Jean-Victor Poncelet

Jean-Victor Poncelet (1788 to 1867) was a French military engineer and mathematician, one of the founders of modern projective geometry. Born in Metz and raised from infancy by the Olier family at Saint-Avold, he studied at the École Polytechnique under Gaspard Monge, Lazare Carnot and Charles Brianchon before joining the Engineering Corps. Left for dead after the Battle of Krasnoi during Napoleon's Russian campaign, he was held as a prisoner of war at Saratov from March 1813 to June 1814. There he rebuilt his mathematical education from memory and developed the projective properties of conics, including the pole and polar construction that led to the principle of duality. Back in France he taught at Metz and published his Traité des propriétés projectives des figures in 1822, introducing the principle of continuity, which Cauchy criticised and which, together with a priority dispute over duality, made his geometry controversial. He turned to applied mechanics, including work on waterwheels that won a prize from the French government in 1826, was elected to the mechanics section of the Académie des Sciences in 1834, became professor of mechanics at the Sorbonne and served on the Committee for Fortifications of Paris. He died in Paris in December 1867.