PONCELET, Jean Victor, French military engineer: b. Metz, 1 July 1788; d. Paris, 23 Dec. 1867. Between the years 1807 and 1810 he attended the Ecole Polytechnique, where he was a pupil of Monge. In 1812 he received the commission of lieutenant in the engineers, but on Napoleon's retreat from Moscow was taken prisoner and transported to Saratov, on the Volga. On returning to Metz in 1814 he worked out the geometrical problems he had begun to consider during his captivity, but these met with little recognition from the French Academy. In 1829 he published his des Proprietes Projectives des Figures.> He henceforth gave himself closely to the study of applied mechan ics; invented the water wheel which bears his name and published numerous works on me chanics. In 1835 he was appointed member of the National Defenses Commission and pro fessor -of applied mechanics in the University of Paris. He was promoted general in 1848
and went to the Exhibition of 1851 at London as president to the Commission of Mechanics. In 1857 he published his important account of the progress of mechanical science, 'Collection des Travaux de la Commiss' n The work which he had begun in captivity in Sara tov — (Application d'Analyse et de Geometric' —he published in 1862. He was really the founder of modern geometry and had gained great influence among German mathematicians at a time that his countrymen had accorded him only scant recognition. Among his other works are 'Les Roues Hydrauliques Verticales' (1826) ; 'Experiences Hydrauliques) (1832) ; 'Traite de Mecanique Appliquee aux Machines) (1845) ; 'Applications d'analy. se et de geome tric' (2 vols., 1862-64), etc. Consult Didion, 'Notice sur la Vie et les Ouvrages du General Poncelet' (1869).