Bissaker's slide rule, 1654, and Thacher's calculating instrument, 1881.

Image number: 10302609

Bissaker's slide rule, 1654, and Thacher's calculating instrument, 1881.

Bissaker's slide rule (bottom) is the earliest dated straight slide rule. The scales are mainly trigonometrical and logarithmic. The instrument is inscribed 'Made by Robert Bissaker, 1654, for TW'. Thacher's slide rule (top) is an extremely important American contribution to slide rules, capable of accurate reading to four decimal places.

Image number:
10302609
Credit:
Science Museum/Science & Society Picture Library
Date taken:
20 October 2003 13:30
Image rights:
Science Museum