixed at each end, having\npaddle-boards fastened round them, like under-shot water-wheels\nthese paddles, or floats, strike the water somewhat similar to com-\nmon oars, and they are placed in such a depth of water that each\npaddle is just immersed when in a vertical position, or as it passes\nthe centre at the bottom of the wheel. An experiment of propel-\nling vessels by means of an archimedian screw has lately been\nmade, which was fixed at the stern ; and it is imagined, from the\nuniformity of its action, and the total absence of all swell in the\nwater, that this plan would be very advantageous : although the\nprinciple is not new.\nDigitized by\nGoogle\n238\nSTEAM-BOAT.\nOne of the first instances, if not the first of a vessel being abso-\nlutely propelled by the power of steam, was that by the Marquis\nde Jouffrey, which took place upon the Saône, at Lyons, in the\nyear 1782 the next was constructed under the direction of a Mr.\nMiller, in the year 1789, and succeeded very satisfactorily, on the\nForth and Clyde Canal : after : which, several experiments were\nmade ; and that of the celebrated American engineer, Mr. Robert\nFulton, was among the most successful, the engines having been\nsupplied and fitted by Messrs. Boulton and Watt. The vessel was\nnamed the \"Vermont,\" which was the first steam-vessel run as a\nregular packet-boat, having been launched at New York, in the\nyear 1807, and plied between that city and Albany, a distance of\nabout 150 miles, performing the voyage in 32 hours, which gives\na speed of nearly 5 miles an hour (about 3ʳᵈ the speed now at-\ntained) : the length of the boat was 133 feet, depth 7 feet, breadth\n18 feet ; the boiler was 20 feet long, 7 feet deep, and 8 feet broad,\nand with only one steam cylinder, which was 2 feet diameter, and\n4 feet stroke of piston the paddle-wheels were 15 feet diameter,\n(dipping 2 feet into the water) and 4 feet broad and the burden\nwas 160 tons.\nIt was not until 1812 that a steam-packet experiment was again\nattempted in this country, which occurred on the Clyde ; another\nwas tried at Bristol ; and these were shortly after followed by\nmany others : at length they became pretty general-although the\nengines were of very imperfect construction, one steam cylinder\nonly being employed whereas two are now invariably used, each\nworking a crank, fixed upon the axle of the paddle-wheels, and\nsituated at right angles to each other, so that when one is passing\nthe dead points, the other is exerting its greatest power.\nSteam-packets commenced making regular sea voyages in the\nyear 1818, and they have continued extending their bounds ever\nsince, voyages of considerable length being now made ; among\nwhich may be cited those of the Great Western, and other steam-\npackets to America and voyages yet more extensive are talked\nof.\nDigitized by\nGoogle\nSTEAM-BOAT:\n239\nThe arrangement of the several parts of the marine engine is\nsomewhat different to the general land engine, it being important\nto reduce the space occupied by the machinery as much as possi-\nble ; the boilers are consequently of less dimensions, but a much\nmore extensive surface is exposed to the action of the fire : the\nemployment of a pair of engines, instead of one, is independent of\nthe advantages before stated, very beneficial; thus in the event\nof one being disabled the other can work the vessel, which has\nsometimes been the case; and the employment of several distinct\nboilers is also very advantageous, although not always adopted,\nas in the event of a concussion it is not likely that all would be\nruptured. A ready method of disengaging the paddle-wheels is\nanother point of great importance, as it would enable a steam-boat\nto cope with sailing vessels by the same means, both as respects\nspeed and manœuvreing. It may also be remarked that proper\nsafety-valves and gauges should always be constructed, to ensure\nsafety to the passengers and crew.\nThe steam-boats employed in this country at the present time\nare principally upon the low pressure condensing principle, (see\nSteam-Engine) the whole of the machinery being placed below\ndeck, which renders it necessary to diminish the height of the\nengine as much as possible and instead of having a working-\nbeam over the cylinders, a cross head is placed at the top of the\npiston rod, the action of which is conveyed by parallel motions\nto cross beams on each side, which are situated at the bot-\ntom part of the engine ; the motion, compared with regular land\nengines, is consequently inverted ; the proportions of the cylinders\nalso differ from them, the length of stroke being shorter, for the\npurpose of saving height, but the diameter is greater: the valves\nand gearing connected therewith, air-pump, condenser, &c., do\nnot differ essentially from land engines; but the governor is alto-\ngether omitted, it being impracticable to work an engine with\ngreat regularity, in consequence of the agitation of the water, and\nother contingencies.\nDigitized by\nGoogle\n240\nSTEAM BOAT.\nadid\nPipe\nC.H.\nMotion.\nton.\nCylinder\nPis\nPar aleD Par alell\nSlide Box\nLongitudinal Section of one of the Engines of the \" Red Rover \" Steam-packet.\nSleepers\nBeam\nFood\nHot\nWater\nCistern\nTITLE\nvionking\nFeed Pipe\ndam]\nAir\nC.B\nCounceting Rod\n€\nL.H.F\nS. P., the steam-pipe which conveys the steam from the boiler\nto the slide box.\nDigitized by Google\nSTEAM-BOAT.\n241\nCylinder.\nParallel Motion\nCross\nHead\nIT\nParallel Motion\n3\n-\nBeam\nBeam\n0\nPlan of one of the Engines of the \" Red Rover\" Steam-packet.\nU.F.P.\nML 4 e\nCondenser\nHot Water\nCistern\nCondent/ser\nNI -\nAir\n-\n@\nPump\nBV\n21\na\na\nU.H.F\n&\nLHF\nL.H.F\nUHF\nU,E, P, upper eduction pipe.\nL, E, P, lower eduction pipe.\n21\nDigitized by Google\n242\nSTEAM-BOAT.\nThese pipes are employed to pass the steam to the condenser,\nat the termination of each stroke.\nS,S, slides or valves, by which the steam is admitted alternately\nto the top and to the bottom of the cylinder.\nM, G, main gudgeons, upon which the beams are placed.\nC, H, cross heads, fixed at the top of the piston rod.\nS, R, side rods connecting the cross heads with the working\nbeams.\nC, R, connecting rod communicating with the crank.\nC, B, air-pump cross-bar, the air-pump is worked by two slide\nrods from the beams, and the hot water and bilge pumps are also\nworked from the air-pump cross-bar.\nE, eccentric.\nE, R, eccentric rod.\nE, A, eccentric arm.\nThese constitute the eccentric motion, whereby the slide-valves\nor slides are worked.\nW, G, S, working gear shaft, which is operated upon by the\neccentric motion.\nB, V, upper and lower blow valves.\nUpon starting the engines, the steam is admitted into the con-\ndenser through the upper one; it then passes out through the\nlower, blowing out all the air and water, by which a partial va-\ncuum is obtained in the condenser.\nU, H, F, upper head stock frame.\nL, H, F, lower head stock frame.\nThe engine and paddle-shafts are supported by these frames.\nW, waste water stop valve pipe.\nP, injection pipe.\nIn American steam-boats the engines are mostly on the high\npressure principle, and a part of the machinery is placed upon\ndeck, whereby the whole extent of the hull is left open for ca-\nbins, which are, consequently, extremely capacious; their vessels\nnot being much employed for sea navigation, nor subjected\nto winds and waves, as in our country, can be safely built more\nDigitized by Google\nSTEAM-ENGINE.\n243\nslender and of a more delicate form, which increases their speed\nmuch ; their bows also glide over the water instead of cutting\nthrough it, and they are further assisted by the engines being\nmade much more powerful than ours; and the length of stroke is\nvery great, although one engine only is employed, a counterbalance\nbeing generally attached to the paddle-wheels, in some cases, to\nenable the engine to get over the centres ; their great length of\nstroke, however, allows time for a degree of momentum, which is\nmostly found sufficient; the paddle-wheels also assist on account\nof their large diameter, acting like fly-wheels : where two engines\nare employed their connecting rods are not attached to the same\naxle, but each drive a wheel independent of one another.\nThe deposit occuring in the boilers of steam-boats is much\ngreater than those of other engines, owing to the salt and other\nimpurities contained in the water employed; and this incrustation\nbecomes considerable, if not frequently attended to it sometimes\nacquires a thickness of upwards of an inch, and is so hard that it\ncan with difficulty be removed a considerable portion of the\nheat is consequently abstracted by it, and the wear of the metal\nincreased, besides rendering it more liable to accidents. The\nmeans of preventing incrustation were very inadequate previous\nto the introduction of Mr. Samuel Hall's patent condenser, in\nwhich the condensation is effected without the introduction of a\njet of cold water (as in Mr. Watt's engines), but by contact, or\nthe effect of cold water chambers only; the water employed is also\ndistilled, and made available over and over again, allowance being\nmade for leakage, &c. : there are also several other advantages\nconnected with the invention, as the freedom of the condenser from\nthe pressure of any air, which renders the vacuum more perfect.\nThe engines of steam-boats are usually considered to consume\nabout 8tb. of coal per hour, per horse power.\nSTEAM-ENGINE, an engine worked by the power obtained from\nthe expansion and contraction of the steam from boiling water,\nwhich is adopted for the first moving power to the many various\nmachines employed at the present time, as for the raising of water\n2 I 2\nDigitized by Google\n244\nSTEAM-ENGINE.\nfor impelling machinery for mining, manufacturing, and agricul-\ntural purposes, also for navigation and for land carriage.\nEvery modification of the steam-engine derives its power from\neither one of the following causes, or from a combination of both,\nviz., from the property of water to expand in bulk under the action\nof heat, assuming the appearance of vapour; and from the sudden\nreturn of this expanded water or vapour to its original size, upon\nthe introduction of cold, thus steam is generated upon the water\nbeing heated to the boiling point (212° of Fahrenheit's thermome-\nter) and if it be contained in a close vessel, and subjected to\nthe action of increased heat, it becomes yet more rarified, exert-\ning an increased pressure on the sides of the vessel, and this\npressure is regulated by the degree of heat applied; it may be\nincreased until the power of the steam bursts the vessel-a posi-\ntive power is thus obtained, which constitutes the first power be-\nfore stated. If instead of an inclosed vessel a short tube be\nemployed for the reception of the steam, having a sliding top\nworking within it, the power of the steam will force the lid up-\nwards, instead of bursting the tube, and upon a quantity of steam\nhaving forced its way upwards, by removing the fire, and applying\ncold water upon the outside of the tube, such steam will almost\nimmediately be condensed or reduced again to water, occupying\nonly 17 oordth part of its former size, or thereabouts, (as a cubic\nfoot of steam, when its elasticity is equal to 30 inches of mercury,\nonly occupies a cubic inch of water when condensed), a void or\nspace unoccupied either by air, water, or steam, will consequently\nbe left at the upper part of the tube, and the pressure of the\natmosphere upon the outside of the tube, which is equal to a\nforce of nearly 15 lbs. to the square inch, will immediately force\ndown the sliding top to the surface of the water condensed from\nthe steam : here, then, another direct force is obtained, and which\nforms the second description of power before stated; the system of\naction just described constituting the principle of the common\natmospheric engine, the condensation being effected within the\ncylinder.\nDigitized by\nGoogle\nSTEAM-ENGINE.\n245\nIt is very probable that some of the properties of steam were\nknown to the ancients, but it was not until about the early part of\nthe seventeenth century that its power was made available for the\nworking of machines. A mining engineer, named Savery, appears\nto have been the first who constructed and publicly exhibited an\nengine, acting by the expansive force and subsequent condensation\nof steam, and which he applied to the raising of water in the year\n1699; Dr. Papin next introduced the safety-valve to an engine\nof his own contrivance in 1707. The steam-engine also received\nvarious modifications and improvements from Mr. Newcomen,\nin the year 1707, (whose engines are known by the name of\natmospheric engines); and successively by Messrs. Beighton and\nSmeaton, who may be said to have perfected this class of engines.\nThe accompanying cut represents an atmospheric steam-engine\nupon Mr. Newcomen's principle :-\nL/C\nc\nX\nD\nCylinder\nE\nI\nH\nBY\ne\nG\nBotter\nd\nDigitized by Google\n246\nSTEAM-ENGINE.\nA, the regulator, or regulating valve, whereby the communica-\ntion between the cylinder and the boiler is opened and closed\nwhen required.\nB, the gauge-cocks for ascertaining the height of the water in\nthe boiler, which are so arranged that the extremity of the one is\na little below the level of the water, and the other a little above\nit, therefore, upon their being turned, one should discharge water,\nand the other steam, provided the water is at its proper level.\nC, the safety-valve.\nD, the piston working in the cylinder, which is open at the top.\nE, the injection-pipe for conveying water from the cistern, a,\ninto the cylinder, to condense the steam.\nF, the injection-cock.\nG, the pump for supplying the cistern, a, with water from the\nwell.\nH, the eduction-pipe for conveying the condensed steam and\ninjection water from the cylinder to a cistern placed below it, b,\na valve is placed in its lower end to prevent the water rising up\nthe pipe.\nI, the snifting or blowing-off valve, for passing off any air from\nthe cylinder; it is used to expel the air from the cylinder at start-\ning, and opens outwards.\nK, a pipe used to discharge water on the top of the piston,\nwhereby the whole is preserved air-tight; it is furnished with a\nstop-cock.\nL, the beam which turns on an axis fixed in the wall, the piston,\nrod, c, being attached at one end, and the pump-rod, d, at the\nother; a weight, e, is fixed on the latter rod, for the purpose of aid-\ning the descent of the pump-rod.\nIt is necessary to state, that the regulating valve, A, and the\ninjection-cock, F, were not worked by the engine, as the valves\nof steam-engines at the present time, but were attended to by the\nengine man.\nThese steam-engines continued in general use until the time of\nMr. Watt (about the year 1770), who effected great improvements\nDigitized by Google\nSTEAM-ENGINE.\n247\nin them his first engine is known by the name of the single acting\nengine, being applied to the same purposes as former engines, viz.,\nthe drawing up of water from mines, and like purposes; and its\nsummary action was not unlike them. He inclosed the cylinder\nin a case or jacket, and filled the space inclosed between them\nalso with steam, by which the cylinder was kept constantly at the\nsame degree of temperature, but his prime improvement was the\nintroduction of a condenser, which consists of a vessel exhausted\nof air and other fluids, and connected with the cylinder by a pipe,\nthrough which the whole of the steam from the cylinder escapes,\nbeing sucked into it, where it is very speedily condensed : the\ncondenser is placed in a cistern of cold water, which is kept\nconstantly flowing by a small pump, termed the cold water-pump,\nworked by the engine; another pump is also attached, called the\nair-pump, which is employed in drawing off the contents of the\ncondenser at each stroke of the piston. Mr. Watt subsequently\nadapted his engine to drive machinery generally, by converting\nthe reciprocating motion conveyed to the pump-rods into a rota-\ntive movement; and, in order to preserve a constant and uniform\npower, he employed the elastic force of the steam to impel the\npiston up as well as down the cylinder-hence the term double act-\ning engine. He also invented the parallel motion, in place of the\nchains usually employed in connection with the beam, by which\nthe piston was enabled to transmit motion by pushing or thrusting\nupwards, as well as by pulling downwards, as heretofore; and the\nfly-wheel, to render the motion of the piston regular throughout,\nwhich is effected by the momentum of its weight, carrying the\naxle round the dead points, or those parts where the power of the\ncrank has the least effect the crank having been previously pa-\ntented by Mr. Washborough, he constructed another movement,\nsince known by the name of the sun and planet wheels, but the\nformer is generally employed at the present time; and he intro-\nduced a contrivance, called the governor, to regulate the supply of\nsteam from the boiler to the cylinder, and insure the uniform\nvelocity of the piston. He also introduced the improved way of\nDigitized by\nGoogle\n248\nSTEAM-ENGINE.\nworking the piston by the elastic force of the steam, which is said\nto have partly arisen from his having found some inconvenience\nfrom the accelerated motion acquired by the piston towards the\nend of the stroke, when it occurred to him to cut off the steam\nbefore the piston arrived there, and which he afterwards practised\nwith great advantage, thus, by cutting it off at +rd; the rest of\nthe descent was accomplished by the elastic force of the steam\nalone, and a proportionate saving consequently accrued. To\nthese modifications of the steam-engine the term low pressure, or\ncondensing engines, is now applied.\nThe accompanying cut represents Mr. Watt's double acting\nsteam-engine :-\nBeam\nM\nP\nR\nTV\nG\nTMH\nal\nJ\nCylinder\nHAT\nH.W\nHAD\nCon\nFLY\nWheel\nThe cylinder is enclosed in a jacket, j, and C, P, is the piston.\nDigitized by Google\nSTEAM-ENGINE.\n249\nP, R, the piston-rod.\nS, P, the steam-pipe.\nU, V, B, upper valve box.\nL, V, B, lower valve-box.\nThe valves are employed to admit the steam to the cylinder,\nand to draw it off at the termination of each stroke, each box being\nfurnished with a steam-valve and an exhausting valve, and they\nare put into proper action by levers, I, l, connected with them by\njointed rods; and the levers are worked by pins placed on the\npiston-rod of the air-pump. The valves of steam-engines are ge-\nnerally worked at the present time by means of an eccentric\nplaced on the axle of the fly-wheel.\nG, the governor, which is mostly put into motion by a strap or\nrope from the main shaft.\nCon', the condenser.\nI, C, the injection cock.\nA, P, the air-pump.\nA, P, R, the air-pump rod.\nH, W, the hot well.\nC, W, C, cold water cistern.\nH, W, P, the force-pump by which the water is conveyed from\nthe hot well to the supply of the boiler.\nC, W, P, pump to furnish cold water to the condensing cis-\ntern.\nC, the crank.\nP, M, the parallel motion.\nThe difference between a high pressure engine and a low pres-\nsure lies in the former being worked by the expansive force of\nthe steam acting upon the piston, despite of the pressure of the\natmosphere at the back of same (about 15tbs. per square inch, as\nbefore stated); it is consequently required to be of very great\npressure, whereas a low pressure is worked by the force of the\nsteam upon the piston, but a vacuum is formed upon the other\nside by means of the condenser, whereby steam of little pressure\n2 K\nDigitized by Google\n250\nSTEAM-ENGINE.\nmay be used ; a force of 1 or 2 lbs. beyond that of the atmosphere\nis all that is required.\nLeupold gave the first plan for a high pressure engine; Mr.\nWatt also vaguely proposed one ; but Messrs. Trevithick and Vi-\nvian were the first who constructed a high pressure engine, which\nthey effected in the year 1802, and adopted, amongst other pur-\nposes, as a locomotive, for which it suited admirably, enabling\nthem to dispense with the condenser, and the whole of the ma-\nchinery connected therewith.-See Locomotive Engine.\nWhen steam-engines were first introduced, they were used ge-\nnerally for many mechanical purposes where horses had been\npreviously employed, hence the origin of comparing the power of\nengines with that of horses. The resistance which an engine is\ncapable of overcoming is called the power of the engine, and that\nwhich is ascribed to it by its makers, is termed the nominal power,\nwhich of course varies according to the velocity of its action ;\nmost engines work considerably above their nominal power, as\nthat is understood to refer to their power with steam of the ordi-\nnary pressure only. Mr. Watt's standard was an effective pressure\nof steam in the cylinder of 6 lbs. per circular inch for each horse\npower of the engine, and a speed of 220 feet per minute. The\ntotal power exerted by the steam in the cylinder is called the gross\npower, which includes that employed in overcoming the friction and\nresistance of the engine; and the effective power is that portion of the\npower absolutely delivered at the crank-shaft, the remaining por-\ntion of the gross power being employed in overcoming friction\nof the engine; comprising not only that of the piston, pump,\nbuckets, stuffing-box, and bearing parts of the engine, but the\nresistance due to the water lifted by the engine-pumps, which of\ncourse varies according to circumstances. Mr: R. Armstrong\nstates the amount of this last resistance at 2 lbs. per circular inch\non the area of the piston in the best modern engines, but the ratio\nis much less in large engines than in small ones. The term duty\nis used in Cornwall to express the load which an engine is capable\nof raising a given perpendicular height, by the combustion of a\nDigitized by\nGoogle\nSTEAM-ENGINE.\n251\ngiven quantity of fuel, which is partly regulated by the construc-\ntion of the furnace, boiler, &c.\nIt is held by some engineers, that a steam-engine should pos-\nsess an area of piston equal to 27 circular inches per horse power,\nand that a boiler should have 27 cubic feet for the same, half of\nthe latter being reserved for steam, and the other occupied by\nwater. It was shown by Mr. Watt, that the evaporation of a cubic\nfoot of water was the proper measure of 1-horse power, the boiler\nis therefore, cæteris paribus, the real depository of its power; the\nbest length for a cylinder, is twice its diameter, some make it 21 :\nin marine engines it is much less, or about the same as its diame-\nter: whatever be the form of the cylinders of two engines of equal\npower, the quantity of steam passed through them per minute is\nprecisely the same, unless the pressure of the steam differs in\neach, when that possessing steam of the highest pressure will\nhave the smallest cylinder. The greater the diameter of the pis-\nton, compared to its length of stroke, the less will be the velocity\nof its action. The area of steam-ports allowed by Mr. Watt for\nstationary engines was equal to 25ᵗʰ part of the area of the\ncylinders, which admits sufficient steam to move the piston at\na rate of 220 feet per minute, which he states as the best velocity\nfor it; the diameter of the steam-pipe is usually about ¹ᵗʰ that\nof the cylinder; some allow it 1 square inch of section per horse\npower.\nMr. Tredgold gives the following rule for finding the effective\npower of a steam-engine :-\nMultiply the square of the cylinder's diameter in inches by the\nmean effective pressure on the piston in lbs. per square inch, and\nby the velocity of the piston in feet (which is obtained by multi-\nplying double the length of stroke by the number of strokes per\nminute), point off three figures, and divide the product by 42,\nand the quotient will express the number of horses' power; thus,\nsuppose the diameter of the cylinder to be 36 inches, length of\nstroke 4 feet, and number per minute 24, and the mean effective\npressure on the piston 4 lbs. per square inch, then—\n2 K 2\nDigitized by Google\n252\nSTEAM-ENGINE.\nNo. of strokes per minute 24\nDiameter 36 inches\nLength of stroke\n8\n36\nVelocity of piston\n192\n216\n108\n1,296\nMean pressure\n4 tb.\n5,184\nVelocity of piston\n192\n10368\n46656\n5184\n42 ) 995328 ( 23.7 horses' power.\n84\n155\n126\n293\n294\nNumber of horses' power 23.7.\nIn reference to the mean effective pressure on the piston, it may\nbe stated, that not one-half the water evaporated from the boiler\nis absolutely expended in working the piston, the remaining por-\ntion being lost in passing from the boiler to the cylinders, in\nworking the air-pump, and by friction, also on account of\nleakage, and various other contingencies. Mr. Tredgold calcu-\nlated 1000 632 of the power of an engine to be thus lost-now\nsupposing the force of the steam in the boiler be equal to 35\ninches of mercury, or 5 inches above the pressure of the atmo-\nsphere, and the temperature of the uncondensed steam 120°, and\nits force 3.7 inches, then (35 x 632) 35 - 3.7 = 18.42 or 9.05 per\nsquare inch for the mean effective pressure on the piston.\nIn the case of high pressure engines, the whole pressure of the\natmosphere must of course be deducted from the force exerted by\nthe steam in the boiler, in order to ascertain the real effect of the\nengine, and if the engine works expansively, allowance must also\nbe made for it.-See Air-Pump, Fly-Wheel, Governor, Parallel\nMotion, Piston, Steam, Safety-Valve, &c.\nDigitized by\nGoogle\nSTEAM-GAUGE-STONE.\n253\nSTEAM-GAUGE, a contrivance connected with the boilers of\nsteam-engines, and employed to indicate the pressure of the\nsteam, thereby forming a guide, whereby the fire is regulated.\nThe steam-gauge usually consists of an inverted syphon, or bent\ntube, formed of wrought-iron, and secured at one end of the\nboiler, and a sufficient quantity of mercury is placed in it to\ncounteract the pressure of the steam, the other end being open to\nthe atmosphere; the level of the mercury, therefore, varies with\nthe pressure of the steam, the amount of which is communicated\nto an index on the outside; it may also be said to constitute an\nextra safety-valve, for if any thing should prevent the ordinary\nsafety-valve from acting, the whole of the mercury must be driven\nout of the tube.-See Boiler.\nSTEAM-PIPE, the pipe communicating with the upper part of\nthe boiler, through which the steam passes in its passage to the\ncylinders.-See Steam-Engine.\nSTEAM-WHEEL.-See Rotary Engine.\nSTEAM-WHISTLE, a device attached to locomotives, for giving\nwarning to the passengers and others when the engine is starting.\nIt consists of a pipe situated at the top of the boiler, with a cock\nto same, within reach of the engine man who is thus enabled to\nturn the steam on or off at pleasure. When turned on, it issues\nthrough the pipe into a hollow cup, passing through four holes in\na plate placed at the bottom of it ; the steam then escapes at the\ntop, round the thin edge of the cup, striking the same with consi-\nderable force, which produces a loud shrill whistle, and can be\nheard at a distance of many miles.\nSTEPS, or BEARINGS, those parts which receive the lower gud-\ngeons of upright shafts.\nSTONE, or Rock, an aggregation of several hard mineral sub-\nstances, insoluble in water.\nNotwithstanding the general diversity of nature, the same rocks\nare common to all quarters of the globe; the crust or covering of\nthe earth being composed of a number of layers, termed strata,\nof very different appearance compared with each other, yet com-\nDigitized by\nGoogle\n254\nSTONE.\nposed of comparatively few primary elements, but they are so\nconcreted or mixed together, and are in such a number of propor-\ntions, as to produce considerable variety ; and most of the rocks\nlying in beds contain foreign matter, as shells, fragments of other\nrocks, and of animals, fishes, trees, and plants.