Renard, Louis Marie Joseph Charles Clément (X 1866 ; 1847-1905)

Engineer and military engineer, he distinguished himself at Polytechnique in mathematics and mechanics. He was the father of military ballooning, building and developing his airship in 1881: he built with Captain Krebs an airship with an electric motor: "France", the first to complete a closed circuit course (7 km). Interested in aviation, he published his work on aerodynamics, vertical flight, aircraft engines. In mathematics we owe him the "Renard series" (normalization) still used in industry