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TION LIBRARY HOPPENS
STANFORD
UNIVERSITY
LIBRARIES
TC744
C 46 C
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C9208 2952 less 10%
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9
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OBSERVATIONS
ON THE
VARIOUS SYSTEMS
OF
CANAL NAVIGATION,
WITH
INFERENCES PRACTICAL AND MATHEMATICAL;
IN WHICH
Mr. FULTON'S PLAN
OF
WHEEL- BOATS,
AND THE UTILITY OF SUBTERRANEOUS AND OF SMALL CANALS
ARE PARTICULARLY INVESTIGATED,
INCLUDING AN ACCOUNT OF THE
CANALS AND INCLINED PLANES OF CHINA.
WITH FOUR PLATES.
BY WILLIAM CHAPMAN,
MEMBER OF THE SOCIETY OF CIVIL ENGINEERS IN LONDON, AND M.R.I.A.
LONDON:
PUBLISHED BY I. AND J. TAYLOR, AT THE ARCHITECTURAL LIBRARY,
HIGH HOLBORN.
1797.
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TO
HIS GRACE
FRANCIS DUKE OF BRIDGEWATER,
THESE OBSERVATIONS ARE INSCRIBED,
AS A MARK OF THE
AUTHOR'S VENERATION
FOR THE
DIGNIFIED CHARACTER,
TO WHOSE GREAT EXAMPLE
THE CANALS OF THESE KINGDOMS
OWE THEIR ORIGIN:
FROM WHICH HAVE RESULTED
MUCH OF
THE COMMERCIAL AND POLITICAL IMPORTANCE
OF THIS
EMPIRE.
Newcaftle-upon-Tyne, 1797.
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CONTENTS
CHAP. I.
Page.
INTRODUCTION-and Defcription of various Means of overcoming
Afcent in Canals and Rivers
-
-
-
CHAP. II.
On the comparative Expence of forming narrow Canals with Inclined Planes,
and wide Canals with Locks; ftating alfo their refpective Advantages,
and comparing the Confumption of Water by Mr. Fulton's Plan, with
what is requifite for Locks:
14
CHAP. III.
Cafes where the fmall Syftem of Navigation is eligible-and fome Propofals
for its Improvement
and
-
-
-
25.
CHAP. IV.
On the Metacentre or Axis of Motion of Veffels of a uniform Figure
throughout their Length, fhewing. by feveral Theoretic Inftances, to
what Height fuch Boats may fafely carry their Cargoes-Alfo, on the
Means of combining the Navigation of fmall and great Canals
-
34
CHAP. V.
On the Application of Wheel-Boats and Inclined Planes to Collieries, and
Inftances in which that Syftem may be improved
-
5°
CHAP. VI.
On the Application of Inclined Planes to the Great Rivers of America, or of
the Continent of Europe, with Obfervations on the Navigation of Great
Rivers and Lakes
-
-
-
-
60
CHAP. VII.
Account of, and Remarks on the Chinefe Navigations and Inclined Planes
69
CHAP. VIII.
General Obfervations and Conclufion
1.
-
95
CHAP. IX.
Appendix
-
,
-
101
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ERRATA.
THE Author's refidence being at a confiderable diftance from the Prefs, he begs
indulgence for the following Corrections and Additions :
Page 3 line 6, from the bottom, for is read are.
The Note in this Page was written before Sir G. Staunton's account of the Embaffy to
China was published ; and as there is no mention in that work of the Chinefe ufing cradles
with their inclined planes, that idea muft of courfe be relinquifhed.
Page 4, laft line, tome I read tome 4.
5
13, for other read upper.
5, addition to the Note. In the inclined plane at Ketley, the general inclination, as
I was informed by Mr. Reynolds, is nearly 22°, and at the extremities 1191 : befides which,
the declivity of the boat was further reduced by a difference in the diameters of the wheels,
and alfo by the frame being raifed higher above the axle-tree at the defcending end.
Page 9 line 15, for or trough read a trough.
28
11, for because the read becaufe of the.
31
9, for as to read as confiderably to.
32
10, for ares read axis.
36
6, in the middle column, for pofition read depth.
38
10, for giving read given.
39
9, for lk read e k.
49
6, for refting power read refifting power.
57
3, from bottom, for fection read fecant.
62
6, from bottom, for frow read frows.
67
9, for article read vehicle.
73
12, from bettom, for tracked read tracked againft.
76
15, for given read giving ; and line 21, for other read over.
To thefe might be added, feveral fmall typographic errors, which being fufficiently appa-
rent for the reader to correct, are omitted.
OBSER-
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OBSERVATIONS
ON VARIOUS SYSTEMS OF
CANAL NAVIGATION.
CHAP. I.
Introduction.-Defcription of various Means of overcoming Afcent and
Defcent in Canals and Rivers.
SEVERAL ages probably elapfed before the neceffities of mankind caufed
the introduction of highways and bridges; thefe would be adequate to every
purpofe, long after they united into nations, and became ftationary in their
refidence; as they would fix themfelves in fuch places where their wants
could eafily be fupplied, or where navigable rivers would afford the
means of exchanging the produce of their induftry. But, when increafe of
numbers induced them to fettle in lefs favorable fituations, and called forth
their bodily and mental exertions; the neceffity of reducing the vaft charge
of diftant conveyance of heavy articles, would point out the eligibility, and
eventually the means, of obtaining water carriage, in many places where
rivers had not admitted it. Thus Canals began their exiftence, at remote
periods, in the populous countries of China and Egypt; and were adopted
by the Romans in many parts of their extended empire, and were introduced
by them, into this ifland, in the fenny country eaft of the river Trent.
Thofe Canals were, neceffarily, on long continued levels; and the com-
munications, either between thém or to navigable rivers, required land
carriage. This inconvenience, during the courfe of numerous ages, could
not fail attracting the attention of ingenious men; and, accordingly, they
devifed various means of overcoming afcent, both in Rivers and Canals.
A
It,
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It, confequently, is an object of importance, to record all fuch pro-
greffive improvements as have come to the knowlege of any individual;
and to inveftigate every new propolition as, by a fair difcuffion, many
plans may be introduced to the extent they merit, which might otherwife
lie dormant through prejudice, or the caution requifite in all great under-
takings : and, on the other hand, it may prevent enthufiafm for plaufible
fyftems from milleading, and carrying away, their followers beyond what
may be ufeful.
No fyftem can ever be fo perfect, as to be unbounded in the propriety
of application ; and, therefore, the mode of overcoming afcent and defcent
by Locks, which is, undoubtedly, a noble invention, and almoft generally
ufeful, is not without its limits, as to utility. Having conceded this point,
which every impartial man muft do ; I feel myfelf more at liberty to
controvert the opinion thrown out by Mr. Fulton, in his Treatife on the
Improvement of Canals, that Locks will in future be found to be ineligi-
ble in all cafes ; and be fuperfeded by fome fyftem fimilar to what he has
laid down.
t nooian'st /-
His plan poffeffes much ingenuity ; but, like others, is neceffarily li- its and
mited in the propriety of its application : and the extent of thofe limits is.
my
what I fhall endeavour to explain.
in ine
Thofe who adopt any favorite fyftem on practical fubjects, without the
aid of experience to guide them, are liable to be carried away by the warmth
of their imagination; and are led to apprehend they have attained a fome-
thing of univerfal application To this alone I can attribute Mr. Fulton's
reprobation of Locks, fo ufeful for facilitating internal Navigation, and
which the experience of three # centuries has barely brought to perfection.
Previoufly to the commencement of this period, and down to the prefent
The firft Lock was fuppofed to be erected in the year 1488, upon the Brenta nigh
Padua. Immediatelyfafterwards the two Canals of Milan, between which there was nearly
34feet fall, were joined by means of 6 Locks. Traité des Canaux de Navigation, par M. de
la Lande.
time,
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( 3')
time, the communication between different levels interrupted by fall of
ground, by cataracts, or by rapids impracticable to haul boats up, or by
intervening high land, has been effected various ways.
1ft. By portage of the articles from one level to another, and carriage
of the boat itfelf, as is practifed in various parts of North America; for
inftance, at the falls of the Mohawk, the portage from that river to Wood
Creek, and the falls of the Onandaga; and even in our own ifland at the
Ifthmus of Tarbet in the Mull of Cantyre. This mode is alfo practifed
between Tarbet on Loch Lomond, and Arrachar at the head of Loch
Long; at the Tarbet of Jura, and at all the other Tarbets in the Ifles and
Highlands the word Tarbet is derived from two Celtic words, implying
the drawing or hauling of a boat; it denotes a low narrow neck of land
between two feparate waters, or two arms of the fame fea or lake.
2d. By hauling the empty boats up the rapids when difcharged of their
cargoes ; and conveying the latter by land.
3d. By making the rapids themfelves navigable by contraction; and,
where neceffary, affixing machinery to haul up the boats.
4th. By ftopping the water of a river for a time, and letting it off to
occafion an artificial flood; as is yet practifed on the Cam and other rivers.
5th. By Ponts aux Rouleaux, or inclined planes, with rollers at thort
diftances, over which, by means of a water wheel, the boats are hove up
to the ridge feparating the two waters (viz. a little above the level of the
higheft), and launched, or regularly let down, to the pool or level they
are proceeding to. The boats in this method could not be very long, be-
caufe, although, in afcending or defcending the inclined plane, they might
bear upon many rollers; yet, in the change of pofition from the regular
line of afcent, they muft obvioufly bear upon one roller, and be liable to
ftrain *.
In-
The fame inconvenience muft attend the Chinefe method, which, of late, is faid in
fome inftances to differ only by the intervention of a cradle between the boat and the rol-
2
lers.
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In an anonymous # Treatife, published in Paris in the year 1693, this
mode by rollers is particularly deferibed, and faid to have been practifed
for fome time in Holland, with much fuccefs; and that there was a con-
ftruction of that kind in the Canal between Amfterdam and Sardam.
6th. The method recommended by Mr. Leach, land furveyor (in his
Treatife on Inland Navigation), who lays claim to the invention (in the
year 1774), of connecting long continued levels, by inclined planes, which
he propofes to be double parallel planes and furnithed with rollers, on which
caitfons capable of containing water of fuperior weight to a loaded boat were
to move alternately up and down. The boats at the bottom level were to
float over thefe caiffons, which, in their paffage up or down the planes with
the boats upon them, were to be full or empty as the circumftance might
require.
The top of this caiffon is horizontal, and furnifhed with rollers, fo that
when it arrives at the ridge, or fummit of the inclined plane, penning up
the higher water, the boat may from thence be launched into the upper
Ganal.
7th. The fyftem lately introduced into this kingdom by Mr. William
Reynolds of Ketley, viz. that of connecting, as in the preceding inftance,
different levels of Canals, of great intervening height, by means of an in-
clined plane, with two parallel rail-ways; up and down which, by the aid
of a rope paffing over a wheel at the head of the plane, boats of 8 tons
burthen alternately pafs upon carriages, over which they are floated at each
extremity of the fall. The loaded boat (the trade being defcending)
draws up a light boat, or occafionally a half laden one. The firft of
thefe works was at Ketley in Shropfhire. The carriage downwards was
principally coals, and about four hundred tons daily.
lers. According to Magelhaens (as quoted by Belidor, Architect. Hydraul. t.4. p. 355 & 356)
the Chinefe method was to haul the veffels by the power of capftans, or by the immediate
effort of 4 or 500 men, up contracted channels where the water ran with great rapidity,
and was confined by mafonry. He alfo defcribes the dry inclined planes for fmaller boats.
Traité des Moyens de rendre les Rivieres navigable. This mode is alfo mentioned in
Belidor, Architect. Hydraul, tom, 1.
The
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The boats were rectangular boxes of 20 feet in length, 6 feet width, and
nearly 4 feet height; and one horfe drew fifteen of them, connected to each
other by a few links of chain.
The chief difficulty in going from a higher to a lower level, without
wafte of water, lay in paffing the ridge, or dam, which retains the water
at the end of the upper level. This he overcame two ways.
In the firft method, which he carried into effect about feven years fince,
he avoided the afcent from the upper level to the ridge holding up the
water, by the means of two parallel Locks at the head of the inclined plane;
into one of which the laden boat floated on its carriage and the light boat,
when afcended into the other, was by the admiffion of water floated off.
The water confumed in thefe Locks was let into a fide refervoir, and in
dry feafons pumped back by a fteam engine to the other level. Mr. Rey-
nolds has great merit in the invention of this method.
The fecond method, as practifed, at the inclined plane below the iron
bridge at Brofeley, in Shropfhire, differs from the former in haying no
Locks, and the boats being drawn upon the ridge by a fteam engine;
which alfo occafionally draws up the light boats, without waiting for the
laden ones. The boats, as in the other, are floated upon four-wheeled
carriages *, which afcend and defcend alternately.
The merit of this invention, or, at leaft, the firft introducing it into
practice (which was I believe totally unknown to Mr. Reynolds) is due to
the late Mr. Davis Dukart, an Engineer in the Sardinian fervice, who
fettled in Ireland, and became engaged in the Tyrone collieries. Thefe
collieries are lefs than a mile North of Dangannon, and about three miles
from the colliery bafon, at the head of a Canal afcending by eight Locks
A leading feature of difference of effect between thefe two methods, is, that the former is
applicable to fleeper defcents and longer boats; becaufe the frame of the carriage may at its
defcending end be elevated from the inclined plane to any extent; which if done fo confi-
derably, in the latter method, would dip the oppofite end of the boat in coming in or
going out of the upper Canal.
from
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from the river Blackwater, near its junction with Lough Neagh. The rife
from the bafon to the colliery, was little fhort of 200 feet ; and after at-
tempting, very improperly for the particular inftance, to conquer this great
afcent in that fhort fpace, by continuing the Lock Navigation and finding
the fums granted by Government for that purpofe inadequate to the de-
fign; he turned his attention to fmall boats, and inclined planes, of which
he conftructed three, connected by narrow Canals. The falls were feventy,
fixty, and fifty-five feet, which laft terminated about 15 feet above the
colliery bafon; from which by a fhort railway, his boats, again floating
over a carriage, were drawn onwards to the wharf, where the railway was
fupported on geers, or frames, and the boats were turned over to difcharge
their cargoes. They were calculated to carry, each, a ton of the meafure
the coals were fold by, viz. (about 27 cwt.) which they did at lefs than 18
inches draught, fo that his Canal might be every where fordable; and,
accordingly, no bridges were erected on it.
The boats were flat bottomed, and upright at the fides and ends their
width was 4½ feet, their height 2 feet 6 inches, and 10 feet ftraight fide
one end was fquare, and the other pointed, fo as to form a right angle at
the ftem ; and they went, as in all fimilar cafes, a number of them chained
after each other.
His firft attempt differed from the " Ponts aux Rouleaux" in no other
refpect than having a double paffage down his inclined planes; fo that,
by means of a rope leading over a wheel, his loaded boats drew up his
light ones :-but finding various inconveniences from fome of the rollers
not turning, and from the individual inequality of the diameters of others
throwing his boats to one fide, as well as from other caufes; he fuggefted
and put in ufe, the method now practifed on the banks of the Severn, of
having a cradle or frame with four wheels, brought under his boats ; upon
which, over a double railway, they alternately afcended; the fole difference
between the two methods being in the fize of his boats and that, in place
of a fteam engine, he made ufe of a horfe gin to draw his boats upon the
ridge terminating the upper level.
This
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This work was executed a little prior to the year 1777 but, excepting
in paffing a few boats by way of trial, nothing more was done, as Mr.
Dukart could not obtain money to complete fome of the intervening levels,
and died foon after the time mentioned. The works were then entirely
laid afide ; and, a few years fince, a common rail road, cutting off a con-
fiderable portion of the diftance, has with propriety been adopted in their
ftead.
8th. The method fuggetted by the Earl of Stanhope in 1793, viz. the
connecting different levels of Canal by iron rail-roads of a gradual and eafy
afcent; up and down which fmall boats were to pafs fufpended between a
pair of wheels of about 6 feet diameter.
9th. The following invention, which is likewife afcribed to his Lordfhip,
viz. the paffing of boats, up or down an inclined plane, on rollers moving
with the boats for half their length, in which fpace the boats would pafs over
them. The rollers are then to return to their places; by means of weights
acting over pulleys, and connected by a chain to the ends of each roller.
"This method, undoubtedly, would be attended with confiderable expence
in the execution; but has the merit of getting quit of the friction of rollers
moving on gudgeons. It muft however poffefs the other inconveniences of
the " Ponts aux Rouleaux." The moft material of thefe are that the
boats muft reft on a fingle roller in the convex part of the road; unlefs all
convexity be avoided by having a lock at the head of the inclined plane;
in which cafe the afcent muft be very gentle or the boat be fhort, or high
at the ends, to enable her to float from her reclined pofition. If the way
be very fteep, a frame for the boat to reft on, and raifed at the lower end,
would be requifite.
A method of ufing moving rollers attached to fuch a frame has been fug-
gefted by Mr. Fulton. He propofes to connect them, by the gudgeons at
their ends paffing through an endlefs chain, or collar, and thus returning
the rollers over the frame, but under the boat.
By
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By the former method, the frame, or boat, muft frequently reft only on
two rollers; but in this they may be as clofe to each other as requifite : and
by having in place of one fet, a fet of rollers on each fide, this method
(with a regular declivity of plane and locks at the head of it) is capable of
being carried into effect for boats of any magnitude fuitable for paffing on
inclined planes.
10th. The method published by Dr. Anderfon of Edinburgh, in The
General View of the Agriculture and Rural CEconomy of the County of
Aberdeen, for the year 1794."
The Doctor, there, obferves that, for all the purpofes of commerce, no
more width of boat is requifite than four feet; or more than two or three
feet depth; and that the length might be indefinite fo as not to be incon-
venient for afcending and defcending between any two levels of Canal
which he propofes to be done in the following manner, viz. that the
lower level be run up to nearly under the end of the upper, and terminate
by an upright end, and two fide walls of mafonry, to the full height of the
fall; with a pier in the middle, dividing the paffage between the two fide
walls, into two openings of rather greater width than the boat the two
ends of this pier are to be elevated fo as to fuftain the axis of a wheel of a
diameter equal to the width of the pier, and half of each opening. A
chain paffing over the wheel, fufpends, from each end, a rectangular cafe
fo hung that when one fhall be at the bottom ready for a boat to float
into; the other fhall be at the top, and clofe preffed to the wall or frame at
the end of the Canal, fo as to prevent the efcape of water: then, by open-
ing a ftop-gate at the end of either Canal, and another at the correfponding
end of the cafe, it is obvious that the boat may float in or out. The lower
boat and cafe (or cafe with water only) are then in a kind of Lock, juft
containing the cafe, and of fufficient depth to permit it to defcend to the
level of the lower Canal. From this Lock there is a conduit to keep the
water down below the Canal bottom.
Thefe are the outlines of the invention; which, where the connection
between the two levels is a precipice, or fo fteep as to require only a fhort
tunnel
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tunnel to the well, or pit, up or down which the boats are to move, may,
on receiving fuch improvements as it is capable of, be eafily carried into
effect for fmall boats; for which alone the author propofes it.
It is obvious that, under other circumftances as to fituation, the ex-
pences of high embankments above, of deep finking below, and of
bringing up the conduit to lay dry the lower locks, muft more than coun-
terbalance any advantage that can be derived from it.
I 1th. Meffrs. Rowland and Pickering's plan of enabling great boats to
afcend and defcend with inconfiderable wafte of water. This confifts in
having, at the head of the lower level of Canal, a pit funk as much below
the bottom of it, as the difference of height between the two levels, added
to the depth of a covered caiffon of requifite magnitude. This caiffon,
when immerfed in the water, with which the pit is filled to, the level of the
bottom of the Canal, is to fupport, on wooden or iron pillars of height
equal to the fall between the two levels, or trough or cradle, with gates or
draw doors at each end ; containing a fufficient depth of water, to which
the floating power of the caiffon mult then be in equilibrio; and, confe-
quently, capable of moving with eafe between the top and bottom of the
pit.
When the furface of the water of the cradle is level with either of the
Canals, and the end of it clofed againft the framing of the gate of the
Canal, by fcrews, or other means ; and the water let in to fill the vacancy
between the gate of the cradle and that of the Canal, they both may then
be opened, and a boat be admitted, or pafs out.
Excepting what may, if neceffary, be ufed for regulating the equipoife
and change of motion; the intermediate water between the gate of each
level and that of the cradle, is all that is confumed; and with draw doors to
the cradle and fingle gates to each level, as already premifed, the quantity
muft be very trivial. The weight of water difplaced by the bulk of the
pillars fuftaining the cradle, need not be material; and, where requifite, it
is propofed to be counterbalanced by weights acting on a fpiral wheel.
B
This
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This plan, which poffeffes ingenuity, and is applicable in many inftances,
is now carried into execution'on the Ellefmere Canal, near Ruabon in Den-
bighfhire; on a fall of 12 feet, and for boats of 70 feet length, and feven
feet width and the whole is moved up and down by a rack and pinion to-
wards each end of the machine.
Meffrs. Rowland and Pickering's invention alfo extends to another prin-
ciple; that of counterbalancing the cradle containing the boat by weight
which, if carried to the perfection it is capable of, will in high falls have de-
cided advantages.
12th. Mr. Weldon's Caiffon Lock, or Diving Cheft, in which boats with
their cargoes are to defcend, to a confiderable depth, down a pit or well;
and afterwards pafs by a tunnel into a lower Canal and to afcend in a
fimilar manner.
This method is now carrying into effect on the Somerfethire Coal Ca-
nal at Moncton Comb near Bath, on a fall of about 45 feet, and for boats
of 72 feet length, and feven feet width.
The caiffon, OF cheft, is cylindric and, in this inftance, of fufficient
ftrength to bear the preffure of a column of water 54 feet, or upwards; to
which it is fubjected, when oppofite the lower level, on account of the ne-
ceffity of its being covered when oppofed to the entrance of the upper level.
It is fo balanced that when it has fufficient water within it to float a boat, it
is of the fame fpecific gravity as the medium it floats in : and, like an air
balloon, it afcends or defcends by a flight increafe, or diminution of its re-
lative gravity; which, in this machine, is done by raifing out, or admitting
an inconfiderable quantity of water. The pit, in which the diving cheft
moves, has, oppofite each level of Canal, a tunnel or opening clofed with
gates and is fo much higher than the upper Canal as to contain a height
of water juft fufficient, as already mentioned, to cover the caiffon when
oppofite the upper level. In this, or in its lower pofition, when run clofe
to, and abutting againft, the entrance, it is retained by the water being let
out of the fhort part of the tunnel between the gates of the level, and the
end
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end of the caiffon. It is then held there by the preffure of the column of
water intervening between the furface of the pit and that of the Canal to
which it is oppofed. The gates of the level and Canal are then opened,
and the boat goes in or out; and, on the gates being again clofed, and the
water let into the vacancy, the diving cheft is ready to proceed to the
other level.
