The First Nerd Tool

No frontier sheriff ever strode more proudly down Main Street than Tom Apostol did across the campus of the University of Utah in 1941, wearing his own trusty side arm—a 10-inch Keuffel & Esser log-log Decitrig slide rule. "We all felt very macho walking around campus wearing these like guns in holsters," remembers Apostol, now professor emeritus of mathematics at Caltech. "Plus, we knew how to use the things, and this made a big impression on the girls."