\nStones are named either according to their chemical constitu-\nents, physical properties, or from their external appearance, or\nthe names of the places from whence quarried. Stone for engi-\nneering purposes should possess strength, or the power of resist-\nance, in every direction ; also hardness, or the power of attrition,\nwhich enables it to resist blows; and durability, that it shall not be\naffected by any natural agents, as the atmosphere, water, heat, and\nfrost. Stone is classified generally under three heads, although\nthe component parts of some stone partakes of each class, viz.,\n1st, the silicious, which is least liable to decay, comprising granite,\nsandstone, &c. ; 2ndly, the argillaceous, which comprehends basalt,\nand nearly all the slate-stones; stone of this class, though exces-\nsively hard when laying in their beds, are not suitable for building\npurposes, as upon their being quarried and removed, they are\nsoon affected by the atmosphere and 3rdly, the calcareous, which\nis a very plentiful and valuable class, comprising all limestones,\nfrom marble downwards; it is the principal ingredient in all ce-\nments; and the most celebrated statues of antiquity being formed\nof calcareous stones, bear proof of its great hardness and dura-\nbility.\nThe under beds of stone, in most quarries, are harder and\nthicker than the upper ones, it therefore frequently happens that\nthe best stones are neglected, or very rarely worked, on account\nof the expense of blasting and removing those beds covering\nthem, particularly where time and first cost are regarded; and it\nis generally considered that stone employed in the vicinity of its\nnative quarry withstands the effects of the atmosphere better than\nwhen used further off-say a distance of 40 or 50 miles, or up-\nwards.-See Bath-stone, Portland-stone, Lime-stone, Sand-stone,\nGranite, Natural or Quarry-beds, and Quarry.\nDigitized by\nGoogle\nSTONE BLOCKS-STRING.COURSE.\n255\nSTONE BLOCKS, on railways.-See Blocks (Stone).\nSTOP-PLANKS, a certain description of dam employed on\ncanals.\nIt is necessary to provide weirs on the line of a canal, at certain\ndistances from each other, except in cases where the space between\nthe locks is very short, to prevent the loss of water that might\narise from an accident, and for other purposes.\nThis is usually done by contracting the water-way at such\npoints, and carrying up wing-walls from below the bottom of the\ncanal, and vertical grooves are made in the face of the masonry\nupon each side, corresponding with each other, for the insertion\nof the hatches, or stop-planks, as they are called. Provision is made\nfor stop-planks in most hydraulic works-for instance, grooves are\nmade at each end of a lock, on the outside of the chamber, in\norder that the water may be kept out during any repairs.\nSTRAP, a sort of bandage or fastening for securing the junction\nof two or more pieces of timber, consisting of a piece of wrought-\niron, of a flat cross section, and extending over each piece of\ntimber, according to circumstances, being bolted or keyed to\nthem. The annexed cut represents a strap for tying three pieces\nof timber together, as in bridge-building; the ends of the straps\nare taken through a bottom plate, and made tight by\nmeans of nuts on the other side.\nThe straps employed in securing the bottom of\nking or queen-posts to tie beams, are termed stirrups,\nand are passed round the under part of the tie-beam,\ntaken up on each side, and fastened to the posts by\ngibbs and keys.\nSTRETCHING-COURSE (in masonry and brickwork), a course\nconsisting of all stretchers, or stones, bricks, or the like, laid\nlengthways in the longitudinal direction of the wall-See Bond\nand Heading Course.\nSTRING-COURSE, a term applied generally to a course of ma-\nsonry or brickwork, projecting in a slight degree before the face\nof the wall.\nDigitized by\nGoogle\n256\nSURVEYING.\nSTUFFING-BOX, or GLAND, a piece secured\nto the end of a cylinder, pipe, or other ves-\nWHEN\nsel, through which a rod passes ; a little hemp\nbeing pressed tightly against it, by which it\nis kept air or steam-tight. A in the cut is\nthe piston-rod, and B the stuffing-box.\nSURVEY, a measured plan and description of any line or area\nof country.\nSURVEYING, the operation of making a survey, which is either\nperformed by Gunter's chain, both angles and distances being taken\nwith it, or the angles are taken by angular instruments, and the\ndistances by a chain; the distances are also sometimes calculated,\nwhen the survey is said to be performed trigonometrically.\nIn chain surveying, the surveyor is confined to one figure, viz.,\na triangle, which should always be as near an equilateral triangle\nas possible; for when the angle at the top is either very obtuse or\nvery acute, the most trifling error in the admeasurement of either\nof the sides will alter its figure, and consequently its area.\nIn order to explain generally the principles of surveying, sup-\npose the plan of a piece of land is required, such as represented\nin the cut :-First erect a conspicuous 3\n2\nmark at one corner of it, say at 1, then\nlook to the opposite corner, and com-\nmence chaining in that direction, keep-\ning the line straight by the eye, which\nmay be effected by looking towards\nsome natural object upon it; if you\ncannot find any, set up one at the fur-\nther end, and leave some marks near\nthe middle of your line, measuring\ntheir situations ; these are for the pur-\n4\npose of running out lines or checks, and are termedfalse stations;\nupon reaching the extremity, commence running a line along one\nside of it, and take offsets to the boundary (see Offsets) : upon\narriving at the end, put up a mark, and commence another side-\nDigitized by\nGoogle\nSURVEYING.\n257\nline, taking offsets as before, which will bring you to the starting\npoint, then measure a tie-line from the angle formed by the junc-\ntion of the side-lines to one of the false stations left in the diago-\nnal commencing the survey, which completes this side; the same\nsystem must then be pursued with the other, and in fact with the\nwhole survey, of which this may be supposed to form a part; this\nplan of working is termed surveying by diagonals. The plan may\nalso be taken by means of chain angles only; and it is much prac-\ntised, although not so secure from error\nthus, (see side Cut): mark off any conve-\nnient length on each of the side lines, as\n1, 2, or 3 chains, commencing from each\nstation, and, by measuring the distance be-\ntween them or the tie, the angle will then\nbe obtained. It is not absolutely necessary\nto take more than one or two in a field,\nbut if others are taken they would form\nchecks to the work.\nChain angles and offsets may also be taken on the out-\nside of the side lines instead of\nthe inside, if more convenient;\nthus :-\nThe angles may likewise be\ntaken with a theodolite or a sex-\ntant, instead of measuring them,\nif such instruments are at hand.\nA road may be surveyed, suffici-\nently accurate for some purposes,\nby means of chain angles; the\nwidth of it, also the buildings, &c., upon each side being taken\nby offsets; and the commencement of any fences may be sketched\nor taken by chain angles.-(See Cut on next page).\nA surveyor commences chaining by first noting his first station,\nhe then sends his chainsman forward, who takes the further end\nof the chain in one hand, and the arrows (10 in number) in the\n2 L\nDigitized by\nGoogle\n258\nSURVEYING.\nother, and when he arrives at the end\nof the chain he turns round and looks\nto the surveyor for instructions, who\ndirects him to the right or the left, as\nmay be required, by waving his hand ;\nwhen the chainsman is got into the\nright position, he sticks one of the\narrows in the ground at the end of the\nchain, where he leaves it, and again\nwalks forward with the chain. The\nsurveyor, on arriving at the spot where\nthe arrow is fixed, places his end of the\nchain upon it, and directs the chains-\nman as before : he also takes up the\narrow, and proceeds forward until in\nlike manner he obtains all the arrows,\nwhen he returns them to the chainsman,\nmaking a note of it in his Field-book;\nhe of course leaves such false stations\nin the line as he considers necessary ;\nfor instance, upon arriving at a fence,\neither upon one side or upon the other,\nwhich he also notes in his Field-book.\nIn hilly country the chain ought not\nto be laid upon the surface of the\nground, (as represented by Fig. 2, in\nFig. 1.\nFig. 2.\nthe diagram), but it should be laid\nhorizontally, in short lengths, (as Fig.\n1), a plumb-line being suspended from\nit. If the hill is very steep, it may be\nDigitized by Google\nSURVEYING.\n259\nchained straight, and the vertical angles taken with an instrument,\nand the requisite deductions afterwards made.\nThe following Table shows the quantity to be subtracted from\neach chain's length for various angles of inclination of the ground :-\nReduction in Links and Decimals upon each Chain's Length, for the follow-\ning Angles of Elevation and Depression.\nAngle.\nReduction.\nAngle.\nReduction.\nAngle.\nReduction.\no ,\no ,\no ,\no ,\no ,\no ,\n3. 0\n0.14\n9. 0\n1.24\n15. 0\n3.40\n30\n1.38\n30\n3.64\n4. 0\n0.25\n10. 0\n1.52\n16. 0\n3.88\n30\n1.68\n30\n4.12\n5.0\n0.38\n11.30\n1.84\n17. 0\n4.37\n30\n2.01\n30\n4.63\n6. 0\n0.55\n12. 0\n2.19\n18. 0\n4.90\n30\n0.65\n30\n2.37\n30\n5.17\n7.0\n0.75\n13. 0\n2.56\n19. 0\n5.44\n30\n0.86\n30\n2.77\n30\n5.74\n8. 0\n0.98\n14. 0\n2.97\n20. 0\n6.03\n30\n1.10\n30\n3.18\n30\n6.33\nThe reduction for one chain multiplied by the number of chains will give the\nquantity to be subtracted from the measured length of an inclination to\nreduce it to horizontal measure.\nExtensive surveys are usually performed by extending a series\nof triangles over the country to be delineated, and it is always\nbest to refer to some former plan previous to commencing opera-\ntions, if it can be procured; by which the surveyor will be enabled\nto see the best situation for his main lines, in reference to their\njunction and freedom from obstructions :-\nThe first, or base-line, should pass through the centre of the\nsurvey, and intersect the most intricate portions; upon determin-\ning which, set up a theodolite at its commencement, (which should\nbe on some conspicuous land-mark, as a church, house, windmill,\n&c., and, if possible, within the extent of the survey); next ascer-\nDigitized by Google\n260\nSURVEYING.\ntain very correctly the angle formed by this line, with the magne-\ntic meridian, then take angles to some conspicuous objects near\nit, in order to fix the exact spot for the purpose of future refer-\nence; next erect a high pole upon it, and commence measuring\nthe line, driving stakes along it at distances of about 5 or 10\nchains, and numbering them (the chain should be previously\nmeasured, in order to start with a correct standard); the roads,\nrivers, fences, &c., must also be noted, as they are crossed, and\noffsets taken to all conspicuous objects within distance and pro-\nminent points; poles must also be set up along it, occasionally,\nto keep it direct in the event of meeting a house or pleasure-\nground, through which circumstances prevent a line being run,\nmeasure an angle, of exactly 60° on either side, with the theodo-\nlite, and set out a sufficient length upon\nit to clear the obstruction, then take\nanother angle of 60° from it, and measure\nthe distance equal to the last, which\nbrings you on the other side of the ob-\nstruction, and in the direction of the\nmain line. If the poles set up are be-\nyond the limits of vision, measure the\nsupplementary angle of 120° from the\nlast-measured side of the equilateral\ntriangle, which gives the direction of\nthe base, and check it by taking the\nbearing, which, of course, will be the same as at starting, if all is\ncorrect. Upon reaching the end of the base, set up the theodolite,\nand take the angle of one of the side-lines, which should not\nbe very oblique, but as near 45° as convenient, it should also\nhave some natural mark upon it, similar to the base-line;-the mea-\nsurement of this angle being very important it should be repeated\nseveral times, and the mean of them taken; then set up a pole at\nthis station, and measure the new line in a similar manner to the\nbase, driving stakes at regular intervals, and upon arriving at the\nboundary of the survey, or as far as requisite, set up the theodo-\nlite, and take an angle to the opposite side of the survey, crossing\nDigitized by\nGoogle\nSURVEYING.\n261\nthe main line and another angle to the starting point, or first sta-\ntion, then set up a pole on this station, and measure the transverse\nline as before, and upon the exact spot of crossing take the dis-\ntance from the nearest stake previously left upon it, and terminate\nthe line at the extremity of the survey, or as far beyond it as may\nbe necessary, so that the tie-lines taken from it to the extremities of\nthe base shall comprise the entire survey, excepting any small\nportions, which may be determined by small triangles from the\nprincipal ones, thus-the four principal lines may be said to be\nfixed, the internal lines may now be commenced, and run accord-\ning to circumstances.\nIt may be stated generally, that it is best to finish one part of a\nsurvey before proceeding with another, as it prevents confusion ;\nthe boundaries should also be taken, and those parts without the\ntie-lines, previous to filling in any part of the plan, but if consi-\ndered inconvenient, such parts only should be circumscribed where\noperations are about to be commenced.\nIt is advisable to take the angles of all lines, except those which\nare well tied; those determined by their extremities only should\nalways be taken, for which the sextant may be used, and it is best\nfor a surveyor to lay down or plot his work every day, as he pro-\nceeds with his survey.\nThe grand desideratum in all systems of surveying consists in\nobtaining a correct plan, with no more lines than are absolutely\nnecessary, and the avoidance of passing backwards and forwards\nover the same ground, together with a clear method of keeping\nthe Field-book, which should be as simple as possible the system\ngenerally adopted is, to number all the lines of a survey, and\nmeasure the length of each, taking the bearings and offsets from\nthem, as may be necessary; the Field-book being ruled with three\ncolumns, the distance and bearings are entered in the centre co-\nlumn, and the side columns are employed for noting down the\noffsets and breaks on each side, also for observations, sketches,\n&c. It is the custom to begin at the end of the book, and\nwork up the leaf instead of down it, (as in levelling and ordinary\nobservations), commencing at A, in the following diagram:-\nDigitized by\nGoogle\n262\nSURVEYING.\n68\n12.00\n50\n70\n10.20\n55\n81\n9.00\n48\n72\n8.00\n42\n21\n7.20\n40\n30\n5.00\n42\n50\n4.00\n40\n55\n3.20\n35\n30\n1.00\n38\nA\nThe mark O means station, which are numbered as the survey\nproceeds; the figures in the centre column refer to the distance\nfrom the station at which the offsets have been taken, and they\nrepresent links, being the most convenient for plotting; the\nfigures in the side columns show the length of the several offsets\non each side, thus ; it is 38 links at a distance of 100 links\nfrom the station to the fence on the right hand of the station, 35\nat 320 links, and so on. False stations for subsequent operations\nare marked F. S., thus :-\n280\n200\nF.S.\n110\n70\n30\nThe F.S. occurs at a distance of 200 links from the station, and\nthe figures 220 indicate that it is 220 links from the station or\nstarting point to the fence.\nThe commencement of a line is headed thus :-from O 2 (sta-\ntion 2) to right or left of base; or F. S. 200 (false station at 200\nlinks) on last line ; or from F.S. 15.20 to F.S. 23.15 : if the line\nruns into another, and finishes in same, it is called a close, and\nmarked accordingly at the end, as, close at O 6, or close at\nF.S. 700. The length from one station to another is called the\nDigitized by\nGoogle\nSURVEYING.\n263\nlength of the line, which is designated according to the starting\npoint, as the length of the first, second, or third station line.\nWhen the bearing is taken, as in the case of running a base, it is\nentered at the commencement of the line, as follows :-\no\n,\n69 0\nN.E.\n6\nThe following methods are also adopted for taking roads and\nangles:-\n250\n30 x 40\n30\n>\n300\n20\n40\nSome surveyors also sketch their plans in the Field-book, i. e.,\nthey enter the several lines as they are measured, and the offsets\nin the order that they are taken, the system of commencing at the\nbottom, and writing upwards, being pursued the same as usual.\nDigitized by Google\nDigitized by Google\n12 26 12/25 Close at A.\nN\n36\n20\n20\n80\n32\nST\nSURVEYING.\n11 70 11/70 35\n11 65 1165\n11 50\n20 15\n8 90\n7 35\n: -\n6 30 65\nF.S. 5 05\n492\n10 4 0 400\nD GO\n5 00 15\n2 00 40\n5 75 35\n35\nto A\n10 .\n00 40\n30 35\n15 475\n+\n8 00 10\na\n: 0 -\n: €\nD 04 9\n00\nFrom 8:10\n14 6 50\n10 A 60\n010\nF S 35\n2 66\n2 200\n1\n0 4.5\n16\nto\n5\n1\n17 00\n10 1 00\nHIS\n30\n27\n12\nF.S\nFrom 17 15 to left\n17 40\n17 18\n01/11 01 II\n11 2 0 20 F. S. F.S.\n9 30 F. S. F.S.\nCommence Survey st.A. atA.\n264\nSURVEYING.\n265\nThe following engravings represent two different forms of keep-\ning a Field-book (page 264 and 265 constituting one, and page\n266 the other), by Mr. Peter Bruff, each referring to the same\nplan, which is plotted at page 267, and either will be found very\nsimple and efficient :-\n5\n38\nClose at 5.05\n5 40 22\n4\n80\n18\n4 20 20\nS 00 20\n1\n45\nCut\nE.S .enBase\n1 00 10\nFrom F. S.2 90 on last Line to RS.5.05\n8\n25 Close at 4.35\n7\n80\n8\n6\n50\n10\n5\n11\n4\n35\nCut\nF.S on Base\n5\n45 25\nF.S 2\n90\n1\n80\n6\n100 13\n1\nFrom F. S 8-5 to F.S.4.33\n6\n60\n22\nClose at 17.18\n6\n00 20\n5 00 20\n4\n00 18\n2 00 10\n43 20\nFrom 13.75\nto left\nis\n75\nc\n40 13\n0\n16 12\n2\n17 12\n0\n12\n11\n15\n97 10\n70\n990\n9507\n9\n00\nF.S\n8\n85\n15\n800\n40\n7\n00\n45\n6\n00\n50\nB\n00\n40\n450\n30\n4 00 15\n3\n0010\n210\n25 1/00\nFrom to right of Base\n2 M\nDigitized by Google\n266\nSURVEYING.\n17/40\n9\n17/15\n660\nB\n1100\nsool\n&\n500\n18\nBES\n$00/\n100s\n/\n10\nor\n2001\n650\nor\n560\n1870\n\"\n11/40\n600/\nOR\nTHE\n120\nD\nC\n510\n1300\nto\n1220\n6\n&\n?\nto\n120a\n290\nwe\nof\nf\n0\n1003\n9\n15\n/1070\n900\n180\n9\n30\n9/30\na\n200\n0\n000\n=\na\n&\n85\nis\na\n9LT\n800\n70\nd\n200\n566\n505\n4\n00\n$30\n:\n000\nto\n150/\n80\nsool\n:\nto\nfoop\nPIOT\n20\n2/20\nOSTE\n95\n25/10\n58\nSEXT\nDigitized by Google\nSURVEYING.\n267\nB\nC\nC\nD\nHig\n3d\nLinks 100\n5\"\n0\n1\n2\n3\n4\n4\nChains\nIIII\nDigitized by Google\n268\nSURVEYING.\nIn plotting the work, the whole of the lines of the survey should\nbe plotted before any of the fences are commenced, the several\nangles taken by instruments being laid down by a circular or\nsemicircular protractor.-See Plotting.\nIn making subterranean surveys, as plans of coal-pits, mines,\n&c., a circumferenter is generally employed, the method of pro-\nceeding being to plant the instrument at the point of commence-\nment, when the assistant walks forward in the proper direction,\nwith a lighted candle in his hand, and takes his station, the bear-\ning and distance of it are then noted ; the instrument is next fixed\non the spot where the candle was situated, and a second observa-\ntion taken in a similar manner to the first, which system is pur-\nsued until the whole survey is completed.\nThe area of the land is calculated from the finished plot of the\nsurvey ; and the lengths being taken in links, it is readily ascertained\nby multiplying them together, and pointing off five figures on the\nright hand, when those on the left (if any) will be acres ; those\nstruck off are then multiplied by 4, and five more struck off, the\nfigures on the left will then be roods. The same principle may\nbe pursued for the perches ; thus, suppose the area of a piece of\nground, 400 links long, and 260 wide, is required, then\n260\n400\n1|04000\n4\n|16000\n40\n6/40000\nArea 1 acre, 0 roods, 6 perches.\nIf the ground is in the shape of a triangle, multiply the height\nby the base, and take off one-half the product for the area.\nLarge surveys are generally computed by dividing the whole\ninto columns of equal width, say 1 or 2 chains wide, and every\n5 or 10 columns may be also calculated together as a check, and a\nsummary of each drawn out, when any errors will be detected.\nDigitized by\nGoogle\nSUSPENSION BRIDGE.\n269\nThe system of calculating the area of the columns is as follows:-\nSuppose the number of square chains in a column to amount to\n108 (either a column 1 chain widę; with a length of 108 chains,\nor a column 2 chains wide, with a length of 54 chains), then bring\nit into acres, by dividing it by 10, the number of square chains in\nan acre; or otherwise cut off one figure on the right, it may then\nbe multiplied for roods and perches, thus :-\nNumber of squares in column 10|8\n4\n3|2\n40\n810\nContents of column, 10 acres, 3 roods, 8 perches.\nThe content of the whole may also be computed by the mea-\nsured lines, the computer equalizing and arranging such parts\nwhich may be on the outside into triangles and other regular\nfigures. The inequalities of the boundaries may be equalized by\nthe eye with sufficient accuracy, i. e., an extra portion may be\ntaken into the calculation in some parts, and a less area in others,\ncorresponding to that allowed, by which the true area may be\nfound ; this may be effected by equalizing the boundary by a\npencil, or by laying a thin piece of transparent bone, or a piece of\nglass upon it, remedying the irregularities by the eye.\nTables of the contents of various bodies are also very exten-\nsively employed at the present time.-See Arrow, Chain, Theodo-\nlite, &c.\nSUSPENSION BRIDGE, a bridge suspended from inverted bows,\nby means of rods, being usually formed of iron, at the present\ntime; the bows are supported by stone piers erected at each end,\nand from thence carried down and secured in the ground.\nSuspension bridges are generally adopted where the span is\nvery great : the first notice of them appears to have occurred\ntowards the end of the sixteenth century ; the which were com-\nposed of cordage. The most celebrated suspension bridges in\nthis kingdom are those erected by Mr. Telford, of which the Menai\nDigitized by\nGoogle\n270.\nSUSPENSION BRIDGE.\nBridge is the most extensive, being 560 feet between the points of\nsuspension, and 100 feet in the clear above high water-mark : four\narches are built on one side of it, and three on the other, each\nof 50 feet span.\nThe bridge consists of four suspended cables of malleable iron,\nthe versed sine of their curve being about 57 feet, or 1ᵇᵗʰ of the\nspan, and two carriage-ways pass over it, each 12 feet wide, with\na footpath between them, 4 feet wide. The weight of the bridge\nbetween the points of suspension, including the cables, is said to\nbe 489 tons ; and, as the suspending power is calculated at 2,016\ntons, a disposable force of 1.674 is provided to meet any stress\nthe bridge may encounter. This bridge has, however, recently\nsustained considerable damage, principally from the effects of high\nwinds. There are likewise several other suspension bridges of\ngreat span erected ; as that over the Thames, at Hammersmith,\nwhich is of 400 feet.\nIt is imagined by some, that chains introduced under the plat-\nform, in an inverted position to the principal suspension chains,\nwould give greater strength to these bridges, and render them\nproof against the action of strong winds from beneath, and by\nElevation of the Bridge in the Island of Bourbon.\nPlan of Ditto.\nVictoria Bridge, Bath.\nDigitized by\nGoogle\nSUSPENSION BRIDGE.\n271\narching them on the plan, or fixing the\nchains a greater width apart at the piers,\nthey would also be proof against side-\nwinds, and thereby correct any rocking\nmotion. The bridges erected for the Island\nof Bourbon, by Mr. M. I. Brunel, C.E.,\nare constructed on this principle.\nColonel Pasley, R.E., attributes the\ninjuries frequently sustained by suspension\nbridges during heavy gales, to their being\ngenerally constructed without any longi-\ntudinal trussing upon the platform, as he\nconsiders that the wind acts from beneath\nthe rise and fall of the Menai Bridge,\nwhich is not furnished with any, is stated\nto be above 3 feet in ordinary gales; but\nthe Hammersmith bridge, having four ties\nof longitudinal trussing along it, is not\nso affected. .This framing also serves as a\nBow Chains of the Victoria Bridge.\nBow Chains of the Menai Bridge.\nmeans of enclosure to the footways.\nThe latest improvements in suspension\nbridges are comprised in Mr. Dredge's\n\"patent;\" and the Victoria Bridge, erected\nby him, at Bath, is upon this principle.\nThe construction of the bow chains will\nbe readily understood by the following\ndiagram, which exhibits the form of a\nportion of the bow chains of the Menai\nBridge, and those of the Victoria :-\nThe bow chains of the Victoria Bridge\nare tapered gradually to the centre of the\nbridge, and are thereby rendered much\nstronger at the points of suspension; but\nthose of the Menai are formed of similar\nsize throughout the centre portion, there-\nDigitized by Google\n272\nSWIVEL BRIDGE-SWITCH.\nfore, being overcharged, the superfluous weight assists the wind,\nand occasions the rocking motion before noticed; and those por-\ntions of the chain next the piers are deficient in strength to exactly\nthe amount of the excess of the centre portion. - The suspending\nrods are also fixed in an oblique direction instead of vertical, as\nin ordinary suspension bridges.-See Bridge.\nSWIVEL, or SWING BRIDGE, a moveable bridge much employed\nin docks, in order to admit of the passage of shipping, consisting\nof two parts, or platforms, their point of meeting being midway\nbetween the abutments; each portion turning upon a centre pivot,\nand supported upon rollers, on the same principle as a railway\nturn-table : the over-hanging portion is balanced and kept in the\nproper position by a counterbalancing weight, fixed within the\nframing at the other end.\nThe iron Swing Bridge, over the entrance-lock, at the West\nIndia Docks, by Mr. Ralph Walker, C.E., was among the first.\ninstances of this description of bridge. Timber turn-bridges are\nsometimes erected on canals; but iron is the best material for\nthem, on account of its freedom from warping.\nSwing Bridge, London Docks.\nSide Elevation.\nTransverse Section.\nSWITCH, (railway), that portion of moveable rails forming the\njunction of a siding with the main line, which are usually shifted\nby means of an eccentric movement,\nenclosed in a box. It has been the\ngeneral custom to form them of the fol-\nlowing form, on colliery railways :-a,\nbeing the switch rail, which is move-\nable, and b, the check rail, which is im-\nmoveable; and this plan of formation\nis distinguished by the name of the\nThe Switch Rail.\nswitch rail. The switches employed on\nDigitized by\nGoogle\nSWITCH.\n273\nthe London and Birmingham, and some other railways, have both\nIT)\nILTI\nc\nLA\nThe Check Rail.\nrails formed moveable ; and they\nare connected together by two\niron bars; and this system is\nknown by the name of the check\nrail. Double switches are also\nnow becoming used for the out-\nside rail, which is in all cases\nthe guiding rail ; and the inner\nrail continues through entire, according to Mr. Curtis' improved\nplan, thus;-\nCurtis' Sliding Switch.