This fcheme poffeffes much originality, and may often be ufefully ap-
plied. It and the preceding one are fecured to their refpective inventors
by patents; therefore I fhall refrain from giving my fentiments on the fe-
parate advantages of each, and from pointing out the inftances in which
either might have the preference of the other. In general, all methods of
afcending and defcending which fave water, where the want of it for other
purpofes, whether for giving motion to machinery, or the irrigation of
land, would be greater than the advantage the navigation would obtain by
the ufe of it, muft clearly be fo far beneficial to the community.
13th. The laft method introduced to the public, is the one which has
principally occafioned this Effay, viz. Mr. Fulton's wheel boats; which,
when applied to inclined planes, he looks upon as paramount to all other
modes. The novelty of this method confifts principally in having t wheels
affixed to, or underneath, his boats; and in the defcending and afcending
boats each keeping their proper track; and not moving alternately in
oppofite directions, as in the method practifed at Dungannon and Coal-
brook Dale, and as recommended by Mr. Leach and Dr. Anderfon. His
boats, he obferves, may be of a rectangular form, and from 2 to 4 I feet
wide. Thofe of the latter width which he particularly defcribes, he re-
commends to be 20 feet long, and 2 feet IO inches deep; and propofes
A Treatife on the Improvement of Canal Navigation, exhibiting the numerous advan-
tages to be derived from fmall Canals. 4to, with 17 plates, 1796.
t
They are more properly trucks, viz. wheels between whofe diameter, and that of their
axis, there is little difparity, and confequently their friction great; as alfo is their inability
to furmount any cafual obftacle.
I In the title page he fays 2 to 5 feet.
B 2
them
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them to carry four tons each. He fays they may be " compofed of 3 inch
" deal, bolted and fcrewed in the ufual mode, and ftayed at the corners,
" with two knees or ribs infide, exactly above the wheels, and about 5
" feet from the ends, which will leave 10 feet in the centre Under the
boat's bottom, he propofes two pair of wheels of from 6 to 10 inches dia-
meter ; the axle and pair of wheels to be of one piece, and turn on brafs
or iron collars. Each pair of wheels are to tread only two feet, fo as to be
perfectly clear of the fides of the Canal and, to prevent any impediment
from their axle-trees, they are to be cafed over with thin plank, forming
a falfe bottom from one axis to the other. A boat fuch as defcribed will
(exclufive of the frame under the bottom, which I fhall admit to float the
wheels) be equal to a folid mafs of fir timber of the length and width of
the boat, and 8 inches in depth ; and, allowing for the iron work, will
draw at leaft 6 inches when light, exclufive of the wheels; and with 4 tons
bare weight (allowing in round numbers 36 cubic feet of water to be a ton)
will draw 2 feet 3½ inches.
Thefe boats then with wheels fix inches below their bottoms, will draw
2 feet 9 inches water : and as there fhould always be 2 or 3 inches to fpare,
their draught will be too great for # fords ; therefore bridges cannot be
difpenfed with. He propofes, very properly, that the canal fhould be
every where wide enough for boats to pafs each other which, of courfe,
will be 3 or 4 feet more than their joint width of bottom as, otherwife,
the fides of the Canal would be cut down by their fharp angles 3 which,
even then, cannot be effectually avoided.
The fords fhould be all paved ; and if the boats in going over them fhould touch, their
wheels would help them on ; but it would not be advifeable, as one horfe fhould draw feve-
ral boats, to fubmit to that inconvenience.
A fix-inch wheel I look upon as of ar too fmall a diameter ; but as, by fpiking a piece
of board immediately over the wheels, they may be let nearly or quite through the bottom,
and a larger diameter be admitted ; I fhall only add 6 inches below the bottom, which
fpace is requifite to prevent the neceffary curveture of the extremities of the railway touch-
ing the boat.
The
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The depth below the water line cannot, with propriety, be lefs than
3 feet 6 inches, to make proper allowance for filting up : and 9 feet width
of bottom, is the leaft it can be, to admit of the free paffage of thefe up-
right fided boats.
Thefe dimenfions are below what Mr. Fulton has informed me he
propofed and I have purpofely affumed them to fhew that the comparifon,
in the next chapter, is not calculated to depreciate the fyftem he has
brought forward.
CHAP.
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CHAP. II.
On the comparative Expence of forming narrow Canals with inclined
Planes, and wide Canals with Locks; flating alfo their refpective
Advantages, and comparing the Confumption of Water by Mr.
Fulton's Plan, with what is requifite for Locks.
As the great difparity of expence is a leading argument, with Mr. Fulton,
againft the Lock Syftem of Navigation; I fhall, before I proceed, fhew
how far that fyftem ought to be followed, or rejected, for the one he has
recommended; and endeavour to prove, that in general inftances, the
difparity of expence is not nearly fo great as he has ftated. For this pur-
pofe, I will compare his plan with a navigation for 50 to 60 ton boats, of
60 OF 70 feet length, 14 feet width, and 4 feet 6 or 4 feet 9 inches draught
of water ; a fuitable Canal for which would be. of 24 feet width of bottom,
and 6 feet depth of water which would afford room, every where, for
two boats to pafs, as their fection would not be angular, but curved. The
diagrams I, 2, 3, 4, and 1, 5, 6, 7, figure I. plate I. (admitting the
flopes to be what they moft generally are, viz. 18 inches bafe for every
foot in height), will fhew the profile of each Canal, at what is termed
level cutting, viz. where, the level of the ground is equal to the furface of
the water.
The fecond comparative diagrams, viz. a, b, c, 2, 3, d, e, f, and
a, b, c, 5, 6, g, b, k, fhew what they will be at 5 feet extraordinary
finking; allowing, at 2 feet above the water, 9 feet offset on the towing
path fide ; and a berm of, 3 feet on the other, to prevent earth tumbling
into the Canal. The diagrams 8, 9 and 8, 10 in the fame figure, fhew
10 feet extra finking.
Thefe diagrams will be more or lefs near the truth, according to the
tenacity of the foil, and other circumftances; but I have taken them at
the
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the general run of the foils of the navigations of this country ; which, al-
though when firft cut, they will ftand fteeper, will generally crumble down
to 16 or 18 inches bafe, to a foot in height; at which flope, loofe foil will
ftand when not agitated by water.
The fucceeding comparative diagrams, in figure 2, plate I, fhew the
embankments of one fide of each Canal, where the furface of the ground is
2'1 feet, 6 feet, and 10 feet under the furface of the water. The line a b
is the middle of the fmall canal, and d e that of the greater, allowing them
to continue of the fame width as where their channels have to be excavated.
They are generally wider in embankment, particularly in thofe of fmall
beight; which, fo far, would operate againft the fmall canals.
Thefe feven pofitions of comparifon are what will commonly occur, ex-
clufive of greater difficulties (which will ftill more equalize the fyftems)
and for that caufe I have affumed them.
At a given diftance from the fummits of mountains towards the low
grounds of the valleys, a regular tract may be found, where, without much
curvature, a line of level cutting may be uninterruptedly carried.
The falls, in thefe countries, are confequently great; and minerals the
almoft fole articles of carriage.
The fides of the mountains are alfo frequently too fleep, and the foil too
fhallow, to admit of wide Canals without great expence therefore, under
thefe predicaments, inclined planes and fmall boats are moft eligible : but,
on the general elevations through which lines of Canal run, the country is
often croffed tranfverfely to the courfe of the fmaller rivers; and the fur-
face of the ground neceffarily undulates ; fo that no continued line of level
finking can be obtained, without immenfe circuity, viz. without curving
According to Mr. Leach's account (in Page 47, of the 2d edition of his works) the
diftance from Bude Haven, in the Briftol Channel, to the navigable part of the Tamer fal-
ling into the English Channel, is no more than 28 miles in a direct line : but, by the courfe
neceffary to be taken in the feveral intervening valleys in order to preferve the level, the
line was extended to upwards of 80 miles.
to
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to the brow of every fwelling point of land, and returning up every vale,
until the proper level be regained; which, in itfelf, is fo obvioufly abfurd,
that no further reafoning is requifite to fhew the neceffity of frequen.ly in-
curring a fluctuation of more than 10 feet above and below the line. I
fpeak not of the vales of great rivers, which I allow may be P iffed by in-
clined planes, defcending to the valley and rifing on the oppofite fide : but
were this to be done on every ravine that is to be paffed, the inconvenience
would be great indeed : and, therefore, many embankments mul occur far
beyond what I have ftated; and I fhall now proceed to their comparative
examination.
4 Ton
бо Ton
Canal.
Canaf
In the firft ftatement, or level cutting, the comparative
fections and confequently the quantity of earth are,
}
50
198
At the depth of 5 feet extra finking,
-
-
221
482
At
10 feet do.
-
-
-
-
491
864
Surface of ground 2 feet 6 inches under water line,
-
107
107
Do.
6 feet do.
-
-
-
287
287
Do.
10 feet do.
-
-
-
-
577
583
From whence it follows, that under the firft predicament of level cutting,
the quantity of the fmall Canal is fcarcely more than t one fourth of the
greater : that, in the fecond inftance, it advances to more than four ninths
and, in the third, to nearly four fevenths; ftill approaching nearer as the
cutting becomes deeper. And as the embankment, when even fo trivial
as 2 feet 6 inches, and thence downwards to above 6 feet, is equal in
The banks are eftimated at only 10 feet width each ; and one foot mean height above
the furface of the water ; and without allowance for fubfidence.
+
If,no puddling to keep in the water were requifite the expence would be lefs than a
quarter ; becaufe the whole might be caft out but as the puddling (which in the leffer
Canal would be twice as cofily as the excavation) would be nearly as the furface of the fides
and bottom, the difparity would be fo far reduced in what may require puddling, that the
general proportion of expence may fland as the quantity of excavation, or even higher.
both
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both Canals; at TO feet nearly the fame ; and, afterwards, not effentially
in favour of the fmall ones, until the embankments become very high:
it may fairly be concluded, that in the common run of navigable lines, fuch
as defcribed, the expence of cutting the Canal for four-ton boats would be
half that of a Canal for 50 or 60 tons.
2d. The expence of fencing and gravelling the track-way will be the
fame in both.
3d. The next expence I fhall confider is the land, the quantity of
which will be precifely the fame as to the towing paths, the flopes of the
banks above water, and the outward flope of the embankments; the fole
faving being in the reduction of the water line : and taking the average in a
favourable flatement for the fmall canal, the land required will be three
fifths of the larger.
4th. Brooks muft be paffed under the fmall canal in common with the
large ones; and as the expence of the ends of the culverts would be equal
in both cafes; the only faving, unlefs fome excavation under low embank-
ments, would be in their difference of length, which, in the higher em-
bankments, would be only the difference of the width of water, viz. 22's
feet; and, under low embankments, where the culvert would require to
be as high as the depth of water in the fhallow Canal would admit, the
faving in length would be 30 feet, viz. the difference of width of water
added to the reduction of the width of the embankment on the level of the
culvert. If, in this inftance, the culvert under the deep Canal be either
fyphon formed, or raifed at the upftream end, the difparity of length would
be lefs; but the difference of excavation in favour of the fmall Canal has
Dr. Anderfon propofes to fave the expense of moft of the culverts, by bringing the
leffer rivulets into his fmall Canals, and paffing them over paved overflows oppofite to the
inlets; but this fcheme, befides inevitably filling his Canal with fand and gravel, would in
great floods render it impaffable, and overflow the regular height of the banks; and alfo
would never be agreed to by thofe poffeffing mill property on the ftreams into which thefe
brooks flow.
C
alfo
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alfo to be taken into account. The faving, upon an average, will be
nearly one third ; and, affuming it as fuch, the expence of culverts under
the fmall Canal will be two-thirds of what would be required under the
other.
5th. The next point of confideration is bridges, which, in common
with the others, will require towing paths ; and, therefore, ought not to
be lefs than 10 feet fpan, and muft be of fufficient height to let 'the horfes
pafs under. A boat of 14 feet beam (viz. IO feet wider than the fmall
ones) will require a bridge of 20 or 21, feet fpan. The wing walls, and
towing paths, will be common to them both ; and the foundation and pa-
rapets being taken into account, the bridge will, in the fmaller inftance,
average about four-fifths of the greater ; but as a reduction in height will
diminifh the thicknefs of the walls, the whole expence may come to about
one half.
6th. In the general run of countries, fuch as I have defcribed, the fall is
often fo. extremely progreffive that, even where water is in fuch abundance
as to induce the parties to build double locks wherever the fall ad-
mits, they are frequently neceffitated to build locks of moderate fall, to
avoid a long embankment on the one hand, and a continuation of deep
cutting on the other. Under this predicament, they would be equally con-
ftrained to have inclined planes of fmall fall, with all the apparatus that
would be requifite for great ones. The faving, therefore, could not be
more than one third but, on an # average, I fuppofe it would be fully one
half; and under thefe premifes, and the fuppofition of the fame average of
In fituations properly circumftanced for fmall Canals and inclined planes of great fall,
I will admit the difparity to be four to one in favour of the former, as to afcent and defcent.
I am friendly to the ufe, and only controvert the abufe of the fyftem.
proportionate
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proportionate expence in paffing valleys, I will now proceed to a fummary
of the general comparifon.
General propertion.
Frac-
tional
4 Ton:
60 Ton
propor-
Canal.
Canal.
tion.
1ft. Cutting, viz. Sinking and embanking,
-
N/
I
2
2d. Fencing and gravelling the trackways,
-
o
I
I
3d. Land,
3
-
-
-
-
3
5
4th. Culverts, &c.
2
-
-
-
w
2
3
5th. Bridges,
-
-
-
I
2
6th. Defcent and afcent,
-
-
-
I
2
From thefe deductions it follows the favings in fuch inftances as I have
premifed, will be very confiderably lefs than one half by adopting the Na-
vigation, defcribed by Mr. Fulton, for four-ton boats, in place of thofe of
60 tons. I will call the faving two-fifths; and then proceed to exámine
what muft be facrificed for that acquifition.
1ft. The carriage, in a very confiderable degree, of all articles that will
take damage by being wet t : becaufe the narrow boats of 20 feet length,
refting
In tunnels through hills the faving would generally be about three-fourths ; but this is
not taken into account, becaufe, where any confiderable portion of a Navigation muft be
fubterraneous, that circumftance will demand fome reduction of width, accordant with the
extent of it, the difficulty of execution, and the objects of purfuit.
t Under this defcription muft be included grain, the chief produce of the land ; the
eafier difpofal of which forms the general inducement for landed proprietors to encourage
Canals. From this caufe, and the creation of demand for internal products of the earth
that might otherwife lie dormant, and from the conveyance of lime for manure to parts that
could not otherwife eafily obtain it, the landed intereft receives more benefit from internal
Navigation than the adventurers who incur the charge of the works, and run the rifque of
their failure of reafonable fuccefs ; which although dubious to the latter, can never be fo
to the land-owner ; as, by means of Canals, diftant and unfavourable fituations come under
C2
regular
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refting on two tranfverfe lines over the wheels, would, with heavy cargoes,
be very liable to ftrain, fo as to become leaky : and admitting they had 2
raifed ceiling, which they muft have for the carriage of dry goods, the
water from the change of pofition of the boat, on afcending and defcending
the inclined planes, will run to the extremities, and be dafhed about fo as
to damage the goods; unlefs the ceiling were raifed at the ends, fo as
greatly to reduce the ftowage of the boats.
2d. When boats, on the different levels, are committed to the care of
different men, it will be impoffible to fix under whofe charge the damage
happened, unlefs it became a rule to examine the boats at every place of
change of men, which would be attended with too much delay.
3d. From the fame caufes, and the boats having no decks, it will be
difficult to prevent pilferage of liquors and fmall articles.
4th. Whenever the wind blew ftrong, the boats would be liable to take
in water over their gunwales, notwithftanding their tarpaulins, unlefs they
were battoned and nailed down as in fhips hatchways : and, in every crofs
reach, the ftring of boats would blow afhore without a man to every boat
to keep them off, which would be far too expenfive. At Ketley, they had
rails projecting into the Canal, on the convex points, to keep the boats in
their regular courfe, which enabled them to go forward in moderate wea-
ther; but to navigate, in any ftrength of wind, they would, if even they
had rails all the way, require the aid of men to enable boats that were going
oppofite ways to pafs each other. Or, otherwife, they muft track their boats
with fuch fpeed as to keep them off the fhore, and confequently have very
few to a horfe.
regular cultivation, and advance of rents far beyond what could otherwife be given. The
frequent oppofition from that quarter, and the fupport that fuch oppofition meets with,
clearly fhew, that gentlemen of landed intereft do not in general fee this advantage in the
light in which 1 have defcribed it the fame oppofition, I am informed, exifted on the firft
introduction of turnpike roads, the value of which has now been fufficiently experienced;
and the fuperior advantages of Canals cannot fail being foon as generally known.
In
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In moderate weather, it would be difficult for a horfe to drag a line of
them 200 feet long, viz. 10 boats as propofed by Mr. Fulton. The fec-
tion of water oppofed is but fmall but the form of the ends of the veffels is
that which gives the greateft refiftance and they are often repeated, which
muft produce a confiderable effect, although one veffel follows in the wake
of another. Further caufes of refiftance will arife from the line of boats
frequently forming a zigzag, and from their vaft furface expofed to the
water. The whole of the effects combined are not reduceable to calcula-
tion, and muft depend on experience.
5th. Packs of hemp and wool, bales of cotton, facks of hops, crates of
earthen ware and of glafs, oak bark, bavins, &c. &c. would lie too high, fo
as to overturn the boats, unlefs iron, lead, blocks of tin, or other ponder-
ous articles, were carried at the fame time; without which, thefe boats
would not carry half their tonnage of light goods in any package; the
Staffordfhire fquare-fectioned boats of feven feet width, will feldom flow,
without becoming top heavy, more than two-fifths of the weight they can
carry, at a lefs proportionate depth than the boats in queftion muft be
loaded to, to carry four tons.
In addition to the articles already mentioned, thefe boats cannot carry
either long or crooked timber; the former, if of fir, may be floated:
but the latter, if of heavy wood, will fink, and cannot eafily be mana-
ged. Neither would thefe boats be very fuitable for the conveyance of
quick-lime, nor would they carry (becaufe of their foon overturning)
nearly their tonnage of wheat in facks, and ftill lefs of rye, barley, oats and
malt: I, however, do not mean to infer that they will not carry thefe latter
articles at all; but only that the quantities will be lefs, nearly in the ratio
of their fpecific gravities; which deficiency in tonnage may, in fome in-
flances, be compenfated by reduction of toll. This width of boat is, how-
ever, what cannot be recommended for general purpofes.
The broad boats of 14 feet will nearly carry their full tonnage of light
goods, which circumítance arifes from two caufes : the one is their form
(as well as their width) which occafions their metacentre, or point below
which
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which the joint weight of boat and cargo may lie without overturning, to
be higher than in the other boats and the other is, that they are funk,
when laden, to a much lefs proportion of their width : befides which, when
their draught of water is indefinite (as will further appear from the next
chapter) the quantity of light articles that can be carried by boats of diffe-
rent widths, but of fimilar form and length, will be as the fquares of their
widths ; therefore, a boat of four feet width, in place of carrying half as
much as a fimilar one of eight feet, will only carry a fourth, although of
the fame length ; and but a ninth of one of twelve feet width.
6th. The transfhipping of articles removes the refponfibility ; and, as
boats are frequently wanted to navigate both canals and rivers, which
cannot be done by the fmall boats, that degree of refponfibility muft be
loft, and the charge and delay of transfhipping be incurred.
7th. The faving in point of reduction of Canal dues, would not, in ar-
ticles of merchandize, be equivalent to the inconveniences defcribed.
Having now mentioned my objections to the univerfality of the fyftem
recommended by Mr. Fulton, I fhall proceed to notice the cafes wherein I
think it eligible, the fteps I think neceffary to its perfection, and the means
of " harmonizing the fyftem of internal navigation ;" which will not confift
in the annihilation of Lock Canals as he has ventured to prognofticate,
but in rendering the modes of conveyance in them all, as far as poffible,
confonant to each other. Previous to this, I fhall make fome obfervations
on the confumption of water. In Locks there is this inconvenience, that,
whether the boats afcend or defcend, be light or laden, they confume, on
an average, a Lock-full of water ; for, although in going downwards, they
fave a quantity equal to the weight of the boat and cargo if laden, or of
the boat alone if light, in confequence of the bulk of the immerfed part
Canoes, ufed on the American and other rivers, becaufe of the curved form of their
tranfverfe fection, carry their lading higher than fquare-fectioned boats of fimilar width,
and are therefore capable of conveying large hogfheads of tobacco, or of other articles,
with fafety.
of
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of the boat being expelled from the chamber, on the boat's entering from
the upper level; this is perfectly counterbalanced by the reverfe taking
place in the afcending boats, on their quitting the chamber to enter the
upper level; confequently, exclufive of leakage, which in well fitted gates
is very inconfiderable, we may eftimate a boat to confume a lockful in
paffing any extent to or from the fummit. Wherever water is fcarce, it
is common not to exceed eight feet falls, and to have no double Locks.
The next confideration is the depth of water in the Canal for the greater
the depth, the tonnage, contained in any: given width and length of boat,
will be the more increafed.
I will affume the depth of Canal I have heretofore compared the fmall
ones with, viz. 6 feet, which will allow of boats of upwards of 4 feet 8
inches draught. Thefe boats, when light, need not draw fo much as 15
or 16 inches water, which will allow 3 feet 4 inches to be funk by the
cargo. If the boats and locks be proportioned to each other, as in all
cafes of want of water they ought to be, the area of that portion of their
height fhould be at leaft equal to three-fourths of the area of an equal height
of the Lock; confequently, in this inftance, 2 feet 6 inches height of the
Lock (viz. three-fourths of 3 feet 4 inches), will be equal to the weight of
the cargo. Therefore, in a fall of 8 feet, the confumption of water would
only be 3'₃ times the weight of the articles that would be paffed, up or
down, in place of the difproportion he * fpeaks of, viz. 133 tons of water
for paffing 25 tons of goods, inftead of 80 t tons (which, as above ftated,
fhould produce that effect).
