Mathematician:Gilles Personne de Roberval

Mathematician
French mathematician whose work was a precursor to calculus.

Worked on the quadrature of surfaces and the cubature of solids. Had a habit of keeping his discoveries secret so as to retain the intellectual advantage over his peers. This led him to lose credit for his discoveries to other later thinkers who published their work.

For example, he supposedly discovered the Area under Arc of Cycloid before, but the latter obtained priority through publishing it in $1644$.

Reputedly quarrelsome and waspish.

Nationality
French

History

 * Born: 9 August 1602 in Noël-Saint-Martin, Villeneuve-sur-Verberie, Oise, France
 * 1628: Arrived in Paris and joined 's circle
 * 1631: Appointed the philosophy chair at Gervais College
 * 1633: Made the chair of mathematics at the Royal College of France
 * Died: 27 October 1675 in Paris, France

Theorems and Definitions

 * Robervallian Line


 * Roberval Balance

Publications

 * 1636: Traité de Mécanique des Poids Soutenus par des Puissances sur des Plans Inclinés à l’Horizontale
 * 1644: Le Système du Monde d’après Aristarque de Samos

Also known as
Some sources give his name as Gilles Persone de Roberval, but this may be a mistake.

His name was originally Gilles Personne or Gilles Personier, adding the de Roberval after $1628$.