\nThe inner pointed switch shuts against a solid, which renders\nthe whole much more secure than in the common switch rail, and\nthere is a counterbalancing weight connected with the lever handle,\nby which the rails are kept right for the direct line, which is an\nimportant advantage : moveable rails of this description are\ntermed sliding switches.\n2 N\nDigitized by Google\n274\nSYPHON-TENDER.\nSYPHON, an instrument frequently employed in hydraulics,\nconsisting of a bent iron tube.\nThe property of the syphon is, that when filled with water, and\nplaced with the bend uppermost, each leg being situated in a se-\nparate basin of water, it will allow the water to pass through in\none direction, but not in the other, viz., from the upper to the\nlower basin, as upon the air being exhausted from the lower, by\nany water situated at the level of the shorter one, it will move up\nand pass out at the longer opening.\nTALLUS WALL, a wall battering on the face.-See Retaining\nWall.\nTEAMING, the operation of leading the earth or excavation from\na cutting to the embankment.\nThe distance from whence the soil is dug, to the spot whence it\nis teamed, (commonly called the head of the embankment) is deno-\nminated the lead, or haul; and continually increases in length as\nthe work proceeds.\nTELEGRAPH, a machine for facilitating the communication\nbetween distant places, and supposed to be of great antiquity ;\nalthough not perfected until modern times. A galvanic telegraph\nis laid down upon a portion of the line of the Great Western Rail-\nway, which is said to answer very well.\nTEMPLATE, a sort of mould employed in cutting and setting\nmasonry and brickwork. Templates consist of a thin piece of\niron, cut to the exact cross section of the moulding or other fea-\nture to be worked.\nTEMPLET, a short piece of timber sometimes placed on a wall,\nto receive the ends of a girder; they are more especially used in\nbrick walls, as a large stone is found sufficiently efficacious in\nstone walling.\nTENDER, a waggon built expressly for the purpose of accompa-\nnying a locomotive engine, for the conveyance of the fuel and\nwater, the fuel being situated at the bottom of it, and the tank\ncontaining the water at the upper part.\nThe communication with the locomotive is effected by two\nDigitized by\nGoogle\nTENON-TIDE.\n275\ncopper pipes fixed beneath the tank, one upon each side, and\nconnected with elastic hose to the suction-pipes of the feed-\npumps, which are worked by the engine. And some tenders\nhave a steam-pipe laid on to them from the engine, to warm the\nwater.\nThe supply of fuel and water carried by a tender depends upon\nthe weight of the load, and upon the resistance offered by the\nroad, and the rate and amount of the clivities upon it. Some\ncarry sufficient to last from 30 to 40 miles, or about 700 gallons\nof water, and 8 cwt. of coke; but tenders are generally refilled at\n18 or 20 mile lengths, and they mostly weigh about 31 tons when\nempty, and 7 tons when loaded full ; they are also usually placed\nupon four wheels, but when of very great weight they are fre-\nquently supported on six.-See Locomotive Engine, &c.\nTENON.-See Mortice.\nTENSION BRIDGE.-See Bow-string Bridge.\nTERMINAL PLANE, the plane at each end of a line of railway.\nTerminal planes should always be upon a descent from the depôt\nor station, for the purpose of starting the departure train, and\nchecking the velocity of the arrival train.\nTERMINUS, the extreme point at either end of a railway.\nTHEODOLITE, an instrument used in surveying, for measuring\nboth horizontal and vertical angles.\nThe theodolite is mostly employed in determining particular\nstations, and in running base-lines, being the most perfect of all\nangular instruments.\nTHROTTLE-VALVE, (in steam-engines) a contrivance to regu-\nlate the supply of steam to the cylinder, and which is brought into\noperation by the action of the governor in fixed engines, but in\nlocomotives it is worked by the engine-man, by means of a lever-\nhandle.\nTHOROUGH.-See Perbend.\nTIDE, the rise and fall of the level of the water in rivers and\nseas, which occurs twice in rather more than 24 hours, and is\nattributed mainly to the influence of the moon. The height of the\n2 N 2\nDigitized by Google\n276\nTIDE-TIMBER.\ntide on any particular day also depends upon the age of the moon;\nthe highest tides being about the time of new and full moons, and\nthe lowest when the moon is in her quarters.\nThe action of the sun also produces tides, but its effects are\nless on account of its distance from the earth being much greater\nthan the moon. When the sun and moon are either together, or\ndirectly opposite to each other, viz., at new and full moon, the\ngreatest influence of each occurs at the same hour, the height of\nthe tide is thereby rendered greater than usual, and is termed a\nspring-tide; when, on the contrary, the moon is halfway between\nthese two positions, or at the quarters, then at any place where it\nwould be high water by the action of the moon, it would be low\nwater by the action of the sun, the tide consequently does not\nrise so high as usual, when it is called a neap-tide.\nTIDE, or GUARD-LOCK, a lock situated between an entrance\nbasin and a canal, harbour, or river, and forming a communication\nbetween them. It is furnished with double gates, whereby craft\ncan pass them either way, at all times of the tide.\nTIDE-MILL, a mill connected with other machinery, and con-\nsisting of a water-wheel, which is put into motion by the ebbing\nand flowing of the tide. The wheel is sometimes made to rise\nand fall with the tide.-See Water-wheel.'\nTIMBER, a term applied to trees after they are felled. The\ntrunk of a full-grown tree presents three distinct parts, viz., the\nbark, or exterior; next to which is the sap; and the centre of the\ntree, which is called the heart, and forms the most essential portion.\nA period of full 3 years should elapse after the felling of a tree,\nbefore making use of it for building purposes, during which period\nit should undergo the process of drying, by being sawed into vari-\nous thicknesses, as may be required, and properly piled.\nOak is a most durable and tough wood, and much used for all\nground purposes, as sleepers, planking, &c.; it is exceeded by\nnone for strength and durability, and is particularly well adapted\nto bear and suspend weights.\nElm is a wood often adopted for piles and the like, being\nDigitized by\nGoogle\nTRACTION-TRAM.\n277\nexcellent when used under water, but it will not stand alternate\ndryness and moisture like oak. Beech is also used for piling.\nForeign fir is much employed in this country, Memel, Riga, and\nDantzic being considered the best. American pine is likewise\nimported; the red pine being a favourite timber for piling.-See\nKyanize.\nTRACTION, the amount of tractive power necessary to overcome\nthe resistance upon a road, railroad, or canal.\nTRACTIVE POWER, the power of draught required to overcome\nthe friction or resistance of a road, canal, or railway, the amount\nof which, is regulated by the state of perfection of each respec-\ntively, and upon the construction of the vehicles to be propelled\nalong them.-See Road, Paved-way, Tramroad, Railroad, and Canal.\nTRAM, a local name given to coal-waggons, in the neighbour-\nhood of Newcastle-upon-Tyne; hence the word tramway was\ngiven to the road prepared to receive them.\nTRAM, or PLATE-RAILROAD, TRAMWAY, or TRACKWAY, a\ndescription of roadway consisting of narrow tracks, plates, or\nrails of wood or iron, the same being prepared to receive the\nwheels of carriages or trams, as waggons were formerly called,\nwhereby the transit of the latter is much facilitated.\nDetails of a Single Way. Longitudinal Section.\na\nb\nb\nf\nb\nO\na\no\nb\nb\nb\nb\nPlan.\na, a, the longitudinal beams or rails.\nb, b, b, the cross sleepers.\nDigitized by Google\n278\nTRAM.\na\nl\nb\n7\nDetails of a Double Way. Longitudinal Section.\nTrackways were employed in this country as early as the year\n1600, and were originally constructed of timber, the transverse\nsleepers being of oak or fir, from 4 to 6 inches square, 5 or 6 feet\nlong, and laid about 2 feet apart. The longitudinal beams or rails\nlaid across the former were generally of sycamore or larch, being\nsecured thereto by pins or pegs of wood, and were from 4 to 6\ninches square, and laid in about 5 or 6 feet lengths, and this de-\nscription of line formed what was called a single way. (See Cut on\nlast page.) When two longitudinal beams were laid one upon the\nother, it was called a double way ; the which constituted a great\nimprovement upon the former, the transverse beams were thus\nprotected from the feet of the horses, as a space was obtained for\nballasting, which was laid up to the bed of the upper rails, and\nthe under rail was also protected by it; the upper one could con-\nsequently be replaced when worn, without disturbing the lower ;\nthe surface of some of these rails was square throughout their\nwidth, in others a small ledge was placed at the side, to keep the\nwheels in their places, similar to iron-plate rails, while some had\nall the edges rounded off like edge-rails, in which case flanges\nwere placed upon the wheels of the waggons.\nAt the period of coal fuel becoming used in the metropolis\ngenerally, instead of wood, which occurred in about the year 1760,\nthe demand for it caused a proportionate increase in the expense\nof conveyance, which led to the use of iron rails, as a means\nof reducing it, and wrought-iron plates, 2 inches by 1 an inch,\nhaving been occasionally laid upon the surface of the beams, and\nsecured by counter-sunk bolts, at sharp curves or steep planes, to\nreceive the wheels of the waggons, gave the first hint to the pro-\njectors. Cast-iron plate rails were first employed in the year\n1767 ; the trams or beds were generally made about 3 inches\nDigitized by Google\nTRAM.\n279\nwide, with an upright ledge, 3 inches high, termed the keel, cast\non the surface and upon the inner side, to keep the wheels on the\ntracks, and they were usually cast in about 6 feet lengths, and\nsecured to the sleepers by spikes and oak plugs.-See Cuts below.\nDetails of a Tramway with a single Flanche.\nPlan of one Rail.\nSection of Rail enlarged.\nTransverse Section.\nLongitudinal Section of one Rail.\nEdge-rails were first introduced in the year 1824, and are those\nin general use at the present time. Although tram-rails form a\nvery excellent road, when properly laid down, yet they are not\nDetails of a Tramway with a double Flanche.\nPlan of one Rail.\nà\nSection of Rail enlarged.\nTransverse Section.\nLongitudinal Section of one Rail.\nDigitized by Google\n280\nTRANSIT INSTRUMENT.\nequal to edge-rails. There are several modifications of them-some\nhave a circular flange or web on the outer edge, projecting down-\nwards, which increases their strength much, and the rounding of\nthe inner angle formed by the meeting of the tram and keel is also\nan improvement, as it reduces the friction.-See Cut on last page.\nTramways are yet much used for both permanent and temporary\npurposes, in collieries, mines, and quarries, and in the formation\nof roads, railroads, and for other purposes, as the ordinary carts\nand waggons may be run upon them; and they derive some sup-\nport from the ground between the bearings, which is rammed be-\nneath the plates; indeed they are frequently laid upon the bare\nground, when employed for temporary purposes.\nThere is a tramway from Wandsworth to Croydon and Mers-\ntham, formed of plates of cast-iron, 4½ inches wide, and 1 inch\nthick, and laid in 3-feet lengths; the plates have an upper verti-\ncal guide-flanche, 2 inches high, and a fish-bellied lower flanche\non the other side. The guide-rails are 4 feet apart, and the space\nbetween each line is 5 feet the plates are bedded on stone blocks,\nand fastened down by iron spikes driven into wood plugs, which\nare let into the blocks vertically. Horses are used upon the line\nthe usual load of a horse being about 4 tons, the waggons weigh-\ning each 1 ton.\nThere is also a tramway at Glasgow, part of which is laid at\n1 in 20, upon which a horse can drag 4 tons, and the amount of\nrepairs upon it is very trifling : the trams are 8 inches wide,\n2 inches thick, and are made in 3-feet lengths.\nTramways are sometimes constructed of stone, which descrip-\ntion of road we have designated \" Paved-way,\" for the sake of\ndistinction, and described under that head. Many of the American\nrailways are constructed of granite or hard stone sills, with flat\nbars of iron laid on them, to diminish the wear and tear; which\nplan has been found to answer very well.-See Railway, Edge\nRailway, and Paved-way.\nTRANSIT INSTRUMENT, an instrument employed in the formation\nof tunnels, for the purpose of ranging the shafts straight together;\nDigitized by\nGoogle\nTRENAIL-TUNNEL.\n281\nit is fixed upon a brick pillar, carried up solid from the ground,\nand quite independent of the building covering it.\nTRENAIL, a wooden pin employed in timber framework, in situ-\nations where iron bolts are considered objectionable.\nTRENAILS, or PLUGS, the hollow oak pins\nusually driven into stone blocks, when any\nthing is required to be secured to them,\nas the chairs employed on railways; in which\ncase iron pins are first passed through the seat\nof the chair, and then driven tight into the\ncentre of the plugs, which are generally 6 inches long, and 21/4\ninches diameter, and formed of good heart of oak, or African oak.\nTRUCK, as applied to railways, a stage or platform running upon\nwheels, and used upon railways for the conveyance of ordinary\nstage coaches and carriages, which are placed upon it. The mails,\nand most of the coaches remaining in the line of the several rail-\nways, are thus conveyed, the passengers and luggage keeping\ntheir respective places.\nTUBE, a hollow cylindrical body.-See Pipe.\nTUNNEL, a subterraneous gallery or passage excavated or dug\nthrough the earth for the passage of a canal, road, or railway.\nThe tunnel on the canal at Languedoc, in France, commenced\nin the year 1666, is one of the first instances of this description\nof work, although the principle is doubtless of much greater an-\ntiquity. The Hartshill Tunnel, on the Chesterfield Canal, and the\nSapperton, on the Thames and Severn navigation, are among the\nearliest applications of the principle in this country-the former\nis 3,000 yards long, and the latter is 21 miles, and lined with\nmasonry throughout; there are also some canals in this country\ncommunicating with coal mines, executed in tunnelling, and that\nto a very considerable extent.\nThe tunnels already formed, or forming, upon the several rail-\nways at the present time, are generally made by sinking vertical\nworking shafts, and then commencing abreast each way, upon\narriving at the proper level ; smaller shafts, termed air-shafts, are\n20\nDigitized by\nGoogle\n282\nTUNNEL.\nalso made, for supplying the tunnel with air: the excavation is\nformed as nearly the size of the tunnel as possible, the sides and\ntop being supported by timber centreing, consisting of leading ribs,\n&c., also by shoars. The brickwork and earthwork are carried\nforward simultaneously, or as nearly so as possible, and usually in\nlengths of about 20 feet and when the brickwork of a length is\ncompleted, the leading ribs are struck, and pushed on further for\nanother length the striking or slackening of the ribs is attended\nwith some degree of danger to the brickwork, if due caution is\nnot used; the space between the back of the brickwork of the\ntunnel and the excavation is carefully filled in with earth, and\nwell rammed, and if any of the timbers should be found difficult\nto withdraw, they are allowed to remain. The soil of the exca-\nvation is drawn up the shaft to the surface of the ground by a\nhorse-gin, which is fixed at the top. It is generally the prac-\ntice to set a strong curb in the crown of the tunnel under a\nshaft, to support it, and cast-iron is at present used for this\npurpose.\nThe following cuts represent a portion of the Primrose Hill\nTunnel, on the London and Birmingham Railway, during the course\nof execution, and which was constructed by the method before\nstated :-\nTunnelsare also sometimes worked\nby horizontal shafts, or galleries, as\nthat taken through the cliffs at Do-\nver, on the South-Eastern Railway ;\nthey are also formed in cuttings si-\nmilar to bridges, the ground being\nshoared up on each side, and again\ncovered over with earth upon the\ncompletion of the brickwork, tech-\nnically termed open tunnels; an in-\nverted arch is generally unnecessary\nTransverse Section of Tunnel.\nin this description of tunnel, although always formed at the bottom\nof those of the former description.\nDigitized by\nGoogle\nTUNNEL.\n283\nLongitudinal Section of Tunnel.\nThe Thames Tunnel, between Rotherhithe and Limehouse, now\nin the course of execution, by Mr. M. I. Brunel, forms a most\n38\nFt\nIn\n9\nIn\nTax &\n16\nJa E\n15\nTransverse Section of the Thames Tunnel.\n202\nDigitized by Google\n284\nTUNNEL.\nsurprising instance of tunnelling; it consists of a double gallery,\nthe width of the brickwork externally, including both galleries,\nbeing 38 feet, and the height 22 feet 9 inches.\nThe centre wall is built up quite solid at first, for the sake of\nsecurity, and afterwards pierced with arches of communication ;\nthe works are conducted by means of an immense framing, termed\na shield, which is divided into several compartments or cells, in\nwhich the miners and artificers are placed, and it is made to move\nforward as the work proceeds.\nThis cut represents the miners and bricklayers at work in the\nshield, which is moved forward by means of the horizontal screws,\nshown at the top and bottom of the tunnel, the moving stage which\nfollows the shield is also represented, upon which the materials\nare placed, and the soil thrown :-\nLongitudinal Section of Thames Tunnel.\nThere are several tunnels upon the London and Birmingham\nRailway, of which the Kilsby was found the most difficult to ex-\necute, one-fourth of its length passing through an extensive quick-\nsand, which required the constant action of 2-28 horse power\nsteam-engines for pumping, independent of other pumps for re-\nmoving the water. The general size of the several tunnels on this\nDigitized by Google\nTURN BRIDGE-UNDERPINNING.\n285\nline is 24 feet wide, and 27 feet 4 inches high from the invert to\nthe crown of the arch, and they are 24 feet 4 inches from the\nsurface of the rails to the crown.-See Shaft.\nTURN BRIDGE.-See Swivel, or Swing Bridge.\nTURN-OUT.-See Siding.\nTURNPLATE, or TURNTABLE, a contrivance for removing rail-\nway carriages from one line of rails to another; they are gene-\nrally made for crossings at right angles with each other, but can be\nadapted to any angle that may be required.\nA turnplate is composed of iron framing, upon which iron gra-\ntings, or wood planking is laid, thereby forming a table or plat-\nform, two pair of rails being fixed on the upper surface of it,\ncrossing each other at right angles, and of a corresponding gauge\nwith those laid down upon the line. The platform is made to turn\nupon a centre pivot, which rests upon another iron frame, set\non masonry; friction rollers being inserted between this frame,\nand that supporting the\nA Turnplate on the London and Birmingham Railway.\nplatform, which are si-\nThe grating is removed in the lower half\nPlan.\ntuated at the edges of\nthe table, and either\nsecured to the circular\ncurb, which encloses the\ntable, or connected with\nthe centre socket by iron\nrods.\nThe size of turnplates\nis regulated by the length\nof the engines employed\non the line of railway :\nthey are 12 feet diame-\nter on the London and\nBirmingham Railway ;\nbut they are made only\n8 feet on some railways.\nSection.\nUNDERPINNING, the operation of making additions or repairs\nDigitized by\nGoogle\n286\nUNDERSETTING-VALVE.\nto the foundations of walls, in which case the latter are supported\nby strong timber shoars and needles.\nUNDERSETTING, the operation of supporting the earth in a\ncutting, when occurring below rock ; and it is effected by the\nstone quarried from the rock, which is laid in courses against the\nface of the soft soil, the rock being formed as nearly perpen-\ndicular as considered safe and convenient to work.\nThe great Blisworth cutting, on the London and Birmingham\nRailway, is a good specimen of this description of work.\nThe Blisworth Cutting, London and Birmingham Railway.\nTransverse Section.\nA portion of the Plan.\nVANE-See Fly-wheel.\nVALVE, a sort of moveable cover to an aperture, and occurring\nin various mechanical contrivances. Valves are used to separate\ntwo different elements, or bodies, and act by the force of that\nwhich is the most powerful, which is regulated accordingly : it\nDigitized by Google\nVERNJER-WAGGONS.\n287\nis also necessary that a valve be well made, so as to move on\nthe application of a very small degree of force.\nValves are constructed in a variety of forms; but they may be\ndescribed generally as being of four kinds, viz., 1st, those of the\nrevolving description, comprising all cocks, from that in common\nuse to the four-way cock employed in steam-engines ; 2ndly, slid-\ning valves, as the D slide valve, which is employed for a similar\npurpose to the last stated ; 3rdly, the lifting kind, as the safety\nvalve in general use for steam-boilers; and 4thly, the hinge class,\nas the clack-valve, which moves similar to a hinge. The two last\nclasses may be said to act in a somewhat similar manner.-See\nAir-valve, Clack-valve, D Valve, Four-way Cock, and Safety Valve.\nVERNIER, a contrivance connected with a graduated scale, and\nemployed for measuring any portions of the space between the\nmost minute dimensions. Verniers are applied to most of the\noptical instruments used in surveying.\nVIADUCT, an elevated erection, usually consisting of a series of\narches, and very similar in appearance to an aqueduct, but con-\nstructed for the conveyance of a road or railway, instead of a\ncanal or other body of water.\nVoussoirs, the stones forming an arch, the beds radiating to-\nwards the centre or centres forming the curve. The centre vous-\nsoir of an arch is called the key-stone.\nWAGGONS (railway) the form of carriages used upon railways\ndepends, in a certain degree, upon the description of goods con-\nveyed by them, although the same form of wheels, axles, and\nbearings, are common to all. The bodies of the waggons first\nemployed were in the form of an inverted pyramid, or the shape\nof a hopper, being much wider at the top than the bottom; and\nthis form is still retained for coal waggons and the like.\nThe wheels of some of the waggons em-\nployed upon the old wooden railway had\nflanges on the edges, similar to those used\non edge rails at the present time ; and as\nmost of the colliery railways descended\nDigitized by\nGoogle\n288\nWALL-WASTE WEIR.\ntowards the depôts, the fore-wheels were made of greater diameter.\nthan the hind ones, according to the angle of the road, in order\nto keep the bodies in a horizontal position; and this system has\nbeen gradually given up, all four wheels being now made of similar\nsize. The modern coal waggons are about 8 feet long by 5 feet\n6 inches wide at the top, and 4 feet deep ; which size will contain\n2 tons 15 cwt., or nearly 3 tons, by heaping the coals up.\nThe bodies of the waggons, upon the Newton and some other\nrailways, are suited both for railway and common road travelling,\nwhich is very economical and convenient.-See_Arle, Bearing, and\nWheel.\nWALL, a solid structure, composed of either stone or brick-\nwork, being usually carried up perpendicular, and of various\nthicknesses, enclosing and supporting other works; the front sur-\nface of a wall is usually termed the face, and the stones or bricks\nforming it the facing ; the inside is the back, or tail, and the\nmaterials composing it, the backing ; the interior, or space enclosed,\nbeing called the core, or filling in. The face of a wall is some-\ntimes sloped, the latter being termed the batter.-(See Batter). A\nwall is carried up in layers, called courses if the courses are of equal\nthickness throughout, the term regular coursing is applied to them,\nand if unequal, they are called random courses: the system of lay-\ning the stones in the several courses forming a wall, is termed the\nbond.\nThe principal cause of decay in most structures arises from the\nunequal settling of the walls, which creates cracks and bulges in\nthem, as they are not usually calculated to resist lateral strains,\nbut are mostly built with a view of sustaining vertical pressure\nonly.-See Bond.\nWAREHOUSE, a strong erection formed for the reception of va-\nrious description of goods.\nWASHER, a piece of iron used in connection with a bolt.See\nBolt.\nWASTE WEIR, a cut constructed through the side of a canal,\nfor carrying off any surplus water that may not be necessary for\nDigitized by\nGoogle\nWATER STATIONS-WATER-WHEEL.\n289\nthe navigation at certain times and seasons, operating as a drain.\nThe front of the cut next the canal is generally faced with masonry,\nwhich is carried up solid from below the bottom of the canal, to\nthe level of the pond at that part; therefore, when the height of\nthe water exceeds this, it escapes into the cut, and hatches, or\nstop-planks, are fixed in the wall, to dam it off, when necessary.-\nSee Weir.\nWATER STATIONS (on railways), a small reservoir of water\nupon a line of railway, consisting of a tank, connected with a\nwell. There is only one water station upon the Liverpool and\nManchester railway, between the termini, a distance of 29½ miles,\nwhich is at Newton, where the trains stop.\nWATER-WHEEL, an hydraulic machine employed in connection\nwith mill-work, filling the situation of prime mover, it being the\ninstrument whereby the motion of the water in a river or stream\nis brought into action.\nThere are four descriptions of water-wheels; viz., 1st, the\nundershot; 2nd, the overshot; 3rd, the breast wheel (each of\nwhich receive the impulse of the water vertically); and, 4th, the\nhorizontal, upon which the water acts horizontally or bodily.\nThe undershot water-wheel is the most simple in action, and\nwas in use long before the others, being the cheapest and readiest\nThe Undershot Water-wheel.\nfor small streams in their natural state ; and it may be used almost\nwithout any fall in the stream, provided there is plenty of water\nand a good current, as it acts principally by the momentum, and\nnot by the weight of the stream ; it also answers equally well both\n2P\nDigitized by Google\n290\nWATER-WHEEL.\nways, which renders it very suitable for tide rivers. The under-\nshot wheel works best where the difference between the ebb and\nflood is not very great, as it should not be immersed in the water\nmuch beyond the width of the float-boards, on account of the loss\nof power occasioned by the action of the water upon them when\nreturning upwards, after having passed through the lower part of\nthe wheel-course; but if adopted under such circumstances, the\ndiameter of the wheel should be made sufficiently large to allow of\na small segment only of its circumference being covered by the\nwater.\nThe overshot wheel is usually made in the shape of a drum,\nupon which a series of buckets are constructed, the water passing\nThe Overshot Water-wheel.\nover the top of the wheel into them; it therefore acts by the\ngravity or weight of the water in the buckets, as well as by the\nmometum of the stream. This plan gives the greatest power\nwith the least expense of water, as the thickness of the stream is\nseldom more than half an inch, or an inch; a penstock or sluice\nbeing fixed at the head of the wheel, in a proper trough, which\nregulates the supply. The overshot wheel requires a fall in the\nstream equal to rather more than its own diameter, which renders\nit necessary to make it of greater length in proportion to its height\nthan is usual with other wheels. Its power is calculated at double\nthat of the undershot wheel.