science · 14 September 1638 · 386 years ago
death
Died 14 Sep 1638 at age 54 (born 19 Aug 1584).
French mathematician who invented the vernier scale, which enabled instruments to make more accurate linear or angular measurements. He first described it in a work entitled La construction, l'usage et les propriétés du cadran nouveau (1631)*. It consists of a small graduated scale or arc made to slide along a larger fixed scale or arc to enable determining the increment between two graduations of the larger scale. The ten divisions of the smaller, vernier scale are equal to nine of the fixed scale. For example, calipers with a larger scale graduated in tenths of inches can be read by use of the vernier scale to within one-hundredths of an inch. Vernier scales are also used on sextants and mercury column barometers.
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