Born July 1, 1788, in Metz; died Dec. 22, 1867, in Paris. French mathematician and engineer. Member of the Paris Academy of Sciences (1834).
Poncelet graduated from the Ecole Polytechnique in Paris in 1810. In 1812 he took part in Napoleon’s campaign in Russia and was taken prisoner; in 1814 he returned to France. He was a professor at the University of Paris from 1838 to 1848 and was director of the Ecole Polytechnique from 1848 to 1850. Poncelet’s principal contribution to geometry is his Treatise on Projective Properties of Figures, written while he was a prisoner of war in Saratov and published in Paris in 1822. In this work the projective properties of figures were treated for the first time as a special group and new methods of geometrical investigation were created. Subsequent use of these methods led to the development of projective geometry. In addition, a number of works deal with engineering mechanics and hydraulics; Poncelet developed an improved water wheel (Poncelet’s wheel) and introduced the kilogram-meter as a unit of mechanical work.