Letters Sent to Dr. James E. Ives, May 8, 1929

May 8th11929. Dr. James E. Ives, Room 1-123 #Ç" Bldg., 16 Seventh St., S.W. Washington, D.C. Dear Dr. Ives: We are shipping you today by express prepaid, the Wulf- Hess electrometer and trust that you will receive seme promptly. This instrument was delivered to us by the Customs Authorities on Friday of less week and, we have delayed sending same to you in order that we might have en opportunity to exemine and nake comparative tests on the sensitivity of the instrument. We find the natural drift to be exceedingly low and the sonsitivity About what has been found in the past with this type of instrument, although slightly less than that of the instrument in the possession of Dr. Flinn. The snall glass bulb for containing a drying agent such as calcium chloride, designed to be attached to instrument at the opening above the window for allowing light to fall upon the fibors, we have not included. In using an instrument of this type in the field, I believe it is advantageous not to have this accessory equipment, and our experience indicates that inas much as the instrument is virtually air-tight, there is little or no necessity for using a drying agent. However, should you desire to use this precaution we shail be glad to forward the equipment to you. We are extremely sorry that there has been so nuch delay in obtaining this instrument and, trust that you will find it quite sat- isfactory for your purpose. Sincerely yours, Vice President. HHBarker*RI