Jean-Charles de Borda

Infobox Scientist
name = Jean-Charles de Borda
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caption = Jean-Charles de Borda
birth_date = May 4, 1733
birth_place = Dax
death_date = February 19, 1799
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nationality = French
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field = mathematics
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Jean-Charles, chevalier de Borda (May 4, 1733 – February 19, 1799), was a French mathematician, physicist, political scientist, and sailor.

Born in the city of Dax, in 1756 Borda wrote "Mémoire sur le mouvement des projectiles", a product of his work as a military engineer. For that, he was elected to the French Academy of Sciences in 1764.

Borda was a mariner and a scientist, spending time in the Caribbean testing out advances in chronometers. Between 1777 and 1778, he participated in the American Revolutionary War. In 1781, he was put in charge of several vessels in the French Navy. In 1782, he was captured by the English, and was returned to France shortly after. He returned as an engineer in the French Navy, making improvements to waterwheels and pumps. He was appointed as France's Inspector of Naval Shipbuilding in 1784, and with the assistance of the naval architect Jacques-Noël Sané in 1786 introduced a massive construction programme to revitalise the French navy based on the standard designs of Sané.

In 1770, Borda formulated a ranked preferential voting system that is referred to as the Borda count. The French Academy of Sciences used Borda's method to elect its members for about two decades until it was quashed by Napoleon Bonaparte who insisted that his own method be used after he became president of the Académie in 1801. The Borda count is in use today in some academic institutions, competitions and several political jurisdictions. The Borda count has also served as a basis for other methods such as the Quota Borda system and Nanson's method.

Another of his contributions is his construction of the standard "metre", basis of the metric system to correspond to the measurements of Delambre.

As an instrument maker, he improved the reflecting circle (invented by Tobias Mayer) and the repeating circle (invented by his assistant, Etienne Lenoir), the latter used to measure the meridian arc from Dunkirk to Barcelona by Delambre and Méchain.

Honours

*Five French ships were named "Borda" in his honour.
*He is honoured by an eponymous crater on the Moon.