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17th-Century Slide Rule
The 17th-century slide rule is an analog calculating tool using logarithmic scales to convert multiplication and division into comparisons of line le…
Timeline
- 1620–1630London · LondonBuilding on Napier's logarithm tables, Oughtred and others converted multiplication and division into addition and subtraction on logarithmic scales, designing a sliding two-scale structure that laid the foundation for the standard form of the 17th-century slide rule.
- 1631–1640Europe · EuropeIn the 1630s, linear and circular slide rules entered observatories, artillery academies, and commercial bookkeeping, used for proportional conversion, trigonometric functions, and approximate root extraction, becoming a signature calculating instrument of the early Scientific Revolution.
- c. 1650–1700European instrument-making centers · EuropeLater craftsmen added cursors to slide rules to improve reading accuracy and extended specialized scales for sine, tangent, and other functions, keeping the tool practically valuable in navigation, surveying, and ballistics for a long period.
Sources
- William Oughtred, The Circles of Proportion and the Horizontal Instrument, 1632 — William Oughtred (1632)
- Encyclopaedia Britannica: Slide rule https://www.britannica.com/technology/slide-rule