\nDigitized by Google\nWATER-WHEEL.\n291\nThe breast wheel is a medium between the two former, and\nconsequently much the most general; but, like the overshot, it\nrequires a considerable force in the stream, and thereby also\ndestroys it for the purposes of navigation. The water usually\nstrikes the wheel at rather below the axis, although sometimes\nsituated above it, and either floats or buckets are employed to\nreceive it; the former are mostly adopted, and no water is allowed\nto escape past the mill-course without first operating upon them,\nthere being no space left between : the supply of water is regulated\nby a penstock, as in the last description. The breast wheel con-\nsumes about double the quantity of water of the overshot wheel,\nin performing the same quantity of work; the diameter of the\nwheels, number of float-boards, &c., being similar in both cases.\nThis method is the most suitable when the fall is between 4 and\n10 feet; when it exceeds the latter, it is best to divide it into two\nfalls, and the supply of water must of course be ample in either\ncase.\nThe Breast Water-wheel.\nIt is a very essential point with every description of water-wheel\nto get rid of the tail-water, or that which has acted, and is conse-\nquently discharged at the bottom of the wheel, as the power of\nthe wheel is considerably reduced by its accumulation ; two small\nculverts or drains are sometimes employed to effect it, which are\nmade in the masonry, passing from the head of the wheel to the\ntail-water, when the impetus of the stream rushing from the upper\n2 P 2\nDigitized by Google\n292\nWATER-WHEEL.\npond down these drains will be found to carry off the spent water\nvery effectually a penstock should also be placed at the top of\neach of these culverts, in order to cut off the escape of water in\ndry seasons, or when scarce.\nIn situations where the supply is large and the fall little, an\nundershot wheel may be used ; if, on the contrary, the fall is large\nand the supply small, the overshot is most appropriate; and in\ncases where the height of fall and quantity of water is but mode-\nrate, the breast wheel should be adopted. An undershot wheel\nworks best when its circumference moves with between a 1 and a\nfrd the velocity of the stream, but overshot wheels are not in-\nfluenced by it, as all the buckets have to be filled in succession.\nMr. Smeaton determined on 3 feet per second as the best velocity\nof fall for the latter, the distance from the spout to the receiving\nbucket being two or three inches.\nThe full power of a stream should always be taken advantage of\nin the construction of mills ; a wide wheel of small diameter is\nbest where great speed is required, if otherwise, a large narrow\nwheel may be employed.\nThe horizontal water-wheel is rarely met with, being very infe-\nrior to the former, on account of the resistance offered by the float-\nboards in returning against the stream, and other defects. Mr.\nRobert Beatson suggested the employment of suspended float-\nboards, which should present a surface for the stream to act upon\nin passing down, and allow the water to pass between them in\nreturning upwards against the stream, the principle being similar\nto that of his patent horizontal windmill.-See Windmill.\nThere is also another form of water wheel, termed Barker's\nMill,\" from the name of the inventor, which, however, is rarely\nemployed; the water passes down a tube placed vertically, and\nescapes from a cross tube at the bottom, through two apertures\nplaced in opposite directions of its extremities, and the engine\nacts by means of the reaction or counter pressure of the issuing\nwater, when the lower tube is caused to revolve horizontally, and\nthe whole machine with it; a vertical axle being placed within the\nDigitized by\nGoogle\nWATER-WINGS-WATER-WORKS.\n293\nvertical tube, which gives motion to a horizontal one at the top\nby means of a pinion.\nThe propelling wheels of steam boats are termed paddles, the\nintent of which differs from the wheels before described, as they\nact upon the water, using it as a resisting force, whereas the for-\nmer are acted upon by the water, i. e., by the motion of the\nstream.\nWATER-WINGS, the walls erected on the banks of a river next\nbridges, to secure the foundations from the action of the current;\nthey are usually battered towards the stream, having good puddle\nfilled in at their backs, and are sometimes further supported by\nsheet piling at the feet; they are usually executed in curved lines,\nthe water-way being contracted at such parts.\nWATER-WORKS, the name applied to all description of works\nemployed for raising or sustaining water, as water-mills, wheels,\nsluices, and various other hydraulic works; but it is not generally\nunderstood at the present time to refer to any other than works\nerected for the purpose of supplying cities and towns with water\nfor the daily use of the inhabitants.\nThe water for the supply of cities and towns is generally ob-\ntained from the neighbouring rivers or streams, and pumps are\nemployed in forcing the water to the requisite height, which are\nworked by powerful steam-engines; where there are no fresh-\nwater rivers within reach, the water is procured from wells, and\nthe power required in this case is stated by Mr. Wickstead to be\ndouble that of the former: the water is also sometimes conveyed\nfrom the rise or upper portion of a river, by a small cut or canal;\nand as the velocity requisite for the water in the cut is small,\ncompared with the usual run of rivers, the level of the cut at its\ntermination is consequently higher than that of the river, and\nupon being taken a sufficient distance the required head of water\nmay be thus obtained: The New River, London, is formed upon\nthis plan, although it is said to be generally the most expensive\nin carrying into execution, but the annual expenses are less than\nwhere steam-power is employed in maintaining the required head\nDigitized by\nGoogle\n294\nWATER-WORKS.\nof water. If there are good springs of water in a town, and they\nare situated at a sufficient elevation to supply the houses, the\ncost will be trifling, compared with any of the above-mentioned\nsystems; but it is an occurrence which rarely happens.\nThe water is frequently conveyed a considerable distance in\niron pipes, through large cities and towns, on account of the num-\nber of houses to be supplied : the principal pipes are called mains,\nor main pipes, which communicate directly with the reservoirs, and\nare laid down in the principal streets only, and pipes of smaller\nbore, termed services, or service pipes, are connected with them, for\nthe use of the remaining streets; a cock is placed at every such\nbranch, whereby the communication with the main is either opened\nor closed, the latter being always charged with water, and there\nis a small lead pipe laid on from the services to each house or\ntenement requiring water.\nThe cocks of the services situated at the most distant parts are\nkept open a longer time than those near to it, in order that the\nwhole district may have an equal supply, the velocity of the water\nat the extreme parts not being so great as where near the source :\nfor when water is forced through pipes, either by a natural or arti-\nficial head, or by steam, or any other power, friction is created\naccording to the velocity of the water, and the distance which it\ntravels in the pipes; therefore if the power be not increased, the\nvelocity of the water is lessened as it proceeds forward.\nIn small towns one line of pipes is generally found sufficient,\nand there are small lead pipes laid on to it, as with the former; the\nwhole of the houses therefore receive an equal supply, and at\nthe same period of time.\nThere are fire-plugs made on the several mains and services, at\ncertain distances, which consist of holes about 2 inches diameter,\ninto which wooden spigots are driven ; they are easily removed\nin case of fire or frost, and the whole force of the water may be\ndirected to one spot, by closing the service-cocks in the surround-\ning portions of the district.\nThe ancients employed lofty aqueducts for the conveyance of\nDigitized by\nGoogle\nWATER-WORKS.\n295\nthe water intended for the supply of cities, and it has been stated\nthat they were ignorant of the circumstance of water situated in\npipes, rising to the level of the reservoir connected with them;\nthe comfort and convenience of having pipes laid on to every\nhouse, as provided at the present day, was also unknown to them,\nat least the superior habitations only possessed it, the means of\ncasting or constructing large iron mains being then unknown.\nThe conveyance of water for the use of the inhabitants of the\ncity of London, and the general purposes of consumption, was first\nintroduced in the year 1236, being brought from Tybourne; after\nwhich period stone conduits began to be used, which were at first\nlined with lead.\nThe Chelsea Water-works are among the most extensive: the\nsupply is first received from the river into a large reservoir, 100\nfeet by 70 feet, and 10 feet deep; it is then passed into another,\nwhich is lined with stone and brick from thence it is pumped\ninto two reservoirs, paved with bricks, laid edgeways-the southern\none is 300 feet by 100, and the northern 540 feet by 140; and\ntheir level being high, the water gravitates downwards, passing\nthrough filtering beds, which are of great extent, the southern\none being 240 by 180 feet, and the northern 351 by 180 feet, and\nthe level of the latter is kept higher than the other : the surface\nof these beds is composed of sand, and disposed in ridges, pre-\nsenting an undulated appearance; their sides rise about 12 feet\nabove the surface of the ground, and are strongly embanked\nand turfed over; the water is let on to the beds at several places,\nthe ends of the pipes being fitted with curved boards, to diffuse\nthe currents of the water, and prevent the surface of the sand\nfrom being disturbed; the bottom is formed of clay, 18 inches\nthick, to keep out the land-springs, and tunnels or culverts, 3 feet\nin diameter, and about 18 inches thick, are laid upon same, ex-\ntending from one end to the other, viz., nine upon the northern;\nand eleven upon the southern; they are built of cemented blocks\nof brickwork, with the joints partially open; the heading joints\nDigitized by\nGoogle\n296\nWATER-WORKS.\nare quite open, and every alternate brick is omitted, the water is\nthus enabled to pass through them; a covering of gravel stones\nis then laid over the whole, 2 feet thick, upon which is a 6-inch\nlayer of shelly concrete, next a bed of coarse sand, and, lastly,\none of fine sand; the two last occupying a depth of about 5 feet :\nwooden troughs, 3 feet by 6 inches, and 3 feet deep, are placed\nbetween the tunnels, and about 10 feet apart, which prevents the\nwater from washing the sand into holes upon its admittance into\nthe filterer.\nThe deposit left upon the surface acquires a thickness of 1 or\n2 inches in about three or four weeks, when about one inch of it\nis raked off, the remainder tending to improve the filtration by\nrendering the interstices less: the grosser portions of silt slide\ndown the ridges, and are easily removed. It has been ascertained\nthat the sediment does not penetrate through a greater depth than\nfrom 6 to 9 inches, according to the state of the Thames water,\nthe greatest occurring during the prevalence of land floods in the\nriver.\nUpon the water having passed through these filterers, it is\nreceived in an open culvert, 15 feet deep, and is from thence\nconveyed to the mains: a steam-engine of 120 horse power is\nemployed in raising the water; 3,500 gallons of which is raised\nper minute, or upwards of 5,000,000 gallons per day. The ex-\npense of these works is said to exceed £60,000.\nAccording to a Parliamentary Commission, appointed a few\nyears back, to enquire into the subject of the supply of water to\nthe metropolis, the average quantity supplied was stated to be 170\ngallons to each house daily; but it must be remembered, that\nvery few of the cisterns are empty when the water is on, therefore\nnothing like that quantity is consumed. Mr. Tredgold states that\nthe supply of water to a town should be 10 cubic feet per day for\neach house, exclusive of other demands, as for manufactories,\nbreweries, watering streets, &c., amounting in the whole to 4 cubic\nfeet per day for each person; in small towns 21 cubic feet is\nDigitized by Google\nWEIR-WHEEL.\n297\nsufficient. He also gives the following Table, which may afford\nsome criterion :-\nTowns.\nInhabitants.\nSupply of water\nEach person\nper day.\nper day.\nCubic feet.\nCubic feet.\nLondon\n1,225,694\n3,888,000\n3.15\nEdinburgh (old service)\n138,235\n80,640\n0.61\nRome (modern)\n136,000\n5,305,000\n39.0\nRome (ancient)\n1,200,000\n10,500,000\n9.0\nParis\n713,765\n293,600\n0.42\nPlymouth\n21,570\n33,400\n1.56\nWEIR, an erection carried across a river or rivulet, for the pur-\npose of damming up the water for the convenience of irrigation,\nand for other uses.\nWeirs are formed of stone and brickwork, or of timber, being\ncomposed of frames placed side by side, in which stop-planks or\nhatches are dropped, by which the head of water is supported ;\ncast-iron is also sometimes used for the paddles and framing : a\nsingle frame is, properly speaking, a sluice; it requires a series of\nthem to constitute a weir.-See Dam and Waste Weir.\nWELDING, the process of uniting or joining two pieces of iron\ntogether by the aid of heat and pressure.\nWELL.-See Artesian Well.\nWELL-HOLE, a hole connected with some mechanical contri-\nvances, and adapted for the reception of a counterbalancing weight,\nand for other purposes.\nWET Dock.-See Dock.\nWHEEL, an agent very extensively employed in machinery the\nwheel, with its axle, constituting one of the mechanical powers.\nRegarding toothed wheels, it may be stated, that they are described\ngenerally as cog-wheels.; although the term cog bears more imme-\ndiate reference to one of the teeth fixed upon the circumference of\na wheel, the same being originally made of wood : when they are\nformed upon the body of the wheel, or both out of one piece, they\n2Q\nDigitized by Google\n298\nWHEEL.\nare termed teeth; and the teeth of a pinion are called leaves, and\nthose of a trundle, staves.\nc\nB\nE\nE\nc\nE\nE\nB\nIn the case of two cog-wheels in contact with each other, as\nrepresented in the cut, the radii up to where the teeth com-\nmence, B, B, is called the proportional radii; a line joining their\ncentres, A, A, is called the line of centres; and the distances to\nthe extremity of the teeth, C, C, is called the real radii; the dis-\ntance of the teeth from centre to centre, D, D, is called the pitch of\nthe wheel ; and the circles from which each commence, E, E, the\npitching line.\nA wheel which acts upon another, is termed a driver or leader,\nand the wheel acted upon, the droven or follower.\nWHEEL (of a carriage), a solid disc or circular frame, con-\nstructed of wood or metal, turning upon an axis, and used for\nfacilitating the conveyance of carriages. It consists of three parts,\nviz.,-1st, the nave, hub, or centre ; 2nd, the periphery, or outside\nring, being usually formed in circular pieces, termed felloes; and\n3rd, the spokes, or radii, which connect the former together.\nThe peripheries of roadway carriages are encircled by tires,\nformed of flat bar-iron, made in pieces, and secured by nails pass-\ning through the felloes, with nuts and washers. The best sort of\nvehicles have the tires of the wheels made in a single piece or\nDigitized by Google\nWHEEL.\n299\nring, which being put on in a hot state draws and binds the whole\nfirmly together by the contraction of the metal in cooling. The\ncommon practice of making the rims of wheels conical is highly\ninjurious to the roads, as it gives the wheels a tendency to move\nout of the line of draught. The plan of rounding the extreme\nedges is less objectionable: but flat edges, or wheels perfectly\ncylindrical, are much the least destructive: they also run much\nlighter than the former.\nThe wheels of railway carriages were originally made of wood,\nwhich material was retained for the wheels acted upon by the\nbrake long after the introduction of cast-iron wheels, as it was\nsupposed to afford a greater degree of adhesion; but metal having\nbeen found to answer equally well for that purpose, iron is now\nadopted for the whole of the wheels. The next\nimprovement was that of case-hardening the\nperipheries of the wheels, which arose from the\ngreat injury they sustained (and consequent\nincreased wear and tear) upon the introduction\nof edge-rails: this plan also reduced the resist-\nance, but was subsequently found objectionable,\non account of its rendering the wheels brittle, which led to the\nadoption of wrought-iron tires, by Mr. G. Stephenson, who was\nthe first engineer that employed them; the wear of which is about\n1½th of an inch per annum, or about $rd those of cast-iron: they\nare also generally formed of a slightly\nMr. George Stephenson's Patent Wheels.\nconical shape, with flanches on the in-\nside, thus :-(See Cut above.)\nThe annexed cut represents Mr.\nGeorge Stephenson's patent wheels;\nthe spokes are of wrought-iron, and\nare formed hollow, the nave and rim\nbeing cast on to them ; the rim is then\nturned in a lathe, and a wrought-iron\nSection.\nElevation\ntire fixed on it.\n2 Q 2\nDigitized by Google\n300\nWHIMS-WINDMILL.\nMr. Losh's patent wheels have ac-\nMr. Losh's Patent Wheels.\nquired great repute. The whole is of\nwrought iron, except the nave.\nMr. Joseph Bramah's are the last\nwheels produced, and certainly surpass\nall former wheels. The whole of this\nwheel is also formed of wrought-iron,\nexcept the nave, and it is finished by\nSection.\nElevation.\na wrought-iron ring being made hot,\nMr. Joseph Bramah's Patent Wheels.\nand contracted on to the spokes; the\ntire is put on in a similar manner, and\nfurther secured by bolts, and properly\nturned and finished.-See Axle, Bear-\nings and Curve.\nWHIMS, large capstans connected\nwith the shafts of mines, and worked\nSection.\nElevation.\nby three or four horses.\nWINCH, the name applied to the bent handle or crank, by which\nthe axles of machines are turned when manual labour is employed\nin effecting it.\nWINDLASS, a circular axis turned round by crank handles, by\none or two men, for the purpose of raising water or minerals from\nwells or mines ; the anchor used on board ships is raised by a\nwindlass worked by shifting levers. The crank handle by which\nany contrivance is turned is also known by the name of a windlass.\nWINDMILL, or WIND ENGINE, a contrivance for acquiring a\nfirst mover or power for machinery from the impulse of the wind,\nand which is adopted for various purposes. Windmills are most\nfrequently employed in grinding corn ; they were also much used\nformerly for draining marshy land, but steam power has superseded\ntheir use considerably, in common with other early machines.\nWindmills are of two kinds, vertical and horizontal.\nThe vertical are those almost invariably met with, having four\ncross vanes or arms fixed at the extremity of an axis lying in a\nDigitized by\nGoogle\nWINDMILL.\n301\nhorizontal position, or nearly so. The vanes are formed in the\nshape of trapeziums, of about 9 yards long, and 2 wide, and are\ncovered with canvas or cloth upon open lattice-work framing.\nThe position of the sails in this kind of windmill is obliged to be\naccommodated to the direction of the wind, and there are two\nmodes of effecting it practised; viz., by the post-mill, which\nis built around and upon the trunk of a large tree, properly braced\nand strutted next the ground, and a certain height is settled for\nthe lower and the upper floors, upon which it is turned bodily\nwhen required, a pivot or centre being formed in the upper floor,\nwhich rests upon the top part of the trunk; the lower flooring has\na collar framed in it, which also rests upon the outer edge of the\ntrunk, the latter being passed through the collar. The mill is turned\nby means of framing at the back, which descends in a sloping direc-\ntion, and is fastened in a temporary manner to posts driven into the\nground, or it is rested on the axle of a moveable wheel, which de-\nscribes a circle round the mill, and thereby takes any position that\nmay be necessary. The other method of setting the sails to the\nwind is accomplished by means of smock mills, and which are built\nin a more substantial manner, the lower part being formed of stone\nor brickwork, and the upper of wood, usually in a conical form.\nThe head is constructed on a moveable plan, and accommodates\nitself to the direction of the wind by means of some small sails\nsituated at the back part of it.\nHorizontal windmills are worked by sails set horizontally, the\naxis being in a perpendicular position. It is natural to suppose\nthat the action of the wind would be much greater when employed\nin a direct manner against the sails, as in this case, than when\nacting in a lateral course, as it does with the\nformer description, but the resistance pre-\nsented by the vanes or sails upon returning\nagainst the wind, forms a great objection to\ntheir use; they are calculated at not above\n₫rd to 4ᵗʰ the power of the vertical.\nMr. Robert Beatson effected a consider-\nMr. Robert Beatson's Patent\nHorizontal Windmill.\nDigitized by\nGoogle\n302\nWINZE-WOOD SCREW.\nable improvement in them by his patent of 1798-he proposed\nhaving the vanes formed of suspended flaps, which were shut by\nthe action of the wind, and upon returning they opened, allowing\nit to pass between them.\nBoth in the case of windmills and water-wheels, for grinding\nflour, the prime mover is connected with large mill-stones, be-\ntween which the corn is ground, the motion being communicated\nto them from the sails by means of a vertical axle.\nWINZE (in mining), a small pit or shaft sunk from one level to\nanother, for the purpose of ventilation. Winzes are generally\nconstructed in mines at regular distances, those of one level\nbeing placed midway between those of the level above or below\nit, thus :-\nA\nA\nA\nA, A, A, represent the winzes.\nWOOD SCREW, an iron screw, in which the body tapers, but\nnot the worm, the latter continuing straight to the extremity.\nDigitized by Google\nINDEX.\nPage\nPage\nAbbrevoir\n7\nBacking\n19\nAbutment.\n7\nBackwater\n19\nAcre\n7\nBalance Beam\n19\nAdhesion\n7\nBalance Gates\n19\nAdit\n8\nBalks\n20\nAir Escape\n9\nBallast Lighter\n20\nAir Pump\n9\nBallast Waggon\n20\nAir Valve\n9\nBallasting\n20\nAir Vessel\n9\nBalustrade\n21\nAjutage\n9\nBank\n21\nAnchor and Collar\n10\nBar\n21\nAngle Irons\n10\nBar (in navigation)\n21\nAngle of Traction\n10\nBarrel (of a drum-wheel)\n21\nAngle of Repose\n10\nBarrel (of a pump)\n21\nAnimal Power\n10\nBarrow\n21\nAqueduct\n11\nBase Lines\n21\nArch\n11\nBat\n21\nArch of Equilibrium\n15\nBath Stone\n21\nArch of Equipollence\n16\nBatter\n22\nArchitecture\n16\nBatter Level\n22\nArris\n16\nBeam\n22\nArrow\n16\nBearings\n22\nArtesian Well\n16\nBeetle\n22\nAshlar\n18\nBench or Berm\n22\nAsphaltum\n18\nBench-marks\n22\nAssistant Engine\n18\nBeton\n22\nAtmospheric Engine\n19\nBevel Gear\n23\nAxle or Axletree\n19\nBlast Pipe\n23\nDigitized by Google\n304\nINDEX.\nPage\nPage\nBlasting\n23\nChair (railway)\n54\nBlock (railway)\n24\nChalk\n56\nBlock\n25\nCheeks\n57\nBoiler\n25\nChimney\n57\nBolts\n29\nChipping Pieces\n58\nBolsters\n30\nChock\n58\nBond\n30\nCircumverenter\n58\nBonnet\n31\nClack Valve\n58\nBooms\n31\nClaying\n59\nBoning\n31\nClinometer\n59\nBoring\n31\nCoal-mine.\n59\nBottoming\n31\nCock\n61\nBoulder Paving\n31\nCoffer Dam\n61\nBoulder Walls\n31\nCogs\n63\nBoundaries\n31\nCog.wheel\n63\nBowstring Bridge\n32\nCoke\n63\nBrake, or Convoy\n32\nCollar, or Gland\n63\nBreakwater\n33\nCompass\n63\nBreakwater Glacis\n34\nConcentric Engine\n63\nBreasts\n34\nConcrete\n63\nBreast Wall\n34\nCondensing Engine\n63\nBrick\n34\nConduit\n63\nBridge\n35\nConical Valve\n63\nBuffer Heads\n43\nConical Wheels\n63\nBuffing Apparatus\n43\nConstant (railway)\n64\nBurn\n46\nContinuous Bearings.\n64\nBush\n46\nConvoy\n65\nButterfly Valve\n47\nCopper Mine\n66\nCore\n66\nCaisson\n47\nCornice\n66\nCamber\n47\nCottar\n66\nCanal\n47\nCounter\n66\nCarriage\n50\nCounterbalance\n66\nCarriage (railway)\n51\nCounterfort\n67\nCatanarian Curve\n51\nCountersunk\n67\nCatchwater Drains\n51\nCouplings\n67\nCauseway\n51\nCowl\n67\nCement\n51\nCrab\n68\nCentres\n52\nCradle, or Coffer\n68\nChain\n53\nCramp\n68\nDigitized by Google\nINDEX.\n305\nPage\nPage\nCrane\n68\nDry Dock\n86\nCrank\n69\nDike\n86\nCrossing (railway)\n69\nDike (mining)\n87\nCrossing (level)\n69\nDynanometer\n87\nCrossing Point\n69\nCross Staff (in surveying)\n70\nEarthwork\n87\nCrown, or Contrate Wheels\n70\nEccentric\n93\nCuddy\n70\nEdge Railway\n93\nCulvert\n70\nElbow-joints\n95\nCurve\n71\nEmbankment\n96\nCutting\n72\nEngine\n97\nCutwater\n72\nEngine-house\n98\nEnrockment\n98\nD, Slide Valve\n72\nEstuary\n98\nDam, or Weir\n73\nExcavation\n98\nDatum Line\n75\nExpansive Engine\n99\nDeflection\n76\nDegree\n77\nFace (of a stone)\n99\nDepôt, or Station\n77\nFacing (in hydraulies)\n99\nDiagonal\n77\nFanner\n99\nDiving Bell\n77\nFalling Sluices\n100\nDock\n78\nFathom\n100\nDouble-acting Inclined Plane\n80\nFeather-edged\n100\nDouble-railed Inclined Plane\n80\nFeeder\n100\nDrain, or Ditch\n80\nFeed Pipe\n100\nDrainage (agricultural)\n80\nFeed Pump\n100\nDrainage (mining)\n82\nFelloes\n100\nDraining Tiles\n83\nFelt\n100\nDraught (in masonry)\n83\nFencing\n101\nDraught (in mechanics)\n83\nFender Piles\n101\nDrawlink (railway)\n83\nFerry\n102\nDrawbridge\n84\nField Book (levelling)\n102\nDredger\n85\nField Book (surveying)\n102\nDredging\n85\nFilling, or Filling-in\n102\nDrift, or Driftway\n85\nFished Beam\n102\nDrop\n85\nFixed Engine\n102\nDrought\n85\nFlanche\n102\nDrove\n86\nFlank Walls\n102\nDrum, or Rope-roll\n86\nFlashes\n102\nDry Rot\n86\nFloat, or Water Gauge\n102\n2 R\nDigitized by Google\n306\nINDEX.\nPage\nPage\nFloat-boards\n102\nHacking\n120\nFloating Bridge\n102\nHalf-tide Dock\n120\nFloating Clough\n103\nHarbour, or Haven\n120\nFloating Harbour\n103\nHard\n121\nFlood, or Tide-gates\n103\nHatch\n122\nFly, or Fly-wheel\n103\nHead (of water)\n122\nFootings\n104\nHeading\n#22\nForeshore\n104\nHeading Course\n122\nFoundations\n104\nHeadway\n122\nFourway Cock\n105\nHedgehog\n122\nFreestone\n106\nHewn-stone\n122\nFriction\n106\nHigh-pressure Engine\n122\nFriction Roller\n110\nHip\n123\nFuel\n110\nHoarding\n123\nHollow Quoin\n123\nGable\n111\nHorse-path\n123\nGallery\n111\nHorse-power\n123\nGasometer\n111\nHorse-run\n125\nGas Works\n111\nHorsing-block\n126\nGates (of locks, &c.)\n114\nHub\n126\nGauge Cocks\n114\nHurries\n126\nGauge of Way\n114\nHydraulic Engine\n126\nGearing\n115\nHydraulic Lime\n126\nGibs\n115\nGirder\n115\nIce Boat\n126\nGland, or Collar\n117\nInclined Plane\n126\nGneis\n117\nInjection Engines\n127\nGovernor\n117\nInlet\n127\nGradient\n117\nIntermediate Space\n127\nGranite\n118\nInvert, or Inverted Arch\n128\nGraving Dock\n118\nIron\n128\nGravity\n118\nIrrigation of land\n131\nGrillage\n119\nIsolated Harbour\n132\nGroin\n119\nGroined Arch\n119\nJib\n133\nGrouting\n119\nJoggle\n133\nGudgeon\n120\nJoint\n133\nGullies\n120\nJoint Chair\n133\nGutter\n120\nJoists\n133\nJournal\n133\nDigitized by Google\nINDEX.\n307\nPage\nPage\nKey, Cottar, or Cottrel\n133\nMitre Sill\n170\nKey-stone\n134\nMole\n170\nKing, or Crown Post\n134\nMortar\n170\nKyan's Patent Preparation\n134\nMortice and Tenon\n. 170\nLand-slip\n134\nNatural, or Quarry-beds\n171\nLeaf Bridge\n134\nNavigators\n171\nLeat\n134\nNon-condensing Engine\n171\nLeggers\n134\nNut (of a screw)\n171\nLevel (marsh land)\n.