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 language, Picard and , , ) is a historical and cultural territory and a former regions of France, administrative region located in northern France. The first mentions of this province date back to the Middle Ages: it gained it ...

. 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,

François Arago Dominique François Jean Arago (), known simply as François Arago (; Catalan: , ; 26 February 17862 October 1853), was a French mathematician, physicist, astronomer, freemason, supporter of the Carbonari revolutionaries and politician. Early l ...

and Pierre Dulong. Baro 3

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'' (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 Messier may refer to: People with the surname *Ashley Messier (born 2002), Canadian ice hockey player *Charles Messier (1730–1817), French astronomer * Doug Messier (born 1936), Canadian ice hockey player and coach * Éric Messier (born 1973), Ca ...

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 artisans 19th-century French scientists {{France-scientist-stub