The Marvelous Slide Rule
Source: Thompson, J.E., A Manual of the Slide Rule, D. van Nostrand Co., N.Y. 1930
John Napier of Scotland announced the discovery of logarithms in 1614, whose intended purpose was to remove "hindrance and tedium" from calculations; two decades earler, in 1594, Napier had privately comunicated a summary of his results to Tycho Brahe (p2). In 1617 Henry Briggs transformed logarithms to the form described in modern definitions (p3); following this, Edmund Gunter laid off on a strip of wood (p4).
Prior to 1630 William Oughtred invented the double rule and the circular rule. In 1657 Seth Partridge devised the duplex slide rule - 3 strips with numbers sliding. As described by F. Stone in 1726, the first recorded use of "runner", moving marking line, was by Newton to solve cubic equations (p7).
In 1880 the Mannheim rule was introduced in the U.S. (p17); in 1891, Cox patented a modified "duplex" slide rule.
Copyright 1996 S H Shakman. All rights reserved. [HOME]