\n134\nLevel, or Gallery (mining)\n135\nOblique Arch\n171\nLevel (spirit)\n135\nOffset\n172\nLevel (crossings)\n135\nOffsets (in surveying)\n172\nLevelling\n136\nOffset Staff\n173\nLevelling Staff\n140\nOptical Square\n!\n173\nLift Wall\n140\nLighthouse\n140\nPaddle, or Clough\n173\nLime\n143\nPaddle-holes\n173\nLime-stone\n144\nPaddle-wheels\n173\nLining\n144\nParallel Motion\n176\nLink\n144\nParallel Rail\n176\nLock, or Hydraulic Lock\n145\nPassing Place\n176\nLock-gates, or Hatches\n147\nPaved Crossing\n176\nLock-sill, or Cill\n149\nPaved Ways\n176\nLock Weir\n149\nPaving\n178\nLocomotive Engine\n149\nPenstock\n179\nLode\n166\nPentagraph\n179\nLow-pressure Engine\n166\nPerbend, or Thorough\n179\nPerpendicular Lift\n179\nMachine\n166\nPermanent Way\n180\nMarine Engine\n166\nPier (marine)\n181\nMasonry\n166\nPier (of a bridge)\n182\nMechanical Power\n167\nPier (in buildings)\n182\nMechanical Powers\n167\nPig Iron\n182\nMetalling\n167\nPiles, or Pile Timbers\n182\nMile\n167\nPile-driving Machine\n183\nMill\n167\nPinion\n184\nMine\n168\nPinning, or Pinning-in\n184\nMitre\n170\nPipes\n185\nMitre Drains\n170\nPiston\n185\nDigitized by Google\n308\nINDEX.\nPage\nPage\nPiston Rod\n185\nReservoir\n204\nPlan\n185\nRetaining Wall\n205\nPlane\n185\nRetort\n205\nPlane Table\n186\nRib\n205\nPlanking\n186\nRigger\n205\nPlate Railway\n186\nRiver\n205\nPlot\n186\nRiver Wall\n207\nPlotting\n186\nRivet\n207\nPlunger\n187\nRoad, or Common Road\n207\nPlumber Block\n187\nRock\n214\nPointing\n187\nRolley\n214\nPolings\n187\nRoman Cement\n214\nPost\n187\nRoof\n214\nPortland Stone\n187\nRope Roll\n218\nPriming\n187\nRotary Engine\n218\nPrincipal\n187\nRubble Work\n219\nPrismatic Square\n187\nProtractor\n187\nSafety Valve\n219\nPuddle\n188\nSand\n220\nPunning\n188\nSandstone\n220\nPump\n188\nScaffold\n221\nPurline\n190\nScantling\n221\nPuzzolana\n190\nScarfing\n221\nScoop-wheel\n221\nQuarry\n190\nScouring Power\n221\nQueen, or Queen-post\n191\nSea Wall\n222\nQuick Lime\n191\nSection\n222\nQuay, or Key\n191\nSectio-Planography\n222\nSelf-acting Inclined Plane\n223\nRace, or Race-course\n192\nSewer\n223\nRack\n192\nSewerage\n223\nRailroad, or Railway\n192\nSextant\n224\nRailway\n203\nShaft\n224\nRailway Link\n203\nShaft (in machinery)\n225\nRailway Slide\n203\nSheave\n225\nRafters\n203\nSheet Piling\n227\nRatch\n204\nShift\n228\nRatchet-wheel\n204\nShore, or Shoar\n228\nReciprocating Engine\n204\nSide Cutting\n228\nReciprocating System\n204\nSide Forming\n228\nDigitized by Google\nINDEX.\n309\nPage\nPage\nSide Space\n228\nSurveying\n256\nSideling Ground\n228\nSuspension Bridge\n269\nSiding\n228\nSwivel Bridge\n272\nSilt\n229\nSwitch\n272\nSkew Back\n229\nSyphon\n274\nSlacked Lime\n230\nSleepers\n230\nTallus Wall\n274\nSleetch\n230\nTeaming\n274\nSlip, or Land Slip\n230\nTelegraph\n274\nSlope\n231\nTemplate\n274\nSluice, or Sluice-gate\n232\nTemplet\n274\nSmelting\n234\nTendon\n274\nSoffit\n234\nTenon\n275\nSough\n234\nTension Bridge\n275\nSpandrel Wall\n234\nTerminal Plane\n275\nSpherical Valve\n234\nTerminus\n275\nSpindle\n234\nTheodolite\n275\nSpirit Level\n234\nThrottle Valve\n275\nSpoil, or Spoil Bank\n234\nTide\n275\nStaith\n234\nTide, or Guard-lock\n276\nStarling\n234\nTide Mill\n276\nStationary Engine\n234\nTimber\n276\nStationary Plane\n235\nTraction\n277\nStationary System\n235\nTractive Power\n277\nSteam\n236\nTram\n277\nSteam-boat\n237\nTram, or Plate Railroad\n277\nSteam-engine\n243\nTransit Instrument\n280\nSteam-gauge\n253\nTrenail\n281\nSteam-pipe\n253\nTrenails, or Plugs\n281\nSteam-wheel\n253\nTruck\n281\nSteam-whistle\n253\nTube\n281\nSteps, or Bearings\n253\nTunnel\n281\nStone, or Rock\n253\nTurnbridge\n285\nStone Blocks\n255\nTurnout\n285\nStop Planks\n255\nTurnplate, or Turntable\n285\nStrap\n255\nStretching Course\n255\nUnderpinning\n285\nString Course\n255\nUndersetting\n286\nStuffing Box\n256\nSurvey\n256\nValve\n286\nDigitized by Google\n310\nDEX.\nPage\nPage\nVane\n286\nWater-works\n293\nVernier\n287\nWeir\n297\nViaduct\n287\nWelding\n297\nVoussoires\n287\nWell\n297\nWell-hole\n297\nWaggons\n287\nWet Dock\n297\nWall\n288\nWheel\n297\nWarehouse\n288\nWhims\n300\nWasher\n288\nWinch\n300\nWaste Weir\n288\nWindlass\n300\nWater Stations\n289\nWindmill\n300\nWater-wheel\n289\nWinz\n302\nWater-wings\n292\nWood-screw\n302\nDRURY, Printer,\n17, Bridgewater Square, Barbican, London.\nDigitized by Google\nERRATA.\nPage 30, line 23, for backs, read bricks.\n- 40, - 10, - 250 feet span, read 25 feet span.\n- 43, - 25, - something, read any thing.\n- 47, - 14, - coffer dams, read coffer dams, or coffre dams.\n- 49, - 2, - boats, hooks, read boat-hooks.\n- 73, - 34, - water, read dam.\n76, - 8, - material, read load.\n- 76, - 26, - strains, read weights.\n- 85, - 25, - straiths, read staiths.\n- 89, - 18, - prismoidal, read prismoid.\n- 100, - 29, - covered, read curved.\n- 101, - 10, - posts, read parts.\n- 105, - 11, - sheep, read sheet.\n- 105, - 32, - C, read D.\n- 105, - 32, - D, read C.\n- 106, - 2, - lower, read upper.\n- 106, - 3, - upper, read lower.\n- 106, - 5, - D, read C.\n- 107, - 21, - roading, read roadway.\n- 109, - 7, - runs, read run.\n- 109, - 21, - 33, read 33*.\n- 129, - 9, - clumps, read clamps.\n- 166, - 34, - crumped, read cramped.\n- 171, - 27, - brick, read bridge.\n- 182, - - 29, - pig-iron, read iron.\n- 224, - 19, - dry, read dug.\n- 242, - 29, - P, read I.P.\n- 269, - 25, - bone, read horn.\n- 290, 15, - mometum, read momentum.\nDigitized by Google\nDigitized by Google\nWORKS RECENTLY PUBLISHED\nON THE VARIOUS BRANCHES OF\nARCHITECTURE, CIVIL AND MILITARY ENGINEERING,\nMECHANICS, NAVAL ARCHITECTURE, &c. &c.\nBY JOHN WEALE,\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN,\nhere an Extensive Stock of all the approved Publications relating to the above Subjects, and the\nFine Arts, whether Foreign or Domestic, is constantly on Sale.\n1.\nJust Published, in large 4to., Price 18s.\nSTUDIES OF MODERN ENGLISH ARCHITECTURE.\nTHE TRAVELLERS' CLUB-HOUSE.\nBy CHARLES BARRY, Architect.\nIllustrated by Engravings of Plans, Sections, Elevations, and Details, by J. H. LE KEUX.\nWith an Essay, including a Description of the Building, by Mr. W. H. LEEDS.\n* This volume, complete in itself, is proposed as the first of a series under the general title of The\nModern School of English Architecture.\"\n6 The Plates, engraved by J. H. Le Keux, from the Drawings of Mr. Hewitt, are examples of\nrfection in this species of art. We do not believe that any artists that ever lived could carry it\nther. They will afford exemplars both to architectural draughtsmen and engravers, as well as to\nchitects themselves; and will go down to posterity as the remains of Grecian architecture have\nscended to us.\n4\nThe author before us seems to be exactly the sort of commentator to grapple with doubts and\nnfficting opinions, since he is not hampered with school prejudices and conventionalities; but com-\nes fresh thoughts and sound reflections on his subject with good taste and elegant diction.'-\nrobe, No. 13.\n2.\n50 Plates, neatly engraved. Imperial 4to., Price £2. 8s.\nORNAMENTAL IRON WORK.\nGATES, LODGES, PALISADING, AND RAILS OF THE ROYAL PARKS;\nWith some others, including the Entrances to the SULTAN'S PALACE at CONSTANTINOPLE.\nrt. I. is just published, containing 25 Plates, Price £1. 4s. Part. II. will be published in Feb., 1840.\nle work consists of Engravings of Plans of Regent's, Hyde, and St. James's Parks, the Lodges,\ntrance Gates, Ornamental Rails, &c.; with those of Hampton Court and Greenwich; the Gates\ninufactured in this country for the Sultan's Palace, together with other very interesting examples of\ne modern improved style. Designed principally by John Nash, Decimus Burton, &c., Architects;\nth some of the old style by Inigo Jones, Sir Christopher Wren, &c.\nDigitized by\nGoogle\n2\nWORKS PUBLISHED BY JOHN WEALE,\n3.\nTREDGOLD ON THE STEAM ENGINE\nAND\nON STEAM NAVIGATION.\nThese very important and interesting volumes, comprising 125 very elaborate and beautifully engraved\nPlates, are, in Sections, Elevations, Plans, Details, &c., of the highest utility to the Engineer and\nStudent, to Manufacturers of Marine, Locomotive, and Land Engines ;-the science being elucidated\nand explained by the most eminent practical men of Britain. In 2 4to. vols., price £4. 4s., entitled\nTHE STEAM ENGINE;\nComprising an account of its invention and progressive improvement, with an INVESTIGATION of its\nPRINCIPLES, and the PROPORTIONS of its PARTS for EFFICIENCY and STRENGTH; detailing also its\napplication to NAVIGATION, MINING, IMPELLING MACHINES, &c., and the Result in numerous Tables\nfor Practical Use, with Notes, Corrections, and New Examples, relating to Locomotive and other Engines.\nREVISED AND EDITED BY W. S. B. WOOLHOUSE, F.R.A.S., &c.\nThe algebraic parts transformed into easy practical Rules, accompanied by Examples familiarly\nexplained for the Working Engineer, with an ample\nAPPENDIX,\nContaining, besides a vast acquisition of Practical Papers, an Elementary and Practical Description of\nLocomotive Engines now in use, illustrated by Examples ; and the Principles and Practice of Steam.\nfor the purposes of Navigation either in Rivers or at Sea; showing its present and progressive state, by\nillustration of the various Examples of Engines constructed for Sea, War, and Packet Vessels, and River\nBoats, by the most eminent Makers of England and Scotland, drawn out in Plans, Elevations, Sections,\nand Details, with a Scientific Account of each, and on\nSTEAM NAVAL ARCHITECTURE,\nShowing, by existing and the latest Examples, the Construction of War, Sea, and Packet Vessels: their\nNaval Architecture, as applied to the Impelling Power of Steam for Sea and River purposes. This\nportion of the work is edited by several very eminent Ship Builders—\nOLIVER LANG, Esq., of H.M. Dock-yard, Woolwich,\nJ. FINCHAM, Esq., H.M. Dock-yard, Chatham.\nT. J. DITCHBURN, Esq., Deptford and Blackwall.\nThe new subjects in this edition consist of the works of\nMessrs. Boulton and Watt.\nWilliam Morgan, Esq.\nThe Butterley Company.\nMessrs. Hall, Dartford.\nMessrs. Maudslay, Sons, and Field.\nEdward Bury, Esq., Liverpool.\nMessrs. Seaward.\nMessrs. Hague.\nRobert Napier, Esq., Glasgow.\nMessrs. Claude, Girdwoord, and Co.\nMessrs. Fairbairn and Murray.\nMessrs. Stephenson and Co., Newcastle upon Type.\nDedicated, by Permission, to Der Majesty.\nLIST OF PLATES.\n1. Isometrical projection of a rectangular steam boiler.\n20. Side elevation and cross section of a steam carriage.\n2. Two sections of a cylindrical steam boiler.\n21. Kingston's valves.\n3. Brunton's apparatus for feeding furnaces by machinery.\nblow-off valves.\n4. High pressure engine with four-passaged cock.\ninjection valves.\n5. Section of a double acting condensing engine for work-\nhand pump valves.\ning expansively.\n22. Boilers of Her Majesty's steam vessel African.\n6. Section of a common atmospheric engine.\n23. Boilers of Her Majesty's steam frigate Medea.\n7. Represents the construction of pistons.\n24. Paddle wheels of Morgan and Seaward.\n8. Parts of Fenton and Murray's double engine.\n25. Positions of a float of a radiating wheel, and also of &\n9. Apparatus for opening and closing steam passages.\nvertical acting wheel, in a vessel in motion.\n10. (A). 10 (B). Parallel motions or combinations used to\n26. Cycloidal paddle wheel fitted to the Great Western.\nproduce rectilinear motion from motion in a circular arc.\n27, 28. Illustrate Captain Oliver's paper.\n11. Plan and elevation of an atmospheric pumping engine\n29. Exhibits the various situations of a trial at sailing of\nfor raising water from a mine.\nthe Medea, with the Caledonia, Vanguard, and Asia.\n12. Boulton and Watt's single acting engine.\n30. Side view of the engines of the Red Rover, and City of\n13. Double acting engine for raising water.\nCanterbury, steam vessels.\n14.\nfor impelling machinery, by Fen-\n31. Longitudinal section of ditto.\nton, Murray & Co.\n32. Cross section of engines of ditto.\n15. Maudslay's portable engine.\n33. Side elevation of the engine of the Nile steam ship.\n16. Indicator for measuring the force of steam in the\n34. Plan of the engine of the Nile.\ncylinder.\n35. зб. Cross sections of engines of the Nile.\nDiagrams to illustrate the comparative stability of\n37, 38, 39. Engines of Her Majesty's steam frigate Phonis.\nopposite classes of vessels.\n40. Engines of the Ruby Gravesend packet.\n17. Section of a steam vessel with its boiler in two parts.\n41. Section of one of the engines of the Don Juan Penis-\n18. Isometrical projection of a steam boat engine as first\nsula Company's packet.\nnged by Boulton and Watt.\n42. Boilers of Her Majesty's ships Hermes, Spitfire, 1\nand plan of steam boat engine.\nFirefly.\nDigitized by\nGoogle\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN.\n3\n43, 44, 45, 46. Elevation, plan, and two sections of the\n70. (A). 70 (B). Sections of the engines of the Berenice\nengines of the armed Russian steam ships Jason and\nsteam vessel.\nColchis.\n71, 72. Beale's patent rotatory engine.\n47, 48. Hall's improvements on steam engines.\n73. Mr. Ayre's contrivance for preventing a locomotive\n49, 50. Engines of Her Majesty's steam ship Megæra.\nengine from running off a railway.\n51, 52, 53, 54. Engines of the Hull and London packet\n74 to 83. Relate to the very important subject of all kinds\nWilliam Wilberforce.\nof paddle wheels.\n55. (A). Longitudinal section of Humphrys's patent marine\n84 to 88. Sixty-five inch cylinder engine, erected by\nengine.\nMessrs. Maudslay, Sons, and Field, at Chelsea water-\n55. (B). Longitudinal elevation of Humphrys's marine\nworks.\nengine.\n89 to 92. Patent locomotive engine, made by Messrs. R.\n56. (A). Midship section of the steam packet Dartford,\nStephenson and Co. for the London and Birmingham\nshowing a front elevation of a pair of Humphrys's\nRailway.\nengines.\n93. Drawings of the Comet, the first steam boat in Europe.\n56. (B). Plan of the engines of the Dartford.\n94. The Pacha's steam vessel of war, the Nile.\n57, 58, 59. Forty-five horse power engine, constructed by\n95, 96. The Hon. East India Company's steam vessel\nW. Fairbairn and Co.\nBerenice.\n60, 61, 62, 63. Ten-horse power engine, constructed by\n97. Draught of the Forbes steamer, Chinese rigged.\nW. Fairbairn & Co.\n98. Herne Bay steam packet Red Rover.\n64. Elevation of a locomotive engine, Stanhope and Tyne\n99. Diamond Company's steam packet Ruby.\nRailway; constructed by Messrs. R. Stephenson and\n100 to 103. Her Majesty's steam vessel of war Medea.\nCo., of Newcastle upon Tyne.\n104 to 107. Construction of the Nile steam ship, built for\n65. Section of ditto.\nthe Pacha of Egypt.\n66. Safety valves of ditto.\n108, 109, 110. His Imperial Majesty's armed steam vessel\n67. (A). Cylinder cover and connecting rods of ditto.\nColchis.\n67. (B). Cylinder and piston at large of ditto.\n111, 111 (A). Engines of the steam ship Tiger.\n68. Plan and section of boiler seating for a twenty-horse\n112. The Admiralty yacht Firebrand.\nengine, at the manufactory of Messrs. Whitworth and\n113. Portrait of the late Mr. Watt.\nCo., Manchester.\n114. Portrait of the late Mr. Tredgold.\n69. Messrs. Hague's double acting cylinder, with slides, &c.\n115, 117, 118. Illustrate steam navigation in America.\n4 The first publication of Mr. Tredgold's work,\nlightened philosophers as well as experienced\non one of the most important mechanical and\nartisans, are explained to us, and set before our\nscientific subjects of our age, was so highly suc-\neyes 80 as to be palpable to the understanding.\ncessful, that, besides being translated into the\nIn the same way the locomotives of the Messrs.\nFrench, and, we believe, other languages, a new\nStephenson, of Newcastle, the construction of\nedition was imperatively called for. That call\nthe elegant government steam boats of Mr. Lang,\nhas been answered by the present enlarged work,\nof Woolwich, and Mr. Fincham, of Chatham, (ves-\nin which has been embodied the progress and\nsels it is a delight to notice as we pass up or\nimproved application of that mighty agent Steam,\ndown the river,) are rendered familiar to us; and\nan investigation of its principles, and a practical\nwe care little to vex ourselves about hypothetical\nview of its uses and effects in steam vessels, steam\nimprovements and untried experiments. We have\ncarriages, and railroads. When we look around\nwitnessed so many pseudo certain and undeniable\nus and see the face of the country changed and\ninventions fail, that we have become rather scep-\nchanging; the expedition of a week compressed\ntical when we hear of patents that are to supersede\ninto a single day the limits of pleasure and of\nall that has been done before, or listen to the dic-\nbusiness widely extended among all classes of\ntatorial laws of people whom we have known to\nsociety new wants created, and new wishes\nbe more frequently wrong than right. We are\ngratified; sedentary easily and readily converted\nglad to observe, however, that in this new edition\ninto ambulatory life; the sphere of city homes, as\nmost of the errors of the former have been cor-\nit were, enlarged by a circle of rural miles ;-\nrected ; and what questionable statements or\nwhen, in fact, we see the prodigious alteration\nmistakes may remain are not such as to impeach\nmade in our social, statistical, economical, po-\nthe vast utility of the publication.\nlitical, national, and international system, by the\nThe Appendix, indeed, is deserving of much\ngrowing powers of this vast engine, we cannot\npraise. The rules of practice are well expounded,\nbut consider the effort to offer us a just and com-\nand the mathematical calculations, remodified into\nprehensive account of it to be one of the most me-\nsimple arithmetic, are excellent for the purpose of\nritorious within the scope of individual industry,\nenabling the working man \"operative\" is the\nskill, and labour. We, therefore, think the public\nfashionable phrase) to perform his duty.\ndeeply obliged to Mr. Tredgold, the author, and\n' Upon the whole, not to dwell upon either real\nMr. Weale, the enterprising publisher, who must\nor supposed imperfections, inseparable from a\nhave expended a very large sum on the risk, for\nproduction embracing so vast a number of com-\nthe very important volumes now before us.\nplicated matters-a production treating of things\n6 It is apparent that it is a publication of great\nin an almost daily state of partial transition-we\nmagnitude and great worth. Above a hundred\nfeel bound to pronounce this treatise to be a very\nplates of steam engines, &c. &c., illustrate its\nable and satisfactory exposition of the state of\ndescriptions; and many wood-cuts serve further\nsteam navigation and railroad travelling to the\nto render the contents plain and intelligible to\npresent time and as such we heartily recommend\nevery capacity. Thus the actual operations of\nit to the public at large, both at home and on the\nsuch men as Boulton and Watt, Maudslay and\ncontinent, where its predecessor has hitherto been\nField, Seawards, Napier of Glasgow, and other\nesteemed a standard work.-Literary Gazette,\neminent mechanicians, and, we may add, en-\nAugust 3, 1839.\nDigitized by\nGoogle\n4\nWORKS PUBLISHED BY JOHN WEALE,\n4.\nIn 2 vols., very neatly half-bound in morocco or russia, gilt tops, Price £5. 5s.\nTREDGOLD ON THE STEAM ENGINE AND ON STEAM NAVIGATION.\n5.\nIn 2 vols., elegantly bound in russia or morocco, gilt leaves, Price £5. 15s. 6d.\nTREDGOLD ON THE STEAM ENGINE AND ON STEAM NAVIGATION.\nThis work having been selected as a Prize-book by the Institution of Civil Engineers, and several\nother Institutions, and by practical Engineers for presents to their Pupils, can be had in any other style\nof binding by giving seven days' notice.\n6.\nIn 2 vols., very neatly half-bound in red morocco, gilt tops; the Text in quarto, and the Plates printed\nseparately on fine Columbier folio paper, Price £7. 78.\nTREDGOLD ON THE STEAM ENGINE AND ON STEAM NAVIGATION.\n7.\nThe Plates sold separately, on Columbier folio, very neatly half-bound in red morocco, gilt tops,\nPrice £5. 5s.\nTREDGOLD ON THE STEAM ENGINE AND ON STEAM NAVIGATION.\nIn many instances purchasers of the work in 2 vols. have also possessed themselves of these\nPlates in a separate form, not only for practical use and reference, but as a Table-book, to exhibit the\nsplendour of the Steam Machinery of Britain.\n8.\nIn quarto size, with four elaborately engraved Plates, and numerous Wood-cuts of Details, Price £1. 1s.\nin cloth boards.\nDESCRIPTION OF THE PATENT LOCOMOTIVE STEAM ENGINE\nOF MESSRS. ROBERT STEPHENSON AND Co.,\nNEWCASTLE UPON TYNE.\n*** The above Work is affixed to the publication of the 2nd edition of Tredgold, and has been pub-\nlished separately for the use of those who desire a perfect knowledge of the Locomotive Engine\nseparate from other Steam Engines. The description is both popular and scientific, and was drawn up\nunder the immediate superintendence of Robert Stephenson, Esq. The Engravings are large, and are\nunique examples of mechanical engraving. The cost of the four Plates was £400; the wood-cuts,\n40 in number, are explanatory of such details of the Engine as cannot be shown in the Elevation,\nPlan, Cross or Transverse Section; nor so well described in language as by the ocular demonstration of\nthese, intermixed as they are with the descriptive text. It will be found that this extraordinary modern\nEngine, which owes its present improvements to the Stephensons, is made available to the million by\nbeing explained in the plainest language, and divested of mathematical formulæ.\n9.\nSTEAM NAVIGATION.\nJust published, in Atlas folio size, uniform with Telford's works and the Atlas copies to Tredgold,\nPrice 12s.\nAPPENDIX A. TO THE NEW EDITION OF TREDGOLD ON THE\nSTEAM ENGINE.\nCONTENTS.\nPlate I.-Iron Steam (achtGlow-worm, constructed\npower each, 50-inch cylinders, 4-6 stroke, made\nby John Laird, Esq., Birkenhead, Liverpool.\nby G. Forrester and Co., of Liverpool, and fitted\nPlates II. and III.-Iron Steam Ship Rainbow,\non board of the Rainbow.\nbelonging to the General Steam Navigation\nPlate V.-Side Elevation and Section of ditto.\nCompany, draught lines at bottom, fore body\nPlate VI.-Transverse Section of ditto.\nto a large scale, by Ditto.\nPlate VII-Draught of the American Armed\nPlate IV.-Plans of the Engines of 90-horse\nSteam Ship Fulton. Half the main breadth,\n)\nDigitized by\nGoogle\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN.\n5\n17 feet distance between the water lines, 2\nPlates IX. and X.-Plans of the Upper and Lower\nfeet ; fore and after body precisely alike.\nDecks of the Iron Steam Ship Nevka, con-\nPlate VIII. - Plans of the Upper and Lower\nstructed for Her Imperial Majesty the Empress\nDecks of the Admiralty Yacht Firebrand,\nof Russia, by Messrs. Fairbairn and Murray, of\nshowing the fittings and conveniences; drawn\nMill Wall, Poplar.\nby Mr. James Henry Lang, of Woolwich.\nAPPENDIX B. is in preparation. To contain the remaining five Engravings of the Nevka, the\nSteam Engine in the Royal Arsenal at Woolwich, and other interesting subjects together with the Text\nfor both Parts. Price 12s.\n10.\nJust published, vol. 3, with several Plates, Price £1. 5s.\nPAPERS ON SUBJECTS CONNECTED WITH THE DUTIES OF\nTHE CORPS OF ROYAL ENGINEERS.\nCONTENTS.\nIntroduction.\n205 feet span, at Paradenia, with an account of\nMemoranda relative to the Lines thrown up to\nthe execution of the work and the means em-\ncover Lisbon in 1810. By Colonel JOHN T.\nployed in throwing it across the river Mahavil-\nJONES, Royal Engineers.\nlaganga, in the island of Ceylon. By Captain\nMemoranda relating to the Defence of Cadiz, and\nOLDERSHAW, Royal Engineers.\nexplanatory details of the Position intrenched\nDescription of a Series of Bridges erected across\nby the British troops under Lieutenant-General\nthe river Ottawa, connecting the provinces of\nGRAHAM, in 1810.\nUpper and Lower Canada, and especially of a\nInstructions of the Minister of War concerning\nwooden arch of 212 feet span which crossed\nthe Model-towers approved of by Napoleon.\nthe main branch of the river. By Lieutenant\nTranslated by Lieut. LAFFAN, Royal Engi-\nDENISON, Royal Engineers.\nneers.\nDescription of a Barometer that requires no cor-\nReport on the Demolition of the Revetments of\nrections either for Zero or for Temperature.\nsome of the Old Works at Sheerness, on Sa-\nBy SAMUEL B. HOWLETT, Esq., Chief Draughts-\nturday the 14th July, 1827.\nman, Ordnance.\nLetter from Lieut.-Colonel ROBERT THOMSON to\nNotes to aid in correcting the operation of ascer-\nLieutenant DENISON on the subject of Furnaces\ntaining the Heights of Mountains by means of\nfor heating Shot.\nBoiling Water; furnished by Major ORD, Royal\nMemoir on Posen, by T. R. STAVELY, Esq., late\nEngineers.\nCaptain Royal Engineers.\nOn the Decomposition of Metallic Iron in Salt\nReport on Beaufort Bridge. By R. J. NELSON,\nWater, and of its Reconstruction in a Mineral\nLieutenant Royal Engineers.\nform. By Lieut.-Col. REID, Royal Engineers.\nRough Sketch of the Suspension Bridge over the\nReport on the Effect of Climate on Yorkshire\nLahn at Nassau. By R. J. NELSON, Lieutenant\nPaving, communicated by Colonel FANSHAWE,\nRoyal Engineers.\nRoyal Engineers.\nDetailed Description of some of the Works on the\nReport of Paving Stables at Brighton.\nRideau Canal, and of the alterations and im-\nExperiments tried at Quebec as to the properties\nprovements made therein since the opening of\nand adhesive qualities of Cements, by order of\nthe navigation. By Lieutenant DENISON, Royal\nColonel NICOLLS, Commanding Royal Engineer,\nEngineers.\ndated 17th November, 1834.\n)n the mode of Bending Timber adopted in\nProof of an Earthen Ware Pipe for Lieutenant\nPrussia. By R. J. NELSON, Lieutenant Royal\nDenison. By Mr. BRAMAH.\nEngineers.\nDescription of a Drawbridge on the London and\nDescription of the Coffer-dam used in the Con-\nBirmingham Railway, at Weedon. By Captain\nstruction of the Piers of the Alexandria Aque-\nJEBB, Royal Engineers.\nduct, being an abstract of a report addressed\nTable of the Description and Weight of the\nby Captain TURNBULL to Lieutenant-Colonel\nPackages of various Articles of Traffic, By\nABERT, and by him submitted to the House of\nMajor H. D. JONES, Royal Engineers.\nRepresentatives of the United States.\nAPPENDIX.-Notes on Lintz.\nDescription of the one-arch Wooden-Bridge, of\nNotes to pages 36 and 39.\n11.\nVol. 2, uniform with the preceding, Price £1.\n12.\nVol. 1, reprinting, Price 15s.\nDigitized by\nGoogle\n6\nWORKS PUBLISHED BY JOHN WEALE,\n13.\n153 Plates, engraved in the best style of Art, half-bound, very neat, Price £4. 48.\nPUBLIC WORKS OF GREAT BRITAIN;\nCONSISTING OF\nRailways, Rails, Chairs, Blocks, Cuttings, Embankments, Tunnels, Oblique Arches, Viaducts, Bridges,\nStations, Locomotive Engines, &c.; Cast-Iron Bridges, Iron and Gas Works, Canals, Lock-gates,\nCentering, Masonry and Brickwork for Canal Tunnels; Canal Boats; the London and Liverpool Docks,\nPlans and Dimensions, Dock-gates, Walls, Quays, and their Masonry; Mooring-chains, Plan of the\nHarbour and Port of London, and other important Engineering Works, with Descriptions and Specifi-\n:ations; the whole rendered of the utmost utility to the Civil Engineer and to the Nobility and Gentry,\nIS Monuments of the useful Arts in this Country, and as Examples to the Foreign Engineer.\nEDITED BY F. W. SIMMS, C.E.\nThis Work is on an Imperial folio size, the Drawings and Engravings have been executed by eminent\nArtists, and no expense has been spared in rendering it highly essential to the Civil Engineer and\nStudent also, as an ornamental Volume of Practical Representations of important Engineering Works\nn several Parts of the Kingdom. The Work is bound in half-morocco. There are some Plates in the\nVolume that may be preferred in Colours, viz., the elaborate subject of the Blisworth Cuttings, in the\nBirmingham Line, 18 Plates, geologically coloured; Glasgow and Gairnkirk Railway Cutting through\nMoss, geologically coloured, &c. making 20 Plates, to be carefully coloured, and for which an\ndditional £1. 