Where the defcending trade does not bring up the afcending, he fup-
pofes that, by his own fyftem, the weight of water confumed will be I twice
Vide Fulton, page 69.
The above clearly relates to a paffage only one way ; but, if a boat pafs a fummit,
the confumption of water will be twice as much ; unlefs another boat pafs down with the
fame lockful the former role with. And if boats país and repafs a fummit, laden one way
only, the water requifite would be nearly 13 times the weight of the goods conveyed but
thefe extreme circumftances are never permitted to take place wherever water is fcarce.
I In fome inftanccs much more. Vide Fulton, page 79.
that
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that of the tonnage. And every valley he paffes, by the double inclined
plane (defcribed in chapter xi.) defcending on one fide of the valley, and
rifing on the other to that or any other level will, of courfe, repeat the
preceding confumption, fo that the wafte of water may become as confi-
derable as by the Lock fyftem, particularly if the method invented by Mr.
Dubie, in the laft centusy, and defcribed by Belidor, be put in practice,
as may, in fome few cafes, be eligible, viz. the drawing off the upper half
of the height of the Lock into a fide refervoir, and the remainder into the
lower level; fo that, in refilling the Lock, the lower half may be filled
from the refervoir, and t half only be drawn from the pond, or level above.
Or, nearly the whole water may be faved by the Locks defcribed in the
11th and 12th articles of the preceding chapter.
Mr. Fulton has ftated feven minutes as requifite in the paffing a Lock,
which in fome inftances is the cafe; but, where fufficient water way is given
to the fluices, and expeditious means of opening them adopted, a large
Lock may be filled or emptied in two minutes, and a boat paffed through
(inclufive of the filling) in three minutes, which degree of expedition is
requifite wherever paffage boats are an object.
Architect. Hydraul. t. 4, P. 412.
t
This may often be eligible in Locks of two or more falls, as a refervoir may be given
to each. The fubdivition of height of a chamber, may be extended to three or more, fo as
to reduce the quantity ftill further; but it would be counteracted by the increafe of ex-
pence, and the delay in paffing the Lock: neither will the faving be quite in the propor-
tion of the number of the refervoirs, becaufe of the fluctuation of the level of their furface,
which will be more or lefs according to their proportionate magnitudes. The method taken
by Mr. Dubic, in a Lock of 20 feet fall, on the Canal of Ypres, was to have three divifions
for admiffion of the water.
CHAP)
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CHAP. III.
Cafes where the Small Syftem of Navigation is eligible--with Some
Propofals for its Improvement.
THE fyftem of fmall Canals 'is particularly eligible in all countries
where limeftone, coal, iron ore, lead, and other ponderous articles not
liable to damage from being wet, or likely to be ftolen, are the objects
chiefly to be attended to; and where the regular declivity of the country
runs tranferfely to the courfe of the Canal: which will generally be the
cafe along the fides of mountains, at an elevation above the irregular ground
at their feet.
In thofe fituations, the great falls, or inclined planes, may be made at
the forks of rivers; fo that the upper levels may branch up both the
vales, and thus give the moft extended communication. A fituation fuited
for thofe canals will often alfo be found in countries that are not abfolutely
mountainous, but where the ground regularly declines towards the vales of
large rivers.
Bridges, whether of high roads, or of communication between divided
property, form an effential article of expence, and may be confiderably
avoided in the fmall fyftem. The only thing militating againft it, in the
wheel boats, is the great projection of their wheels below the bottom,
which renders fords impracticable. The fords ought not to exceed two
feet nine inches depth; as, otherwife, hay, fheaves of corn, &c. in com-
mon carts, would be liable to get wet. The depth might always be nearly
uniform, from the fords being paved, and overflows immediately adjoin-
ing, which, to allow for cafual fluctuation, might be fixed at two feet fix
inches above the pavement of the fords: then, in place of communication-
bridges, it would only be neceffary to form a paved road obliquely down
the bank on one fide, croffing the Canal in the fame direction, and floping
D
up
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up the oppofite bank. In country roads, wherever the fteepnefs of the
ground does not prevent, the defcent and afcent may be more rectangular
to the line of Canal, or in the direction of the road itfelf: in which cafe,
the water would extend eight or ten yards on each fide, to admit of a pro-
per Поре to the road. In great high roads it would be requifite to have
bridges. It, confequently, becomes an object of confideration to reduce
their expence by having no towing pashs under them; and at the fame time
not to interrupt the regular tracking of the boats. This end may be ef-
fected by a mode fomewhat fimilar to what is used to país fmall veffels
through one of the bridges at Rotterdam, without either ftriking their
mafts or interrupting the foot paffengers; which is done by railing and
turning back a fmall leaf in the centre of the bridge of about a foot or
eighteen inches opening, which opening the paffengers ftep over, and the
veffels maft paffes through it. The mode I advife, differs only in there
being no neceffity for a central leaf; as the bridge may confift of two abut-
ments, juft fo far afunder as to afford room enough for the boats to pafs,
and of two permanent leaves properly fupported, with an inch and a half
opening between the edges of them, guarded with rounded iron. This
opening would be no impediment to the road, and through it the rope (pro-
perly guided by a leading piece of wood or iron) would pafs without in-
terruption. If the Canal be defigned for heavy articles only, viz. for the
ufe of particular collieries, limeworks, or mines; then, thefe bridges would
be of little charge as they might be low-but if paffage-boats be in con-
templation, the requifite height would be fuch, and alfo fome increafe of
width t, that the faving would be inconfiderable; and it would, in moft
fuch inftances, be better to build bridges with towing paths over great
They would coft little more than paved fords, and not limit the boats to to fmall a
draught of water; therefore, unlefs confiderable height above water be wanted, or confider-
able width, paved fords are not eligible; and where they are not ufed, the wheel-boats may
have the axle-trees of their wheels under their bottoms, and a cavity or channel be left
for the upper part of each wheel to turn in, which will funplify the propofed conftruction of
the beat, as calculated for fords.
+ Thefe boats ought not to be lefs than five feet to admit of pallengers fitting oppofite to
each other conveniently; and as the fection of their bottoms might be curved, they would
as eafily pafs each other as the fquare boats of four feet width.
roads,
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27
roads, where they could ill be difpensed with ; and where, if Fards were
admitted, the frequency of paffage would interrupt the trade of the Canal.
Thefe Canals undoubredly admit of paffage and market boats to deformed or
afcend the inclined planes, the ufual way on carriages, with an advantage
in expedition beyond what can be had where many Locks interrupt which
circumftance counterbalances, in thofe boats, the inconvenience arifing
from their finallnefs. This fpecies of Canal, alfo, obvioully admits of rafts
of fir timber being conveyed, as deferibed by Mr. Fulton; but it mult be
admitted, that they, as well as the tharp-angled beats, will rapidly tear
down the banks of the Canal, Yo as to fill up the bottom and require :fre-
quent repairs. From what has been faid, it becomes an object to decrease
the draught of the boats, fo that they Thall not draw more with their wheels
than 'two feet four inches; and, alfo, that the diameter of the wheels should
be a little increafed, both to avoid excefs of friction, and to evercome
eafier any obftacle arifing either from gravel, pieces of ftone, or any other
impediment, 'lying cafually on the railway, or from the junction of each
piece of rail. It is likewife requifite, that the hoats, to avoid ftraining;
be fhorter and, to prevent their too eafily overtuming with almoft any
thing but minerals, that'they be Tomewhat broader. Thefe purposes will all
be anfwered by a trivial alteration of their form, which I fhall proceed
to deferibe, after premifing that Propofe their width to be not lefs than
four feet frx inches.
re Rafts of timber are-permitted to pafs on the Canal from the Forth to:the Clyde ; and
frequently confit of 70 tons and rupwards, compofed of five tiers -timber eroffed with
deals between each; but, in many Ganals, they are prohibited on account of the damage
they do by cutting the banks with their angles, and the difficulty of fteering them; the
firft of thefe inconveniencies may be done away by inclofing the loweft tier with two fide
pieces (each compofed of one breadth and a half of fir balk) nearly of the flope of the bank,
but rather rounded; and with fimilar ends, curved inwards for about three feet, taking care
that none of the next or immediately fubfequent tiers project beyond. it. The fteerage may
be managed-by the track-rope being faftened towards the-rear end of the raft, and connect-
ed with the middle of the fore end of it by another rope, or a fmall luff-tackle, which a
man upon the raft may haul in or let out at pleafure, fo as to fteer it as effectually as a boat
by its rudder.
t This álfo will be wanted for a purpofe hereinafter mentioned.
D 2
ift. 1,
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1ft. I propofe their wheels to be I2 or 14 inches diameter, and only to
project two inches below the bottom. Thefe wheels muft, neceffarily, be
fheltered by the fides, not only to avoid ftriking againft the banks, but
that the boats may not entangle with each other.-(Vide Plate II).
This purpofe might have been effected by means more fimple than fhewn in
the plan, &c. were it not for the neceffity of attending to the vertical curvature
of the railway, which will project upwards, alternately, between the wheels,
or towards the ends of the boats. The part of the boat below the wheel's
axis, although contracted 6 inches in width, on each fide, as fig. 3, will
not only add confiderably to the burthen, but afford the means of preferving
the cargo from being injured by leakage: becaufe the ceiling of the boat
being neceffarily raifed above the thwart timbers, and a confiderable fpace
left between the ceiling and bottom plank.
2d. The increafed width of the boat from 4 feet to 4 feet 6 inches, will
add both to the burthen and ftability of the boat, without any fenfible dif-
ference of expence in the Canal, as one foot more width, which requires
only a vertical fection of that width, will afford the neceffary increafe of
fpace to allow the boats to pafs each other, and the increafe of excavation
of the Canal is comparatively nothing, becaufe the fides are common to
all widths of the fame depth; from which caufe, excepting where fubterra-
neous navigation is requifite, there are no fufficient advantages arifing from
a very limited width and, even under that predicament, if there be any
material length of carriage, either under ground, or fubfequently, it will
be eligible to keep, at leaft, to the width I have mentioned.
The boats in the Duke of Bridgewater's works at Worfley, where there
are fubterraneous Canals on different levels, are of this width. There are
fome cafes in fhort fubterraneous Canals where 4 feet or lefs width of boat
may anfwer the purpofe. It may be frequently fo with iron, OF other ores,
and fometimes with coals, when fent forward in the fmall corves or boxes,
in which they are brought from the face of the mine ; as, in this inftance,
the boat would only be laden to a fmall depth, and the cargo not lie fo
high as to endanger its overturning.
3d. If
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Feet.Inches.
3ᵈ. If the boats be from 3 to 4 times as long as they are
broad, their draught of water, when light, may be
O
8
-
Projection of wheels below their bottom
-
o
2
Depth to be funk by their loading
-
-
I
6
Total
2
4
at which draught I have before ftated, they may navigate over the fords
without danger of impediment.
Under the above predicaments, every 5 feet 4 inches length of boat
will carry a ton ; therefore, 4 tons may be carried in one of 21 feet 4 inches
length, and 3 tons in one of 16 feet; which latter fize, as being lefs liable
to ftrain when refting on its wheels, and for other caufes will, in general,
have fuperior advantages.
In boats laden with coals, lime, iron ore, or other minerals, it will
evidently be a great convenience to empty them with equal facility as a
waggon which, particularly in fhort boats, may be effected in the two
following ways the boats, in both inftances, having their ends ceiled,
with a flope of about 18 inches bafe to a foot in height. The Canal (in the
firft method that I fhall defcribe) fhould terminate above, and near to, the
place of difcharge, which, in this inftance, I will fuppofe to be a coal
ftaith. At the end of the Canal there may be a dock juft containimg a fet of
boats (which will be hereafter defcribed) or a gently afcending railway in
the latter cafe the boat may eafily be drawn out, by a horfe acting on 2
two-fold purchafe, viz. by a rope attached to a poft clofe to the fide of the
railway, and above the head of the flope, which rope being paffed through
a block hooked to the head of the boat, and returning to a horfe harneffed
to it, upon the railway, will give power fufficient to raife the boat out, in
the fpace of IO yards the firft part of the afcent being fteep, on account
of the boat being waterborne.
If a dock be ufed, the wafte of water will be fmall, as there will be no
defcent of the boat; and the only difference will be, that the boats will be
more eafily run forward over the frame-way of the ftaith. When arrived
at
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at any place of difcharge (whether upon the Italth, or into weffels lying
below) the boat will have to run upoh a frame fufpended on two gudgeons
at half its length, a fittle below the centre of gravity of the loaded, and
above that of the Hight boat ; the frame (being fo contrived that the boat
on taking its pofition, becomes fecured in its place) will then readily be
turned up to fuch pofition as will permit the contents of the boat to
fhoot out, and will, afterwards, be as readily turned back again, from the
polition of the centre occafioning it to preponderate each way alternately.
Where the coals, or other minerals, are not wanted to be occafionally
lodged in a ftaith, but to be only turned over into larger veffels, on a
greater navigation a method practifed in a part of South Wales, with
fmall boats bringing iron ore from a drift out of the mine, may be made
ufe of. It confifts in continuing the Canal (which may be a wooden trough)
to the place of difcharge, and terminating it on a caiffon, fufpended on a
tranfverfe centre. The boat being arrived in its place, the end of the
Canal is clofed by a ftop-gate and the -fmall quantity of water contained
in the caiffon, which the boat fhould as nearly as may be fill, being let
out, the cafe, or frame, with the boat in it, may be turned over as already
defcribed.
In the former method (which will be more generally ufeful) the boats
will, occafionally, have to fhoot their cargoes, in different places, on a
coal ftaith, or quay, and confequently will have to turn; therefore, boats
of 16 feet length, which I have already faid will carry 3 tons each, cannot
conveniently be made ufe of; that circumftance may render it eligible, in
many inftances, to have them fhorter, and of lefs burthen; which, accord-
ing to the fyftem I fhall proceed to lay down, will be attended with no dif-
advantage of moment.
The turning of the frame muft be limited to the extent of this pofition, which, with
the end Поре of the boat's ceiling, already mentioned, will be fufficient at dittle more than
70° from the plane of the horizon. The fides of the frame fhould fit clofe to the boat's gun-
wale, and rife fufficiently above it, to prevent the matter it contains from running over its
fides when rufhing out of the boat.
I have
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I have already mentioned the extreme difficulty of managing a train of
boats, when the wind blows ftrong; and alfo the great refiltance to their
pallage through the water from the form of their ends, as well as the da-
mage done to the banks from the angles of the Boats, which principally
4
arifes from the corners plowing up the banks. To remedy this, for any
great extent, by any thing placed along the banks of the Canal, would be
worfe than the difeafe; fome other mode muft therefore be adopted,
The way, that occurs to me, is to conftruct and connect the boats, in
fuch a manner as to avoid cutting the banks, and likewife enable them to
go fufficiently faft through the water, fo as to be capable of fteering, and
not to be driven by the wind on either bank, and, at the fame time, retain
the power of being fent down the inclined planes without being feparated.
Two, three, or more boats, according to their length and the fuddennefs
of the curvature of the Canal, may be firmly connected, one clofe behind
the other, fo as to form one boat; and, by having a flight overhanging at
the end of each, they will, when on their wheels, bend to the convexity of
the upper part of the railway, and being faftened near the gunwale at each
angle on either end, there is no impediment to their equally fuiting the
concavity of the lower part. The boats, thus connected, would ftill oppore
great refiftance to motion; and although, by giving the extreme ones a
triangular end (which would be the eafieft executed), the refiftance would
be leffened nearly as the t fines of the angles of incidence: yet other in-
.
The damage arifing from the rectangular tranfverfe fection of boats for inclined planes
is confiderable, and can only be remedied by incurring inconveniences in the conftruction
of the boat; and the capability of its fuftaining itfelf on a frame without ftraining, unlefs
uncommon accuracy were attended to, in faiting the boats bottoms and their cradles to each
other.
t At firft in a greater ratio, afterwards in a lefs, according to the experiments of
Abbé Boffut.
If one leg of the ifofceles triangle forming the entrance, or end, of a boat be affumed as
radius, the refinance would be as the fquare of the fines of the angle of incidence; but then
the width of the boat would decreafe or increafe, as the fine is to radius; confequently, in
boats of equal width, the refult would be as the fine.
conveniences
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conveniences would enfue; as the boats would be attended with a great
lateral wave, tending to tear town the banks, and a reduction of burthen
equal to half the projection of the ends, which muft, of courfe, be coun-
terbalanced by an increafe of length. I therefore recommend the ends of
each fet of boats, to be formed like an obtufe pointed gothic arch, as
the dotted lines in fig. II. plate II. where, by only an increafed length of
one foot, an equal, or rather fuperior burthen to the fquare ended boats
will be obtained; and the refiftance reduced, according to the experiments
of Admiral Chapman and Monf. de Rommé, becaufe the half width of
the boat is only three fourths of the axes of the curve forming each fide of
its end ; and, by their experiments, the refiftance is equal (under any pro-
portion of extreme width and fpace from thence to the ftem), whether the
fides for that extent form a curved water line, or go ftraight forward to
the ftem, and form two fides of a triangle.
According to the experiments tried at Greenland Dock, by the Society
for the Improvement of Naval Architecture, the refiftance of a veffel with
femicircular ends, moving at the rate of eight feet per fecond, and I 1½
times as long as broad, was nearly 78 of that of the fame veffel (or body
compofed of logs of timber) with fquare ends. By thefe experiments,
and thofe tried at Verfailles by L'Abbé Boffut, the chief advantage is de-
rived from the form of the end moving foremoft: which will hold good
in all velocities with which boats can move on Canals ; and, as the pro-
pofed ends are formed of half fegments of circles, whofe axis, in the line
of the keel, is once and a third the greateft ordinate, or half width of the
boat, the refiftance fhould, according to the fines of the angles of incidence
of equal threads (or minute portions) of the width of the water intercept-
ed, be .901 of the refiftance of a femicircular end, and therefore .702 of
that of a fquare end, according to the experiments quoted, which nearly
agrees with the fines t of the angles of incidence on equal and minute por-
tions of width.
This advantage, in the experiment quoted, would be partly derived from an equal
fharpnefs in the after end, which will not operate againft the prefent cafe, as each end of
every fet of boats fhould be fimilar for the purpofe of tracking either way.
t According to this theory the refiftance of a femicircular end proportioned to a fquare
one is as 7854 to one, becaufe the fum of the natural fines of a quarter of a circle, taken
on equal portions of its greateft ordinate, infinitely near, muft obvioufly form its area.
In
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In all experiments, the proportionate lengths of the rectilinear part of
the bodies to their widths, and in many inftances of the latter to their
depths immerfed, will produce different refults : therefore, until the effects
of thefe and of other attendant circumftances be known, and introduced
into the formulæ, no theoretic refult can be perfectly correct; but will give
more or lefs than any particular experiment, unlefs where oppofite caufes
counterbalance each other; amongft which, friction on the furface expofed to
the water, and the inequalities of that furface, are not the leaft confiderable.
E
CHAP.
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CHAP. IV.
On the Metacentre or Axis of Motion of Veffels of a uniform Figure
throughout their Lengtb, Shewing by feveral Theoretic Inflances to
what Height fuch Boats may Safely carry their Cargoes. Alfo on the
Means of combining the Navigation of Small and great Canals.
As Canal veffels, efpecially the narrow ones, which are principally the
fubject of this Treatife, are generally of a uniform figure throughout their
length, or axis of motion ; except a fhort fpace at each end, which, from
their great comparative length, conftitutes an inconfiderable portion of the
whole, I fhall confider them as fuch; as it not only fufficiently approxi-
mates the truth, but divefts the queftion of the intricacy that would other-
wife attend it. This fubject having been treated with great ability by Mr.
Atwood in the Philofophical Tranfactions for 1796, I fhall occafionally
recur to him, for the rules neceffary for inveftigating this matter.
In all veffels there is, at every given depth to which they may be laden,
a certain altitude of the centre of gravity, at which the veffel will be on
an equilibrium of indifference whether to remain at reft, or move a greater
or leffer diftance round its axis of motion; which axis (in the line of the
veffel's length) is ufually called the Metacentre : confequently, if the cen-
tre of gravity of the veffel and cargo combined, lie above the meta-
centre, the veffel muft overturn; and, according to the diftance of the
centre of gravity below that point, the greater or lefs will be the ftability
of the veffel. Its refiltance to overturning, if it be of a circular tranfverfe
fection, will be equal to the fine of the angle of heeling, multiplied into
The Conftruction and Analyfis of Geometrical Proportions determining the Polition
affumed by Homogeneal Bodies which float-freely, and at reft on a Fluid's Surface; alfo
determining the Stability of Ships, and of other Floating Bodies: by George Atwood,
Efq. F. R. S.
the
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the diftance between the centre of gravity and the metacentre multiplied
by the weight of the veffel and cargo, which muft, confequently, increafe
until it arrive at its maximum at 90°.
Alfo, in veffels of this form, the metacentre continues at the fame height
above its bottom, at whatever depth the veffel may float; but, in poly-
gons, the cafe is varied, and in the rectangular form very confiderably.
It is obvious, that no floating body can be naturally at reft, unlefs its
centre of gravity be fupported vertically by the centre of gravity of the
fluid difplaced; or, in other words, of the part immerfed.
In a parellelopiped, or fquare beam of timber (fuppofed to be homoge-
neous), its centre of gravity will clearly be where its diagonals interfect
(vide plate I. fig. III. and IV.), and if its tranverfe fection be equilateral,
it would, when floating on the water, obvioufly reft on an equable fupport,
either on one fide, or with one angle downwards; but yet, it will not re-
main indifferently in either pofition; for, according to circumftances, one
of thefe politions would be what Mr. Atwood calls, " the equilibrium of
ftability, in which the folid floats, permanently, in a given pofition;" and
the other would be " the equilibrium of inftability, in which the folid,
although its centre of gravity and that of the part immerfed are in the
fame verticle line, fpontaneoufly overfets, unlefs fuftained by external
force."
