EQUIPMENT AND SUPPLIES - Well-numbering slide rule UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY Water Resources Division Washington 25, D.C. In reply refer to: August 26, 1964 Code: 4056 0001 GROUND WATER BRANCH MEMORANDUM NO. 65.3 To: District Chiefs and Staff Officials (GW) From: Chief, Ground Water Branch Subject: EQUIPMENT AND SUPPLIES - Well-numbering slide rule The Long Beach offices of the California District has been using the Gerber Variable Scale for the determination of latitude and longitude well-code numbers, and found that it is faster than an interpolation grid, is accurate, and can be used on any map which shows latitude and longitude on the edge. The scale was recently brought to our attention by W.R. Morle, Jr., GW, Long Beach. Attached is information concerning this piece of equipment. We are not endorsing the Gerber Scale, but because it may facilitate determination of latitude and longitude, we would like to bring it to your attention. O.M. Hackett Attachments WRD Distribution: A, B3, S3, without attachment FOL3, SL, with attachment