1s. is charged.\nThe following is a list of the Authors whose works are comprised in the volume.\nBrindley\nHartley\nM'Adam\nTelford\nBrunel\nHosking\nPalmer\nThomas\nBuck\nJessop\nRennie\nTierney Clark\nG. and R. Stephenson\nLandmann\nRhodes\nWalker.\n14.\n22 Plates, large folio, bound, Price £1. Is.\nTHE HARBOUR AND PORT OF LONDON,\nSCIENTIFICALLY, COMMERCIALLY, AND HISTORICALLY DESCRIBED;\nContaining Accounts of the History, Privileges, Functions, and Government thereof; of its Extent,\nDivisions, and Jurisdictions, Municipal and Commercial; of its Docks, Piers, Quays, Embankments,\nMoorings, and other Engineering Works Tidal and other Observations, and every other necessary\nnformation relative thereto, accompanied by Charts of the Port and its Dependencies, its Shoals and\nloundings, surveyed by order of the Port of London Improvement Committee; Plans of Docks, Gates,\n'iers, Swivel Bridges, Methods of Mooring Vessels, &c., as directed by the Corporation By-Laws\nkc., &c., &c.\nBy JAMES ELMES, Architect and Civil Engineer, Surveyor of the Port of London.\n15.\nIn 8vo., with Engravings and Wood-cuts, cloth bds. extra, Price 12s.\nOUTLINE OF THE METHOD OF CONDUCTING A\nTRIGONOMETRICAL SURVEY,\nor the Formation of Topographical Plans; and Instructions for Filling-in the Interior Detail, both b)\nMeasurement and Sketching; Military Reconnaissance, Levelling, &c., &c.\nWith the Explanation and Solution of some of the most useful Problems in Geodesy and Practical\nAstronomy; to which are added, a few Formulae and Tables of general utility for facilitating\ntheir calculation.\nBy Lieutenant FROME, ROYAL ENGINEERS, F.R.A.S., & A.I.C.E.\nDigitized by\nGoogle\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN.\n7\n16.\nRAILWAYS.\nIn Imperial folio, 83 Engravings, with explanatory Text, containing the Specification of the Works as\nexecuted.\nEDITED BY F. W. SIMMS, C.E.\nPrice £2. 12s. 6d. in half-morocco.-Subjects\nTHE LONDON AND BIRMINGHAM RAILWAY-THE GREAT WESTERN RAILWAY-THE SOUTH-\nAMPTON RAILWAY-THE GREENWICH RAILWAY-THE CROYDON RAILWAY-THE BIRMINGHAM\nAND BRISTOL THAMES JUNCTION RAILWAY-GLASGOW AND GAIRNKIRK RAILWAY. In 83 Plates,\nwith Sections, Details, &c.\nLONDON AND BIRMINGHAM RAILWAY.\n1. Frontispiece-London Entrance to the Primrose Hill\n18, 19. Entrances to ditto-Vignettes, pages 31 and 34.\nTunnel.\n20 to 29. Working Section, Blisworth Excavations and\n2. Title Page, vignette-Railway Station at Watford.\nEmbankments.\n3. Chimneys at Camden Town fixed Engine Station.\n30, 31. Undersetting of Rock in Blisworth Cuttings-En-\n4. Entrance to Railway Station at Euston Grove-Vig-\nlarged Scale.\nnette, page 1.\n32, 33. Plan and Elevation of Retaining Walls, Counter-\n5. Euston Grove Station, ground-plan.\nforts, Inverts, Drains, &c. in the Blisworth Cuttings.\n6. Camden Town fixed Engine Station, ground-plan.\n34, 35. General Plan and Section of the Undersetting of\n7. Iron Roof-Euston Grove Station.\nthe Rock in the Blisworth Cuttings.\n8. Stanhope Place and Park Street Bridges.\nзб, 37. Plan, Elevation, and Section of the West End of\n9. Bridge over the Regent's Canal.\nthe Blisworth Cuttings.\n10. Details of ditto.\n38 to 47. Plan, Elevations, and Details of the Kilsby Tun-\n11. London and Birmingham Railway-Harrow in the\nnel, Warwickshire.\ndistance. Vignette, page 17.\n48. Method of fixing the Fifty-pound Rails in the\n12. London and Birmingham Railway-Watford Tunnel.\nChairs.\nVignette, page 28.\n49. Method of fixing the Sixty-five-pound Rails in the\n13. Road Bridge over Railway.\nChairs.\n14. Colne Viaduct.\n50. Mr. Buck's Railway Chairs.\n15. Bridge over Excavation south of Watford Tunnel.\n51. Plan of Siding or Passing Place.\n16. Box Moor Oblique Bridge.\n52. Plans and Sections of a Twelve-feet Turn Rail.\n17. North Church and Primrose Hill Tunnels Cross\n53. Plan and Elevation of First Class Carriages.\nSections.\nGREAT WESTERN RAILWAY.\n54. Plan and Elevation of the Brent Viaduct.\n57. Plan and Elevation of Maidenhead Bridge.\n55. Sections of the Brent Viaduct.\n58. Sections of Maidenhead Bridge.\n56. Transverse Sections of the Brent Viaduct.\n59. Occupation Bridge over the Railway.\nSOUTHAMPTON RAILWAY.\n60. Bridge under Railway.\n63. Occupation Bridge.\n61. Plan of ditto.\n64. Elevation and Details of Earth-work and Timber\n6a. Occupation Bridge in Embankment.\nWaggons.\nGREENWICH RAILWAY.\n65. Oblique Arch over Neckinger Road.\n68, 69. Sections of ditto.\n66. Sections of ditto.\n70. Viaduct of the Greenwich Railway.\n67. Oblique Arch over Spa Road.\nCROYDON RAILWAY.\n71. New Cross Bridge over Railway.\n72. Method of fixing the Permanent Way.\nBIRMINGHAM AND BRISTOL THAMES JUNCTION RAILWAY.\n73. Cast-iron Arch Suspension Bridge over the Paddington\n74. Railway Gallery under the Canal, &c.\nCanal and the Railway.\nGLASGOW AND GAIRNKIRK RAILWAY.\n75. Transverse Section at Robroyston Moss.\nMISCELLANEOUS.\n76. Comparison of the Transverse Section of numerous\n80. Flat Rail with Flange.\nRailway Bars.\n81. Rail by Losh, Wilson, and Bell.\n77. Comet Locomotive Engine.\n82. Hetton Rail.\n78. Mr. Stephenson's Patent Locomotive Engine.\n83. Sidings or Passing Places.\n79. Railway Waggons.\nDigitized by\nGoogle\n8\nWORKS PUBLISHED BY JOHN WEALE,\n17.\nThe new Bork on Bridge Building.\nVol. 1, royal octavo, is just completed, Price £1. 16s., containing 380 pages of Text and 55 elaborately\nengraved Plates, with every detail and dimension for practical use, entitled,\nTHEORY, PRACTICE, AND ARCHITECTURE OF BRIDGES.\nTHE THEORY BY JAMES HANN, OF KING'S COLLEGE,\nHon. Mem. of the Philosophical Society of Newcastle upon Tyne, Mem. of the Mathematical Society\nof London, and Joint Author of \" Mechanics for Practical Men;\"\nAND\nTHE PRACTICAL ENGINEERING AND ARCHITECTURAL TREATISE\nBY WILLIAM HOSKING, F.S.A.,\nArchitect and Civil Engineer, Author of \" Treatises on Architecture and Building;\"\nPROFESSOR MOSELEY, M.A., KING'S COLLEGE; T. HUGHES, AND ROBERT STEVENSON,\nCivil Engineers.\nThe Work will be completed in 2 Vols., to contain 700 pages of Text, and illustrated by 110 En-\ngravings of examples of Stone, Timber, Iron, Wire, and Suspension Bridges, from Drawings furnished\nby the principal Engineers of Great Britain and France.\nVol. 2 is preparing, and is to be published in 6 Parts, at intervals, in the course of the year 1840.\n*** This Work, when completed, will be found to be of a most valuable character, the highest talent\nhaving been engaged for the Engravings, and the price made convenient to the Student.\nAtlas copies of the Plates may be had.\n18.\nIn demy 8vo., numerous Wood-cuts, extra cloth bds., Price 8s.\nAN ESSAY ON THE BOILERS OF STEAM ENGINES:\nTheir Calculation, Construction, and Management, with a view to the SAVING OF FUEL. Including\nObservations on Railway and other Locomotive Engines, Steam Navigation, Smoke Burning, Incrus-\ntations, Explosions, &c. &c. A New Edition, considerably enlarged and improved.\nBy R. ARMSTRONG, Civil Engineer.\n19.\nVol. 1, Price 30s., extra cloth bds., containing a Portrait of the late President, Thos. Telford, Esq.,\nand 27 finely engraved Plates.\nTRANSACTIONS OF THE INSTITUTION OF CIVIL\nENGINEERS.\n*** Except 15 copies, which only remain of this Volume, all of them being deficient of Mr. Macneill's\nTables, the Volume is out of print, and scarce. It will however be reprinted some time in the year\n1840.\n20.\nVol. 2, Price 28s., extra cloth bds., containing 23 finely engraved Plates.\nTRANSACTIONS OF THE INSTITUTION OF CIVIL\nENGINEERS.\nLIST OF SUBJECTS.\nAccount of the Bridge over the Severn, near the\nA Series of Experiments on different kinds of\nTown of Tewkesbury, in the County of Glou-\nAmerican Timber. By W. DENISON, Lieut.\ncester, designed by THOMAS TELFORD, and\nRoyal Engineers, F.R.S., A.Inst.\nerected under his superintendence. By W.\nOn the Application of Steam as a moving Power,\nCKENZIE, M.Inst.C.E.\nconsidered especially with refereráce to the\nDigitized by Google\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN.\n9\neconomy of Atmospheric and High Pressure\nOn certain Forms of Locomotive Engines. By\nSteam. By GEORGE HOLWORTHY PALMER,\nEDWARD WOODS.\nM.Inst.C.E.\nAccount and Description of Youghal Bridge, de-\nDescription of Mr. Henry Guy's method of giving\nsigned by Alexander Nimmo. By JOHN E.\na true Spherical Figure to Balls of Metal, Glass,\nJONES, A.Inst.C.E.\nAgate, or hard Substances. Communicated by\nOn the Evaporation of Water from Steam Boilers.\nBRYAN DONKIN, V.P.Inst.C.E.\nBy JOSIAH PARKES, M.Inst.C.E.\nOn the expansive action of Steam in some of the\nAccount of a Machine for cleaning and deepening\nPumping Engines on the Cornish Mines. By\nsmall Rivers, in use on the Little Stour River,\nWILLIAM JORY HENWOOD, F.G.S., Secretary\nKent. By W. B. HAYS, Grad.Inst.C.E.\nof the Royal Geological Society of Cornwall,\nDescription of the Perpendicular Lifts for passing\nH. M. Assay-Master of Tin in the Duchy of\nBoats from one Level of Canal to another, as\nCornwall.\nerected on the Grand Western Canal. By\nOn the effective power of the High Pressure ex-\nJAMES GREEN, M.Inst.C.E.\npansive condensing Engines in use at some of\nOn the methods of Illuminating Lighthouses, with\nthe Cornish Mines. By THOMAS WICKSTEED,\na description of a Reciprocating Light. By J.\nM.Inst.C.E. A letter to the President.\nT. SMITH, Captain Madras Engineers, F.R.S.,\nDescription of the Drops used by the Stanhope\nA.Inst.C.E.\nand Tyne Railroad Company, for the Shipment\nExperiments on the Flow of Water through small\nof Coals at South Shields. By THOMAS E.\nPipes. By W.A. PROVIS, M.Inst.C.E.\nHARRISON, M.Inst.C.E.\nExperiments on the Power of Men. By JOSHUA\nOn the Principle and Construction of Railways of\nFIELD, V.P.Inst.C.E., F.R.S.\ncontinuous bearings. By JOHN REYNOLDS,\nParticulars of the Construction of the Floating\nA.Inst.C.E.\nBridge lately established across the Hamoaze,\nWooden Bridge over the River Calder, at Mirfield,\nbetween Torpoint in the County of Cornwall,\nYorkshire, designed and erected by WILLIAM\nand Devonport in Devonshire. By JAMES M.\nBULL, A.Inst.C.E.\nRENDEL, M.Inst.C.E., &c. &c.\nA Series of Experiments on the Strength of Cast\nAPPENDIX.-Officers, Members, &c.\nIron. By FRANCIS BRAMAH, M.Inst.C.E.\n21.\nVol. 3, Part I., extra cloth boards, Price 4s.\nTRANSACTIONS OF THE INSTITUTION OF CIVIL\nENGINEERS.\nCONTENTS.\nOn Steam Boilers, by JOSIAH PARKES, M.Inst.C.E.\n22.\nVol. 3, Part II.\nTRANSACTIONS OF THE INSTITUTION OF CIVIL\nENGINEERS.\nCONTENTS.\nOn Steam Boilers and Steam Engines, Part. II.\nthat and other Suspension Bridges, in reference\nBy JOSIAH PARKES, M.Inst.C.E.\nto the action of violent gales. By C. W. PAS-\nOn the Comparison between the Power of Loco-\nLEY, Colonel R.E., Hon. M.Inst.C.E. 1 Plate.\nmotive Engines and the Effect produced by\nOn the Expansion of Iron and Stone in Structures,\nthat Power at different Velocities. By Pro-\nas shown by observation on the Southwark and\nfessor BARLOW, Hon. M.Inst.C.E.\nStaines Bridges. By GEORGE RENNIE, F.R.S.,\nOn the Properties, Uses, and Application of Turf,\n&c. &c.\nTurf-Coke, and Resin Fuel. By C. WYE WIL-\nThe Gravesend Pier. By W. TIERNEY CLARK,\nLIAMS, A.Inst.C.E.\nM.Inst.C.E. 6 Plates.\nDescription of a Sawing Machine for cutting off\nOn Well-sinking near the Metropolis, with an\nRailway Bars. By JOSEPH GLYNN, M.Inst.C.E.\naccount of the Well sunk by the New River\n1 Plate.\nCompany at their Reservoir in the Hampstead\nOn the State of the Suspension Bridge at Mon-\nRoad. By R. W. MYLNE. 1 Plate.\ntrose after the hurricane of the 11th of October,\nOn Locomotive Engines. By EDWARD BURY,\n1838, with Remarks on the Construction of\nM.Inst.C.E. 4 Plates.\nDigitized by\nGoogle\n10\nWORKS PUBLISHED BY JOHN WEALE,\n23.\nIn 8vo., Price 8s.\nA PRACTICAL TREATISE ON THE CONSTRUCTION AND\nFORMATION OF RAILWAYS,\nShowing the Practical Application and Expense of Excavating, Haulage, Embanking, and permanent\nWaylaying; also, the method of fixing Roads upon continuous Timber Bearings; including the prin-\nciples of Estimating the Gross Load and Useful Effect produced by Mechanical or other Motive Power,\nupon a Level and upon any Inclination. Illustrated with Diagrams and Original Useful Tables.\nBy JAMES DAY.\n24.\n12mo., Price 3s. in boards.\nTHE RAILWAY CALCULATOR, OR ENGINEER'S AND\nCONTRACTOR'S ASSISTANT.\nBy JAMES DAY.\n25.\nA Sheet, Price 2s.\nTABLE SHOWING THE CONTENTS OF EXCAVATIONS,\nIntended to facilitate the Estimating of Public Works.\nBy GEORGE P. BIDDER, C.E.\n26.\nIn 4to., with 12 large folding Plates, extra cloth boards, Price 14s.\nA PRACTICAL AND THEORETICAL ESSAY ON OBLIQUE\nBRIDGES.\nBy GEORGE WATSON BUCK, M.Inst.C.E.\n27.\nIn Imperial 8vo. Second Edition with Additions. 11 Plates, extra cloth boards, Price 8s.\nA PRACTICAL TREATISE ON THE CONSTRUCTION OF\nOBLIQUE ARCHES.\nBy JAMES HART, Mason.\n28.\nIn demy 8vo., with 107 Wood-cuts, extra cloth boards, Price 7s.\nEXPERIMENTAL ESSAYS ON THE PRINCIPLES OF CON-\nSTRUCTION IN ARCHES, PIERS, BUTTRESSES, &c.\nMade with a view to their being useful to the Practical Builder.\nBy W. BLAND, Esq., of Hartlip, Kent.\n29.\nIn royal 8vo., in boards, with nine Charts and one Meteorological Table, Price £1. 1s.\nAN ATTEMPT TO DEVELOP THE LAW OF STORMS,\nBy means of Facts arranged according to Place and Time ; and hence to point out a Cause for the\nVARIABLE WINDS, with the view to PRACTICAL USE in NAVIGATION.\nBy Lieut.-Colonel W. REID, C.B., of the Royal Engineers.\nSome copies with the Charts in a separate Atlas form, Price £1. 5s.\nDigitized by Google\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN.\n11\n30.\nIn demy 8vo., extra cloth boards. A New Work, Price 12s.\nTHE THEORY OF THE STEAM ENGINE;\nShowing the Inaccuracy of the Methods in use for calculating the Effects or the Proportions of\nSteam Engines, and supplying a Series of Practical Formulæ to determine the Velocity of any Engine\nwith a given Load, the Load for a stated Velocity, the Evaporation for desired Effects, the Horse-\npower, the useful Effect for a given Consumption of Water or Fuel, the Load, Expansion, and Counter-\nweight fit for the Production of the Maximum useful Effect, &c., with\nAN APPENDIX,\nContaining concise Rules for persons not familiar with Algebraic Signs, and intended to render the use\nof the Formulæ contained in the work perfectly clear and easy.\nBy COMTE DE PAMBOUR,\nFormerly a Student in the E'cole Polytechnique, late of the Royal Artillery, on the Staff in the French\nService, of the Royal Order of the Légion d'Honneur, &c.\n31.\nIn 8vo., cloth, Price 2s. 6d.\nA NEW SYSTEM OF SCALES OF EQUAL PARTS,\nApplicable to various purposes of Engineering, Architectural and General Science. Illustrated by a\nFacsimile of the Scales on Copper-plate.\nBy CHARLES HOLTZAPFFEL, Associate of the Institution of Civil Engineers.\n32.\nIn demy 8vo., extra cloth boards, with 16 Plates, Price 12s.\nA SKETCH OF THE CIVIL ENGINEERING OF NORTH\nAMERICA.\nComprising Remarks on the Harbours, River and Lake Navigation, Lighthouses, Steam Navigation\nWater-works, Canals, Roads, Railways, Bridges, and other works in that country.\nBy DAVID STEVENSON, of Edinburgh, Civil Engineer.\n33.\nCOLONEL PASLEY'S COMPREHENSIVE WORK ON GEOMETRY.\nSecond Edition, demy 8vo., much enlarged, Price 16s. cloth boards, (instead of £1. 4s.),\nA COMPLETE COURSE OF PRACTICAL GEOMETRY AND\nPLAN DRAWING;\nTreated on a principle of peculiar Perspicuity. Adapted either for Classes, or for Self-Instruction.\nOriginally published as the first volume of a Course of Military Instruction.\nBy C. W. PASLEY, C.B., Colonel Royal Engineers, F.R.S., &c. &c.\n34.\nIn demy 8vo., extra cloth boards, numerous Wood-cuts, Price 14s.\nOBSERVATIONS ON LIMES, CALCAREOUS CEMENTS,\nMORTARS, STUCCOS, AND CONCRETE,\nAND ON PUZZOLANAS, NATURAL AND ARTIFICIAL; TOGETHER WITH RULES DEDUCED\nFROM NUMEROUS EXPERIMENTS FOR MAKING AN ARTIFICIAL WATER CEMENT,\nEqual in Efficiency to the best Natural Cements of England, improperly termed Roman Cements ; and\nan Abstract of the Opinions of former Authors on the same Subjects.\nBy C. W. PASLEY, C.B., Colonel in the Corps of Royal Engineers, F.R.S., &c. &c. &c.\nDigitized by\nGoogle\n12\nWORKS PUBLISHED BY JOHN WEALE,\n35.\nSecond Edition, with Additional Corrections, in 8vo., with a fine Frontispiece of a Locomotive Engine,\nPrice 8s.\nANALYSIS OF RAILWAYS;\nConsisting of Reports of RAILWAYS projected in England and Wales; to which are added, a Table of\nDistances from the proposed London Terminus to Eight well-known Places in the Metropolis, with a\ncopious GLOSSARY, and several Useful Tables.\nBy FRANCIS WHISHAW, C.E., M.Inst.C.E.\n36.\nJust published, in 8vo., bound, Price 3s. 6d.\nTHE PRACTICE OF MAKING AND REPAIRING ROADS;\nOF CONSTRUCTING FOOTPATHS, FENCING, AND DRAINS;\nAlso a Method of comparing Roads with reference to the Power of Draught required: with Practical\nObservations, intended to simplify the mode of Estimating Earth-work in Cuttings and Embankments.\nBy THOMAS HUGHES, Esq., Civil Engineer.\n37.\nWith folding Plates, in 4to., Price 3s.\nSECTIO-PLANOGRAPHY;\nA DESCRIPTION OF MR. MACNEILL'S METHOD OF LAYING DOWN RAILWAY SECTIONS\nAND PLANS IN JUXTAPOSITION.\nAs adopted by the Standing Order Committee of the House of Commons, 1837.\nBy FRED. W. SIMMS, Civil Engineer.\n38.\nIn 8vo., with several Plates, Price 16s.\nA TREATISE ON THE STRENGTH OF TIMBER, CAST IRON,\nMALLEABLE IRON, AND OTHER MATERIALS,\nWith Rules for Application in Architecture, Construction of Suspension Bridges, Railways, &c.; with\nan Appendix on the Powers of Locomotive Engines on Horizontal Planes and Gradients.\nBy PETER BARLOW, F.R.S., &c. &c.\n39.\nThird Edition, with 28 additional Plates, Edited by PETER BARLOW, Esq., F.R.S., M.I.C.E., in extra\nhalf-morocco, Price £2. 2s.\nELEMENTARY PRINCIPLES OF CARPENTRY, AND ON\nCONSTRUCTION.\nA Treatise on the Pressure and Equilibrium of Beams and Timber Frames, the Resistance of Timbers,\nand the Construction of Floors, Roofs, Centres, Bridges, &c. ; with Practical Rules and Examples. To\nwhich is added, an Essay on the Nature and Properties of Timber; including the Methods of Seasoning,\nand the Causes and Prevention of Decay; with Descriptions of the Kinds of Wood used in Building:\nalso numerous Tables of Scantlings of Timber for different purposes, the Specific Gravities of Materials,\n&c. Illustrated by 50 Engravings.\nBy THOMAS TREDGOLD, Civil Engineer.\n)\nDigitized by Google\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN.\n13\n40.\nIn Quarto, 28 fine Plates, Price £1. 18.\nTREDGOLD'S ELEMENTARY PRINCIPLES OF CARPENTRY,\nAND ON CONSTRUCTION.\nSUPPLEMENT TO THE SECOND EDITION.\nSold separately for the convenience of those possessing the former Edition.\nComprising Engravings of Iron and Timber Roofs of Italian Palaces, Churches, Theatres, &c.; of a\nJuvenile Prison, Pantheon Bazaar, &c. &c., by Mr. SYDNEY SMIRKE; Iron and Timber Roof, &c. of\nChrist's Hospital and St. Dunstan's in the West, by Mr. JOHN SHAW; Timber Roofs of White Conduit\nHouse Tavern and others, by Mr. DUNCAN; Iron and Timber Construction of Croydon Railway Station,\nby Mr. Jos. GIBBS; Iron and Timber Roofs of the Trent Water-works, Nottingham, and the Roofs of\nthe Model Room, the Smithery, and Engine Manufactory, at Butterley, by Mr. Jos. GLYNN with Mr.\nMACKENZIE'S elaborate Drawings of the Construction of King's College Chapel, Cambridge. The\nwhole described by the different Contributors, and edited by PETER BARLOW, Esq., F.R.S., &c. &c.\n41.\nRoyal 8vo., Price 7s. 6d.\nAN ESSAY ON THE MODERN SYSTEM OF FORTIFICATION\nAdopted on the Rhine and Danube, and followed in all the works constructed since the Peace of 1815,\nin Germany. Illustrated by a copious Memoir on the Fortress of Coblentz, and accompanied by\nbeautiful Plans and Sections of the works of that place.\nBy Lieutenant-Colonel J. H. HUMFREY, K.S.F.,\nFormerly of the Royal Artillery and Royal Staff Corps, and late Commanding Engineer to the Corps of\nCantabria, Author of several Military Works, &c. Long resident in Germany, where he had oppor-\ntunities of collecting information from the best sources.\n42.\nIn 8vo., upwards of 500 pages, Price 8s.\nAN ELEMENTARY INVESTIGATION OF THE THEORY OF\nNUMBERS,\nWith its Application to the Indeterminate and Diophantine Analysis, the Analytical and Geometrical\nDivision of the Circle, and several other curious Algebraical and Arithmetical Problems.\nBy PETER BARLOW, Esq., F.R.S., M.Inst.C.E., and of several other Learned Societies and Academies.\n43.\nWith Plates, 8vo., Price 6s.\nA PRACTICAL TREATISE ON THE PRINCIPLES AND PRACTICE\nOF THE ART OF LEVELLING,\nWith Practical Elucidations and Illustrations, and Rules for Making Roads upon the principle of\nTELFORD; together with Mr. MACNEILL'S Instrument for the Estimating of Roads, &c.\nA work most essential to the Student.\n44.\nEngraved in aquatinta and coloured, 38 Plates. Quarto. Price £1. 48.\nARCHITECTURAL SKETCHES FOR COTTAGES, RURAL\nDWELLINGS, AND VILLAS;\nWith Plans, suitable to persons of genteel life and moderate fortune, proper for Picturesque Buildings.\nBy R. LUGAR, Architect.\n(\nDigitized by\nGoogle\n14\nWORKS PUBLISHED BY JOHN WEALE,\n45.\nLarge Atlas folio, 17 very finely engraved Plates, Price £4. 14s. 6d.-A few copies only of proofs on\nIndia paper, Price £6. 6s.\nSUSPENSION BRIDGES.\nA SCIENTIFIC and an HISTORICAL and DESCRIPTIVE ACCOUNT of the SUSPENSION\nBRIDGE constructed over the MENAI STRAIT, in North Wales; with a brief Notice of CONWAY\nBRIDGE. From Designs by and under the direction of THOMAS TELFORD, F.R.S., L. and E., &c. &c.,\nand ALEXANDER PROVIS, Esq., Resident Engineer.\n46.\nIn 8vo., with Plates, Price 12s.\nCEMENTS.\nA PRACTICAL and SCIENTIFIC TREATISE on the Choice and Preparation of the Materials for, and\nthe Manufacture and Application of, Calcareous Mortars and Cements, Artificial and Natural, founded\non an Extensive Series of Original Experiments. By M. L. J. VICAT, Chief Engineer of Roads, &c.\nTranslated from the French, with numerous and valuable Additions, and Explanatory Notes, com-\nprehending the most important known Facts in this Science, and with additional new Experiments and\nRemarks.\nBy Captain J. T. SMITH, Madras Engineers.\n47.\nIn 12mo., Price 2s. 6d. in boards.\nRULES AND DATA FOR THE STEAM ENGINE,\nBOTH STATIONARY AND LOCOMOTIVE;\nAnd for RAILWAYS, CANALS, and TURNPIKE ROADS being a Synopsis of a Course of Eight Lectures\non MECHANICAL PHILOSOPHY; illustrative of the most recent modes of Construction, and an Exposition\nof the Errors to which Patentees and others are liable, from their not being acquainted with the\npractical departments of Engineering.\nBy HENRY ADCOCK, Civil Engineer.\n48.\nIn 5 Parts, large oblong folio, with a Letter-press Description in 4to. to each, Price £1. 18. each Part\nwith the Text.\nTHE CIVIL ENGINEER AND MACHINIST:\nPRACTICAL TREATISES OF CIVIL ENGINEERING, ENGINEER BUILDING, MACHINERY,\nMILL-WORK, ENGINE-WORK, IRON-FOUNDING, &c. &c.\nBy C. J. BLUNT.\nCONTENTS.\nDIVISION 1.-Boulton and Watt's Portable Steam\nwheels and Iron Roofs, by the late THOMAS\nEngine, complete, with all the details, in 10\nTELFORD; Plans, Sections, and Machinery of the\nPlates.\nWemyss Colliery, &c.\nDIVISION 2.-Marine Steam Engines and Ma-\nDIVISION B.-Bridges and Viaducts, with the\nchinery; Steam Corn Mills, &c., complete.\noriginal Specifications of the London and Bir-\nDIVISION 3.-Sugar Mills, on horizontal and verti-\nmingham Railway, Locomotive and Bogie En-\ncal construction; Steam Corn Mills, by MAUDS-\ngines of do. in detail, the Goods Waggons,\nLAY and FIELD; the Kent and Surrey Sewers,\nTenders, and divers Specifications of Works,\nSluices, &c.; Smith's Forge, and Great Forge\n&c. &c., by ROBERT STEPHENSON, Esq. Loco-\nHammer.\nmotive Engines on the Newcastle and Carlish\nDIVISION A.-Sea Entrance Gates, Swing Bridges,\nRailway, by GEORGE STEPHENSON, Esq.; the\nCanal Bridge, Specifications of the Works, &c.,\nGreat Western Railway Bridge, &c,, by J.E.\nof the Gloucester and Berkeley Canal, Water-\nBRUNEL, F.R.S., &c. &c.\nDigitized by\nGoogle\n(\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN.\n15\n49.\nFive Livraisons. Plates Atlas folio, with Text in 4to.\nLOCOMOTIVE ENGINES AND CARRIAGES.\nPOPULAR FRENCH WORK.\nL'INDUSTRIE DES CHEMINS DE FER, ou Dessins et Descriptions des Machines Locomotives, des Four-\ngons d'approvisionnement (Tenders), Wagons de Transport et de Terrassements, Voitures, Diligences,\nRails, Supports, Plates-Formes mobiles, Aiguilles, Machines accessoires, &c. &c., en usage sur les\nRoutes en Fer, de France, Angleterre, Allemagne, Belgique, &c. &c.\nPar MM. ARMENGAUD.\n50.\nSecond Edition, in 8vo, extra cloth boards, 10 Plates, Price 7s. 6d.\nPERSPECTIVE SIMPLIFIED;\nContaining a new PRELIMINARY CHAPTER, in which the subject is treated in the most plain and easy\nmanner, for the convenience of readers not acquainted with Geometry.\nBy Z. LAURENCE, Esq.\n51.\nIn 4to., with Wood-cuts, and 4 fine Engravings by JOHN LE KEUX, Price 7s. 6d.\nAN ACCOUNT OF THE ROOF OF KING'S COLLEGE CHAPEL,\nCAMBRIDGE.\nBy F. MACKENZIE, Author and Draughtsman of some of the finest Architectural Works.\n52.\nIn demy 8vo., 3 Engravings, Price 7s. 6d.\nMECHANICS FOR PRACTICAL MEN;\nContaining Explanations of the Principles of Mechanics; the Steam Engine, with its various Pro-\nportions; Parallel Motion, &c.; Tables of the Weight of Cast-Iron Pipes, Strength and Stress of\nMaterials, &c.\nBy JAMES HANN, King's College, and ISAAC DODDS, C.E.\n53.\n4to., Price £1. 18. Revised and corrected.\nTHE CARPENTER AND JOINER'S ASSISTANT;\nContaining Practical Rules for making all kinds of Joints, and various methods of hingeing them\ntogether; for hanging of Doors; for fitting up Windows and Shutters; for the construction of Floors,\nPartitions, Soffits, Groins, Arches for Masonry ; for constructing Roofs in the best manner from a given\nquantity of Timber, &c. Also Extracts from M. Belidor, M. du Hamel, M. de Buffon, &c., on the\nStrength of Timber. Illustrated with 79 Plates.\nBy PETER NICHOLSON, Architect.\n54.\nIn 8vo., with two large folding Plates of Sections of Roads, Price 2s.\nMAKING AND REPAIRING ROADS.\nRULES for MAKING and REPAIRING ROADS, as laid down by the late THOMAS TELFORD, Esq.,\nCivil Engineer. Extracted, with additions, from a Treatise on the Principles and Practice of Levelling.\nBy F. W. SIMMS, Surveyor and Civil Engineer.\nGoogle\n(\nDigitized by\n16\nWORKS PUBLISHED BY JOHN WEALE,\n55.\n4to., with Plates. Price 15s.\nA TREATISE ON RIVERS AND TORRENTS,\nWith the METHOD of REGULATING their COURSE and CHANNELS. By PAUL FRISI, Member\nof numerous Academies. To which is added, an ESSAY on NAVIGABLE CANALS, by the same.\nTranslated by Major-General JOHN GARSTIN.\n56.\nWood-cuts, 8vo. Price 5s.\nSECOND REPORT ON THE LONDON AND BIRMINGHAM\nRAILWAY,\nFounded on an Inspection of, and Experiments made on, the Liverpool and Manchester Railway.\nBy PETER BARLOW, F.R.S., &c. &c.\n57.\nWood-cuts, 8vo. Price 4s. 6d.\nAN ESSAY ON THE CONSTRUCTION OF THE FIVE ARCHI-\nTECTURAL SECTIONS OF CAST-IRON BEAMS,\nEmployed as Girders, Bressummers, and other Horizontal Supports for Buildings, &c.\nBy WILLIAM TURNBULL.\n58.\nThird Edition. Folio, with a large Atlas of Plates. Price £4. 4s.\nNAVAL ARCHITECTURE;\nOr, the RUDIMENTS and RULES of SHIP BUILDING: exemplified in a SERIES of DRAUGHTS\nand PLANS with Observations tending to the further Improvement of that important Art. Dedicated,\nby permission, to His late Majesty.\nBy MARMADUKE STALKARTT, Naval Architect.\n59.\nThree vols. large 4to., numerous fine Plates. Price £3. 3s.\nHISTORY OF MARINE ARCHITECTURE.\nBy JAMES CHARNOCK, F.S.A.\nIllustrative of the Naval Architecture of all Nations from the earliest period, particularly British.