Slide rules
John Napier published his invention of logarithms in 1614. Adding the logarithms of two numbers is equivalent to multiplying the numbers themselves, while subtraction of logarithms can replace tedious long division. Logarithms were soon arranged as a scale, and moving two scales against each other represents their addition and subtraction. This is the principle of the slide rule as a general purpose calculating device.
Slide rules were also adapted for specialised tasks, such as for gauging barrels [1, 2]. Rules were often made in boxwood [3], but new materials such as metals and plastics [4] were adopted in the 19th and 20th centuries. Efforts were even made to find the best background colour for reading the scales [5].
Other narratives:
Related Objects:
- Inventory No. 50253, "Gauging Slide Rule, by Isaac Carver, London, 1688" [1952-92], Carver, Isaac
- Inventory No. 34558, "Slide Rule for Gauging, by Dring & Fage, London, Late 19th Century", Dring & Fage
- Inventory No. 36178, "Engineer's Slide Rule, by Hoare, London, 19th Century" [1968-401], Hoare
- Inventory No. 55011, "Slide Rule for Vickers Machine Gun, by B. J. H. & Co. Ltd., English, 1928", B.J.H. & Co. Ltd,
- Inventory No. 90632, "Slide Rule, by Pickett & Eckel, Chicago and California, 1960s?" [1997-8], Pickett & Eckel