Logarithms, the basis of slide rules, were invented by the Baron of Merchiston, John Napier, in Scotland in 1614. After a couple of centuries of tinkering and development, advanced mathematics took a quantum leap with a game changing device that made calculating complex formulas and mathematics easier: the slide rule. They effectively become obsolete in 1976 as the hand held calculator became available (at prices in the hundreds of dollars). A complicated device, the slide rule allowed the user to do basic multiplication, wrap around multiplication, folded-scale multiplication, division, square roots and reciprocals. Things really got crazy when it turned to trigonometry. Then the world transmogrified into sines, cosines, roots, cube-roots and powers. It was at that point that most people left the building.

A slide rule owned by a Cornell University engineering student

However, for engineers and mathematicians, slide rules were cool: they were the Sony Walkman and iPhones of their day. Whoever had them was looked up to. Man, they were not only cool, but wicked smart. The heyday of the slide rule was between the 1930s and 1960s. The Keuffel & Esser Company were one of the primary makes of slide rules, and today we highlight two specimens made by the company: one for Cornell students and another for those at Yale. Not only did you have your slide rule, which made you a cool dude, but like today’s iPhone cases, you also had a cool case to carry it in. See the Yale case below featuring the school’s mascot, the bulldog.

The Yale slide rule made by Keuffel & Esser

We have a nice selection of original vintage slide rules and other collegiate collectibles on our website.