When veffels of a rectangular fection are ufed in Canals, they are necef-
farily to float on one fide, or face of the fquare; but Mr. Atwood has
clearly demonftrated, that in many inftances they have, when the centre of
gravity is in the centre of the fquare, a tendency to overturn and float on
their angles; which fhews, that under thefe predicaments, Mr. Fulton's
boats of four feet width, could not carry their mean weight of boat and
cargo fo high as two feet from the outfide of their bottoms ; even without
When the tranfverfe fection is a portion of a circle, the metacentre muft obvioufly be
in the centre of that circle, becaufe, a cylinder of homogeneous matter, floating on its
fide, would reft indiffer(3'y with any part upwards,
E2
any
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any allowance for the requifite refiftance, they fhould be capable of making
to the weight of a man ftepping on one fide.
The following are, according to Mr. Atwood, the equilibria of ftability
of a fquare parallelopiped, whole centre of gravity is in the centre of the
fquare, the full depth or one fide of the fquare being unity.
Pofition of Body immerfed.
Pofition in which it would float perma-
nently.
1ft.
O to .211 and from .789 to I
With a flat furface horizontal.
The flat furface inclining progref-
fively on fundry angles. increaf-
ing to 26° 34' when correfpond-
2d.
.211 to .25
-
-
ing with .25, at which time the
furface of the fluid will be coin-
cident with one of the angles.
With the diagonal lines in various
angles with the vertical, until it
.25 to .2813, viz. $/2 to I's
becomes upright at I's in afcend-
3d.
and from .71877 to .75,
viz. 13 to 14.
ing from Is, and at Hin defcend-
-
-
ing from 14, at which, and ITS,
the angles are 18° 26'.
e
From .2813 to .71877, viz.
4th.
With the diagonal line vertical.
from is to H,
-
-
The laft mentioned depths obviously include all the proportions at
which narrow boats could conveniently fwim ; therefore, they will be the
lefs able to carry their burthens at any reafonable height.
Thefe different pofitions arife from two caufes ; the one is, the natural
tendency that the centre of gravity of the whole mais has to become as low
as poffible : and the other, the tendency which the ceKTe of gravity of the
part
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part immerfed has to become as high as poffible; which, confequently, in
creafes the width of the line of flotation, OF the fupport on the water's edga
I have already fhewn*, that Mr. Fulton's boats of four feet width, will,
with the lading he mentions of four tons in 20 feet length, draw two feet
3'⁻ inches water; and the boat itfelf, without the wheels, which are of no
moment in this inveftigation, would draw fix inches.
As the depth the boat would draw laden, bears the fame proportion to
the width or fide of the fquare, as .5729 to 1. it falls under the 4th, of
laft predicament mentioned in the preceding table; and would naturally
overturn if the centre of gravity were as high as the point of interfection of
the fquare, viz. two feet from the bottom. With iron-ore, limeftone,
and other minerals, coals excepted, there can be no doubt of its carrying
its cargo fufficiently below the metacentre, or overturning point and, as
coals are effential to this fpecies of Navigation, I now proceed to inveftigate
how far it will carry the quantity eftimated.
Coals, although fpecifically heavier than water in general, more than one-
fourth, yet, when broken, as ufually fent from the mines, a ton weight
occupies a fpace of nearly 50 t ctibic feet; confequently, as 20 feet length
of boat is to carry four tons, or 200 cubic feet, it follows, that each foor
length muft require a fection of 10 feet, which, divided by four feet, the
outfide width, leaves two feet fix inches to which we have to add eight
inches I for the proportionate quantity of matter the boat is compofed of 3
and the whole height will be three feet two inches: the centre of gravity of
Vide Page 12.
t When the fleck, or fmall of the coals fill up the varuicies of the large pieces, lefs than
45 cubic feet will weigh a ton ; but it would be unfafe to calculate on this extreme.
$ Vide Page 12.
which
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which will be one foot feven inches, admitting the boat itfelf and the
cargo to be of equal fpecific weight* *.
Another circumftance is, that unlefs the centre of gravity lie fufficiently
low, boats of this form and depth, inftead of progrefively increafing their
refiftance as they heel, or incline to one fide, will at fome given point di-
minifh it. We have, however, only now to confider, how far a Canal
boat can be admitted with fafety to heel, which I conceive to be about one-
tenth of its width = 5° 44' 21"), which I fhall affume as a datum ; and
proceed, according to the method laid down by Mr. Atwood, to examine
how high the metacentre would be under this giving inclination ; and
what weight the boat would bear upon its gunwale, with its centre of gra-
vity at the height of one foot feven inches from its bottom.
Plate I. figure V. A B C D fhews the fection: of the boat defcribed;
which is bifected by the line x 6. w v is the line of flotation, or water-
line when upright, and drawing 2 feet 3½ inches: b the water-line when
inclined 5° 44' 21" : g the centre of gravity of boat and cargo at one foot
feven inches above the bottom.
The centre of gravity of the part immerfed in water, when the boat's
bottom is horizontal, is clearly at the croffing of the diagonal lines w C and
B, viz. at e, and whenever the boat heels, it muft turn on the point x to
which is the middle of the line of flotation ; and on immerfing the triangle
b x v, it muft raife a fimilar triangle w x c out of the water. Let a repre-
fent the centre I of gravity. of the latter of thefe triangles, and d that of
According to the premifes affumed, the fpecific gravity of the boat is to that of the
cargo, as 48 to 50, confequently, fufficiently near the fame. This fmall difference will
be more than counterbalanced by the cargo being higher in the middle than at the fides ;
which, according to the height given, are but two feet ten, which is four inches fhort of the
eftimated prifmatic height,
t Any effect in removing the centre of gravity arifing from the caufe that may occafion
the heeling, not being taken into account as too inconfiderable.
I The pofition of which will be two-thirds of the diftance from x along a line, bifecting
the fase ws, viz. two-thirds of z r.
the
d
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the other; then>the difeance between:thefe points (which taken horizon-
tally, may in all fmall angles be affirmed as + of the width of the boat)
will be the extent which the fupporting power of the triangle has moved
therefore, the centre of gravity immerfed will be removed horizontally
from a, fuch part of (32 inches) the horizontal diftance between a and d,
as the quantity of the triangle is to the whole bulk immerfed, viz. as .603
is to 27.5 or, as one fourth of the fpace b V is to the fpace U C, which in
the prefent inftance amounts to .7017 inches, and is expreffed by the line
I k.-If from k a vertical line be drawn, it will at m, where it interfects
the line x 6 (bifecting the boat) fhew the height at which the equilibrium
of indifference will be, under the given inclination, which, in this inftance;
will be at 7.017 inches above e, or the half draught of the boat; and
confequently, 20.767 above the bottom, viz. only 1.767 inches above
what has been ftated as the centre of gravity of the boat and cargo there-
fore, the fole power that the boat has to right itfelf, is the fhort fpace
that g ties withinfide of the vertical line from the centre of fupport k;
which, at the given angle of inclination, is only one-tenth of the fpace m g,
viz. .1767 inches; on which the whole weight of the boat and cargo is,
as it were, fufpended from that length of arm projecting from the meta-
centre m, viz. on 0 m, which is capable of fuftaining a weight upon the
gunwale D inverfely to the length m n=25.203 inches. The difpro-
portion between thefe is 142.6 to I. and as the weight of the boat and
cargo is 102 cwt. the power capable of giving the inclination 5° 44' 21"
(the vertical depreffure of one tenth of the width of the boat) is only .715
cwt. or lefs than half the weight of a man; confequently, Mr. Fulton's
and Dr. Anderfon's boats are not fuited to carry coals to the extent men-
tioned; and if not fuited for coals to that extent, it is felf-evident they
are not fuited for light goods, for grain t or malt, or even for timber and
deals.
Not vertically, but in the bifocting line x b, which is referred to throughout ; the boat,
as before ftated, drawing 2 feet 3 1-half inches.
t The fpecific gravity of wheat in bulk is nearly that of coals, or from 46 to 50 cubie
feetto a ton ; but in bags (as it muft be in thofe boats) it will occupy more fpace ; the
other fpecies of grain are lighter; oats are particularly fo, and malt is under the fame
predicament.
It
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It muft alfo further be confidered, that no articles, capable of damage
from water, could be fuffered to reft on the floor of thefe boats; from
all which it follows, that fuch boats as I have recommended of 4 feet 6.
inches width, are of the leaft breadth that a Canal for any general purpofes,
fhould be calculated for, in any fituation; and, that the raifed ceiling, in
thefe boats, is neceffary to afford a receptacle for leakage, or other water.
It alfo clearly follows, from thefe premifes, that boats defigned to dif-
charge their cargoes with floped ends for that purpofe, muft be of a ftill
greater width becaufe, carrying their cargoes higher :-That width,
without entering into calculation, I would propofe to be five feet, and the
boats to be made proportionably fhorter ; in which cafe, a greater num-
ber might be fixed together, to form what I fhall call a conjoined-boat;
either two or four of which, according to circumftances, may be tracked
by one horfe. If the Canal be remarkably ftraight, a greater number may
be conjoined; and then only two fuch boats be drawn by one horfe at-
tached to a chock, or fhort maft, ftanding about one-third of the diftance
from ftem to ftern, of fuch conjoined boat as may go foremoft to the
ftern of this, the ftem of the fecond conjunction of boats being faftened,
a boy may fteer the whole by means of a pole fixed like a flat-lying bow-
fprit, to the headmoft of the fecond fet, which will ferve as a tiller to fteer
the preceding one, the latter acting as a rudder t.
But fhould the Canal not admit of a great length of boat, then, two fets,
as above defcribed, may be drawn by one horfe; thefe two fets being con-
nected not by their ends, which would prevent their being well fteered;
but by a line communicating between two fhort mafts, one in the latter
conjoined boat of the firft fet, and the other in the leading one of the
fecond fet (in the fame pofition as the maft in the firft conjoined boat),
which will give room for the fecond fet of boats to be fteered as well as
the firft. In the narrow boats defcribed by Mr. Fulton, he does not feem
Quick-lime is of courfe excluded.
This method is practifed in Cambridgefhire and Lincolnfhire.
to
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to be aware of the refiftance arifing from friction through the water;
which, according to Mr. Atwood's remarks on the experiments made by
order of the Society for the improvement of Naval Architecture, amounts,
on wood planed very fmooth, to golb. on 258 fquare feet, when moving
at 8 feet per fecond; and, confequently, muft be confiderable on rough
fided boats, which all will fooner or later become.
In feveral inftances, it might be eligible to navigate thefe fmall boats in
long levels of exifting Canals on the large fcale and it may frequently be
done to advantage, by making the boats nearly one half or one third of the
width of the locks on fuch Canals and each conjoined boat, either equal
: Car
Ciangir
al:
to the whole length, or half length of the Lock, fo that the greateft ton-
be
proper.
nage poffible may pafs at one time t. It muft, however, be admitted, that
hand
in
the
Sach
Mr. Fulton, in Page 35, fays, that he hopes he has fhewn " that refiltance from fhape,
in flow movements, is inconfiderable, and that the strue principle of conveying goods
" cheap, when expedition is not required, is to move flow and take a quantity."
then
is
"
That this principle to the extent he propofes, is ineligible, and not always practicable,
of
lower
I think is fufficiently clear, from what has been faid of the neceffity of confiderable motion
D-nol
through the water, to keep the boats off the fhore, or off the Canal Banks, which, to the
number of 10, 15, or 20, could by no means be kept right by one man with a boat-hook,
seauly
h.
(on
as fuggefted by Mr. Fulton, Page 38.
The explanatory note he has given at the word quantity, is not relevant to what ought
to have been proved ; as the reafoning and mathematical deductions there, are only appli-
cable to the refiftance of different velocities of one and the fame boat and not to diffe-
rence of weight or quantity difperfed in numerous fmall boats, in place of all, or a portion
of it, being placed in a fingle greater one, the truth of which will appear by adverting to
what is well known to be the cafe in fhips-veffels of fimilar forms, but of different dimen-
fions, will carry burthens proportionate to the cube of any of their dimentions, viz. if
double in their proportions, their burthen will be increafed eight-fold; but the fails, which
form their moving power, will only be enlarged as the fquare of that proportion, of courfe
only four-fold Yet the large veffels will move with equal or greater celerity than the
fmaller, therefore, a veffel of twice the width, &c. will only require half the proportionate
force to give equal motion to the fame quantity of tonnage in the leffer veffel, fo far as re.
lates to general principles: the reft depends on form, proportionate weight of the veffel it-
felf, quantity of furface, &c. as has been already noticed.
t
It may fometimes be eligible to have 3 conjoined boats, each confifting of two parts, to
occupy the area of the Lock; which would be attended. with no material trouble, as it
would be eafy to feparate and conjoin the two parts of the middle boat.
F
thefe
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thefe boats thus joined, will be liable to accident from the fhock of the
great boars, as well as much inconvenience from the agitation of a wide and
deep t Canal, and alfo, that the boats would be very liable to become
leaky if they have far to travel on land, either from coal mines to the
Canal, or from the Canal to any particular place of confumption : there-
fore, I conceive that in fome inftances, particularly in the conveyance of
minerals, it will be better to have boats of great length, fo conftructed, as
to have 'a double railway upon them, and to carry two parallel ranges of
waggons ; a plan nearly fimilar has long fince been talked of; but, excepting
on a fmall fcale as to magnitude of waggon, has, I believe, never been
carried into effect, from the following caufes, viz. the difficulty of getting
the waggons in and out ; the danger of ftraining the boats in performing
that operation, and the rifk of their being overfet in high winds, or from
other caufes.
The two firft objections I propofe to remedy, by having a dock at the
place of loading and unloading, in which the boats fhould be laid aground ;
which may be done with very little lofs of water, as they fhould be uniform
in their dimentions, flat bottomed I, and nearly filling the dock ; the bot-
tom of which fbould be fo high as juft to admit the laden boat to float
over it. The boats being always laden and unladen in a dry dock, in
If the boats be fo large as to go unconjoined, or with only one junction, which may
be done on the plan of carriages under the boats; then little inconvenience or hazard will
arife from navigating the large Canals. But even in the plan of moving on carriages, the
boats are fo fhook in moving up and down the inclined planes as to become leaky : to re-
medy which, I would propofe that the carriages, where the boats are large, fhould move on
eight wheels, four on each fide, and refting on two axes paffing through the middle of
parallel bars connecting each pair of wheels ; of courfe, the railway would be lefs liable to
injury, and the fhock from impediments would be reduced. The latter may be nearly ob-
viated by any fimple contrivance to fweep the rails, which may project from the carriage and
precede the wheels.
In fhallow Canals, the waves cannot rife fo high as in deep ones, or be fo far afunder.
1 Excepting a deep keel to keep them from driving to leeward to receive which, there
muft be a groove in the floor of the dock.
follows,
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follows, that they may have leaves at their ends to let down to any requi-
fite depth; which, when raifed up and fecured, may be kept tight by
the preffure of the water :-the fuftaining platform may, therefore, be on the
ceiling of the boats, which may be raifed by deep floor timbers, fo as to
Tupport the boats fides, and raife the ceiling* above the light mark, both
for the purpofe of preventing the boats finking from the leakage of the
leaves, when not in ufe ; and to avoid unneceffary defcent and afcent for
the waggons to and from the docks, the railways at the end of which,
Thould coincide with thofe on the platform of the boats.
The tranfverfe fection of thefe boats I propofe to be a portion of a poly-
gon, as carrying the metacentre higher than a fquare, and as being lefs lia-
ble to cut down the fides of the Canal.
Waggons of feven feet fix inches outfide length, fix feet outfide width
at top, and four feet depth, with their fides and ends contracted towards
their bottoms, contain a meafure (inclufive of the heap at top) of 135 cube
feet, or a Newcaftle chalder t of coals, which fhould weigh 53 cwt. ; and
rating the waggon and wheels at 15 ewt. I, each laden waggon will then
be 3.4 tons; confequently, 16 waggons, which will occupy a fpace of at
Leaft 60 feet length and 12 feet width, will weigh 54.4 tons. The boat for
this purpofe, I propofe to have floping ends, fo far contracted as juft to
admit the paffage of the waggons, and to be of 64 feet average length, II
feet width of bottom, 14 feet on the gunwale, and 4 feet height from the
bottom of the boat, to the gunwale, as by the fection in Figure L Plate
III.
Which fhould be caulked and made tight.
t I fhall form my deductions from waggons of this meafure, as being the ftandard of the
great coal country ; and equally capable of being reduced to other meafures, as any other
proportion I might have affumed.
I The waggons with heavy wheels of upwards of three feet diameter, weigh above a ton,
but may be reduced to the weight ftated, or lefs.
F 2
The
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The light draught of the boat may be lefs than 10 inches, but I will af-
fume it to be brought to that depth by ballaft between the timbers :-
the breadth, on the water's edge, will then be II feet 7½ inches, and the
fection immerfed will be 9.427 fuperficial feet. The cargo as afore-men-
tioned will be 54.4 tons, which multiplied by 36, the cube feet of water
in a ton, and divided by 64, the length in feet of the boat will give 30.6
feet for the fection the boat has to be depreffed, which will require an in-
creafed draught of nearly 2 feet 43 inches, or in all 3 feet 23 inches, but
fay 3 feet 3 inches.
Admitting the pyramidal heap of coals on the top of the waggon to be
equal to an additional height of four inches on the width of its bafe a b,
the centre of gravity of the middle part of the waggon (of three feet bafe)
allowing the top and bottom to be of equal length t, will be at two feet two
inches ; and by the two triangular prifms (each of 18 inches bafe), it will
be moved nearly 3 inches higher, viz. to 2 feet 5 inches above its bottom,
which will be about 3 inches above the centre of its wheels and calling the
wheels 2 feet diameter, the centre of gravity will be raifed 3 feet 8 inches
above the fupporting rail which, according to the plan, being I foot 5
inches above the boat's bottom, makes the elevation of the centre of gra-
vity of the lading to be at 4 feet I inch. The centre of gravity of the
boat will depend on the proportionate timbering of its bottom and fides,
and the iron or ftone ballaft it may have in to fink it to IO inches ; and if I
Let s exprefs the fection to be immerfed, viz. 30.6 fup. feet.
3 a=the width of light flotation, viz. 11.625 feet.
=the increafed depth fought.
Then, as the boats fides overhang each of them n/o of their height, the equation will ftand
thus. 34 s. and the refult will be x = + 16 - 4 a=2.405.
3
t They generally are not fo, but were I to make any other calculation, it would only
be on a particular inftance, and the weight and pofition of the wheels mut afterwards have
to be accounted for : I therefore, fhall calculate as above, and leave the wheels and axle-
trees as a counterbalance for the deficiency of the length of bottom, which they will in ge-
meral be fully equal to,
affume
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affome it at 18 inches from the bottom, it will be more than fufficiently
high. The mean centre of gravity will confequently lie between 18 and
49 inches, in the inverfe proportion between 9.427 and 30.6, (the propor-
tionate magnitudes of boat and cargo), which will fix it at 41.55 inches.
The centre of gravity of the bulk immerfed will be fo much above the
half draught of water, 19.5, as the two triangles W P B and V q C. (Plate
III. Fig. I.) whofe centre of gravity is at the height of 26 inches, (viz. } of
the draught of water) will, in their ratio to the whole bulk raife the com-
mon centre, viz. as 132 + 3 of 39: .6.5 :: 3/80 of 39:, ,648*, which, added
to 19.5, will give 20.148 inches for the mean centre of gravity of the part
immerfed. I fhall in this boat, the fame as in the preceding one, admit
the utmoft extent of heeling to be 5° 44' 21" but the mode of finding the
refult, will be fomewhat more complicated than in the former operation,
becaufe of the diffimilarity of the triangles formed by the interfection of the
two lines of flotation, and the confequent inftability of the point of inter-
fection, which, in veffels of parallel fided fection at the water's edge,
throughout the extent of heeling, remain uniformly the fame.
The deviation from the preceding rules, will eafily be explained by
having recourfe to the diagram Fig. III. Plate III. in which A B E b is
the tranfverfe fection of a veffel with ftreight overhanging fides; and q is
the point of interfection where the fides would meet, if prolonged down-
wards.-x q is a line bifecting the angle of junction of the boats fides: and
w v, is the line of flotation at right angles with x q, when the boat is, of
courfe, upright.- b is a line parallel to the line of flotation, on the boat,
having heeled any given quantity equal to the < b x v. This line paffes
through the middle of the level line of flotation, but cannot be the true
pofition of the inclined line ; becaufe the quantity of water difplaced on the
fide heeled towards, and left unoccupied on the other, muft of neceffity be
equal ; and the triangle b V x, is obvioufly larger than the triangle w x c, :-
Viz. As the width of the boats bottom + the overhanging of one fide on the line of
flotation, is to the difference between the two centres of gravity (viz. 26.-19.5) fo is the
value of the two triangles (which, as they are equal, is expreffed by the bafe of one of them)
to the refult.
therefore,
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therefore, the real line of flotation will be moved fo far downwards, to-
wards v, (fay to C H) as to equalize the two triangles, w X C, and
H X v.-To find the precife pofition of this line we have the following
data-The triangle, C q H muft be equal in area to the triangle, W qu,
becaufe the triangle, HX v. is equal to the triangle, w X C, and the
L A q P being common to both the great triangles in queftion, the rectan-
gle C q X q H muft be equal to w q x q ; viz. to w q 2 as both thefe
lines are equal. Thefe circumftances, combined with all the angles being
given, lead to the following operation.
Let w P be drawn parallel to the inclined line of Hotation; on which line
w P, let fall the perpendicular U s, the value of which will be the fine of the
angle of heeling, the level line of flotation being radius :- s will be the
fine complement of that angle. The angle s V P is equal to the angle of
overhanging of the boats fide + the angle of heeling (viz. = < x q v + < s w
v) and U.S being affumed as radius, s P will be the tangent of the angle
mentioned, and v P its fecant confequently, all the fides of the triangle
w v P are attainable ; and the triangle H X V being fimilar in fpecies, its
fides will alfo be determinable from the data premifed.
Let a reprefent the line W q or qu
b
qp
d
wp W
g
W v, the level line of flotation.
y
q H
u
C q
We then have the following equations and proportions u y=aa..'u=
a a
y
Asa:u::b:y a y = b u = y and yy = b a confequently y =
Vbafay=m. V
Then
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Then as b-a : : : m-a :mg-ba = line X v; which will give the pofi-
tion of the interfection of the lines of flotation. The value of q H having
been acquired, that of C H the inclined line of flotation follows of courfe.
