The Columbia Encyclopedia, Sixth Edition. 2001-07.
Desargues, Gérard
(zhrär´ dzärg´) (KEY) , 15911661, French mathematician and engineer, a founder of modern geometry. He discovered the theorems on involutions and transversals known by his name and worked on conic sections. His writings, lost for a time, were republished in 1864. His purely mathematical texts, in French, ed. by René Taton, were republished in 1951.