Science Fair Project Encyclopedia Born to a poor family in Metz,
France, Poncelet won a scholarship to the lycée' and then the
École Polytechnique where he studied under Gaspard Monge. In
1810 he entered the military engineering college at Metz. He was
commissioned a lieutenant of engineers and served in Napoleon's
invasion of Russia in 1812. Abandoned as dead at the Battle of
Krasnoy , he was imprisoned by the Russians at Saratov before
being repatriated to France in 1814. During his imprisonment, he
studied projective geometry and started to investigate those
properties that figures share with their shadows, drafting the
book Applications d'analyse et de géométrie that was to be
published in two volumes in 1862/1864. He studied conic sections
and developed the principle of duality independently of Joseph
Gergonne . On his repatriation to France, he resumed military
engineering duties at Metz, being appointed professor of
mechanics at the école d'application in 1825. There, in his
lectures, he coined the ter