The lines X H and V S will be attainable, by the fimilar proportions of the
two triangles P W V and H X v as above ftated; and X H X vS 2 will give
the area of the triangle immerfed by heeling #. The mean centres of gra-
vity of the triangles immerfed and raifed out of the water (viz. a and d)
will, according to well known principles, be at two thirds of the diftance
from X along the lines X r and X t; thefe lines bifecting the oppofite
faces of their refpective triangles; then C H (the inclined line of flotation).
being affumed to be horizontal, the horizontal fpace between r and t will
obvioufly be a mean between the lines C.S and w n: and as S H and s n
are equal, it will therefore be a mean between c H and W s: confequently
C H + w
the horizontal removal of the triangle of immerfion will be
viz.
3
the inclined line of flotation + the level line of flotation X N.S. Ct. of L ot
3
heeling, (rad. I.)
The level line of flotation of the boat in queftion being 13.4375 feet,
and the angle of heeling 5° 44' 21"; the area of the triangle in queftion
will be, according to the preceding deductions, 2.26728 fuperficial feet,,
and its horizontal removal 107.5398 inches. The confequent lateral re-
moval of the immerfed centre of gravity will be 6.0915 inches, viz. as
40.027 feet, the fection of the boat immerfed when laden 107.54 inches,
the horizontal removal of the triangle of immerfion ;:: 2.2673 feet, the
magnitude of the triangle immerfed by heeling 6.0915 inches, the lateral
removal of the immerfed centre of gravity, which, divided by .I, (the na-
tural fine of 5° 44' 21" when radius is 1.) will raife the metacentre 60.915
The angle of heeling in the diagram (fig. III. plate III.) is 12°, which is more than
double what I have fuppofed to take place in Canal boats, and is drawn of that magnitude
to make the explanatory lines more feparate and diffinct.
inches
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inches above, 20.148, the height of the centre of gravity immerfed, and
fix it at 81.063 above the bottom of the boat, viz. 39,513 inches above the
centre of gravity of the boat and cargo, which will give a power of refift-
ance equal to 71.15 tons upon an arm of lever of 3.9513 inches, viz. a
ratio of 281.13 tons and inches; a refifting force far fuperior to what is
needful, and, confequently, the boat cannot ever heel fo far.
According to the rules for upright fided boats, the volume of the triangle
immerfed would be the line of level flotation X N. Tt. L of heeling, (rad.I.)
8
= 2.26835 feet. The fpace of removal, at two thirds of the width of level
of flotation, would be 107.5 inches ; which, multiplied by the fum pre-
ceding, gives a ratio of 243.847 in fuperficial feet and linear inches. The
ratio, according to the method above proceeded on is 243.823 : therefore,
under fmall overhanging of the boats fide, the operation may be fhortened
for all practical purpofes, by adopting throughout the fame rules as for up-
right fided boats.
The power that was mentioned as neceffary to be guarded againft is that
of the wind. To judge of that extent of it, under which the boat may be
navigated, with the wind on one fide, the beft criterion will be drawn from
what falls under univerfal obfervation. I-have found from different expe-
riments, that wind mills generally begin to reef their fails ; and fhips clofe-
hauled to reef their topfails, when the wind blows with an impulfe of two
pound on a fuperficial foot; and under fuch preffure it is pretty clear, that
a flat boat oppofing an extended furface to a fide wind, could not be kept
off the leeward bank, without greater head-way than is ufually given by
track horfes; confequently, no further refiftance of moment has to be
guarded againft.
The height of the waggons when the boat has heeled 5° 44° 21", will
be lefs than 6 feet above the water's furface. The whole range of them will
be 60 feet long, and, admitting the projection of the ends of the boat to be
equal to the vacancies in the lower part of the waggons, we have 60 X 6 x 2,
viz. a force of 720lbs. acting on an average height of 3 feet above the
waters
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waters furface. The refifting point will be nearly half the draught of water
of the boat, which, if it have twelve inches depth of keel, will be a little
more than 2 feet below the furface : confequently, the above force would
act with an arm of lever of бо inches, and be equal to a ratio in inches and
pounds of 43200. viz. 19.285 tons and inches, which, compared with the
refting power, is upwards of 141/2 to I. therefore, from any other caufe but
that of avoiding the being blown afhore, there is nothing material to prevent
the deck being raifed nearer the laden water line.
As various cafes will arife different from thofe I have affumed, I fhall
conclude with giving a theorem on the equipoife of ftability, coincident
with the rules inveftigated by theoretic authors on Naval Architecture,
and fufficiently felf-evident to need no demonftration.
Let s reprefent the natural fine of the angle that may be heeled, radius
being I.
d the diftance between the centre of gravity of the boat and cargo and
the metacentre = line g m, fig. V. plate I.
w the weight of the boat and cargo.
Thefe combined, viz. s d W will form the refilting power to overturning.
Let P reprefent the quantity or preffure of the power tending to overturn
the boat, or to keep it in equipoife in any pofition.
b the arm of lever with which it acts.
Then we have the equation of s d w = P b. from which the value of any
one of the requifites to a ftate of equipoife may be found, where the reft
are given.
G
CHAP.
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CHAP. V.
On the Application of Wheel Boats and Inclined Planes to Collieries, and
Inftances in which that Syftem may be improved.
THE ufual method, in the great coal countries, is to lay waggon or rail-
ways from the different pits leading to one general way, which terminates
at the river or navigation, where the coals are to be difcharged : fome of
which railways are in Northumberland and Durham, from 6 to 10 miles in
length.
The mode that fhould be adopted muft depend on the diftance the article
has to be conveyed to the main river or navigation; and on the form or
pofition of the intervening ground, which I fhall clafs under the three fol-
lowing general heads.
1ft. Planes nearly horizontal, or with moderate declivity, and without
valleys.
2d. Gently declining countries, with deep valleys leading to the river or
navigation, taking off the coal.
3d. Mountainous countries.
In the firft inftance, if the horizontal line point towards the place of dif-
charge, a Canal of fome fpecies is clearly eligible, if the length require it :
but, if the courfe of difcharge be in the line of gentle declivity, a railway
would generally be the beft. In the fecond inflance, viz. of deep valleys ;
it is fufficiently plain, that fome part of the bottom of the vale would be
a proper place for difcharging the water of the colliery by a drift, which
would
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would either reduce the lift of the water, or lay the colliery quite dry :
In either inftances, particularly the latter the drift may, as obferved in a
preceding Chapter, be made navigable for boats of about four t feet width,
fuitable to the bafkets or boxes, in which the coal may be brought from
the face of the works, and be continued as a Canal along the fide of the
vale, until it attain the level of the flat country. Then, if the diftance to
the river or navigation be fhort, or otherwife unfavourable for the conti-
nuance of the fmall boats, they may difcharge their contents to be led away
in waggons. But if, by defcending to the bottom of the vale, a confider-
able length of level can be obtained in a proper direction, an inclined plane
for the boats may then be advifeable.
In the 3d inftance, that of a mountainous country there, generaily, will
be fufficient difference of elevation on a regular acclivity, tranfverfe to the
line of Canal to obtain long levels: If otherwife, a rail-way will clearly be
the beft.
If a Canal be refolved on in any of thefe inftances, it will become a
matter of enquiry, what mode of it fhould be adopted: but, previoufly to
the difcuffion of this point, I will confider how far wheel-boats may be
made ufe of under-ground.
In the great coal mines of Worfeley, there are Canals on three differ-
ent levels. The firft is on the level leading all the way to Manchefter,
which branches to the right and left in every feam of coal that it paffes
through: in each of which, by means of drifts at regular diftances, the
coals are brought down the declivity of the feam to the boats.
In this, the navigation would, of courfe, be continued through the level of every feam
of coal interfected.
t Boats of this width will frequently be fufficient if the coals be brought out in boxes or
bafkets fuited to the land conveyance in the mines. The bafkets, if circular, are in moft
places called Corves, and when fquare, or if with fledge bottoms, their name is more local.
G₂
From
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It is obvious, that the diftance which the coals may be brought down,
will progreffively become fo great ás to be attended with material expence :
From this caufe, the Duke of Bridgewater has fouud it convenient to run
other levels through his coals at a height confiderrbly fuperior to the tun-
nel from the Manchefter Canal, which interfects all his feams, and from
which other Canals branch, as already obferved.
The higher Canal where it croffes the main tunnel, has a pit communi-
cating with the fide of it, down which the coals are fent from the upper to
the lower boats, and by their defcent raife a proportionate quantity of lime-
ftone up another pit to the furface of the ground. The charge of the oper-
ation is not great; but the frequent delay attendant upon this method, is
fuch, as may render it eligible in fome inftances to convey the boats them-
felves from the upper to the lower Canal* ; and in all fituations where the
dip or fall of the feam is fufficiently great, for the weight of the laden
boats to overcome friction and other impediments to drawing the light ones
up, I conceive the fyftem of inclined planes and wheels under the boats
might be adopted with advantage. It may likewife fometimes be fo, where
the navigation through the coals is below the principal level but, in both
cafes, if the coals have to be drawn up a pit, it will frequently be better
to communicate between each Canal and the pit, by a navigable ftone
drift; the propriety of which muft be determined by the probable coft of
the drift, and the quantity of coals that would have to pafs through it.
Parallel Canals along the feam of coals, if eafily executed, would be eli-
gible every 2 or 300 yards, at leaft, and would require fo many drifts or
tunnels to the pit. The more diftant tunnels would become long and ex-
penfive ; therefore, if the depth of the pit and the feeders of water be not
very confiderable, it is obvious, that new pits fhould be funk to correfpond
with every Canal, or every other one, according to circumftances. If the
inclination of the feam be moderate, and it be not eligible to fink more
pits than one, it will be advifeable to fink deep enough to correfpond with
They were laft year preparing to do this, by cutting an inclined plane through the
ftone and other ftrata, which I am informed is now completed.
the
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the furtheft propofed Canal through the coal, and to run a navigable tun-
nel to interfect it. The intervening Canals through the coal, may com-
municate with this tunnel, where they crofs it by pits, down which the
coals may be lowered to other boats. This may be rapidly done by pro-
per machinery, as the bafkets # or boxes will only have to be lifted above
the fides of the upper boats but, where the quantity is very great, it may
often be advifeable to form fteep inclined planes for wheel-boats, taking
care, of courfe, that the extremities be fufficiently horizontal.
I by no means defign to infer, that fubterraneous Canals are proper in
all collieries. Thofe, whofe beds of coal lie nearly horizontal, and are
much troubled with dykes or fiffures, raifing or depreffing the ftrata on
each fide, and have, at the fame time, but one workable feam are under
the worft predicaments; as the re-obtaining of the level of the Canal, in
the coal, on croffing a dyke, would be attended with a comparatively
great length of ftone drift, and no opportunity afforded of ftriking into any
other feam, brought nearly to the fame level, by the rife or fall of the
ftrata on the other fide. Alfo, in collieries favourably circumftanced for
the formation of Canals through their feams, they can only be eligible
where thofe Canals communicate with fome other navigation, as at Worfe-
ley ; or their depth below the furface, or other caufes, prevent the pro-
priety of having pits near to each other. The ineligibility of many pits
in deep collieries, particularly where the water is to be drawn a great heght,
is often fuch, as to render fubterraneous Canals eligible, under a confidera-
ble degree of the unfavourable predicaments mentioned.
As the Duke of Bridgewater is the parent of Canals in thefe kingdoms,
and the country ftands highly indebted to him, I fhall draw another ex-
ample from his collieries, to explain how the coals are raifed from the
feams below the level of his great drift or tunnel, that communicates with
the tranfverfe branches.
Thefe bafkets or boxes being the fame as the coals are firft filled into at the face of the
workings, unlefs, from local circumftances they be very fmall, and then it may be eligible
to fhoot them into larger boxes as at Worfeley.
The
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The boats in the lower Canal contain a number of fquare boxes exactly
filling them acrofs, and ftanding clofe to each other. The coals being
filled into thefe boxes, the boats are then brought under a pit funk from
the fide of the main tunnel from the Manchefter Canal; to which, by
means of water tubs defcending from the furface of the ground to that
tunnel, the coal boxes are drawn, and are then placed in other boats to
convey them away.
In diftricts where the coals are not conveyed out of the mines by drifts
as above-mentioned, but up coal pits to the furface, and have to go from
thence a confiderable diftance; they may either be filled at the mouth of
the pits into wheel-boats and fent forward, as already defcribed by fmall
Canals to the coal-ftaith or main navigation: or they may be fent in
waggons to be placed on the decks of boats-Likewife, whenever coals in
large quantities, lime, lime-ftone, or other minerals, have to be conveyed
along Canals where there is a fcarcity of water, it will be eligible where it
can be done, to overlap the levels in a fteep place, and communicate them
by an inclined plane for boats, or a double rail-way for waggons, leaving
the lock communication to anfwer all the general purpofes of commerce,
and to occupy as fhort a fpace as it can. But, where there is no aid of
exifting Canals, and circumftances are favourable for long levels, I think,
that in place of wheel-boats from every pit, which would inevitably, in a
fhort time become leaky, it would be better to make ufe of waggons to go
into fmall boats, in a fingle range, and for one horfe to draw a couple of
them. The points then to be attended to, will be, that the boats occupy
as little width of Canal as may be, without being liable to overturn, or to
draw too much water for fords.
Confonant to thefe requifites, a boat of 6 feet 6 inches width of bottom,
and 3 feet 6 inches height, with each fide overhanging three quarters of its
vertical height, to the extent of two feet above the bottom, and then
This may be eligible where branch Canals on the fmall fcale bring in a great quantity
of carriage ; but if otherwife, and there be a general fcarcity of water not to be remedied
by refervoirs, then the methods of Mr. Weldon or Mr. Rowland, or fimilar plans, muft be
reforted to.
curving
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curving upwards fo as to make the full width only IO feet 6 inches, will
be found fuitable as at 36 feet length (exclufive of the ends) it will carry
4 chalder waggons, at nearly 2 feet 3 inches draught of water.
I propofe two of thefe boats to be drawn by one horfe; and fteered by a
fhort fteer-beam, fixed as already defcribed. If both ends of the boats be
fquare, they muft be kept fo far afunder as to admit of forming a fufficient
angle in fteering.
The fole alteration of the waggons from thofe defcribed before, is, that
I propofe their wheels to be 18 inches, in place of two feet diameter; and
the height of their bodies 3 feet 6 inches, in place of 4 feet : which defi-
ciency of height will be compenfated by making the bottom one foot
wider than the former, and nearly of the fame length as the top, which
will only require an additional fet of falling leaves at the bottom.-Thefe
waggons, admitting the raifed heap of coals to average fix inches above
them, will carry their centre of gravity (with the fame allowance as to
wheels, &c. as in the preceding eftimate) at two feet one inch above their
bottom; which being three inches above the axis of their wheels (of 18
inches diameter and treading 15 inches above the boats bottom) fixes the
centre of gravity of the cargo at 4 feet 4, or 52 inches.
The boat may draw lefs, but will be affumed to draw 9 inches water
its width of flotation will then be 7 feet 7½ inches, and the weight of one
waggon, of 68 Cwt., refting on 9 feet length, will fink it; as already ob-
ferved, to nearly 2 feet 3 inches.
The centre of gravity of the boat will be nearly at 15 inches from its
bottom, fo that the difference between the two centres, will be (52-15)
=37 inches. Their proportionate gravities, according to the premifes,
will be 5.28 and 13.6, fo that the mean centre of gravity will be raifed
26.65 inches and be at 41.65 inches from the bottom. At 2 feet inches
draught, the laden width of flotation will, in the form defcribed, (vide
plate III. figure 2) be nearly 9 feet IO, or 118 inches; which, according
to the approximate method of proceeding, defcribed in the preceding chap-
ter,
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ter, will, on heeling 5° 44' 21" raife on one fide, and immerfe on the other,
a triangle of 1.2146 fuperficial feet, and remove its centre of gravity 78 1
inches, which will remove the centre of gravity of the whole mafs, of the
fection 18.88 fuperficial feet, 5.060 inches laterally, and fix the metacentre
at 50.6 inches above the centre of gravity immerfed: which, according to
the rules already explained, will be nearly at 14.7 inches and, confequent-
ly, the metacentre at 65.1 above the bottom, and 23.45 above the centre
of gravity of the boat and cargo, which is above all refiftance that can be
required. However, as, from the narrownefs of the boat's bottom, it may
have the appearance that it will be otherwife when it is light; I fhall alfo
inveftigate the circumftances of it in that cafe.
The light waggons being affumed, as before, at 15 cwt.; and occupy-
ing 9 feet length, their fection of fupport in the water will be 3* fuperfi-
cial feet, the increafed depth 4-55 inches; and the boat's line of flotation
98.325 inches (correfponding with 13.55 inches draught.)-Then, ad-
mitting the centre of gravity of the light waggons to be 2 feet 4 inches
above their tread, or 3 feet 7 inches above the bottom, which is full as high
as it ought to be ; and taking, as before, the boat's centre of gravity to be
15 inches, there will be a difference of 28 inches, which proportioned ac-
cording to their maffes, will fix the mean centre at 25.145 inches above the
bottom. The centre of gravity immerfed is according to the premifes, at
7.035 inches, and the effect of heeling 5° 44' 21" well, according to the cal-
culation for boats with overhanging fides, remove it 6.51472 t inches la-
terally, fo as to fix the metacentre at 72.1822 inches above the boat's bot-
tom ; and confequently 47.0372 inches above the centre of gravity of the
boat and cargo: therefore, there will be a weight of 8.28 cubic feet of wa-
ter on an arm of lever of 470372 inches = 2434. lbs. and inches t, on
every foot length, to refift any overturning force; and as the waggons in
That of the light boat is 5.28, and confequently the whole is 8.28.
it Triangle immerfed .829098 removed 65.061, as 8.28 : 65.061 : .829098 6.51472.
I 4.70372 x 8.28 X 62 1/2 (the weight in lbs. of a cube foot of water = 2434 lbs. and
inches. N. B. Where the weight has been calculated in tons, 36 cubic feet of water have
been affumed as a ton in place of 35.84.
the
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the light boat will, when heeling, be 5 feet above the water's furface, and
the half depth will then be about IO inches; there will, with a wind of
two pounds to the fuperficial foot, (admitting the waggons to occupy the
whole length) be an overturning force of rolbs. x 40 inches, = 4colbs. and
inches, which will leave a fpare refifting force of 2034lbs. and inches; equal,
as the top width of the boat is 10 feet 6 inches and the line, m n, 59.66
inches, to a weight on the gunwale of 34lbs. on every foot in length, which
is more than there ever need be, and confequently no impediment can arife,
if the boat be kept going with fufficient velocity to prevent it from being
driven afhore to leward.
According to the method of calculation purfued for upright-fided-boats
of the fame width of flotation line, the triangle immerfed would have been
.8434, and the fpace removed 65.55, which would raife the metacentre
above the centre of immerfion nearly 4/5 part more than true calculation,
viz. 1.622 inches; which, where there is much room to fpare, as in the
prefent and preceding inftance, would be of little moment: but, where the
metacentre barely rifes above the conjoint centre of gravity of boat and
cargo, the difference, under large angles of overhanging of the boat's fides,
will be material.
In figures I and 2 of plate III. M. G and E fhew the politions of the
metacentre, combined centres of gravity of boat and cargo, and centres of
gravity of the part immerfed, when the boats are laden, and under the
given inclination : and m, g and e, fig. 2, fhew the fame pofitions when the
waggons of fig. 4 (of which, fig. 2, is the profile) are empty. Whence it ap-
pears that o m is the arm of lever, with which the weight of the boat and
waggons refifts any overturning force and m n (which is equal to the fection
of the angle of heeling, the half width of the boat being radius,-the fine of
the angle of heeling, the vertical height of the metacentre above the de-
This vertical height is the fine complement of the angle of heeling, when the radius
is the difference (on the bifecting line of the boat) between the metacentre and the height
of the boat's gunwales + the fine of the angle of heeling, the half width being radius.
In practical inflances, the admeafurement on the line m n on the figure, or diagram, may
fuperfede the calculation.
H
preffed
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preffed gunwale being radius) is the arm, with which any weight upon the
gunwale would act.
As the boats, No. I and 2, are propofed to reft with their cargoes in
docks, they are neceffarily flat bottomed, and the flat part fhould at leaft
extend as wide as the railways of the waggons, that they may have a firm
fupport. The form of fig. 2 is calculated for a limited depth, in a narrow
Canal ; and fo as not to cut its banks, and may be improved by fwelling out
the ftreight part of the fide in a gentle curve. Fig. I admits of being con-
fiderably fo by adopting the curved form of the fides fhewn by the dotted
lines ; which, by leffening the injury to the Canal-banks, would more than
compenfate any greater expence there may be in conftructing the boat, or
in obtaining proper knee timbers of that form. The cafual injury to the
banks from particular forms of boats, although of no immediate moment to
the boat owner, is of material confequence to the Canal proprietors, and
deferving of attention in their bye-laws.
To enter into a difcuffion of the correct methods of obtaining the depths
of immerfion, the lines of flotation, and metacentres under thofe forms,
would be unneceffary; as the reader will clearly fee, from the preceding
examples, approximate methods of obtaining them fufficiently near for all
practical purpofes.
Thefe boats, as already defcribed, fhould be laden and delivered in a
dock, nearly of their form : the bottom of the dock, to prevent accidents
from flones being thrown in, may confift of a number of tranverfe ribs,
fufficient to fupport the boat; and with cavaties between them. The
fame circumftance fhould, of courfe, be attended to in the dock for the
large boats.
It has already been fuggefted, that the ends of the boats may be of leaves
to be let down which, being fo narrow as only to admit the wheels to
pafs, will be no way unmanageable ; and, in boats carrying two ranges of
waggons, fhould confift of two parts, viz. a feparate leaf for each range :
It is fcarcely neceffary to fay that they muft fhut againft a lining of bend-leather, or of
coarfe woollen, or other compreffible fubftance, to keep them water tight.
and,
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and, they need only be at one end, unlefs the inconvenience of turning
the boat be deemed of moment.
As thofe fingle ranged boats are propofed, principally, for the ufe of
collieries, and for the faving of railways, which are not only expenfive in the
firft conftruction, but even in their maintenance; it remains to be confi-
dered how far the propofed Navagation will come within proper bounds as
to charge.
This muft depend on the nature of the country, which I have fufficiently
claffed, and defcribed. The dimenfions of the Canal need be no deeper
than for the wheel-boats, viz. 3 feet 6 inches in-clear water, and 2 feet
6 inches over the paved fords: but, it will require to be 5 feet broader in
the bottom than eftimated for thofe boats, viz. to be 14 feet at the bottom
and 24 feet 6 inches on the water's furface in place of 9' feet, and 19 feet
6 inches. The difference of expence will be inconfiderable. Each run-
ning yard of level cutting will contain 7½ cubic yards of earth, which at 4d.
would only be equal to 2S. 6d.; to which is to be added the track-road,
highway bridges, tunnels, &c. &c.; all of which will depend on local cir-
cumftances: but, in favorable fituations, will coft lefs than a double railway
of timber only, and not require nearly the repairs, and be attended with the
advantage of a horfe drawing 8 large waggons in place of one.
