BIOT, jean Baptiste, French mathemati cian and physicist of distinction: b. Paris, 21 April 1774; d. there, 3 Feb. 1862. He was edu cated at the College I-ouis-le-Grand and in 1793 entered the artillery service. Shortly after ward he entered the Ecole Polytechnique and thenceforth devoted himself to the study of mathematics and the natural sciences. After teaching physics for some years at Beauvais, he became professor of the same subject in the College de France in 1800, and in 1803 was elected a member of the Institute. He stood neutral on the question of the founding of an empire. In 1804 he made a balloon ascent with Gay-Lussac, and in 1806 was made a member of the Bureau des Longitudes. In 1809 he became also professor of physical astronomy in the University of Paris. With the exception of three journeys, undertaken in connection with the measurement of a degree of the meridian, — namely, to Spain in 1806-08, to Scotland, Orkneys and Shetland in 1817, and to Spain and Italy in 1824-25,— his whole life was quietly passed in study and teaching. He published
some excellent text-books, which became widely known beyond France. Important works by him are the (Traite elernentaire d'Astronomie Physique' (3 vols., Paris 1805, and 3d ed., 6 vols., 1850) ; (Mélanges scientifiques et litter aires' (1858) ; as well as works on the astronomy of the ancient Egyptians, Indians and Chinese. His most valuable contributions to science, how ever, are chiefly contained in communications to learned societies and periodicals. There are few branches of physics which were not ad vanced by his labors; and in optics especially he made some valuable investigations, particu larly in connection with refraction and polariza tion. See Claim.