Polytechnician Jean-Victor Poncelet was captured in 1812 during the French invasion of Russia. But neither the forced marches in the harsh Russian winter nor the total absence of books prevented this man from devoting himself to geometry and subsequently co-founding modern projective geometry. After returning to France in 1814, he published essays on drawbridges, buildings and water mills. He was a professor of machine science at the Metz School of Application (École d’Application de Metz), then of physical and experimental mechanics at the Paris Faculty of Sciences (Faculté des Sciences de Paris). Following the overthrow of the July Monarchy in 1848, he became a deputy of the Constituent Assembly, and Commander of l’X. Poncelet also invented a vertical water wheel with curved blades, and his name is used for a unit of power.