Jean-François Callet

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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.[1] 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.[2][3] It was influential and led to other improved logarithm tables such as those of Edward Sang.[4] 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.[5]

References

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  1. ^ Feller, Francois Xavier de (1850). Biographie universelle, ou Dictionnaire historique des hommes qui se sont fait un nom par leur génie, leurs talents, leurs erreurs ou leurs crimes. Édition revue et continuée jusqu'en 1848, sous la direction de M. Ch. Weiss. Tome II (in French). Paris: Leroux, Jouby. p. 338.
  2. ^ Archibald, Raymond Clare (1943). "Tables of Trigonometric Functions in Non-Sexagesimal Arguments". Mathematics of Computation. 1 (2): 33–44. doi:10.1090/S0025-5718-43-99136-7. ISSN 0025-5718.
  3. ^ Roegel, Denis (2020). A reconstruction of Edward Sang's table of logarithmic sines and tangents (K43,1888) (report thesis). LORIA (Université de Lorraine, CNRS, INRIA).
  4. ^ Craik, Alex D.D. (2003). "The logarithmic tables of Edward Sang and his daughters". Historia Mathematica. 30 (1): 47–84. doi:10.1016/S0315-0860(02)00018-6.
  5. ^ Thümmel, O. (2017). "Der trigonometrische Zirkel des Bürgers Richer: eine Episode aus der Geschichte der Navigation". Deutsches Schiffahrtsarchiv (in German). 40: 249–294.
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