Jean-François Callet (25 October 1744 – 14 November 1798) was a French professor of mathematics who wrote an influential book of logarithm tables and taught spherical trigonometry and navigation.
Callet was born in Versailles and became a professor of hydrographic engineering. Callet's most influential work was a portable table of logarithms (based on the work of
William Gardiner) ''Tables Portatives de Logarithmes'' published in 1795 which went into many editions until 1906. It has fifty pages with logarithms of the sine, cosine and tangent, as well as natural sines and cosines. It was influential and led to other improved logarithm tables such as those of
Edward Sang
Edward Sang FRSE FRSSA LLD (30 January 1805 – 23 December 1890) was a Scottish mathematician and civil engineer, best known for having computed large tables of logarithms, with the help of two of his daughters. These tables went beyond the ta ...
. Another work of his was a spherical trigonometric text for use in navigation published in 1798. It was made in collaboration with instrument maker Jean François Richer who was attempting to create a navigation instrument called the trigonometric circle or ''Compas Trigonométrique'' in his application for the Abbe Raynal Prize which sought a reliable and accurate method for the reduction of the apparent to the true distance between two stars. This would be usable to determine the longitude of the ship's position. Richer's application won the 1791 price.
References
External links
Tables Portatives de Logarithmes(1808, 3rd edition)
Supplément à la Trigonométrie sphérique et à la navigation de Bezout(1798)
{{DEFAULTSORT:Callet, Jean-Francois
1744 births
1798 deaths
18th-century French mathematicians