H 2
CHAP.
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CHAP. VI.
On the application of Inclined Planes to the Great Rivers of America,
or on the Continent of Europe, with Obfervations on the Navigation of
Rivers and Lakes.
GREAT rivers, in their natural ftate, are moft of them unnavigable in
dry feafons for any confiderable extent, through want of fufficient depth
of water in the rapids; and if navigated from their mouths to their head
branches, they frequently ufe different veffels, as in the Ohio, for the con-
veyance of the fame cargo in different diftricts of the river, according to
the depth of water, the gentlenefs or rapidity of the current, and the means
of advancing againft it.
In the higher diftricts, many of thofe veffels would be fuited for paffing
on carriages, up or down inclined planes and might, with propriety, be
transferred by fuch conveyance to different levels of canal, fo as eventu-
ally to pafs through any gap of the Allegany Mountains, or of any other
ridge, feparating rivers of contrary courfes; but, in the rivers themfelves,
inclined planes will very feldom be advifeable, particularly in thofe that
rife 15 or 20 feet or upwards. The banks of fuch rivers would not often,
without great expence, admit of a guard Lock and Canal from the head of
a fall, to fuch diftance downwards, as to place the head of the inclined
plane out of the reach of the floods. The inclined plane navigation in
rivers would always be dependent on Locks, to the extent of the rife of
floods; and at thofe periods the rife uncovered below the Locks would, in
fmall falls be trivial, if any thing at all, and attendant with all the trouble
of paffing great heights. The expence of their conftruction would, like-
wife, be nearly the fame. In rapids, the declivity -would, in general, be
too gentle to ufe the inclined planes in dry feafons, without the aid of a
long
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long collateral Canal : and the quantity of defcent would moftly be too
inconfiderable to render the ufe of thofe planes eligible. Therefore, they
would rarely be fuitable in rapids, and never in fmall falls. In the large
falls they can feldom be advifeable, but in the higher parts of the rivers,
where only canoes or batteaux are ufed. The Cohoes fall, near the mouth
of the Mohawk, may be an exception on account of the general rapidity of
the river.
The falls of the Potowmack, above Wathington, differ from the pre-
ceding inftance, in their occupying a confidera length of the river, in
place of being precipitous, like the Cohoes, which is 75 feet perpendicu-
lar; and in the Potowmack, being fuited for much larger veffels than the
Mohawk.
The great falls of the Potowmack are 14 miles above the City of
Wafhington, and defcend 72 feet in one and a half miles length of the
river. The little falls defcend nearly 37 feet in about two miles length,
and are four miles above the City. In the year 1794, there were fix Locks
building to pafs the upper falls, and three to país the lower
The length occupied by falls, will not, fimply in itfe'f, militate againft
inclined planes, becaufe there are many inftances where a Canal, on one
level, may be continued from the head of a feries of fmall falls, to a fteep
declivity at their termination, where the whole fail may be obtained at
once but in general, it will be found lefs expenfive to adopt different
levels, fuited to different portions of the fall, to which the Locks may alfo
be fuited.
Inclined planes, according to fome of the methods mentioned in the firft
Chapter, and explained in the fubfequent one, may be applicable to veffels
of 15 or 2b tons, but would not, I think, be eligible where there is plenty
of water, and proper fituations for Locks and their intervening ponds: as
Obfervations on the river Potowmack and City of Wafhington, publifhed at New York,
in 1794.
Locks
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Locks on an economical plan, and complete in their effential parts, might
(where materials are at hand, as they generally are in fuch fituations)
be built on falls not exceeding 30 or 40 feet, at as little expence as a
double inclined plane and its apparatus; and with fuch boats would, in all
cafes, be attended with lefs hazard. In lower falls, if even precipitous,
Locks and their Canals would be the lefs expenfive of the two methods.—
In great falls, as already implied, much will depend on the length of river
occupied by the fall, and the circumftances of its adjacent fhore.
In general, in great rivers, where partial contraction will not give depth
in the places wanting it, or the current is too rapid to be navigated againft,
Locks have decidedly the advantage.
It not being the defign of this effay to difcufs how far Rivers or Canals
are preferable to each other, I fhall confine myfelf to a few general obfer-
vations.
Rivers, with fimilar declivities and impediments, and of equal magni-
tude as to the quantity of water paffed to the fea in the courfe of the year,
may be effentially different as to the duration of time they may be navi-
gable. If fupplied from great lakes, their navigation will be more uni-
form and more fuited for boats afcending, than if more immediately effect-
ed by rains. Much alfo depends on the foil, the fuperior ftrata, and the
declivity of the adjacent country, as to the abforbtion and flow tranfmiffion
of incidental rains.
In fuch great Continental rivers as have not the aid of lakes to equalize
the paffing off of the ftreams that fall into them, the winter's fnow in cold
climates, anfwer, to a material extent, the fame end as, in the courfe of
their diffolving, they give a confiderable duration to the navigable period,
which fo far as it may be fhorter than it would be with the intervention of
lakes, is counterbalanced by an increafe of depth; which, in fome inftances,
is of more moment than longer duration. In warm climates, the fame end
is produced by the length of the periodical rains.
When
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panded, and forms Lake St. Francis, where the current of water, if any at
all, muft be trivial. The upper part of the river is gentle; but the re-
maining diftance of nearly 100 miles, is a feries of rapids #, which makes
the Navigation difficult, even with batteaux carrying 35 to 40 cwt. The
paffage depends partly on the wind on Lake Francis, which frequently de-
lays the batteaux for feveral days. The whole paffage, from Montreal to
Kingfton, is fometimes performed in 9 days, or in lefs time, but is, gene-
rally, from 2 to 3 weeks, or upwards, fo that they do not average 10 miles
a day, and that with great labour, generally with 8 men poling againft the
ftream; and occafionly, as in other fimilar rivers, getting into the
water, and hauling the batteaux over the fhoals. They often perform the
voyage downwards in 3 or 4 days but, on account of the danger of run-
ning againft rocks or ftones with the great velocity they defcend with, they
only carry about half the lading which they take upwards.
The freight up, is, as I am informed, generally 16s. per barrel of 280lb.,
equal to 61. 8s. per ton for the whole diftance, or 9'd. per ton per mile
confequently as dear as land carriage in fome parts of England. In this
inftance, the utility of a Canal becomes obvious; notwithftanding the St.
Lawrence has the advantage of iffuing from great lakes.
Upwards, from Port Kingfton, packets, or fea veffels, of 2 to 300 tons
or more, navigate Lake Ontario: and, obvioufly, can carry articles much
cheaper than batteaux, or canoes, which are ill-fuited to large lakes unlefs
fheltered from the wind, by the fhore or by iflands. There are, however,
many inftances where imperfect Navigations admitting of difpatch, are pre-
ferable to others, much cheaper, that are attendant with delay, which arifes
from the fame principle, that land carriage, by waggons, is preferable to
fea conveyance ; and the more expenfive carriage of articles, by coaches,
preferable to either : but this can only take place in articles of high value.
On this principle, canoes of birch bark, carrying from 3 to 4 tons in pack-
ages of 80 or 100lbs. weight, are navigated, by about 14 men, from Mon-
treal to Machilimakinac, frequently in 15 days, afcending from Montreal
Here and throughout this work, I include rifts (or fmall falls navigable for canoes or
batteaux) under the general denomination of rapids.
I
up
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up the Outawa, carrying the cargo and canoe paft the fide of feveral fteep
falls on that river, and over the carrying place from it to lake Nipiffing,
through which, and down the French river, they proceed to lake Huron,
and along its north fhore to Machilimakinac. The whole of this diftance
is nearly 600 Englifh miles, and clearly proves that falls and portages are
impediments far inferior to long continued rapids. The ridges of rocks,
which form the falls, penn up the water above them, and anfwer, naturally,
the fame purpofe as Locks and Weirs, in ftilling the current, and giving
depth of water, which Governor Pownal has juftly obferved in his Topa-
graphic account of America.
With articles of fuch high value as furs, that have alfo to be collected in
different rivers, and confequently, with the goods fent to purchafe them,
the line of navigation defcribed would probably be eligible, if even a fhip
communication were open between lakes Ontario and Erie.
In mixed navigations, where Lakes, Rivers, or Canals alternate with
each other, and where the lakes are fo fmall as not to admit of the expence
and delay of tranfhipping the cargoes at each end, the commerce will be
beft carried on in boats that are not too large for rowing, particularly
where there are any narrow paffes among fhoals, through which fuch veffels
as the river would otherwife admit of, could not turn to windward, and
where towing paths could not be conftructed. In thefe cafes, boats inca-
pable of rowing, would often be fo long delayed by contrary winds, as to
add more charge on the tonnage conveyed, than would take place in boats
of IO to 20 tons, capable of both rowing and failing; exclufive of the de-
cided advantage arifing from fuperior expedition, and from the lefs delay
in lading and delivering, particularly if the cargo have to be collected in
different packages. But, where the quantity of commerce is great, and
the articles bulky, then, wherever practicable, it will be advifeable to pafs
fuch lakes by a collateral Canal.
The
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The Czar, Peter the Great, fet a praife worthy example in the Canal of
Ladoga, through which there paffed in the year 1778*, four thoufand nine
hundred and twenty-feven veffels, which, through the large lake of La-
goda would have been attended with great danger and delay, particularly
as the veffels are, from the nature of the upper Navigation of the rivers,
and other caufes, ill fuited for the paffage through fuch a lake.
Having given my fentiments againft inclined planes, on the great falls in
the lower parts of rivers, on the foundation, principally, of changing the.
article of conveyance, we may now examine their eligibility where a necef-
fity of that change takes place.
A communication between the lakes Ontario and Erie, for the fhipping
that navigate thofe lakes would be highly defireable ; as then, the fame
veffels might navigate the lakes Michigan, Huron, Erie, and Ontario :-
but the height ot the cataract of Niagara t, and the fall and continued ex-
tent of the rapids are fuch, as to preclude at this period, the idea of fuch a
navigation therefore, as tranfhipping is requifite, and great falls are fuited
to inclined planes, that fyftem, as being attended with difpatch and fmall
expence, appears fo far to be favourable.
Deficiency of local knowledge muft prevent a decifive opinion on what
meafures ought to be adopted but I can fcarcely hefitate to fay, that
wheel-boats would be ineligible even there, becaufe of their incapability of
carrying many of the articles wanted to be transferred, and their being to-
tally unfuitable to enter the Streights of Niagara confequently, if inclined
planes be there preferable to other methods, it muft be on the plan of con-
Travels through Sweden, Ruffia, Denmark, &c. by W. Coxe, F.R.S. Since that
period, I fuppofe, the number has confiderably increafed.
t The fall of Niagara is about 240 feet, and, inclufive of the rapids immediately above,
and for about three leagues below, is fuppofed to be more than 400 feet. Were it fimply
like the falls of St. Mary, feparating lake Superior from lake Huron, the magnitude of the
object in the prefent ftate of population, would probably warrant fuck an undertaking as a'
navigation for fhips.
I 2
veying
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work, which the Chinefe have purfued as well as the Europeans, pro-
bably without either copying from the other.
On thefe principles, they have invented their juftly famous Canal, which,
running through an extent of upwards of 500 miles, conjoined with the
aid of natural rivers, gives, with the exception of one carrying place, an
interior navigation nearly from the North to the South of the Empire,
through an extent of upwards of 16° of Latitude, viz. from `ong-fchoo-foo
within I2 miles of Pekin, to Canton, the great mart for their foreign com-
merce.
To effect this purpofe, it was only requifite to unite the Yun-leang-
ho, or Eu-ho, with the river Yangtfe-Kiang, a diftance of about 350 geo-
graphic miles in a direct line, which the comparatively flat ftate of the
intervening country eafily admitted of as the fall from the fummit, either
way, did not exceed that of many navigable rivers, On this principle,
they contrived to feparate the river Luen-ho, which running from the
Eaftward from a higher level than the fummit of the Pafs, they divided
into two diftinct channels, the one running North to the Eu-ho, and the
other South to fuch part of the Yellow River as had fufficient elevation to
admit an artificial branch from it, to difcharge part of its waters into the
river Kiang from whence, as already mentioned, they had a natural navi-
gátion to Canton, with the exception of one carrying place. Here the
artificial navigation for the great purpofe of traverfing the Empire ended;
but, as the river Kiang had fufficient elevation at this place to admit of a
new channel to the head of the arm of the fea Weft of Tchuzen, at Hang-
tchoo-foo, on the river Chen-tang-chiang *, within the flow of the tide ;
which,
The termination of the Canal is in the Pe-hoo, a fmall lake adjoining the town and
river, which forms a bafon for the veffels, which are exceedingly numerous here and
throughout, and exceed all ideas that could have been reafonably formed They are, in-
deed, confined to the navigation of the Canal and Rivers it communicates with to the
North, there being no navigable connection between the bafon and the adjoining river,
(probably from the fall being too great to be conquered by their flood-gates) and confe-
quently, Hang-choo-foo has become a great Emporium.
In
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CHAP. VII.
Defcription of the Internal Navigation of China, with Remarks an its
Principles, and further Obfervations on Rivers and Inclined Planes.
SIR George Staunton's acconnt of the travels of the late Britifh Em-
baffy in China, affording an ample defcription of the artificial navigations
of that Empire, which lays claim to a longer and more uninterrupted period
of civilization, than any other nation of the globe : I prefume a few com-
ments on the fkill they have attained in overcoming afcent and defcent, the
great difficulties in that art, will not be unacceptable even if attended with
no inftruction. I fhall, therefore, avail myfelf of the information given
in the account of the Embaffy, and draw from thence fuch conclufions as
it may warrant.
The Chinefe, in their interior navigations, appear to have exercifed lefs
of the inventive than the imitative powers; as all their attempts in that ufe-
ful fcience, amount to nothing more than a fervile imitation of Nature, in
the navigation the affords upon thofe rivers, where the quantity of water is
fuch as to give depth, notwithftanding the inclined pofition of their furface.
Where that inclination is fmall, they have obferved that both depth and
width of furface may be combined, but that where it is great, the one of
thefe muft ceafe to be extenfive ; and where from natural caufes, the width
has done fo, a navigable depth has ftill been retained, notwithftanding the
rapidity with which the water runs off: they have alfo obferved, that thofe
rapids, even when contracted, are not navigable in dry feafons in the
fmaller rivers, which naturally fuggefted the idea of preventing the wafte
of water when not immediately wanted for the paffage of boats 3 from
whence' arofe the plan mentioned in 4th article of the 1ft Chapter of this
work,
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I fhall now refume the information to be derived from the travels of the
Embaffador and his retinue, in their route from Pekin.
The Embaffy embarked on the river Pei-ho, at Tong-fchoo-foo, about
12 miles from Pekin, in covered barges of about 70 feet length, and 15
feet width, and only about 10 inches draught of water, with their paffen.
gers, and fuch portion of their baggage as they took on board. The river
was then become fo low as to caufe the boat to be dragged with difficulty
over feveral of the fhoals. After 60 miles of navigation, they arrived at
the tide-way, and in 30 miles further, arrived at Tien-fing (about 60 miles
from the fea, or gulf of Pe-chee-lee) at the confluence of 3 rivers, up
one of which, the Yun-leang-ho, or Eu-ho, running from the fouth, they
proceeded in the beginning at the rate of about a mile an hour, againft a
ftrong current by the force of 18 or 20 trackers: as the river was confined
within narrow bounds between two artificial banks, for the apparent purpofe
of given depth. Above it was wider, deeper, and more gentle. Upthis
river they proceeded nearly 2½ degrees of latitude to the city of Lin-fin-
choo, where they entered the Imperial Canal which is carried in a line
almoft directly South, and nearly parallel to the general line of the fea-
coaft. " This enterprize, the greateft and moft ancient of its kind, which
" was found to extend from Lin-fin-choo to Han-choo-foo, in an irre-
" gular line of about 500 miles, not only through heights and other val-
" leys, but acrofs rivers and lakes." It is faid by Sir George Staunton, to
be " often winding in its courfe, of unequal and fometimes confiderable
" width, and its waters feldom ftagnant." On its junction with the Eu-ho,
the Canal was cut through ground of the height of 30 feet, to permit its
water to flow with a gentle current into the Eu-ho. The current of the
water was moftly flow; and to prevent its running off too rapidly, its de-
fcent is occafionally checked by flood-gates, which were feldom fo near as
within a mile of each other. Thefe flood-gates confift of two abutments
of ftone, one projecting " from each bank, leaving a fpace in the middle
" juft wide enough to admit a paffage for the largeft veffels employed
The width, according to the Plate, appears to be a little more than 21 feet. Accord-
ing to De la Land, lefs than 30 feet.)
" upon
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or: upon the Canal." Few parts of the Canal are entirely level; and they
have overflows or paffages through the banks to prevent the water rifing,
beyond a given extent ; and alfo to prevent unneceffary wafte of it through
the flood-gates, the paffages are occafionally clofed by planks let down
tranfverfly and feparately one above another, their ends refting in a vertical
groove in each abutment. " Some fkill is requifite to be exerted, in order
65 to direct the barges through them without accident. For this purpofe,
" an immenfe oar projects from the bow of the veffel, by which one of the
" crew conducts her with the greateft nicety. Men are alfo ftationed on
" each pier with fenders made of fkins ftuffed with hair, to prevent the
" effect of the veffels ftriking immediately againft the ftone, in their quick
" paffage through the gates, which are only open at certain ftated hours,
" when all the veffels collected near them in the interval pafs through on
" paying a fmall toll. The lofs of water occafioned by the opening of
" the flood-gates is not very confiderable, the fall at each feldom being
" many inches, which is foon fupplied by ftreams conducted into the
" Canal from the adjacent country on both fides. The fall is, however,
" fometimes above a foot or two, when the diftance between the flood-
" gates is confiderable, or the current rapid. The Canal was traced often
" in the beds of ancient rivers, which it refembled in the irregularity of
" its depth, the finuofity of its courfe, and the breadth of its furface, when
" not narrowed by a flood-gate. Wherever the circumftances of the ad-
" jacent country admitted the water in the Canal to be maintained in a
" proper quantity, without any material deficiency or excefs, by means of
" fluices managed in its fides, for the purpofe of influx or difcharge, as
" was the cafe farther to the Southward, few flood-gates were neceffary
" to be conftructed, nor were there any where met with more than half a
" dozen in a day."
On the higheft part of the Canal, which by the map is about one-fifth
of its entire length in proceeding from the North, " the river Luen, the
" largeft by which the Canal is fed, falls into it with a rapid ftream, in a
" line which is perpendicular to the courfe of the Canal. A ftrong bul-
" wark of ftone fupports the oppofite weftern bank; and the waters of the
" Luca
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" Luen ftriking with force againft it, part of them follow the northern, and
" part the fouthern courfe of the Canal."
In proceeding from the fummit to the South, the Canal, or artificial
river, paffed by the verge of the Lake, and was there fupported on high
embankments, to enable it to pafs over fome rifing land farther South,
through which it runs at leaft 20 feet below the furface of the adjacent
ground. The Canal afterwards paffed collateral to the Lake of Wee-
chaung-hoo, which " reminded the Embaffador of the great Canal of
" Ruffia, with which he was well acquainted. This ran in like manner,
" at certain dittances parallel to the Lake Ladoga, from which it was fe-
" parated by vaft earthen embankments." From this circumftance, it is
poffible, that Peter the Great (although his genius was equal to the fuggef-
tion of any thing ufeful to his country), may have borrowed the idea from
China, as previous to the formation of the Canal of Ladoga, he had a
direct acquaintance with the Chinefe Empire, by an Embaffy in the com-
mencement of his reign, in the year 1693, whilft his brother John fhared
the throne conjointly with him.
At a further diftance, " the Canal widened, flowing to the fouthward in
" a current of upwads of 2 miles an hour. Several branches went off
" from the main trunk of the Canal, on which, as well as on the diftant
" Lakes feveral barges were feen failing. During the next ftage, the
" Canal was conducted again through low grounds fubject to inundation,
" with Lakes and Moralles intervening."
The Embaffador, Everard Ifbrand, was necefitated to go through the ceremonious
proftrations of the Chinefe, which the prudence and firmnefs of the British Embaffador, aided
by the good fenfe of the Chinefe Emperor enabled him to avoid. In another Embaffy from
the Czar Peter to the Court of Pekin, in the year 1719, his Embaffador Leoff Vaffilovich
Ifmayloff, was under the fame difagretable conftraint as his predeceffor. According to
Father Du-Halde, a former Embaily from Molcovy in the year 1631, was not favourably
received, because the Embaffador would not fubmie. to the Chinefe cestmonies. Thefe ob-
fervations are quite irrelevant to the fubject of this Treatife, and are only inferted on the
prefumption that, to many readers they may be acceptable at this time, when the circum-
fances of the Britith Embaffy have attracted the public attention:
It
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It then approached the Yellow River into which ic falls by a gentle
current. The Canal is here about three quarters of a mile in widch, and
forms an excellent harbour for the veffels navigating it. The Yellow River
has here run through a courfe of 2200 miles, and is not more than 70 miles
from the fex: " Its width little exceeds a mile, and its depth in the middle
" of the Aream is not more than 9 or 10 feet, and its velocity is about 7
" or 8 miles an hour," which it appears to continue downwards, confe-
quently, there is a confiderable fall to the fea, which enabled a defending
branch to ftrike off fouthwards to the river Kiang. " On the fouthern
" fide of the Yellow River, the yatches began to proceed more quickly ;
as the current of the Canal as it quitted that river being more rapid, in
BC confequence of which, the number of flood-gates were increafed upon
as this part of it farther on, it was carried by the margin of the Lake
« Payo-yng, whole furface was much lower than that of the Canal, which
K was feparated from the Lake by a ftrong embankment. Beyond the Lake
45 there was again fwamps and moraffes."
" In the midit of the low grounds of this part of the route, a town of
" the third order was fituated the tops of its walls being little more
" than level with the furface of the Canal, which formed an aqueduct raifed
" 20 feet, was 200 feet in width, and ran at the rate of three miles an
" hour. This Canal, on proceeding fomewhat further, ceafed to have a
" current and the ground rifing to the fouthward, it was found necef-
" fary, in order to give level, to cut down about 20 feet deep for a track
" of 7 or 8 miles, to a large city where not lefs than a thousand veffels of
" different fizes were lying at anchor."
