Report on the operation of Barnaby, summer, 1948

Barnaby is a self-contained truck-mounted unit for gamma-ray logging of diamond drillholes less than 200 feet deep. The radiation is detected by Geiger-Muller counter and the impulses are transmitted up a single-conductor shielded cable by a special circuit. At the surface the impulses are electronically counted and the average counting rate is automatically plotted by a recording meter synchronized with the advance of the G-M counter in the hole. Barnaby was designed and built for the Union Mines Development Corp. by Robert J. Smith and the writer in the spring of 1945 at the shops of the Metallurgical Laboratories, University of Chicago.