1911 Encyclopædia Britannica/Charles, Jacques Alexandre César

CHARLES, JACQUES ALEXANDRE CÉSAR (1746–1823), French mathematician and physicist, was born in Beaugency, Loiret, on the 12th of November 1746. After spending some years as a clerk in the ministry of finance, he turned to scintific pursuits, and attracted considerable attention by his skilful and elaborate demonstrations of physical experiments. He was the first, in spring 1783, to employ hydrogen for the inflation of balloons (See Aeronautics), and about 1787 he anticipated Gay Lussac's law of the dilatation of gases with heat, which on that account is sometimes known by his name. In 1785 he was elected to the Academy of Sciences, and subsequently he became professor of physics at the Conservatoire des Arts et Métiers. He died in Paris on the 7th of April 1823. His published papers are chiefly concerned with mathematical topics