" In three days after the yatches had croffed the Yellow River, they came
" to that of Yang-tfe-kiang, which is confidered to equal, if not exceed
.
The cities of the third order terminate their names with pien; the fecond order with
*choo ; and the firft with fee, which three defcriptions are furrounded with walls. Many of
the cities appear to have increafed within this century, as feveral of them which Du-Halde
has terminated with tchee, have-now the additional termination of foo,
" the
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« the fize of the former. It was at this place about two miles wide. The
" current where the yatches of the Embaffy paffed, did not exceed in the
" ftrongeft part .of it two miles an hour but it was much deeper than the
" Yellow River.
" The ground to the fouthward of the Yang-tfe-kiang gradually rofe to
" fuch a height, that it was found neceffary to cut down the earth in fome
" parts to the depth of near 80 feet, in order to find a level for the paffage
" of the Canal."
High ftone arches, fome of them elliptic, the longer axis vertical, and
high enough to take junks under fail, are erected over the Canal, and are
afcended and defcended by fteps. They have alfo bridges over the piers of
their flood-gates, which, to prevent interruption to the mafts of veffels,
are-conftructed fo as to be eafily withdrawn when veffels are about to pafs.
They are flat wooden bridges, narrow and light, each refting on rollers
fixed in its frame, and running on a couple of loofe fpars that are withdrawn
Pafter the bridge.
The Canal, in its courfe through the city of Sou-choo-foo, divided into
various branches through the ftreets as in Venice. Some idea of the im-
portance of the commerce of this city may be entertained, from the cir-
cumftance of 16 veffels of 200 tons each, being on the ftocks in one fhip-
builder's yard.
Near this city, " the great Canal was without a current, and fo wide,
« that a ftone bridge of no lefs than 90 arches was in one place thrown
" over it : the Canal continued to be of a width between бо and 100 yards,
" and its banks generally faced with ftone for about 90 miles in length,
" between Sou-choo-foo and Han-choo-foo.
" A large irregular bafon at Han-choo-foo terminates the Imperial
" Canal. It is increafed by waters from a lake lying to the weftward of
" the city; the latter furnifhes alfo a copious ftream running in a channel
" round
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«
round the city walls, and fmall Canals pafs through its principal ftreets.
"
This bafon difcharges into the river Chen-tang-chiang, which falls into
" the fea at little more than бо miles to the eaftward : the tide when full
" increafes the width of the river to about 4 miles oppofite the city, but
« at low water, leaves on that fide a level ftrand of nearly 2 miles width."
From the preceding extracts, an idea may be formed of the magnitude
and diverfity of this great Canal, as to width and velocity of current, which
being variable, frequently in counteracting degrees, viz. often narrow in
deep finking, where the water is nearly ftagnant, and wide where the
ftream runs with confiderable velocity it follows, that to give depth in
the rapid ftreams, additional rivulets muft be taken in, and difcharged
again in the commeacement of the ftagnant parts; which it appears is their
mode of proceeding, as they have overflows to difcharge their fuperfluous
water, which is frequently applied to irrigation; and they repeatedly receive
additional influx where it is neceffary.
There now only remains to be noticed their Inclined Planes, which are
particularly defcribed in the route from Hang-choo-foo to Tchufan, which
was purfued by Colonel Benfon and Captain Mackintofh, of the Hin-
doftan, after they had parted with Lord Macartney, and the remaining at-
tendants of the Embaffy, who followed the route already defcribed to Can-
ton.
The Tchufan party croffed the river and entered a fmall Canal. After
they proceeded about three days, they arrived at the city of Loo-chung,
where they changed their inland barges for junks of about бо tons burthen
each, neatly fitted up for paffengers, but conftructed for falt-water navi-
gation, and lying on a river into which the tide flowed beyond Loo-chung.
They failed from thence to Nimpo near Tchufan; the river was of the
breadth of the Thames between London and /Woolwich.
Before their arrival at Loo-chung, " it fometimes happened in the
"
route to Tchufan, that the water of a higher Canal paffed immediately
L
" into
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*Mo another of a lower level; and in two inflances the travellers were
launched in their barges with prodigious velocity down the ftream
The upper Canal is bounded by a ftrong and well-compacted wall, the
top of which is level with the forface of the upper water. A beam of
wood is laid on the upper edge of the wall, which is wounded off towards
"
the water. Beyond (or below) the wall, a floping plane of ftone work
extends to the lower Canal in the form of a glacis, with an inclination
of about 45°, and defcending near 10 feet in perpendicular depth; at the
bottom of which, the Canal is carri d along as the level of the country
will allow, when another wall and glacis for another Canal ftill lower, are
conftructed as before.
" In paffing from an upper to a lower Canal, the velfel lifted over the
crofs-beam flides down by its own gravity, and to prevent the water
from flufhing over the decks, or her plunging into the Canal below, a
railing is fixed at the head of the weffel about to be launched, before
which is placed a ftrong matting at the time of its defcent. To draw
up a large veffel from the lower Canal along the glacis into the upper
Canal, requires fometimes the affiftance of near a hundred men ; whofe
"
ftrength is applied by means of bars fixed in one or more capitans,
placed on the abutments on each fide of the glacis. Round the capftans
is a rope, of which the oppolite extremity is paffed round the veffel's
ftern, which is thus conveyed into the upper Canal, with lefs delay than
can be done by locks, but by the exertion of much more human force in
a force, indeed, which in China is always ready, of little colt, and con-
ftantly preferred there to any other."
tappears, from this defcription, that water was running down the Inclined Planes;
and if to, it is accordant with fome of the deferiptions of the Jefuit miffionaries. This
however, is probably only occafional ; and caused by the fluctuation of the furface of the
Canal.
The
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This defcription of the Chinefe inclined planes, appears to be carrect
in the outline, but cannot be taken literally, as 45° deolivity is far top
fteep, unlefs the fall be to little as to bear a fmall proportion to the
dength of the boat; and then the fteep inclination of the plane would be
of little moment, as the boat need never touch it but on fliding off with its
heel.
In the plate, the defcription is partly corrected, as the inclination is but
"4° from the horizon, viz. one foot fall for every four feet bafe, which is
alto too fteep, unlefs the boats that pafs thofe planes be much fhorter than
the general run of their boats $ which is the more probable, as otherwife,
they would ftrain and break in two with any lading, on turning over the
crofs-timber at the head of the plane. Thefe boats, according to the plate
of the inclined plane are of about 3 feet height, and 56 feet tread on the
ground, with sharp overhanging ends, projecting 9 or 10 feet, and rifing
with a bend equal to the defcent of the plane, therefore tending at one end
to raife the veffel in its defcent, and at the other to produce the fame
effect, in a fmall degree, by the weight of the boat's end behind the tread
of her heel. I fhall affame the boat to be fo far laden as to have as much
buoyancy above as below water, and the effect of the projecting ends to
be under that predicament, equivalent to a fhortening of it to 8 feet lefs
than its tread on the ground, viz. to make it equal to a boat of fimilar
fection from end to end of only 48 feet, in place of 75 feet extreme length.
From thefe premifes, and admitting the tranfverfe fection to be fquare,
which will not materially alter the cafe, (as their fection, exclufive of the
ends, is uniform), we may deduce what the floating power of fuch a boat
would be.
Under this predicament, it is obvious, that a diagonal line from the
fummit of one end of the boat to the lower extreming of the other end,
would divide its bulk into equal parts, one of which immerfed in water,
would be juft equal to its whole weight therefore, as under the given
angle of inclination and weight of boat, the water would only flow -12 feet
L 2
along
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along the boat's bottom, or 1/4 of its length ; it follows, that at the inftant
of immerfing one end under water, it would only have 1/4 of its weight
water-borne. The centre öf gravity of this tendency to lift the boat would
be at 4 feet inwards from its lower extremity, viz. at 1/2 of the diftance
from the boat's heel, which latter would be its turning point. It is evi-
dent, that a power equal to half the weight of the boat and cargo, ap-
plied at its lower extremity, would enable the boat to rife, as the other
extremity would bear half the weight # ; but, in the prefent inftance, there
is only half the neceffary power acting at TF of the requifite arm of lever,
confequently, only equal to 1/4 of the requifite force ; therefore, with the
aid of matts towards the head of the boat ftill unequal to the end t. If,
however, we combine the defcription of the fall, viz. " near IO feet in
" perpendicular depth" with the length of plane, in the plans accompany-
ing the work (which the eye might judge of, comparatively with the
length of boat) we fhall have a declivity of about 1/6 Qr nearly 9° 1/2
from the-horizontal line, which will pretty well accord with the circum-
ftances.
I have entered into this difcuffion principally to fhew the points to be
attended to, in the facility of boats floating from off inclined planes, and
the neceffity either of their being of a gentle declivity on their junction.
with the water, or that the axis of the hinder wheels be placed not far be-
hind the centre of gravity of the boat.
I can eafily conceive, that the travellers might be miftaken in the declivity
of the plane, if they judged by the eye, as angles of afcent and defcent are
Nearly fo, the turning point being only thrown backward the tangent of the L of in-
clination upon 1-third of the boat's height. To make the other deductions perfectly true,
the centre of gravity of the boat and cargo muft lie at 1-third of its height ; and if higher,
as it generally muft be, it will operate more against the power of the boats' rifing.
Unlefs there were at the bottom of the glacis an apron or fmooth platform at fuch 2
depth as not to admit the boats to fink, which does not appear to be the cafe, nor could
well be fo under fuch fluctuation of furface as the Canals are liable to.
very
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very deceitful in their appearance. That the boats are longer than on re-
flection we fhould conceive them to be, appears corroborated by a tra-
veller of the laft century, Father le Comte who obferves, that " in
" fome places where the difpofition of the ground does not permit the
" forming of a communication between two Canals, they ftill contrive to
" pafs veffels from one to the other, notwithftanding they may have more
" than 15 feet height to furmount. At the extremity of the upper Canal,
" they conftruct a double glacis, or inclined plane, of hewn ftone. When
"
a veffel arrives at the extremity of the lower Canal, it is raifed by the
" help of capftans to the fummit of the firft glacis, from whence its own
"
weight makes its flide on the fecond into the upper Canal, and they de-
"
fcend to the lower by reverfing the operations."
This author could fcarcely comprehend how the Chinefe barges, which
are commonly very long and very heavy laden, did not break in the mid-
dle when fufpended in the air on the angle between the double glacis ;
neverthelefs, he did not learn, that the leaft accident ever happened.—
" Thefe inclined planes (he fays), are not to be found in the grand Canal,
"
becaufe the Imperial barks could neither be raifed by manual force, nor
"
fecured from the misfortune to which the others have the appearance of
" being liable."
In inclined planes of fmall fall, fuch as are ufed in China, and for boats
of confiderable length and magnitude, the fide-way motion t might be
made to anfwer. It would alfo do for longer inclined planes (particularly
if very fteep) by the aid of counterbalancing weights down feveral pits,
and a caiffon for the boat and its furrounding water to defcend on many
wheels, or rollers, into a dock fuch as defcribed in feveral inftances in the
firft Chapter. The counterbalancing weights may be cylindric tubs, fitting
the pits and laden with water; the two end ones fo regulated, as to move
Vide Belidor's Architecture Hydraulique, Tom. IV. P. 355-
Ships are fometimes launched this way, where there is want of room to go end fore-
moft
perfectly
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perfectly equal to each other, and keep the caiffon during its progrefs in
the fame parallel pofition The pits fhould at leaft be down to the level
of the drift, from the dock or lower receptacle of the caiffon.
The weight of water and of the veffels in the pits, under fimilar vertical
defcent with the inclined plane, will theoretically be no more than that of
the caiffon and its contents, be the angle of declivity what it may ; and
their different fpaces paffed through would be ealily provided for, by the
difference of diameters of the wheels, on the axis communicating the
counterpoifing powers but in gentle declivities particularly, friction and
refiftance from irregularities of the furface acting on the wheels or rollers
fuftaining the caiffon, will be very confiderable, and occafion a lofs of
water far beyond that of the plans of Mr. Weldon or Mr. Rowland; but
of little confequence compared to Locks. Another circumftance alfo mi-
litates againft this plan in moderate declivities, which is, the difficulty of
keeping a large caiffon water-tight, becaufe of the greater effect from
cafual checks under the neceffarily increafed velocity. From both the
above caufes, I conceive the plan fuggefted, will feldom be eligible but in
fteep declivities of 30° and upwards.
It is an argument againft the inventive powers of the Chinefe, that they
have not hitherto conftructed Locks, as a great part of invention lies in the
conception of the poffibility of the event; and the Chinefe have been in-
formed, for upwards of a century, of its abfolute poffibility ; as the Jefuit
Miffionaries fent to China by Lewis the XIVth, in 1685, acquainted them
with the principles of a Lock, with which they appeared aftonifhed. The
Fathers alfo thought that any one who would carry to China the model of
a Lock would be well received ; and caufe as much admiration as the firft
watches that the Miffionariers prefented to the Emperor.
Chains muft of courfe be made ufe of in the machine both to fufpend the water veffels
and retain the caiffon. A prejudice, no doubt, exifts againft chains, on account of the un-
certainty of their ftrength; but this may eafily be remedied, by fubmitting every link to a
Brefs far fuperior to what they are propofed to bear, which may be done before the chain is
put together, as for this purpofe, it fhould confift of links connected by bolts.
The
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The Chinefe method of overcoming afcents appears to be long Subfe-
quent to the attempts of the Egyptians, under the fucceffors of Alexan-
der; who, according to Monf. Huit, Bilhep of Avranches, had the art
of conftructing fluices, or Locks of one fet of gates, fo as to ftop the im-
petuofity of the current, and be occafionally opened. Though termed
gates, the openings were moft probably clofed with beams of timber, let
down in grooves as gates of large width and depth could not be opened
without difficulty, even againft 2 fmall difference of level. There are,
however, fuch fluices with gates upon feveral of the running Canals an the
verge of the Shannon. They were erected about the middle of this
century, and are- of difficult use, because of the force requifite to open
them.
Thefe running Canals are on the Chinefe principle, and nothing more
than new Channels for a portion of the river; which, when it is low, are
ftopped as in China, to retain a head of water fufficient to país the boat.
During the flooded ftate of rivers, all fmall falls are equalized, as they
neceffarily rife higher below than above a rapid; therefore, I am far from
faying, that running Canals with a fmall fall are not, in many inftances,
eligible on the fhores of great rivers; and that well-devifed ftops eafily
opened and clofed, (not fuch as lift up like thofe defcribed in China, nor
open againft the ftream as gates) are not fometimes preferable to incurring
the charge of Locks.
In other nearly Gmilar inftances, where Locks are eligible, their piers and
gates alone will be fufficient without any other floor or fide walls, than &
concave and battered pavement, continued through the bottom and up the
fides of the fpace between the piers.
The eligibility and the particular conftruction of thefe works, will much
depend on the nature and extent of the beds of the rivers, the difference
between their low and flooded ftates, the height and alfo the permanency of
their fhores, and the quantity of floating ice.
Thefe
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Thefe fingle pairs of piers of the Chinefe, are properly called by De la
Lande, half Locks. The cafual polition of two pair of piers near to each
other, has, no doubt, occafioned the invention of Locks; as it would foon
be feen, that when the gates or ftop beams of the lower piers were clofed,
and of fufficient height that the water would be nearly ftill between the
upper pair of piers, and afford an eafy paffage. On this principle, in place
of fingle pairs of piers, two pair would be erected, fufficiently near to each
other for the purpofe, and capacious enough to hold a fleet of boats. It
would foon afterwards be found, that in dry feafons the wafte of water was
greater than could be conveniently afforded, and the operation tedious for
fingle boats thus would progreffively arife the invention of Locks with
walled chambers, and fluices through their gates or walls.
There are at this day exifting on rivers, Locks of the firft conftruction
compofed fimply of two pair of piers, without any connection of walls or
pavement between them.
The following account of the antiquities and defcription of the Chinefe
Canals, is principally extracted from Monf. De la Lande's Treatife, " Des
Canaux de Navigation;" and from Du Halde's Hiftory of China, in which
authors will be found a more full and particular account than the defign of
this effay requires me to give.
The commencement of the Chinefe Canals was fomewhat lefs than two
centuries before the Chriftian æra, viz. foon after the coming in of the
dynafty of Han, which took place 202 years before Chrift. Previous to
this, grain and other neceffaries were carried on men's fhoulders, where
they had not the convenience of Rivers or Lakes. The Emperor being
fhocked at this flavish occupation of his fubjects, employed many ouans of
men (each ouan being 10,000), to dig Canals for the conveyance of rice
and grain from the provinces to the capital, which was then in the pro-
vince of Chen-fi : and, before the middle of the fecond century preceding
the Chriftian æra, all the great rivers communicated with each other by
Canals, and were navigable almoft every where.
Between
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Between that period, and the commencement of the dynafty of Yuen, or
the Monguls, which began in 1260, the capital of the empire was fuccef-
fively changed into different provinces, which occafioned new combina-
tions of Canals, for .conducting to each new capital the immenfe number
of veffels laden with grain that it required.
Yangti, of the dynafty of Tfin, who mounted the throne in the year
605, and reigned 13 years, commenced the firft year of his reign with
making new Canals, and enlarging the old ones, that veffels might pafs
from the Yellow River to the Kiang river, and into the river Ouei (Eu-
ho of Sir George Staunton) and various other rivers. A plan was given
to him for making all the rivers navigable throughout their extent, and to
make them communicate one with another by Canals of a new invention.
This project was executed, and according to it, 1600 leagues of Canals were
made or repaired.
At this period, moft probably, their plan of flood-gates was adopted
as the new invention could only be in this, or in regulating the water by in-
flux of new ftreams and difcharge of fuperfluous quantities, or in lining the
banks with ftone where the ftreams were rapid, the remainder being fimply
excavation or embankment.
About the year 1289, the Emperor Chi-t-fou, the firft of the dynafty of
Yuen, or according to others, the fifth fucceffor of Ghengis-kan, having
conquered all China, and being already mafter of Weftern Tartary, re-
moved the feat of empire to Pekin, to be more central to his vaft domi-
nions. But the neighbouring provinces not being able to furnifh fubliftance
to his court and his numerous army, he caufed to be made, or rather to be
perfected and altered, the famous Canal of Yu-ho # or Yun-lyang-ho, (im-
plying the river for conveyance of provifions), which runs through the
empire from North to South.
From Sir G. Staunton giving thefe names to the river Ouei, between Lin-tfin-choo
and Tien-fing, it appears, that the improvement in the channel of the Ouei, between Tien-
fing and Lin-tfin-choo, have caufed it to be deemed part of the Yu-leang-ho.
M
They
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They had, at firft, no well-connected plan, but made feveral ufelefs at-
tempts full of faults. They went upon improper lines, and had not fuffi-
ciently attended to the effects of dry feafons and inundations, which were,
however, progreffively corrected.
The general depth of water was defigned in the great Canal to be 9 feet;
and its frequent turns are many of them intended to prevent (in aid of the
flood-gates) the too rapid running off of the water. They have fre-
quently a difficulty in keeping up 5 or 6 feet water; and in fome dry years,
the Canal is reduced to 2 or 3 feet, which is not fufficient for the Imperial
barges.
The portage from Nan-gan-foo, over the Mountain Meilin to Canton
river, is fo confiderable, that the road is, at all times, thronged almoft as
much as the ftreets of a great town. They are, however, enabled to avoid
this portage when the rivers are high as they have, for that purpofe,
joined a Weftern branch of the Pe-kiang, (probably that ftriking off from
Tchao-choo-foo) with a river running through the province of Hou-quang
into the Yang-tfe-kiang. This appears to be a different river from the
Kan-kiang-ho, and to lie to the Weftward of it. The navigation by this
route, is faid to be much more circuitous than the other.
The waters which collect from the mountains in the North of the pro-
vince of Quang-fi, form near the city of Hin-ngan-hien a fmall river,
whole courfe is ftopped by a dam, fo as to fend the water to the fummit of
the pafs by a channel for that purpofe; from whence, by a fhort Canal, it
joins the two rivers. It is neither fo convenient nor fo well kept up as the
grand Canal; and the water is often low, fo that the veffels are rather
drawn on the gravel than on the water. The fluices or contracted
paffages on this Canal for the purpofe of ftopping the water, are, for the
moft part, made of earth fupported by ftakes, the paffage through which is
clofed with mats or other fimilar things.
The
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The indultry of the boatmen and inhabitants of the country fupplies all
defects, and gives this rout fufficient advantages to caufe it to be frequented
by many merchants; as in the other rout, a paffage by land is indifpenfa-
ble, and caufes much expence and trouble in tranfporting merchandize ;
however, there is no particular impediment in the circuitous route during
the time of high water in the rivers. This circumftance clears up the dif-
ficulty of accounting for the paffage of the immenfe rafts of timber pro-
ceeding for the middle and Eaftern provinces, which the Britifh Embaffy
met below Tchao-tchoo-foo; as, by this channel, there is an interior
water-communication all the way from Canton, even to the Northern pro-
vinces.
In the journey of the Fathers Boures, Fontenay, Le Comte, &c. from
the port of Ningpo (the Nim-po lately mentioned), they relate, that
they foon " came to a place where they hoift up. the barks, in order to
er convey them to a Canal which is 9 or 10 feet higher than the level of
«
the river. They hoift up the bark by means of a flope or declivity,
" paved with large ftones, and when they have got it to the top, they let
" it flide down another into the Canal." " There are people who wait to
" be hired for this purpofe; they are not above a quarter of an hour about
<< it, having the help of two capftans."
This inclined plane is in the fame diftrict defcribed by the Tchu-fan
travellers (probably one of thofe they "defcended), and differs in nothing
but the time of paffage, which will depend much on the force employed.--
If the aid of capftans be ufed, in which both narrators agree, the paffage
cannot be fo quick as by a well-regulated Lock. Their account of the
Kiang and Yellow Rivers, and of the Canal in their route to Pekin, confi-
derably refembles Sir G. Staunton's. Some of the fluices or flood-gates
upon the great Canals, are defcribed as retaining the water in confined chan-
nels of mafonry (apparently of fome extent), through which it rulhes with
The different names given to the fame places by different travellers, is eafily account-
ed for, when it is confidered, that their orthography mult be totally auricular, from the Chi-
nefe not ufing the alphabet.