\nCharnock is a work essential to all who study the construction of ships, large and small craft,\nwhether for war, packet, or mercantile purposes.\n60.\nSupplementary and Fifth Volume to the Antiquities of Athens, by R. C. Cockerell, Esq., &c.\nANTIQUITIES OF ATHENS AND OTHER PLACES OF GREECE,\nSICILY, &c.\nSupplementary to the Antiquities in Athens, by JAMES STUART, F.R.S., F.S.A., and NICHOLAS\nREVETT; delineated and illustrated by R. C. COCKERELL, R.A., F.S.A., W. KINNARD, T. L. DONALD-\nSON, Member of the Institute of Paris, W. JENKINS, and W. RAILTON, Architects.\nImperial folio, uniform with the Original Edition of Stuart and Revett, and the Dilettanti Works\nVery finely printed, and with numerous beautiful Plates of Plans, Elevations, Sections, Views, Orna-\nments, &c. In extra cloth boards and lettered, Price £6. 12s.\nDigitized by Google\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN.\n17\n61.\nVery neatly half-bound in morocco, gilt tops, Price £3. 3s.\nARCHITECTURE OF THE METROPOLIS.\nDEDICATED TO SYDNEY SMIRKE, ESQ., ARCHITECT, F.S.A., F.G.S.\nA New and Considerably Enlarged Edition, with many Additional Subjects and Plates, of\nILLUSTRATIONS OF THE PUBLIC BUILDINGS OF LONDON,\nIn Two Volumes 8vo., with 165 Engravings, originally edited by the late AUGUSTUS PUGIN, Architect,\nand JOHN BRITTON, F.S.A., &c., and now newly Edited and Enlarged\nBy W. H. LEEDS.\nManifold as are the publications which represent\nthem no plans and elevations are to be met with\nthe various structures of the metropolis, this is\nin any other publication, which materially en-\nthe only work which describes them, not ad libi-\nhances the interest of this collection, and it pre-\ntum, in views which, even when perfectly correct,\nserves to us authentic and tolerably complete\nshow no more than the general aspect and locality\nrecords of many buildings which no longer exist.\nof each building from a certain point, and conse-\nAmong these are CARLTON HOUSE, illustrated\nquently afford no information beyond mere ex-\nwith several plates, including sections, and a plan\nternal appearance-but exhibits them architec-\nof the private apartments; the late ENGLISH\nturally by means of plans, elevations, and occa-\nOPERA HOUSE; Mr. NASH'S GALLERY, which\nsionally both sections and interior perspective\nhas since been dismantled of its embellishments;\nviews. Thus a far more complete and correct\nand THE ROYAL EXCHANGE.\nknowledge may be obtained of each edifice, in its\nAmong the subjects introduced in this New\nentire arrangement in all its parts and dimensions,\nEdition will be found the following:-The TRA-\nthan by pictorial views of them.\nVELLERS' CLUB HOUSE-LONDON UNIVERSITY\nAs studies for the Architect, the subjects con-\n-ST. GEORGE'S HOSPITAL-GATEWAY, Green\ntained in these volumes strongly recommend them-\nPark-Post OFFICE-FISHMONGERS' HALL-ST.\nselves,-more particularly so, as of the majority of\nDUNSTAN'S, Fleet Street, &c. &c.\n62.\nRoyal 8vo., 18 Engravings, cloth boards, 10s. 6d.\nILLUSTRATIONS OF THE PUBLIC BUILDINGS OF LONDON,\nWith descriptive Accounts of each Edifice.\nSUPPLEMENT:\nContaining the NEW SUBJECTS and DESCRIPTIONS by W. H. LEEDS, incorporated in the second\nedition, and now sold separate for the accommodation of those possessing the first edition.\nAlso a few copies in imperial 8vo. for large paper copies of the first edition, Price 15s.\n63.\nIn demy 8vo., cloth boards, Price 9s.\nA TREATISE ON THE LAW OF DILAPIDATIONS AND\nNUISANCES.\nBy DAVID GIBBONS, Esq., of the Middle Temple, Special Pleader.\nDedicated to the Honourable Sir John Taylor Coleridge, Knt., one of Her Majesty's Justices of the\nCourt of Queen's Bench.\n64.\nOne large sheet, very accurately coloured, size within the line of work 251 inches by 181. Price 10s.\nGEOLOGICAL STRUCTURE OF ENGLAND, IRELAND, AND\nSCOTLAND.\nAn Index Geological Map of the British Isles constructed from published documents, communications\nof eminent Geologists, and personal investigation.\nBy JOHN PHILLIPS, F.R.S., G.S., Professor of Geology in King's College, London.\nEngraved by J. W. LOWRY.\nMounted in a case, Price 13s. ; on black roller, 16s. ; mahogany do., 18s.\nDigitized by\nGoogle\n18\nWORKS PUBLISHED BY JOHN WEALE,\n65.\nBathic Architecture.\nThe following very valuable and interesting Work has been withheld from sale for several years;\nthe publication price was fixed at £2. 2s., but, as a favourable purchase has been made, the price\nis now 16s. in extra cloth boards, and lettered.\nA SERIES OF ANCIENT BAPTISMAL FONTS, NORMAN, EARLY\nENGLISH, DECORATED ENGLISH, AND PERPENDICULAR\nENGLISH.\nDrawn by F. SIMPSON, Jun., and Engraved by R. ROBERTS.\nLarge 8vo., containing 40 very beautifully engraved Plates, in the best style of the Art, and the Text\nwritten by an accomplished and talented Gentleman, whose attainments in Architecture and as an Anti-\nquarian are well known and appreciated.\nA few copies on large paper, Price £1. 88. and only six copies India proofs, with Etchings, at £2. 2s.\n66.\nOne large 4to. The Plates engraved in the finest style of Art. Cloth boards, lettered, Price £1. 10s.\nTHE MONUMENTAL REMAINS OF NOBLE AND EMINENT\nPERSONS,\nComprising the Sepulchral Antiquities of Great Britain, engraved from Drawings by\nEDWARD BLORE, Architect, F.S.A.\nWith Historical and Biographical Illustrations.\nCONTENTS.\n1. Eleanor, Queen of Edward the First. Westminster\n17. John Gower. St. Saviour's Church, Southwark.-\nAbbey.-1290.\n1408.\n2. Effigy of the same.\n18. King Henry the Fourth and his Queen. Canterbury\n3. Brian Fitzalan, Baron of Bedale. Bedale Church.-\nCathedral.-1412.\n1301.\n19. Effigy of the same.\n4. Aymer de Valence, Earl of Pembroke. Westminster\n20. Thomas Fitzalan, Earl of Arundel. Arundel Church.\nAbbey.-1324.\n-1415.\n5. Sir James Douglas. Douglas Church.-1331.\n21. Ralph Neville, Earl of Westmorland. Staindrop\n6. Gervase Alard, Admiral of the Cinque Ports. Winchel-\nChurch.-1425.\nsea Church.-No date.\n22. Archibald, 5th Earl of Douglas. Douglas Church.-\n7. Philippa, Queen of Edward the Third. Westminster\n1438.\nAbbey.-1369.\n23. Richard Beauchamp, Earl of Warwick. Beauchamp\n8. Effigy of the same.\nChapel, Warwick.-1439.\n9. Thomas Beauchamp, Earl of Warwick. Beauchamp\n24. Effigy of the same.\nChapel, Warwick.-1370.\n25. John Beaufort, Duke of Somerset. Wimborn Minster.\n10. Edward, Prince of Wales. Canterbury Cathedral.-\n-1444.\n1376.\n26. Humphrey, Duke of Gloucester. St. Alban's Abbey.-\n11. Effigy of the same.\n1446.\n12. King Edward the Third. Westminster Abbey.-1377.\n27. Sir John Spencer. Brington Church.-1522.\n13. Effigy of the same.\n28. Archbishops Warham and Peckham. Canterbury\n14. Thomas Hatfield, Bishop of Durham. Durham Cathe-\nCathedral.-1532.\ndral.-1381.\n29. Margaret Plantagenet, Countess of Salisbury. Christ's\n15. William of Wykham, Bishop of Winchester. Win-\nChurch, Hampshire.-1541.\nchester Cathedral.-1404.\n30. Sir Anthony Browne. Battle Abbey.-1548.\n16. Effigy of the same.\n67.\nIn folio size, Price £1. 18. in boards.\nBRIDGEN'S INTERIOR DECORATIONS, DETAILS, AND VIEWS\nOF SEFTON CHURCH, IN LANCASHIRE,\nErected by the Molineux family (the ancestors of the present Earl of Sefton), in the early part of the\nreign of Henry VIII.\nThe Plates (34 in number) display the beautiful Style of the Tudor Age in Details, Ornaments\nSections, and Views. Etched in a masterly style of Art.\nDigitized by\nGoogle\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN.\n19\n68.\nRoyal 4to., very neatly half-bound in morocco, gilt, Price £2. 12s. 6d.\nDRAWINGS OF THE FINEST EXISTING SPECIMENS OF\nANCIENT HALF-TIMBERED HOUSES OF ENGLAND,\nAnd of their Details; with an Essay, showing the Classification of the Style, and the Age to which it\nbelongs.\nBy M. HABERSHON, Architect.\n*** The work contains upwards of Twenty Views, taken from the finest remaining Specimens of this\ninteresting branch of the Ancient Architecture of England, comprising Manor Houses, Town Resi-\ndences, and Cottages, some of which are particularly striking and picturesque; and, in order to give a\nmore complete illustration of it, such Views are accompanied by Drawings, to a large scale, of Chim-\nneys, Tracery, Porches, Doors, Windows, and other Details. To which is added, an Essay, giving a\nGeneral Historical View of English Architecture.\n69.\nWith Plates, imperial 8vo., cloth boards, £1. 18.\nCLARKE'S ELIZABETHAN ARCHITECTURE.\nCONTENTS.\nWimbledon House, Surrey, built by Sir Thomas Cecil,\nBrereton Hall, Cheshire, Sir Walter Brereton.\n1588.\nHolland House, Middlesex, Sir Walter Cope.\nEaston House, Essex, Sir Henry Maynard.\nHaughley House, Suffolk.\nAston Hall, Warwickshire, Sir Thomas Holt.\nStreete Place, Sussex, Dobell.\nGrafton Hall, Cheshire, Sir Peter Warburton.\nMontacute House, Somersetshire, Sir Edward Philips.\nStanfield Hall, Norfolk, family of Flowerdews.\nWestwood House, Worcestershire.\nSeckford Hall, Thomas Seckford.\nWakehurst Place, Sussex, Sir Edward Culpeper.\nBramshill House, Hampshire.\nCarter's Corner, Sussex.\nFenn Place, Kent, Lord Zouch.\nEastbury House, Essex, Lord Monteagle.\nQueen's Head, Islington, Sir Walter Raleigh.\nEast Mascall, Sussex, Newton.\nChasleton, Oxfordshire, Walter Jones.\nOld House, near Worcester, &c.\n70.\nSixty Plates, Title-Page printed in colours and gold, elegantly half-bound in morocco, and lettered,\nPrice £1. 16s.\nSPECIMENS OF THE ARCHITECTURE OF THE REIGNS OF\nQUEEN ELIZABETH AND KING JAMES I.,\nFrom Drawings by CHARLES JAMES RICHARDSON, GEORGE MOORE, and other Architects, with\nObservations and Descriptions of the Plates.\nEighteen Plates illustrate the Old Manor House, the Gardens, Terraces, &c. at Claverton, the Seat of\nGeorge Vivian, Esq.-six the Duke of Kingston's Picturesque House at Bradford-and eight the\nprincely Mansion of Lord Holland at Kensington.\nThe volume contains examples of Ceilings, Porches, Balustrades, Screens, Staircases, Monuments,\nPulpits, &c. and a rich collection of Facsimiles of Old English Drawings, chiefly of John Thorpe,\nthe most eminent Artist in Queen Elizabeth's time.\n71.\nIn 8vo., extra cloth boards, and lettered, Price 7s.25 copies are printed on India paper, Price 10s. 6d.\nSecond Edition, corrected.\nHAKEWELL'S ATTEMPT TO DETERMINE THE EXACT\nCHARACTER OF ELIZABETHAN ARCHITECTURE,\nIllustrated by Parallels of Dorton House, Hatfield, Longleate, and Wollaton, in England; the Pallazzo\ndella Cancellaria, at Rome.\nThe Plates (8 in number) consist of compartments of the Pallazzo della Cancellaria, at Rome, by\nBramante, 1495; and Longleate, by John of Padua, 1547. Compartment of the South Front of\nHatfield, 1611, with compartment of Wollaton Hall, 1580; Dorton House, Bucks-a Plan, Screen in\nDigitized by\nGoogle\n20\nWORKS PUBLISHED BY JOHN WEALE,\nthe Hall Longitudinal Section of the Staircase Transverse Section of the Staircase Chimney-piece\nin Queen Elizabeth's room ; Ceiling in the same room ; a front view of the Queen occupies the centre\ncompartment; the corresponding compartments are filled with the Portraits of her principal Ministers\nin profile.\n72.\n8vo., cloth boards, and lettered, Price 8s.\nMOLLER'S GERMAN GOTHIC ARCHITECTURE,\nTranslated. With Notes and Illustrations by W. H. LEEDS.\n73.\nIn 8vo., with Notes and Illustrations by W. H. LEEDS. Price £4. 4s.\nGerman Bothic Architecture.\nMEMORIALS OF GERMAN ARCHITECTURE;\nOr, the ARCHITECTURAL ANTIQUITIES OF GERMANY.\nBy GEORGE MOLLER, of Darmstadt, Architect to the Grand Duke of Hesse.\n2 vols., large folio, with 130 Plates, a Description of each Edifice, and an Essay on the Origin and Pro-\ngress of Gothic Architecture, with reference to its Origin and Progress in England; in the German\nLanguage, accompanied by an English Translation.\n6 The Transition, or Early German, has not yet, 50 far\nmore will probably appear in a short time. Dr. Moller's\nas I know, received much distinct attention. Dr. Moller,\nwork (Denkmaehler der Deutschen Baukunst) already con-\nhowever, in the course of his valuable Denkmaehler, has\ntains excellent specimens of every style of German build-\nrecently given us excellent representations of the Cathedral\nings, and offers additional interest and beauty in each new\nat Limburg, on the Lahn, which is a very admirable speci-\nnumber.' Whewell's Notes on German Churches, pp.\nmen of this kind and has noticed the intermediate and\n28, 29.\ntransition place which this edifice seems to occupy in the\nThe Church of St. Catharine, at Oppenheim, near\ndevelopement of the German style.'-Whewell's Notes on\nWorms, also in part a ruin, is another fine example of this\nGerman Churches, p.25.\nstyle, and has been worthily illustrated in the magnificent\n6 There exist, however, several valuable publications, with\nwork of Dr. Moller.' - Whewell's Notes on German\ngood plates, on the subject of German Architecture, and\nChurches, p. 113.\nSeveral copies of Seventy-two Plates, making Vol. I., have been sold in this country : some copies of\nthe 2nd Vol. to make up these sets can be had for £2. 12s. 6d.\n74.\nRoyal 4to., with Plates. Price £1. 1s.\nPROLUSIONES ARCHITECTONICE;\nOr, ESSAYS on Subjects connected with GRECIAN and ROMAN ARCHITECTURE. Illustrated by\nForty Engravings by eminent Artists. Dedicated, by permission, to EARL GREY, K.G.\nBy WILLIAM WILKINS, A.M., R.A., F.R.S.,\nFormerly a Senior Fellow of Caius College, in the University of Cambridge; Professor of Architecture\nin the Royal Academy of Arts.\n75.\n2 vols 4to., upwards of 70 Plates and Wood-cuts, Price £2. 2s.\nLETTERS OF AN ARCHITECT FROM FRANCE, ITALY,\nAND GREECE;\nOr, CRITICAL REMARKS on CONTINENTAL ARCHITECTURE, ANCIENT and MODERN, and\non the CLASSIC ARCHITECTURE of GREECE. Written in a Series of Letters.\nBy JOSEPH WOODS, F.A.S., F.L.S., F.G.S., &c.\nDigitized by\nGoogle\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN.\n21\n76.\n8vo., with Plates, Price 7s.\nVENTILATION, WARMING, AND TRANSMISSION OF SOUND.\nREPORT OF THE COMMITTEE OF THE HOUSE OF COMMONS ON VENTILATION, WARMING,\nAND TRANSMISSION OF SOUND,\nAbbreviated, with Notes. By W. S. INMAN, Architect, F.I.B.A.\n77.\nIn 8vo., illustrated with a very fine Frontispiece of ST. PAUL'S CATHEDRAL, by GLADWIN. Extra\ncloth boards, Price 10s. 6d.\nTHE PROFESSIONAL PRACTICE OF ARCHITECTS AND THAT\nOF MEASURING SURVEYORS,\nAnd Reference to BUILDERS, &c., &c., from the time of the celebrated EARL OF BURLINGTON.\nBy JAMES NOBLE, Architect, F.I.B.A.\n78.\n78 very fine Plates, royal folio, neat in cloth boards and lettered, Price £3. 3s.\nTHE UNEDITED ANTIQUITIES OF ATTICA.\nBy the Society of Dilettanti. Comprising the Architectural Remains of Eleusis, Rhamnus, Sunium,\nand Thoricus.\n79.\n8vo., with Plates, Price 7s.\nCOTTAGES AND HOUSES FOR THE PEASANTRY AND\nEMIGRANTS.\nELEMENTARY AND PRACTICAL INSTRUCTIONS ON THE ART OF BUILDING COTTAGES AND HOUSES\nFOR THE HUMBLER CLASSES.\nAn Easy Method of Constructing Earthen Walls, adapted to the Erection of Dwelling-houses, Agri-\ncultural and other Buildings, surpassing those built of Timber in comfort and stability, and equalling\nthose built of Brick, and at a considerable saving. To which are added, Practical Treatises on the\nManufacture of Bricks and Lime; on the Arts of Digging Wells and Draining; Rearing and Managing\na Vegetable Garden; Management of Stock, &c. For the use of Emigrants for the better Lodging of\nthe Peasantry of Great Britain and Ireland; and the Improvement of those Districts to which the\nbenevolence of Landed Proprietors is now directed.\nBy WILLIAM WILDS, Surveyor.\nThe work contains\nCHAP. I. The Art of Constructing Houses and Cottages\nIV. On the Properties, Uses, and Manufacture of Lime.\nwith Earthen Walls made easy, being intelligible to all\nV. On Well-digging, Draining, Well-sinking, &c.; on\nclasses, and to the most ignorant in building, with\nFuel, on Gardening; what quantity of Land will keep a\nWood-cuts of tools, plans, and sections, &c.\nFamily in culinary Vegetables; Pork, Eggs, Milk, and\nII. On Bricks, how they are to be advantageously applied\nBread Corn; on the Keeping of Cows, Hogs, Poultry,\nin conjunction with rammed earth; rules for selecting\nBees, and Art of making of Candles, Soap, Storing Fruit,\nthe best earth, &c.\nRoots, &c.\nIII. On the Manufacture and Choice of Bricks.\n80.\nIn 4to. Plates, very neatly coloured, cloth boards and lettered, Price 16s.\nA SERIES OF DESIGNS FOR VILLAS AND COUNTRY HOUSES,\nAdapted with Economy to the Comforts and to the Elegances of Modern Life, with Plans and\nExplanations to each.\nBy C. A. BUSBY, Architect.\nDigitized by\nGoogle\n22\nWORKS PUBLISHED BY JOHN WEALE,\n81.\nSecond Edition, 4to., Price £1. 1s.\nDESIGNS FOR VILLAS AND OTHER RURAL BUILDINGS.\nBy the late EDMUND AIKIN, Architect.\nEngraved on 31 Plates, with Plans and Elevations, elegantly coloured, and an Introductory Essay,\ncontaining Remarks on the prevailing Defects of Modern Architecture, and on the Investigation of the\nStyle best adapted for the Dwellings of the Present Times. Dedicated to the late Thomas Hope, Esq.\n6 Modern Architects profess to imitate antique examples,\nwhich is superior to the details that guide them ? This is\nand do so in columns, entablatures, and details, but never\na subject which it may be useful and interesting to pursue.'\nin the general effect. Is it that they imitate blindly, and\n-Vide Introduction.\nwithout penetrating into those principles and that system\n82.\n16 Plates, large 4to., Price 16s.\nDESIGNS FOR RURAL CHURCHES.\nBy GEORGE E. HAMILTON, Architect.\n83.\nSecond Edition, in 8vo., illustrated with numerous large folding Plates, Price 12s. 6d.\nA POPULAR TREATISE ON THE WARMING AND VENTI-\nLATION OF BUILDINGS,\nShowing the advantages of the Improved System of Heated Water Circulation, &c. &c. &c.\nBy CHARLES JAMES RICHARDSON, Architect.\n84.\nThe Sixth Edition, Price 18s. bound.\nTHE PRACTICAL HOUSE CARPENTER, OR YOUTH'S\nINSTRUCTOR;\nContaining a great variety of useful Designs in Carpentry and Architecture; as Centering for Groins,\nNiches, &c. ; Examples for Roofs, Skylights, &c. ; Designs for Chimney-pieces, Shop Fronts, Door\nCases; Section of a Dining-Room and Library; variety of Staircases, with many other important\nArticles and useful Embellishments. The whole illustrated and made perfectly easy by 148 4to.\nCopper-plates, with Explanations to each.\nBy WILLIAM PAIN.\n85.\nIn small 8vo., for a Pocket-Book. A New Edition, with the Government Tables of Annuities.\nPrice 7s. boards.\nTABLES FOR THE PURCHASING OF ESTATES,\nFreehold, Copyhold, or Leasehold, Annuities, &c., and for the Renewing of Leases held under Cathedral\nChurches, Colleges, or other Corporate Bodies, for Terms of Years certain, and for Lives also, for\nvaluing Reversionary Estates, Deferred Annuities, Next Presentations, &c. Together with several\nuseful and interesting Tables connected with the subject. Also, the Five Tables of Compound Interest.\nBy W. INWOOD, Architect and Surveyor.\n86.\n12mo., Price 3s. 6d.\nA MANUAL OF THE LAW OF FIXTURES.\nBy DAVID GIBBONS, Esq., of the Middle Temple, Special Pleader.\n*** A work purposely written for the use of Builders, House Agents, and House and Land Proprietors.\nDigitized by Google\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN.\n23\n87.\nPrice 2s. 6d., pocket size, cloth boards.\nTHE BUILDING ACT (at Large), side References.\nWith Extracts from the Sweeps' Acts; and with Explanatory Notes and Cases.\nBy A. AINGER, Architect.\n88.\n8vo., Price 16s.\nCOMPLETE ASSISTANT for the Landed Proprietor, Estate and House\nAgent, Land Steward, Proctor, Architect, &c.\n89.\n8vo. volume, with a folding Plate, Price 5s.\nON THE SAFETY LAMP,\nFor Preventing Explosions in Mines, Houses Lighted by Gas, Spirit Warehouses, or Magazines in\nShips, &c. ; with Researches on Flame.\nBy SIR HUMPHREY DAVY, Bart.\n90.\nNew Edition, 8vo., Price 16s. With 35 Copper-plate Engravings.\nA TREATISE ON ISOMETRICAL DRAWING,\nAs applicable to Geological and Mining Plans, Picturesque Delineations of Ornamental Grounds, Per-\nspective Views and Working Plans of Buildings and Machinery, and to General Purposes of Civil\nEngineering; with Details of improved Methods of preserving Plans and Records of Subterranean\nOperations in Mining Districts.\nBy T. SOPWITH, M.I.C.E.\n91.\nSecond Edition, with Examples, Price 3s. 6d.\nA SET OF PROJECTING AND PARALLEL RULERS,\nFor constructing Working Plans and Drawings in Isometrical and other Modes of Projection.\nInvented by T. SOPWITH.\n92.\nPrice 10s. 6d.\nGEOLOGICAL SECTIONS\nOf Holyfield, Hudgill Cross Vein, and Silver Band Lead Mines, in Alston Moor and Teesdale, showing\nthe various Strata and Subterranean Operations. Engraved on three coloured Plates, with De-\nscriptions, &c.\n93.\n12mo., Price 48. 6d.\nAN ACCOUNT OF THE MINING DISTRICTS\nOf Alston Moor, Weardale, and Teesdale, in Cumberland and Durham; Descriptive Sketches of the\nScenery, Antiquities, Geology, and Mining Operations in the Upper Dales of the Rivers Tyne, Wear,\nand Tees.\nDigitized by\nGoogle\n24\nWORKS PUBLISHED BY JOHN WEALE,\n94.\nIn 4to., with 5 Plates, in boards, Price 10s. 6d.\nOBSERVATIONS ON THE CONSTRUCTION AND FITTING UP\nOF MEETING HOUSES, &c. FOR PUBLIC WORSHIP;\nIllustrated by Plans, Sections, and Descriptions, including one erected in the City of York embracing,\nin particular, the METHOD of WARMING and VENTILATING.\nFURNITURE AND INTERIOR DECORATIONS.\n95.\n102.\nRoyal 4to., Price £1. 18.\nOn 33 folio Plates, engraved in imitation of\nCHIPPENDALE'S 133 DESIGNS OF\nChalk Drawings, Price 15s.\nINTERIOR DECORATIONS IN THE OLD\nORNAMENTS DISPLAYED, on a full\nFRENCH STYLES, for Carvers, Cabinet-\nsize for working, proper for all Carvers, Painters,\nMakers, Ornamental Painters, Brass-Workers,\n&c., containing a variety of Accurate Examples\nModellers, Chasers, Silversmiths, General De-\nof Foliage and Friezes.\nsigners, and Architects. Fifty Plates 4to., con-\nsisting of Hall, Glass, and Picture-Frames,\n103.\nChimney-Pieces, Stands for China, &c., Clock\nand Watch Cases, Girandoles, Brackets, Grates,\nWith 30 Plates, coloured in a superior manner\nLanterns, Ornamental Furniture, and Ceilings.\nand -hot-pressed, bound in cloth, and gold\nlettered, with a letter-press descriptive list of\n96.\nthe contents, Price £1. 7s.\n15 Plates, 4to., Price 10s. 6d.\nDESIGNS OF VALANCES AND DRA-\nSPECIMENS OF THE CELEBRATED\nPERIES, consisting of New Designs for Fashion-\nORNAMENTS and INTERIOR DECORA-\nable Upholstery Work. By T. KING.\nTIONS of the AGE of LOUIS XIV., selected\nThis work contains a variety of Valances and\nfrom the magnificent work of Meissonnier.\nDraperies of the richest description, adapted\n97.\nfor Dining and Drawing-rooms, with many\nnovel Designs for Four-post and French Beds.\n11 Plates, 4to., Price 7s.\nAs a limited number of this work is prepared,\nCHIPPENDALE'S DESIGNS for\norders are requested as early as possible.\nSconces, Chimney and Looking-Glass Frames,\nin the old French style: adapted for Carvers\n104.\nand Gilders, Cabinet-Makers, Modellers, &c.\n46 Coloured Plates, oblong, Price £1.\n98.\nORIGINAL DESIGNS FOR CABINET\n12mo., Price 4s. 6d.\nFURNITURE. By T. KING.\nDESIGNS FOR VASES, on 17 Plates.\n105.\n99.\n32 Coloured Plates, oblong, Price £1.\n10 Plates, 8vo., Price 4s.\nORIGINAL DESIGNS FOR CHAIRS\nDESIGNS FOR CHIMNEY-PIECES\nand SOFAS, with MUSIC STOOLS, FOOT\nAND CHIMNEY GLASSES, the one above\nSTOOLS, OTTOMAN SEATS, &c. &c. By\nthe other, in the times of Inigo Jones and Sir\nT. KING.\nJohn Vanburgh.\n106.\n100.\nPart I., large quarto, 16 Plates, Price 12s.\n5 Plates, oblong, Price 18. 6d.\nTHE UPHOLSTERER'S SKETCH-\nA BOOK OF ORNAMENTS, suitable\nBOOK OF ORIGINAL DESIGNS FOR\nfor Beginners. By THOMAS PETHER,\nFASHIONABLE DRAPERIES. By T. KING.\nCarver.\n101.\n107.\nIn large folio, 126 Plates, boards, Price £4. 4s.\nPrice 12s.\nETCHINGS, representing the BEST\nTHIRTY-SIX NEW, ORIGINAL, AND\nEXAMPLES of ANCIENT ORNAMENTAL\nPRACTICAL DESIGNS for CHAIRS, adapted\nARCHITECTURE, drawn from the Originals\nfor the DRAWING and DINING-ROOM,\nin Rome. FRAGMENTS of GRECIAN OR-\nPARLOUR and HALL. By W. TOMS, junior,\nNAMENT. By C. H. TATHAM, Architect.\nCarver.\n)\nDigitized\nby\nGoogle\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN.\n25\n108.\n114.\nParts 1, 2, 3, 4, complete, 10s. 6d. each, (the\nPrice £1.\nwhole £2. 2s.,) containing 84 Plates.\nSUPPLEMENTARY PLATES\nAN ENTIRE NEW SERIES OF\nCABINET AND UPHOLSTERY DESIGNS,\nTo the work entitled The Modern Style of\nintended to embrace every variety of elegant\nCabinet Work Exemplified in New Designs.\"\nand useful Furniture, suited to the Palace or\nBy T. KING.\nCottage, including the various styles of Greek,\nThe Supplementary Plates consist of 68 New\nGothic, Louis the 14th, &c. By GEORGE\nDesigns, on 28 Plates.\nSMITH.\n109.\n115.\nPrice £1., 4to. post, common paper, 15s., contain-\nPrice £2., medium 4to., half-bound; common\ning 37 Plates, and 44 pages of letter-press.\nedition, £1. 12s. in boards.\nTHE MODERN STYLE OF CABINET\nUPHOLSTERERS' ACCELERATOR,\nWORK EXEMPLIFIED IN NEW\nBeing Rules for Cutting and Forming Draperies,\nDESIGNS,\nValances, &c., accompanied by appropriate Re-\nmarks, and containing a full description of a New\nOn 72 Plates, containing 227 Designs for Cabinet\nSystem, which will greatly facilitate and improve\nWork. By T. KING.\nthe execution. By T. KING.\n116.\n110.\nPrice £1., 42 Plates, on royal 4to., many of which\nOn 80 Plates, conveniently small for the pocket,\nare neatly coloured.\nPrice £1. 3s.\nDESIGNS FOR CARVING AND\nDECORATIONS FOR WINDOWS\nGILDING,\nAND BEDS,\nWith Original Patterns for Toilette Glasses.\nConsisting of 100 Fashionable Designs for Uphol-\nBy T. KING.\nstery Work, with the Varieties of the present Style,\ndivided into parts. By T. KING.\n117.\nPrice 58., 8vo.\n111.\nR. MAINWARING'S CHAIR-\nPrice 15s. coloured, containing 21 Plates, 4to.\nMAKERS' GUIDE,\ndemy, half-bound.\n200 Genteel Designs (1766).\nMODERN DESIGNS FOR DRAPERY\nAND VALANCES,\n118.\nDisplayed in Beds and Windows.\nBy T. KING.\nLarge 8vo., Price 7s.\nHOUSEHOLD FURNITURE,\n112.\nIn the taste of a century ago, containing upwards\nof 350 Designs on 120 Plates.\nJust published, 3 Parts, Price £1. 10s.\nWORKING ORNAMENTS AND\n119.\nFORMS,\nPrice 15s., 18 Plates, on folio demy.\nFull size, for the use of the Cabinet Manufacturer,\nChair and Sofa Maker, Carver, and Turner.\nSHOP FRONTS AND EXTERIOR\nBy T. KING.\nDOORS,\nDisplaying the most approved of London execu-\n113.\ntion, and selected as being those of the best taste\nand greatest variety ; drawn to a scale by accurate\n2 vols., large 4to., 60 Plates, Price £2. 5s.\nmeasurement, accompanied by the proper Sections\nand Plans, with several New Practical Designs :\nCABINET-MAKERS' SKETCH\nfor the use of the Architect, Builder, and Joiner.\nBOOK. By T. KING.\nBy T. KING.\nDigitized by\nGoogle\n26\nWORKS PUBLISHED BY JOHN WEALE,\n120.\nOrnaments.\nGRECIAN ORNAMENTS.\nA SERIES of EXAMPLES, in 21 Plates, of GRECIAN ORNAMENT, in royal folio, very finely\nengraved from Drawings made by the most celebrated Architects. Price 15s.\nCONTENTS OF THE WORK.\nDetails of the Ceiling of the Propylea, at Eleusis.\nRestored Elevation to the Entrance of the Subterraneous\nOrder of the Antae of the Inner Vestibules, at Eleusis.\nChambers at Mycense, commonly called the Treasury of\nCapital of the Antse at large, at Eleusis.\nAtreus.\nFragments found at Eleusis.\nMarble Stele, in the possession of Mr. Gropius, at Athens.\nTiles and other Details of the Temple of Diana Propylsea,\nTerracotta Antefixa, at Athens, and Marble Fragments\nat Eleusis.\nfrom Delphi.\nCapitals and Profile of the Temple of Nemesis, at Rham-\nPilaster Capitals from Stratonice and Halicarnassus.\nnus.\nFragments from Halicarnassus, Teos, and Temple of\nOrnamental Moulding, Jambs, Mouldings of Interior Cor-\nApollo, at Branchydæ, near Miletus.\nnice, the Painted Mouldings of the Panels of the Lacu-\nEntasis of the Columns of the Portico of the Propyleea.