Jean Nicolas Fortin (1750–1831) was a French maker of

scientific instrument A scientific instrument is a device or tool used for scientific purposes, including the study of both natural phenomena and theoretical research. History Historically, the definition of a scientific instrument has varied, based on usage, laws, an ...

s, born on 9 August 1750 in Mouchy-la-Ville in

Picardy Picardy (; Picard and french: Picardie, , ) is a historical territory and a former administrative region of France. Since 1 January 2016, it has been part of the new region of Hauts-de-France. It is located in the northern part of France. Hi ...

. Among his customers were such noted scientists as

Lavoisier Antoine-Laurent de Lavoisier ( , ; ; 26 August 17438 May 1794),
CNRS (

for whom he made a precision balance,

Gay-Lussac Joseph Louis Gay-Lussac (, , ; 6 December 1778 – 9 May 1850) was a French chemist and physicist. He is known mostly for his discovery that water is made of two parts hydrogen and one part oxygen (with Alexander von Humboldt), for two laws ...

François Arago Dominique François Jean Arago ( ca, Domènec Francesc Joan Aragó), known simply as François Arago (; Catalan: ''Francesc Aragó'', ; 26 February 17862 October 1853), was a French mathematician, physicist, astronomer, freemason, supporter of ...

and

Pierre Dulong Pierre Louis Dulong FRS FRSE (; ; 12 February 1785 – 19 July 1838) was a French physicist and chemist. He is remembered today largely for the law of Dulong and Petit, although he was much-lauded by his contemporaries for his studies into ...

Fortin is chiefly remembered for his design of

barometer A barometer is a scientific instrument that is used to measure air pressure in a certain environment. Pressure tendency can forecast short term changes in the weather. Many measurements of air pressure are used within surface weather analysis ...

, now called a ''Fortin barometer'', which he introduced in about 1800. In this, the mercury cistern has a glass portion through which the mercury exposed to the atmosphere can be seen, and an ivory needle which was made just to touch its mirror image in the mercury before the reading was taken. This allows for the fact that, when the mercury column in the closed tube falls, the level in the cistern rises, and the difference in height between the two cannot be accurately determined unless the height of the latter is taken into account. In 1776 Fortin produced the ''Atlas céleste de Flamstéed'' a revised and updated edition of Flamsteed's ''

Atlas Coelestis The ''Atlas Coelestis'' is a star atlas published posthumously in 1729, based on observations made by the First Astronomer Royal, John Flamsteed. The ''Atlas'' – the largest that ever had been published and the first comprehensive telescopic ...

'' (celestial atlas) of 1729, at about 1/3 of the original scale and in French. Maps from a later 1795 edition of this work were used by Messier to show the location of his discoveries. On 15 May 1831 he died in Mouchy-le-Châtel (Oise).death certificate
AD60 ()

References

External links

''Atlas céleste de Flamstéed''
(Google books: ''2nd. ed.'' since Flamsteed's original is counted as the first) 1750 births 1831 deaths 18th-century French people 18th-century French scientists 19th-century French people 19th-century French scientists {{France-scientist-stub