Vintage Slide Rules

The slide rule, invented by William Oughtred in 1622, consists of two divided scales, one fixed and one movable, and a sliding window called a cursor. Slide rules were the primary tool for performing multiplication, division and other scientific functions up through the 1960s and the development of the electronic calculator. There are straight, circular and cylindrical slide rules, all collectible. Major manufacturers included Keuffel and...Continue Reading