\nnasia, &c. &c. of the Temple of Nemesis, at Rhamnus.\nof the North Wing of the Propylæa.\nDetails of the Roof, Tiling, &c. of the Temple of Nemesis,\nof the Temple of Theseus.\nat Rhamnus.\nof the Temple of Minerva, or Parthenon.\nThe Chairs and Sepulchral Bas-reliefs found in the Cella of\nof the Choragic Monument of Lysicrates.\nthe Temple of Themis, at Rhamnus.\nof the Columns of the North Portico of the Triple\nAthenian Sepulchral Marbles, Capitals, and Triglyphs, at\nTemple, termed the Erechtheum.\nDelos.\nof the Columns of the East Portico of that Temple.\nEntablature of the Order of the Peristyle and Roof, Orna-\nof the Temple of Jupiter Panhellenius, at AEgina.\nments, &c. of the Temple of Apollo Epicurus, at Bassae.\nof the Columns of the Pronaos of the same\nDetails of Sculptured and Painted Shafts of Columns of the\nTemple.\nSubterraneous Chamber, at Mycense.\nThis work is very desirable for Sculptors, Modellers, Masons, (in designing for Monuments, Tombs,\nTablets, &c.) Builders, and Architects. Those who possess the Dilettanti work of the Unedited\nAntiquities of Attica, and the Supplementary volume of Antiquities of Greece, Sicily, &c., will not need\nthis work, as the subjects are selected from them.\nVALUABLE ENGRAVINGS ON ARCHITECTURE, CIVIL AND\nMECHANICAL ENGINEERING.\n121.\n124.\nLONDON BRIDGE: engraved on Steel,\nGLADWIN'S Fine Engraving of the\nin the best style, by J. W. Lowry, under the\nPatent Self-Acting Slide Lathe, manufactured\ndirection of B. ALBANO, Esq., C.E., from his\nby Messrs. J. WHITWORTH and Co., Man-\nDrawing presented to the Institution of Civil\nchester. 5s. India paper, 7s. 6d.\nEngineers, and made from the Original Draw-\nings and Admeasurement, with permission of\n125.\nSir JOHN RENNIE, F.R.S., the Engineer. 1st.\nGLADWIN'S Fine Engraving of a Drill-\nPart. Plan and Elevation on a large scale, 25\ning and Boring Machine, by Messrs. WHIT-\nfeet to 1 inch. 15s. On India Paper, £1. 18.\nWORTH and Co., Manchester. 7s.\n122.\n126.\nSTAINES BRIDGE: a fine Engraving\nGLADWIN'S Elevation of STEPHENSON'S\nby J. H. LE KEUX, under the direction of\nPatents Locomotive Engine, printed on hard\nB. ALBANO, Esq., C.E., from his Drawing pre-\npaper for colouring. Columbier size. 3s. 6d.\nsented to the Institution of Civil Engineers,\nand made from the Original Drawings and\n127.\nAdmeasurement, with permission of GEORGE\nGLADWIN'S Splendid Engraving of\nRENNIE, Esq., F.R.S., the Engineer. 1st. Part.\nPlan and Elevation on a scale of 10 feet to\nSTEPHENSON'S Patent Locomotive Engine.\nLarge folio, Price 7s.\n1 inch. 10s. On India Paper, 15s.\nThis is a master-piece of Mechanical En-\n123.\ngraving, and may be considered unique in its\nexecution.\nPARIS-BRIDGE OF JENA, 2 fine Prints.\n128.\nPlan, Elevation, Section, and Details. Draw-\nings made by L. GOLEMBROWSKI, C.E. (Polish\nLithographed Folio Print of the Verte-\nEngineer residing in Paris), from admeasure-\nbrated Train Carriage for Railways, to diminish\nment, by permission of the French Government.\nFriction and Concussion. Mr. B. ADAMS,\n10s.\nPatentee. 2s.\nDigitized by\nGoogle\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN.\n27\n129.\nTemple of Serapis.\nTomb of Virgil.\nPrice £1. 8s.\nTemple of Jupiter Stator.\nTemple of Antoninus and Faustina.\nCLERRISSEAU'S Fourteen Plates of\nGate of Cuma.\nEngravings, on a large Atlas folio size, of the\n130.\nfollowing, being a set.\nArch of Pola in Istria.\nGilt frames and glazed, very neat, 118. the pair.\nArch of Trajan.\nTemple of Pola in Istria,\nPORTRAITS FRAMED AND GLAZED\nTemple of Venus.\nFOR AN OFFICE.\nAmphitheatre of Capua.\nInside of the Temple of Concord.\nA Pair of Portraits of GEO. STEPHENSON, Esq.,\nAncient Sepulchre situated in Naples.\nArch of Septimus Severus and of Caracalla.\nof Newcastle upon Tyne, and ROBERT STEVEN-\nAmphitheatre of Beneventum.\nSON, Esq., of Edinburgh, Civil Engineers.\n131.\nHandsomely engraved on Steel, (size I6 inches by 10} inches,) Price 2s. 6d. plain, 3s. coloured.\nA CHART OF THE HARBOUR AND PORT OF\nLONDON,\nExhibiting the River Thames and the adjacent Docks from London Bridge to Bugsby's Hole, and\nincluding the Greenwich Railway, the Commercial Railway, and the commencement of the Croydon\nRailway.\nIn this Chart the Low-water Mark, Soundings, Shoals, and other important features, are inserted\nfrom the most recent surveys; and, from the care which has been exercised in indicating correctly the\nvarious Wharfs, Dock-yards, Warehouses, and Factories, on each side of the River, it will be found of\ngreat utility to all persons engaged in nautical or commercial pursuits.\nSIR CHRISTOPHER WREN'S\n140.\nARCHITECTURE.\nWESTMINSTER HALL.\nSection from admeasurement by Mr. George Allan,\n132. Plan of his First Design of St. Paul's, 18.\n(Clerk of the Works to Sir Robert Smirke, Architect to the\n133. Elevation and Section of Bow Church, 18. 6d.\nlate Renovation). Very neatly engraved by Mr. HAWKS-\nWORTH. Folio size, 2s. 6d.\n134. Interior of St. Stephen's, Walbrook, 18.\n135. Section of St. James's Church, Piccadilly, 18.\n141.\n136. Roof of the Theatre at Oxford, 18.\nSECTION OF ST. PAUL'S CATHEDRAL.\n137. Plan for the Rebuilding of the City of London, 18.\nTHE ORIGINAL SPLENDID ENGRAVING by GWYN, of\nthe SECTION of ST. PAUL'S CATHEDRAL, decorated\n138. Elevation, Plan, and Section of the College of Phy-\nsicians, London, 18. 6d.\nagreeably to the original intention of Sir Christopher\nWren; a very fine large Print, showing distinctly the\n139. Elevation of the Tower and Spire of St. Dunstan's\nconstruction of that magnificent Edifice. Price 10s.\nin the East, London-Elevation and Section of Chichester\nThis is a magnificent Plate, the only one of its kind,\nSpire, 18. 6d.\nshowing constructively the genius of Sir Christopher Wren.\nThe following Prints, 8vo. size, are 6d. each; 4to. size, on India paper, 18. each.\n142. Mr. Greenough's Villa. 2. D. Burton.\n164. Terraces in the Regent's Park. 2. Nash and D.\n143. Catholic Chapel. 2. Newman.\nBurton.\n144. York Stairs' Water Gate. 1. I. Jones.\n165. Council Office, &c. 1. Soane.\n145. Somerset House, (Elevations, Interiors, and Views).\n166. Bank of England. 3. Soane.\n6. Chambers.\n167. Law Courts, Westminster. 3. Soane.\n146. Society of Arts. 1. Adam.\n168. House of Lords, &c. 3. Soane.\n147. College of Physicians. 2. Wren.\n169. Colosseum, Regent's Park. 1. D. Burton.\n148. Newgate. 1. Dance.\n170. Hanover Chapel. 1. Cockerell.\n149. Church of St. Peter le Poor. 1. Gibson.\n171. Temple Bar. 1. Wren.\n150. East India House. 1. Jupp.\n172. House of Mr. Nash, &c. 2. Nash.\n151. Ashburnham House. 2. 1. Jones.\n173. Belgrave and Eaton Squares. 2.0 Nash.\n152. Church of St. George. 3. Hawksmoor.\n174. Mr. Kemp's Villa. 2. Kendall.\n153. Church of All Souls. 1. Nash.\n175. London, Southwark, and Waterloo Bridges. 6.\n154. Westminster Hall. 2. Nash.\nRennie.\n155. Banqueting House. 1. I. Jones.\n176. Bridge of Blackfriars. 1. Mylne.\n156. Mansion House. 1. Dance, &c.\n177. Bridge of Westminster. 2. Labelye.\n157. County Fire Office. 1. Abraham.\n178. King's Entrance, House of Lords, Section and In-\n158. University Club House. 1. Wilkins and Gandy.\nterior Views. 3. Soane.\n159. Tower of Bow Church. 1. Wren.\n179. Plan and Interiors of St. Stephen's, Walbrook. 2.\n160. Westminster Abbey Church. 6. Wren.\nWren.\n161. Hall, Christ's Hospital. 1. Shaw.\n180. Plan and Interiors of Temple Church. 3. Wren.\n162. Carlton Palace. 5. Sir R. Taylor.\n181. Plans, Elevation, and Section of Custom House,\n163. College of Physicians and Union Club House. 2.\nLondon. 2. Laing.\nSir R. Smirke.\n182. Plan and Elevation of Uxbridge House. Vardy.\nDigitized by Google\n28\nWORKS PUBLISHED BY JOHN WEALE,\n183. Plans, Elevations, Views, and Sections of St. Paul's\n201. Plan, Elevations, Interiors, and Sections of G\nCathedral. 8. Wren.\nGarden Theatre. 6. Sir Robert Smirke.\n184. Elevations and Sections of St. Martin's Church. 3.\n202. Plan and Elevation of Sir John Nash's House. Nash\nGibbs.\n203. Plan and Transverse Section of St. James's, Picca\n185. Plan, Section, and Elevation of the Queen's Theatre.\ndilly. Wren.\n2. Nash and Repton.\n204. Interior of Freemasons' Hall. Sandby.\n186. Plan and Elevation of the Diorama. Pugin and\n205. Plan, Elevation, and Sections of St. Luke's Church,\nMorgan.\nChelsea. 2. Savage.\n187. Plan, Elevation, and Interior View of Haymarket\n206. Elevations, Sections, and Plan of St. Pancras\nTheatre. Nash.\nChurch. 3. Inwood.\n188. Plan, Side Elevation, and Interior of Westminster\n207. Plan and Elevation of All Saints Church, Poplar\nAbbey. 2.\nHollis.\n189. Plan, Elevation, Section, and Interior of St. Mary\n208. Elevation and Section of St. Dunstan's in the East\nWoolnoth. 2. Hawksmoor.\nWren.\n190. Plan, Elevation, and Section of St. Philip's, Regent\n209. Elevation and Section of Bow Church. Wren.\nStreet. 2. Repton.\n210. Plan and Elevation of St. Marylebone Church.\n191. Plan and Elevation of Bethlem Hospital. Lewis.\nHardwicke.\n192. Plan and Elevations of Burlington House. Lord\n211. Plan, Sections, and Interior of the Roman Catholic\nBurlington and Colin Campbell.\nChapel, Moorfields. 3. Newman.\n193. Elevation and Sections of St. Bride's Church. 2.\n212. Plan, and Garden Front of the British Museum\nWren.\n(Old). Pouget.\n194. Interiors of Sir John Soane's House. 2. Soane.\n213. Plan and Elevation of the Horse Guards. Kent.\n195. Plan, Elevation, and Section of St. Paul's, Covent\n214. Plan and Elevation of the Villa of James Burton,\nGarden. Inigo Jones.\nEsq. Burton.\n196. Elevation of the Royal Exchange. 2. Jerman.\n215. View of the East side of Belgrave Square. Basevi.\n197. Plan and Elevation of the Russell Institution.\n216. Plan, View, Sections, and Interiors of Drury Lane\n198. Interior of the Mansion of Thos. Hope, Esq. 2. Hope.\nTheatre. 6. B. Wyatt.\n199. Plan, Elevation, and View of the Library of the\n217. View of the Interior of the English Opera House.\nLondon Institution. 2. Brooks.\nBeazley.\n200. Plan, and Transverse and Longitudinal Sections of\n218. View of the Interior of the Amphitheatre, West-\nKing Henry 7th's Chapel. 2. Begun 1502.\nminster Bridge.\n219. View of the Five Elliptical Arch Bridge across the\n231. Geometrical Elevation of the West Front of the\nTweed at Kelso. Constructed by the late John Rennie,\nCathedral of St. Paul's, London, before the fire; St.\nEsq., Civil Engineer. Large print, 5s.\nStephen's, Vienna; Strasburg, Cologne, the Tower of\n220. View of the Centering of Blackfriars' Bridge, by R.\nMechlin, and the Great Pyramid of Egypt, to one scale,\nMylne. Engraved by the celebrated Piranési. Large\nfolio print, 58.\nprint, 4s. 6d.\n232. Plan of Westminster Hall and the adjacent Law\n221. View of the Progress of the First Arch of New\nCourts, 18.\nLondon Bridge, with Centering, 18. 6d.\n233. View of the West Front of the Propyles at Athens,\n222. View of the Menai Suspension Bridge. By W. A.\nfolio, 18. 6d.\nProvis, Esq., C.E., &c. Fine large print, India, 10s.\n234. Map of Attica with part of Boeotia, improved from\n223. View of the Cast Iron Bridge across the Galton\nthe observations of recent travellers, particularly by Captain\nCanal. By R. Bridgens. Large size, 48. 6d. India proofs, 6s.\nSmith, R.N., 2s. 6d.\n224. View of Hammersmith Suspension Bridge. Finely\n235. Portraits of Eminent Architects and Engineers, men\nengraved, large size. 58.\nwho have done honour to Britain. Engraved in the best\n225. Plan and Elevation of Shrewsbury Bridge, 1s. 6d.\nstyle by superior artists, folio and 4to. sizes, £1. 18. the\n226. Dr. George Moller's very Elaborate Detailed Plates\nSet:\nof the Cathedral of Cologne, on nine very large sized sheets,\n1. Sir Christopher Wren.\nshowing the minutest detail to a large scale: this very fine\n2. James Stuart.\nstructure is nearly coeval with St. Stephen's Chapel, Glas-\n3. Nicholas Revett.\ngow Cathedral, and other Edifices of the best age of Archi-\n4. Sir William Chambers.\ntecture in this Country. With a text, small folio, in the\n5. James Watt.\nGerman language, £4. 4s.\n6. Humphrey Repton.\n227. Mr. Britton's Views of the West Fronts of 14\n7. Thomas Telford.\nEnglish Cathedrals, folio size, 88.; acquatinted, 10s. 6d.\n8. Thomas Tredgold.\n228. Mr. Britton's Series of Picturesque Views of the\n236. Transverse Section of the Temple of Jupiter Olym-\nInterior of 14 Cathedrals, with a Border of Architectural\nplus at Agrigentum, folio size, 18. 6d.\nand Sculptural Ornament, folio size, 8s.\n237. Mr. Blair's Drawing of a Corinthial Capital, lithe-\n229. Vardy's Perspective View of the Gothic Hall,\ngraphed, large size, 2s. 6d.\nHampton Court, finely engraved, folio, 5s.\n238. Mr. Cheffin's large Lithographed Print of the Lts.\n230. Mr. Coney's View of the Interior of the Cathedral at\ndon and Birmingham Railway Entrance Front of the\nMilan, fine large print, 5s.\nLondon Station, 58.\n239.\nFine large print, 5s.\nSHEER DRAUGHT OF HER MAJESTY'S STEAM SHIP OF\nWAR \" MEDEA,\"\nBuilt by Oliver Lang, Esq. at Woolwich first commanded by Captain H. Austin in the Mediterranes\nfor nearly four years, and since on the North American station by Captain Nott.\nDigitized by\nGoogle\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN.\n29\nPREPARING FOR PUBLICATION IN THE COURSE OF\nTHE YEAR 1840.\n240.\nTHE PUBLIC WORKS OF THE UNITED STATES,\nCONSTRUCTED BY EMINENT AMERICAN ARCHITECTS AND ENGINEERS;\nConsisting of Plans, Elevations, and Sectional Details of all the principal Improvements of the States.\nBy WILLIAM STRICKLAND, Architect and Engineer,\nEDWARD H. GILL, and HENRY R. CAMPBELL, Engineers.\nTHE FOLLOWING SUBJECTS ARE PREPARING\nPlan, Elevation, and Sections of the Bank of the\nPlan, Elevation, and Sections of the United States\nUnited States, Philadelphia.\nNaval Asylum, near Philadelphia.\nPlan, Sections, and Details of a Locomotive Steam\nPlan of the Aqueduct over the Allegheny River, at\nEngine, as constructed by M. W. Baldwin,\nPittsburg, Pennsylvania.\nPhiladelphia.\nPlan, Elevation, and Sections of a Canal Lock,\nPlan, Elevation, and Section of the double outlet\nwith improved gates, Sandy and Beaver Canal,\nLock on the Schuylkill Canal at Plymouth,\nOhio.\nPennsylvania.\nPlan, Elevation, and Sections of the Exchange\nPlan, Elevation, and Sections of the Schuylkill\nBuildings at New York.\nViaduct on the Columbia and Philadelphia\nPlan, Elevation, and Sections of the Eastern Peni-\nRailroad, Pennsylvania.\ntentiary at Philadelphia.\nPlan, Elevation, and Sections of a Timber Dam,\nPlan of the Reservoir Mound and Gates, with\non the Sandy and Beaver Canal, Ohio.\nDetails, on the Schuylkill Canal, near Pottsville,\nPlan, Elevation, and Sections of the United States'\nPennsylvania.\nMint, Philadelphia.\nPlan, Elevation, and Sections of a Cut Stone Aque-\nPlan, Elevation, and Sections of the Schuylkill\nduct being constructed on the line of the New\nPermanent Bridge, Philadelphia.\nYork Water-works.\nPlan, Elevation, and Sections of the Philadelphia\nPlan, Elevation, and Details of the Troy and Sara-\nExchange.\ntoga Viaduct and Draw constructed over the\nPlan, Elevation, and Sections of the Philadelphia\nHudson River, New York.\nGas-works.\nPlan, Elevation, and Sections of the Bridge over\nPlan, Elevation, and Sections of the Stone Via-\nthe Delaware River at Trenton, New Jersey.\nduct over the Schuylkill River at Phoenixville,\nPlan, Elevation, and Sections of a Stone and\nPenusylvania.\nTimber Lock, as constructed on the Schuylkill\nPlan, Elevation, and Details of a Locomotive\nCanal, Pennsylvania.\nSteam Engine, as constructed by H. R. Camp-\nPlan and Details of a Hudson River Steam Boa\nbell.\nfor Passengers.\nPlan, Elevation, and Section of the Philadelphia\nPlan and Details of the Delaware Breakwater at\nCounty Prison.\nthe entrance into the Bay of Delaware.\nHan, Elevation, and Sections of a Cut Stone\nPlan of the Timber Dam constructed across the\nAqueduct, constructed over the James River,\nSwatara Union Canal, Pennsylvania.\nVirginia, on the James River and Kanawha\nPlan, Elevation, and Section of the Stone Viaduct\nImprovement.\nat the \" Horse Shoe Bend,\" Allegheny Portage\nPlan, Elevation, and Section of a Canal Bridge.\nRailroad, Pennsylvania.\nPlan, Elevation, and Sections of the Philadelphia\nPlan of a Burden Car with Eight Wheels, as used\nAlms-house.\non the Pennsylvania Railroad.\nPlan, Elevation, and Sections of the Girard Col-\nPlan, Elevation, and Sections of the Towing Path\nlege for Orphans, Philadelphia.\nBridge, constructed over the Schuylkill River at\nBan, Elevation, and Sections of the Fairmount\nManayunk, Pennsylvania.\nBridge, Philadelphia.\nPlan, Elevation, and Sections of a Steam-boat\nlan, Elevation, and Sections of the Philadelphia\nLock, as constructed on the Kentucky River,\nWater-works, with a Map of its location.\nKentucky.\nlan, Elevation, and Details of an improved Eight-\nPlan and Details of a Floating Dry Dock, now in\nwheeled Day and Night Passenger Car, as\nuse on the Mississippi River.\nused on many of the Railroads in the United\nPlan, Elevation, and Sections of a Timber Bridge,\nStates.\nas constructed by Col. S. H. Long.\nDigitized by\nGoogle\n30\nPREPARING FOR PUBLICATION BY JOHN WEALE,\nSections and Details of the various Rails used in\nOhio Canal.\nthe United States.\nPlan of a Lock of 30 feet lift, constructed on the\nPlan, Elevation, and Sections of a Cut Stone\nLehigh Canal, Pennsylvania.\nAqueduct, constructed on the Chesapeake and\nThe Plates will be engraved by Mr. JOHN LE KEUX in his best style, and to be sold in the separate\nDivisions of A, Architecture,\nB, Mechanical Engineering,\nC, Civil Engineering.\nTo be published on fine Imperial folio paper, in Parts of 20 Plates, faced by a particular Description\nof the Subject. Price £1. in England, and 5 dollars in the States.\n241.\nTHE PUBLIC WORKS OF GREAT BRITAIN,\nVOL. II.\nTo be published in Parts of 20 Plates, engraved by Mr. JOHN LE KEUX and the best Engravers; each\nPlate to be faced by a particular Description of the Subject. Price £1. each Part.\nThe following are some of the very important subjects chosen from the highly scientific works of\nGeorge Leather, Esq., C.E., of Leeds.\nCast Iron Aqueduct over the River Calder at Stanley\nA Drainage Culvert and a Warping Sluice.\nFerry, near Wakefield.\nA set of Lock Gates, both geometrically and isome-\nGoole Docks and Locks.\ntrically projected.\nGoole Lock Gates, with the machinery for opening and\nDouble acting Cloughs and Drawing Geer, Collars\nshutting them.\nand Anchors, Pivots and Steps, Forebay Defenders,\nGoole Bascule or Hoist Bridge.\nand other Iron-work connected with the Locks.\nHull Hoist Bridge.\nLock and Bridge Keepers' Houses.\nAire and Calder Navigation.\nDunham Bridge,-Details, Elevations, &c.\nGoole Canal.\nHunslet Bridge, Leeds.\nRiver Don Navigation.\nAstley Bridge.\nGeneral Plan of Aire and Calder Navigation, from\nMonk Bridge, Leeds.\nLeeds and Wakefield to its junction with the Goole\nVictoria Bridge, Leeds.\nCanal at Ferrybridge.\nGott's Bridge, Leeds.\nDo.\ndo. from Ferrybridge to Goole, with\nThorp Hall or Waterloo Bridge, near Leeds.\nthe Docks at the latter place.\nStockton and Hartlepool Railway.\nGeneral Transverse Section of the Canals, with the\nPublic Road Bridge under.\nside walls, &c.\nOccupation Bridge under.\nTwo examples of Locks,-a Flood Lock and a Fall Lock.\nDo.\ndo. (iron).\nTwo Stone Bridges-one square, another askew.\nSea Embankment at Stranton.\nOne Swivel Bridge.\nNocton, &c. Drainages.\nThese will form 50 well-occupied Plates.\nThe following, in continuation, of other eminent Engineers, are also in preparation.\nSt. Katherine's Docks-Form of Shoes used for Bay Piles\nPile Driving.\nof Coffer-dam.\nBute Ship Canal-Travelling Crane.\nForm of Shoes used for Sheeting\nWinch, Pinion Wheel, Barrel.\nPiles.\nTilting Waggons.\nAbutment for Swivel Bridge.\nInner Basin, Masonry construction, &c.\nDock Gates.\nCommunication Locks.\nPlans of Coffer-dam (2).\nHollow Quoin of Entrance Lock.\nTransverse Section of Coffer-dam.\nSwivel Waggon-Stone Waggon.\nTruss of the Roof over the Long Room, Custom House,\nCounterforts, Sections.\nLondon.\nDock Gates, &c.\nCoal Jetty at Coffin's Wharf, Cardiff.\nFoundry Cranes.\nTaff Vale Railway Culverts.\nPlan and Section of the Great Sea Lock and Sluice at\nPug Mill, Screw Jacks, Wheel Barrows, Draw Crabs,\nLowestoft.\nTram Plates.\nPort-Glasgow Wet Dock Lock Gate.\nWeir for Bromley Mill.\nSwing Bridge between outer and inner Basins of the\nTelford's Timber Turn Bridge on the Grand Surrey Canal.\nEastern Docks, Custom House, London.\nTewkesbury Severn Bridge.\nOutfall at the N. W. corner of Cardiff Castle.\nCentering for Balloter Bridge across the River\nBridge at northern entrance to Cardiff Castle.\nDee, Aberdeenshire.\nBridge at N. W. corner of Cardiff Castle, across Feeder of\nSplendid Drawings of various Cranes.\nBute Ship Canal.\nMiddlewich Branch of the Ellesmere and Chester Canal.\nNewport Road Bridge across Feeder of Bute Ship Canal.\nCross Section of Culvert for conveying the Feeder under the\nCrane at Harrison's Wharf, London, capable of raising\nGlamorganshire Canal and Merthyr Road, and longitu-\nfive tons, cost £135.\ndinal Section.\nDigitized by\nGoogle\nARCHITECTURAL LIBRARY, 59, HIGH HOLBORN.\n31\n242.\nIn 8vo., with Plates, a Second Edition of\nA PRACTICAL TREATISE ON LOCOMOTIVE ENGINES\nUPON RAILWAYS;\nThe construction, the mode of acting, and the effect of Engines in conveying heavy loads the means of\nascertaining, on a general inspection of the Machine, the velocity with which it will draw a given load,\nand the results it will produce under various circumstances and in different localities; the proportions\nwhich ought to be adopted in the construction of an Engine, to make it answer any intended purpose\nthe quantity of fuel and water required, &c. with Practical Tables, showing at once the results of the\nFormulæ: FOUNDED UPON A GREAT MANY NEW EXPERIMENTS made on a large scale, in a daily\npractice on the Liverpool and Manchester, and other Railways, with different Engines and Trains of\nCarriages. To which is added, an APPENDIX, showing the expense of conveying Goods by means of\nLocomotives on Railroads.\nBy COMTE F. M. G. DE PAMBOUR.\n243.\nA New Edition, with Additions, by G. RENNIE, Esq., C.E., F.R.S.\nPRACTICAL ESSAYS ON MILL-WORK AND OTHER\nMACHINERY.\nOn the Teeth of Wheels, the Shafts, Gudgeons, and Journals of Machines ; the Couplings and Bearings\nof Shafts; disengaging and re-engaging Machinery in Motion; equalizing the Motions of Mills\nchanging the Velocity of Machines in Motion; the Framing of Mill-Work, &c.; with various useful\nTables.\nBy ROBERT BUCHANAN, Engineer.\nRevised, with Notes and Additional Articles, containing new Researches on various Mechanical Subjects,\nBy THOMAS TREDGOLD, Civil Engineer.\nIllustrated by Plates and numerous Figures. 2 vols. 8vo.\n244.\n4to., Price £1. 18. Corrected and enlarged.\nTHE CARPENTER'S NEW GUIDE.\nBeing a complete Book of Lines for Carpentry and Joinery, treating fully on Practical Geometry,\nSoffits, Brick and Plaster Groins, Niches of every description, Skylights, Lines for Roofs and Domes;\nwith a great variety of Designs for Roofs, Trussed Girders, Floors, Domes, Bridges, &c. Copper-\nplates : including some Observations and Calculations on the Strength of Timber.\nBy P. NICHOLSON.\n245.\nFourth Edition, improved and enlarged. 8vo., Price 12s. boards.\nA PRACTICAL ESSAY ON THE STRENGTH OF CAST IRON\nAND OTHER METALS;\nIntended for the Assistance of Engineers, Iron-Masters, Millwrights, Architects, Founders, Smiths,\nand others engaged in the Construction of Machines, Buildings, &c. Containing Practical Rules,\nTables, and Examples, founded on a Series of new Experiments ; with an extensive Table of the\nProperties of Materials. Illustrated by Eight Plates and several Wood-cuts.\nBy THOMAS TREDGOLD Livil Engineer.\nGoogle\n@\nDigitized by\n32\nPREPARING FOR PUBLICATION BY JOHN WEALE.\n246.\nFour Plates. Third Edition, Price 8s. boards.\nA TREATISE ON MILLS;\nIn Four Parts. Part First, on Circular Motion Part Second, on the Maximum of Moving Bodies,\nMachines, Engines, &c. ; Part Third, on the Velocity of Effluent Water Part Fourth, Experiments on\nCircular Motion, Water-Wheels, &c.\nBy JOHN BANKS, Lecturer on Experimental Philosophy.\n247.\nIn Imperial folio, about 25 Plates, engraved and lithographed in the best style.\nMR. HOPPER'S DESIGNS FOR THE NEW HOUSES OF\nPARLIAMENT.\nConsisting of Plans, Elevations, and Perspective Views of the Interior. Only a limited number will be\nprinted.\n248.\nREVUE GENERALE DE L'ARCHITECTURE ET DES TRAVAUX PUBLICS.\n(Annals of Architecture and Public Works.)\nAN ARCHITECT AND ENGINEER'S JOURNAL,\nEdited by CE'SAR DALY, Architect.\nGeology, Stereotomy, Machinery.\nMansions, Private Houses, Agricultural Buildings\nFoundations, Masonry. Carpentry, Iron-work.\nGardens.\nDecoration, Furniture, Warming, Ventilation.\nRoads, Bridges, Canals, Public Works, &c. &c.\nEach number of this Journal is arranged under four distinct heads, History, Theory, Practice, and\nMiscellanies. The first comprises every thing relating to Architectural Antiquities, &c. ; the second\nconsists of Memoirs entirely theoretic, relating to the different branches of Architecture and Engineer-\ning; the third contains practical Essays on the different Elements of the Science of Building and\nEngineering, and descriptions of the principal Public Works and Architectural Undertakings carried on\nin the two Continents the fourth, under the title of Miscellanies, comprises Reviews of Books con-\nnected with the subjects treated in the Journal, News, Correspondence, Variations in the Values of\nShares in Public Works, Lists of New Patents, &c. &c. &c. The Journal thus addresses itself at\nthe same time to Architects and Engineers, who will find in it the fruits of the studies and investiga-\ntions of men very eminent in their different departments, and will be apprised of all new inventions\nand discoveries, experiments and publications, connected with the art of building; to Antiquaries.\nwho will find in it the solution of many difficult questions, which required the investigation of men\nuniting the practice of Architecture with the knowledge of history; and to Proprietors, who will be\nfurnished with Models of every description of Urbane and Rural Buildings. A regular correspondence\nhas been established with the principal Architects and Engineers in Europe and America.\nThe Work will be published Monthly, in small folio, double columns, with beautiful type cast\nexpressly for the purpose, on fine satin paper, by the first printers in Paris. Each Number will contain\n64 columns, with numerous beautifully executed wood-cuts, and from three to four engravings, or\nlithographs printed in colours.\nCONTENTS OF NO. I.\nINTRODUCTION, par M. César Daly.\nBitumes et de leurs divers emplois, par M.\nHISTOIRE-De l'Architecture Bysantine, par M.\nPolonceau, Inspect. div. des Ponts et Chaussées.\nAlbert Lenoire.-Musée historique d'Architec-\n-Notice sur les Constructions en Briques crues\nture, par M. Tournal.\ndu Midi de la Russie, par M. Potier, Lieut.-Gén.\nTHE'ORIE-Des Ponts Suspendus, par M. A. A.\ndu Génie en Russie.\nBoudsot.\nME'LANGES-Bibliographie: Compte-Rendu du\nPRATIQUE-Notice sur un nouveau Système de\nlivre de M. Teisserenc sur les Travaux publics\nCharpente en bois et en fer, par M. Camille\nen Belgique et les Chemins de fer en France,\nPolonceau.-Pont sur James-River, à Richmond,\npar M. C. D.-NOUVELLES:-le Tunnel de la\nen Virginie, par M. Michel Chevalier.-Des\nTamise, par M. Polonceau.-Archéologie.\nParis, PAULIN ET HETZEL: London, WEALE.\nOrders Wholesale or Retail executed and sent to any part of the World.\nPRINTED BY W. HUGHES, KING'S HEAD COURT, GOUGH SQUARE.\nDigitized by\nDigitized by Google\nDigitized by Google\nDigitized by Google\nDigitized by Google\nSEP 24 1932\nDigitized by Google"
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