M 2
vaft
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vaft impetuofity, fo as to require great power of capftans and of men, to
get the veffels up ; and that, in place of letting them run down at will,
they are carefully let through by ropes that are flacked away, until they are
below the ftrength of the ftream.
In the Chapter on Lakes, Canals, and Rivers, P. Du Halde obferves,
that " if China happily enjoys fo great a plenty of every thing, it is in-
" debted for it, not only to the goodnefs and depth of its foil, but to the
" great number of Rivers, Lakes, and Canals, with which it is watered.
" There is not a city, nor even a large town, efpecially in the Southern
" provinces, which is not fituated upon the banks of a River, Lake, or fome
" Canal; and there are few provinces where there is not a large Canal of
" fine, clear, and deep water." The principal Canals, L'Abbé Prevot in-
forms us, " difcharge themfelves on both fides into a great number of
" others, which communicate with moft of the cities and towns; for the
" convenience of travellers, and the tranfport of the products of the coun-
" try, which are reciprocally communicated. Thefe little Canals are,
" in the end, fubdivided into a number of brooks to fertilize the adjacent
" plains."
As much oppofition often arifes in this country to the execution of the
moft ufeful Canals, it may not be improper to repeat the well-known
fact, that " Canals in China are cut through any kind of private. pro-
" perty, gardens, plantations, or pleafure-grounds not even thofe of the
" Emperor, or any of his Governors excepted; but when the work ar-
" rives at their gardens or pleafure-grounds, the Governor, or even the
" Emperor himfelf, digs the firft fpade of earth, and pronounces with an
" audible voice, This is to let those of inferior fituations know, that no private
" pleasure fball obstruct the public good."
It appears, that the river Kiang affords an extenfive navigation, and is,
in many places of immenfe depth, and in others has rocky rapids of con-
fiderable extent, which they find dangerous and difficult. The fame cir-
cumftance
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cumftance likewife takes place in fome other of their rivers, which, were
they acquainted with Locks, they might remedy. The Yellow River
gives alfo an extenfive navigation, but it is difficult to Item its current.
The Poyang Lake is faid to be a dangerous navigation, from fudden high
winds, and that many veffels are loft in it ; which accounts for the Bri-
tifh Embaffy being fent to Canton by a different route.
The Chinefe were much influenced to the conftruction of that part of
their navigation, which is parallel # to the coaft, by not being expert fea-
men, and their fear of fhip-wreck and pirates. Caufes totally different
mult, at fome period, produce a fimilar effect in the Ruffian Afiatic do-
minions. The great rivers Oby, Jenifea, and Lena, which rank among
the greateft in the world, all difcharge into the Frozen Ocean, that
a
fea navigation is totally precluded. Thefe rivers, however, fo interlock
their great navigable branches, in a plain country, as to admit of being
eafily united; and by the two former alone being done fo, a water con-
veyance from the Eaft fide of the ridge of mountains dividing the pro-
vinces of Cafan and Tobolfkoi, would be had to Strealka, near the Chi-
nefe frontier, from which a confiderable trade is carried on by caravans to
Pekin, a diftance of about 1000 geographic miles, an extent of land-car-
riage apparently immenfe in this country where every thing is very dear;
but there of comparatively fmall moment., Nothing then would re-
main to be done, to afford water conveyance from the frontier of China,
and from the immenfe provinces of Jenifeifkoi and Tobolfkoi to Pe-
terfburg, but to effect fome of the fpecies of navigations which I have
defcribed, through the vales of the narrow ridge of mountains between
the river Tura, a Weftern branch of the Oby; and the oppofite Eaftern
branch of the Kama, from which river there is an extenfive commerce by
water to Peterfburg, in the conveyance of falt, iron, &c.
In a populous country, like China, that navigation is fufficiently diftant from the
fea, to authorize its conftruction without thofe motives, which, however, were a leading
inducement.
In
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In the travels of Mr. John Bell, from Peterfburg through various
parts of Afia, he informs us, that the river Ket, a navigable branch of the
Oby, above its junction with the Irtifh, " takes its rife in a Lake at a finall
" diftance from the Jenifea," (nearly oppofite to Yenifeik the capital of
the province), " and were a Canal cut between them, which might
" eafily be done, there would be a paffage by water to the frontiers of
" China from Verchaturia," a town on the Eaft fide of the ridge of moun-
tains Weft of the Kama, and fituated on the Tura, which falls into the
Irtifh.
I have only ftated a navigable communication to Strealka ; but from
circumftances, it appears probable, that the navigation might extend from
two to three hundred miles further, through Chinefe Tartary towards Pekin,
by purfuing the Selinga, Orchon, and Tola. The latter is a branch of
the Orchon, which, as well as the Strealka, falls into the Selinga, which
difembogues into the Lake Baykal.-This Lake difcharges its waters by
the Angara, a branch of the Tongufta falling into the Jenifea above
Yenifeik.
Mr. Bell alfo obferves, that from Elimfki, a town on the Elimm, a
navigable branch of the Tongufta, it is about two days journey to the
Lena, from whence it is navigable both downwards and upwards for vef-.
fels of confiderable burthen. The country between thefe places is, how-
ever, though not mountainous, rather hilly.
The full effect of that communication between the Eaftern and Weftern
provinces, thofe who are acquainted with the country, only can judge.
Siberia is, itfelf, fufficiently fertile to receive vaft advantages from a com-
munication between its rivers; and no articles but thofe of value, would
ever traverfe the immenfe diftance from one extreme to the other, parti-
cularly as, from the fhortnefs of the fummers, the paffage would rarely or
ever be performed in one feafon. It would extend through above 75 de-
grees of longitude, or confiderably more than one fifth of the circuit of the
globe in that parallel.
CHAP.
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CHAP. VIII.
General Obfervations and Conclufion.
WHERE the propofed length of Navigation is very confiderable, it be-
comes a great object that the cargoes fhould be larger than the fmall
fyftem admits of, becaufe, many of thofe cargoes concentered in one, will
require lefs aid of men and horfes, confequently be conveyed cheaper
and in general fafer ; alfo, the greater detention from lading and deliver-
ing, larger veffels diminifhes as to its effect proportionately with increafe of
diftance.
The Lock Navigations admit of the largeft veffels, and next to them,
the plans of Mr. Weldon and Mr. Rowland, and that fuggefted in a pre-
ceding Chapter which latter being lefs limited by phyfical caufes, is ap-
plicable to greater heights with lefs proportionate increafe of expence:
and to a greater extent of fall than either of the others can be eligi-
ble : after thefe, follows Mr. Reynold's invention of Locks at the
head of Inclined Planes, which, combined with the eight-wheeled t car-
riages defcribed, or with the frame and rollers paffing under, and con-
nected with it, as fuggefted by Mr. Fulton, will be applicable to decked
Wherever the difference of expence of the two Canals enables a reduction of toll,
equivalent to the increafed charge of conveyance, that advantage ceafes, except as to
light or valuable articles, which never can be fo perfectly fecured, as under a deck and
hatches.
t Thefe carriages are adapted to an Inclined Plane of greater declivity than at its head
or foot; but if the declivity be uniform, fo as to fait a carriage with rollers, it will alfo
be fuitable to a carriage with any number of wheels on each fide ; taking care only, that
the tread of the wheels form a right line, and that there be means of adjufting them.
boats
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boats of 15 or 20 tons, or perhaps more. The next in rotation #, as to
magnitude of cargo, is the inclined plane and carriage fyftem for fmaller or
fhorter boats paffing over the ridge at the end of the upper Canal, which
is chiefly calculated for coals and minerals, and will, probably, admit of
improvement, by making the defcending and afcending way continuous,
like Mr. Fulton's ; and having a Lock at the head of the defcending way,
long enough to contain a feparate carriage for 3 or 4 boats, (or fo many
as form what has been called a conjoined boat). Thofe boats on defcend-
ing, would draw another gang light, or half load upwards, over the
top of the ridge, no Lock being requifite on that fide. The chief ob-
jections to this, lie in the vaft weight of a gang of boats, which, in a
fteep angle of defcent, would require a very heavy rope, and in the diffi-
culty of returning the carriages to their proper place. The latter may be
got over by keeping the two ways at a little diftance, and joining them
above and below by a fimicircular railway for the carriages (coupled t
to each other) to run along under-water, after they have parted with their
veffels.
Both in this, and the method laft defcribed, the water contained in the
Lock may be drawn off into a refervoir, at the head of the inclined plane :
in this refervoir, or a pond communicating with it, may be fixed a broad
under-fhot water-wheel between the two railways, to retard the motion
of the defcending boats, and to throw back the water.
This wheel may run in a clofe cafe, and be divided round its periphery
by different fhroud boards, forming fo many wheels, fo that one or more
portions of its width may be employed. at the fame time, in throwing up
water according to the neceffity of the cafe, to be determined by the velo-
In this, I alfo include the methods of boats alternately lowering and hoifting each other
up and down pits.
In fuch a way as to fuit the different boats that are to reft upon them; and yet admit
of the neceffary extenfion when the boats came over the concave part of the Inclined Plane,
which may be effected by a worm-fpring.
city
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city of the defcending boats, which, by means of a centrifugal regulator #,
will open one or more of the penftocks to let the water below the wheel, or
fhut them all, as occafion may require. The refervoir under the wheel
fhould, of courfe, never be exhaufted; but when drawn down to a certain
extent, fhould, by a floating weight, or any other method, let in water
from the head Canal. Thefe means will anfwer for a defcending trade,
and, if the afcending trade be more than the other can draw up, and water
be deficient, recourfe may be had to a fteam engine.
As boats on the aggregated plan may be 7 or 8 feet wide, they will an-
Twer tolerably well for light goods, and, as one gang, or combination t of
conjoined boats, may be conftantly under the fame charge, no objection
can 'arife from change of refponfibility, particularly, as thefe boats are
not fo fmall but they may fafely navigate larger Canals, and without incon-
venience, when the conjoined or feparate boats are proportioned in length
and width to fuit the Locks.
Wheel-boats of 4 feet width, may andwer well in proper countries for
lead, iron-ore, flates, limeftone, &c. ; and if found to ftrain at 16 feet
length, three of which I have propofed to form one conjoined boat, car-
rying 9 tons ; they may be reduced fo, as. to carry the -fame quantity in
four, and be connected as one boat: they will alfo, in certain inftances,
anfwer in collieries.
A contrivance fufficiently known, confifting of a vertical axis (having near the head of
it a collar connected with a 'lever) croffed diagonally with two bars of iron, moving on a
pin, which paffes at right angles through the vertical axis ; on the lower end of each of thefe
diagonal bars is an iron ball. Thefe balls flying off on their receiving fufficient centri-
fugal tendency to overcome their gravitating force, produce the defigned operation, by
drawing down the lever ; which is done by joints of the fame length of the parts of the
diagonal bars above their interfection, and joined both to the head of them and to the col-
lar. Thefe joints, and the upper part of the diagonal bars form the appearance of a 10-
zenge. This apparatus is frequently ufed to regulate the motion of Boulton and Watt's
fteam-engine, and is called a governor.
t Viz. two or four conjoined boats, according to circumftances.
N
In
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In addition to the methods mentioned, there is another which belongs
more to great diverfity of magnitude of Canal, than to overcoming afcent
and defcent. This is the quick tranfition of articles from one boat to
another, by means of having the cargo in the greater boats, either put ori-
ginally, or difcharged into cafes fuited to the form of the fmaller ones
confequently, eafily transferred to the latter, and as eafily taken out from.
them. This has been elucidated in the 'fifth Chapter, fo far as it is appli-
cable to afcent and defcent.
In the difcuffion of every fubject where a diverfity of opinion prevails, it
is requifite that the writer fhould be free from prejudice: Engineers have
in general been charged with being inimical to the introduction of the fyf-
tem of navigation fo warmly recommended by Mr. Leach, Dr. Anderfon,
and Mr. Fulton; which, if eligible to the extent afferted by shofe Gentle-
men, would have thrown deferved cenfure on all who have been concerned
in the chief direction of public works : I fhall, therefore, in an Appendix,
fhew by Extracts from fome of fuch of my Reports on projected Naviga-
tions as have been printed, that I have been no way hoftile to the leading
principles of their plans, and confequently, poffefs fufficient impartiality. to
be guided by no other object than the inveftigation of truth.
The general conclufion from the whole that I have faid, is, that the-
fyftem of narrow Canals is ufeful in various inftances, particularly for mi-
nerals and all heavy articles not liable to damage from. water, and much.
cheaper in particular fituations, where the declivity of the country runs re-
gularly tranfverfe to the general line of the navigation, and the falls are
great; but, that for general purpofes, and with the ufual circumftances
through which lines of Navigation run, the difference of expence between.
the two fyftems is lefs than might be imagined, and frequently more than.
counterbalanced by the difference of conveniences: alfo, that Mr. Fulton's
boats are too narrow, even for the carriage of coals in bulk, to the quan-
tity they ought to carry, and draw too much water to produce the faving
of occupation bridges and that with the increafe of width and other alter-
ations recommended to fave occupation bridges, and to prevent the boats.
from overturning, they would ftill require, compared with other boats, ¡a
greater
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greater power of horfes to move any given tonnage with fpeed, fufficient
to keep them from driving afhore with a fide wind :-that they would
not carry any due proportion of light or bulky articles :--and that any
thing liable to be pilfered or damaged by water, would not be conveyed
with equal fafety : that the boats when travelling far upon land, as fome-
times would be requifite with coals, lime, &c. would be liable to become
very leaky: and that, in thefe inftances, it would be better to convey
thofe articles in waggons to be carried in boats for the purpofe and to
fubftitute, in place of the narrow Canal, a fhallow one a little broader :-
that Mr. Fulton's boats of 20 feet length, refting only on two tranfverfe
axes, would be liable to ftrain and become leaky, in the paffage up and
down the inclined planes :-that this circumftance only admits of temedy
from another inconvenience; that of being much fhorter, and the more of
them requifite to be coupled together to carry any given tonnage :-that,
therefore, it will frequently be better to lay afide the advantage of wheels
affixed to the boats, and to follow the Dungannon and Coalbrook Dale
fyftem of floating the veffels over ftrongly framed carriages, on which
they will reft even and free from ftrains, and may, by the means defcribed,
be of much greater dimenfions than any that are now ufed on inclined
planes :-that great Canals with Locks, and fmall Canals with inclined
planes may be made, wherever requifite from fcarcity of water of other
caufes, to coincide with each other, provided the great Carals be laid out
in as long levels, and as great intermediate defcents as conveniently practi-
cable, occupying as fhort a fpace as may be by the Locks; and over-
lapping the levels, fo as to join each other in fteep places by inclined
planes.
In fine, Canals have been, and muft ftill continue to be, of dimenfions
varied according to the form and fpecies of the boats defigned to navi-
gate them: which fhould differ, fo as to coincide with the circumftances of
the country paffed through; the nature of its commerce and products ;
and the Canals, and Rivers, or Lakes, that muft eventually be navigated
by the fame veffels. Thus no general fyftem can be adopted, and nothing
extenfive can be determined on with propriety, without the-aid of great ex-
perience and abilities.
N2
APPEN-
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APPENDIX.
Extracts from " A Report on the Improvement of the Harbour of Ark-
" low, and the Practicability of a Navigation from thence, by the
" Vales of the various Branches of the Quoca."
Dublin, 1792.
I SHALL now proceed to the Interior Navigation, which, on account of
the declivity of the ground through which the Canal muft pafs, and alfo the
rapid afcent which has to be furmounted to go even a moderate diftance
into the country, does not favourably admit of being entirely carried on by
the ufual means.
Thefteep face of the hills the Canal has to run along, will, neceffarily,
confine its width, and produce a fimilar effect on the width and depth of
the boats; which will, likewife, in a certain degree, be limited in length.
by the necefity of quick curves round the points of the hills.
Their dimenfions I recommend to be 7 feet width on the gunwale, 5 feet
at the bottom, 3 feet 6 depth, and 40 feet extreme length if properly
built, they will carry upwards of 8 tons each, at 2 feet draught of water,
and about 11 tons at 2 feet 6.
The
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The fize of Canal fuitable to them, fhould be 18 feet on the water line
where the banks are fteep, and in favourable ground 21 feet, to admit two
laden boats to pafs; wherever not fo, for any confiderable extent, it muft, at
convenient diftances, be made that width for the length of a couple of boats.
Where 24 feet wide, 3. feet 6 inches depth of water will be fufficient ; and
where narrower it fhould be deeper; for, wherever the fection of the Canal
approaches nearly fo low as only 3 to I of that of the boat, confiderable
inconveniencies arife both from the increafed refiftance of the boat, and the
damage to the banks from the counter current to fill up the fpace the boat
leaves in her rear.
In the proportion mentioned of 3 to 1, the increafed refiftance to any
ufual rate of going, will be nearly 2 1/4 times what it would be in open
water, as the boat muft move 3 feet through the water for every 2 along
the Canal bank, and the counter current along the banks will run with half
the rapidity the boat goes along the land from which may be conceived
the tendency of narrow Canals to fill. up by the wafhing in of their banks,
and that the tracking againft a moderate current in an open river, requires
lefs force than the moving in fuch a Canal, befides poffetling the advantage
of favouring the boats in going downward. Thefe circumftances I chiefly
mention, becaufe the Navigation I thall recommend, will be a confiderable
diftance in the river.
Thofe acquainted with the County of Wicklow, may reafonably object
to the practicability of extending the Navigation far into the country, on
account of the vaft afcent, which would be too expenfive to be overcome
totally by Locks ; but on reflecting that the fteep and winding face of the
hills neceffarily confine to the ufe of fmall boats, and that there are fitua-
tions for afcending at once 70 or 80 feet, or whatever heights may be ne-
ceffary to penetrate into the country, the difficulty will vanifh ; and it will
be found, that the means of effecting this work will be fcarcely half as ex-
Not uniformly fo, becaufe at a diffance from the extremities of any level, the water in
front will partly recede without rifing to its full oppofition ; and that in the rear, partly
come in to fill up the vacuity left by the boat.
penfive
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penfive as the ufual methods of penetrating fo far, and afcending fuch:
heights in countries favourable for the common ftyle of Navigation.
Part of the plan propofed is only. applicable to mountainous countries,
which enjoy this peculiar advantage, that if the rife of level be made on a
point dividing two rivers, the afcent enables both valleys to be navigated.
This mode of Navigation has its limits in point of eligibility and, in ge--
neral, where extenfive, muft be a mixed one.
Extracts from a Report on the Meafures to be attended to, in the Surveys
of a. Line of Navigation, from: Newcaftle-upon-Tyne to. the Irifh
Channel.
Newcaftle, 1795.
TO make a Branch Canal, to and through the mining country, of fimi-
Iar magnitude with that propofed from fea to fea, would be extremely ex-
penfive as well as unneceffary.
On the face of a mountainous country, where there are fudden bends and
little foil, boats, from the firft caufe, ought not to be long ; and, from the
thinnefs of foil and declivity of the ground, the Canal would be expenfive
to be either wide or deep. Bridges would alfo be coftly, not only from the
expence of their erection, but the difficulty of filling their approaches on.
the downward fide: I therefore recommend a Ganal of only 3 feet 6
inches depth, and at every high and bye road, that there be a paved ford
of 2 feet 9 inches-depth, the downward fide. of the ford to be an overflow,
fo that the water can never rife materially higher, and horfes and carriages
may at all times fafely pafs. The width and length of boats on this
Navigation, I would advife to be half of what they will be on the main
Eanal; fo that, if found more eligible than re-fhipping their cargoes into
the large boats, four of the fmall ones may proceed together, and pafs
through the Locks with the leaft wafte of water that the feparate plans will
admit of. Thefe boats, fhould be of the construction of the Birmingham
trows
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trows (upright fided and flat-bottomed), and when light, fhould only draw
6 inches water ;-they will then, at 32 feet length and 6 feot width *,
carry, according to the form of their ends, from 8 to 10 tons each, when
laden to 2 feet 6 inches :-four of them, which may be navigated with one
horfe and four boys t, will, at the lefter quantity, carry 32 tons. Thefe
boats fhould be connected together in pairs, each hind one, as in the Lin-
colnfhire Navigation, acting as a rudder to the fore one, in each of which,
from a fmall maft a light track-line may go to the fwingle-tree of the
horfe.
In defcending from the line running through the lead country, which
probably may be confiderably higher than the branch from the fummit of
the main Canal, various meafures may be adopted, either paffing the boats
down inclined planes, as at Coalbrook Dale, or perpendicularly I, if the
advantage of a precipice can be obtained, in each cafe a defcending boat
drawing up an afcending one, or by fimple means of difcharging the car-
goes of the boats of one level into thofe of another.
But if water be to be had, Locks of a rude and eafy conftruction may,
in that country, be executed at nearly as little expence as the inclined
planes and requifite machinery, and not fo liable to accidents and mifma-
nagement from unfkilful men.
So far as relates to the fmall boats propofed to go in fleets of four to-
gether, they will jointly confume the fame quantity of water in paffing fe-
parately through one of their own fingle Locks, as they will by paffing col-
lected through one of the large ones on the main trunk.
If the declivity of the ground fhould limit the main Canal to boats of 12 feet width.
t
A driver, two fleerers, and one to manage the ftop-ropes in going into a Lock.
I Similar in the leading features to the plan ingenioufly fuggefted by Dr. James Ander-
fon, in one of his late Publications.
FINIS.
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Plate.1
Fig.1.
9,
10
k
b
c
3
5
Fig. 2.
2:6
Fig.3.
Fig.5.
D
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0
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Fig. 4.
B
C
I. ondon. Published by I&J Taylor, 56. High Holborn
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Plate 2
Fig.1.
Elevation of a proposed Wheel Boat.
Fig.2.
Plan
Fig.3.
Fig. 4.
Profile
Profile
in line ab.
in line c.d.
Laden
Water line
Light
Water line
Sale , Feet to an Inch
11 i 11
Feet
London:Published by Jk J.Taylor 56 High Holborn.
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Plate. 3.
Fig 1.
M
M/:
P
G
q
E
K
B
C
Fig 2.
0.m
n
M
Fig 3.
n
G
h
H
&
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c
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B
Fig. 4
9
London Published by1& JTaylor, 56.High Holborn
-
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TC 744 .C46
Observations on the various by
Stanford University Libraries
3 6105 041 645 743
KR 16 'C3
9 1972
25 '85
Stanford University Library
Stanford, California
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