Pierre Varignon (1654 – 23 December 1722) was a French

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

. He was educated at the

Jesuit , image = Ihs-logo.svg , image_size = 175px , caption = ChristogramOfficial seal of the Jesuits , abbreviation = SJ , nickname = Jesuits , formation = , founders ...

College and the

University of Caen The University of Caen Normandy (French: ''Université de Caen Normandie''), also known as Unicaen, is a public university in Caen, France. History The institution was founded in 1432 by John of Lancaster, 1st Duke of Bedford, the first rector ...

, where he received his

M.A. A Master of Arts ( la, Magister Artium or ''Artium Magister''; abbreviated MA, M.A., AM, or A.M.) is the holder of a master's degree awarded by universities in many countries. The degree is usually contrasted with that of Master of Science. Tho ...

in 1682. He took Holy Orders the following year. Varignon gained his first exposure to mathematics by reading

Euclid Euclid (; grc-gre, Wikt:Εὐκλείδης, Εὐκλείδης; BC) was an ancient Greek mathematician active as a geometer and logician. Considered the "father of geometry", he is chiefly known for the ''Euclid's Elements, Elements'' trea ...

and then Descartes' ''

La Géométrie ''La Géométrie'' was published in 1637 as an appendix to ''Discours de la méthode'' (''Discourse on the Method''), written by René Descartes. In the ''Discourse'', he presents his method for obtaining clarity on any subject. ''La Géométrie ...

''. He became professor of mathematics at the Collège Mazarin in Paris in 1688 and was elected to the

Académie Royale des Sciences The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research. It was at the ...

in the same year. In 1704 he held the departmental chair at Collège Mazarin and also became professor of mathematics at the Collège Royal. He was elected to the Berlin Academy in 1713 and to the

Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...

in 1718. Many of his works were published in Paris in 1725, three years after his death. His lectures at Mazarin were published in
Elements de mathematique
' in 1731. Varignon was a friend of Newton,

Leibniz Gottfried Wilhelm (von) Leibniz . ( – 14 November 1716) was a German polymath active as a mathematician, philosopher, scientist and diplomat. He is one of the most prominent figures in both the history of philosophy and the history of ma ...

, and the

Bernoulli family The Bernoulli family () of Basel was a patrician family, notable for having produced eight mathematically gifted academics who, among them, contributed substantially to the development of mathematics and physics during the early modern period. ...

. Varignon's principal contributions were to graphic

statics Statics is the branch of classical mechanics that is concerned with the analysis of force and torque (also called moment) acting on physical systems that do not experience an acceleration (''a''=0), but rather, are in static equilibrium with ...

and

mechanics Mechanics (from Ancient Greek: μηχανική, ''mēkhanikḗ'', "of machines") is the area of mathematics and physics concerned with the relationships between force, matter, and motion among physical objects. Forces applied to objects r ...

. Except for l'Hôpital, Varignon was the earliest and strongest French advocate of

infinitesimal calculus Calculus, originally called infinitesimal calculus or "the calculus of infinitesimals", is the mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithm ...

, and exposed the errors in

Michel Rolle Michel Rolle (21 April 1652 – 8 November 1719) was a French mathematician. He is best known for Rolle's theorem (1691). He is also the co-inventor in Europe of Gaussian elimination (1690). Life Rolle was born in Ambert, Basse-Auvergne. Rol ...

's critique thereof. He recognized the importance of a test for the convergence of series, but analytical difficulties prevented his success. Nevertheless, he simplified the proofs of many propositions in mechanics, adapted Leibniz's calculus to the inertial mechanics of Newton's '' Principia'', and treated mechanics in terms of the composition of forces in ''Projet d'une nouvelle mécanique'' in 1687. Among Varignon's other works was a 1699 publication concerning the application of differential calculus to fluid flow and to

water clock A water clock or clepsydra (; ; ) is a timepiece by which time is measured by the regulated flow of liquid into (inflow type) or out from (outflow type) a vessel, and where the amount is then measured. Water clocks are one of the oldest time-m ...

s. In 1690 he created a mechanical explanation of gravitation. In 1702 he applied calculus to spring-driven clocks. In 1704, he invented the U-tube

manometer Pressure measurement is the measurement of an applied force by a fluid (liquid or gas) on a surface. Pressure is typically measured in units of force per unit of surface area. Many techniques have been developed for the measurement of pressur ...

, a device capable of measuring rarefaction in gases.

Works

Varignon, Pierre – Traité du mouvement et de la mesure des eaux coulantes et jaillissantes, 1736 – BEIC 12415414

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References

* * {{DEFAULTSORT:Varignon, Pierre 1654 births 1722 deaths Clergy from Caen University of Paris faculty 17th-century French Roman Catholic priests 18th-century French Roman Catholic priests 17th-century French mathematicians 18th-century French mathematicians Fellows of the Royal Society Mathematical analysts Members of the French Academy of Sciences Catholic clergy scientists University of Caen Normandy alumni Scientists from Caen

Works

See also

References