LAGRANGE, Joseph Louis, la-granzh, Comm, French mathematician: b. Turin, 25 Jan. 1736; d. Paris, 10 April 1813. His great-grandfather was a cavalry officer in the French army, who afterward passed into the service of Sardinia. When scarcely 19 La grange was made mathematical professor in the artillery school at Turin. In 1764 he ob tained the prize of the Academy of Sciences in Paris for a treatise on the libration of the moon, and in 1776 for another on the theory of the satellites of Jupiter. About this time he made a visit to Paris, where he became per sonally acquainted with D'Alembert, Clairaut, Condorcet and other savants. Soon after his return he received an invitation from Frederick the Great to go to Berlin, with the title of Director of the Academy. Here he lived for 20 years, and wrote his great work Mee anique analytique.' After Frederick's death (1786) the persuasion of Mirabeau and the offer of a pension induced him to settle in Paris. He was the first professor of geometry
in the Polytechnic School, and the first inscribed member of the Institute. He took no active part in the Revolution, and the law for the banishment of foreigners was not put in force against him. In 1794 he was appointed pro fessor in the newly-established Normal School (Ecole Normale Superieure) at Paris (1794), as well as in the Ecole Polytechnique. Napo leon bestowed upon him distinguished tokens of his favor, and he became member of the Senate, grand officer of the Legion of Honor and count of the empire. The most important of his works are his
analytique' (1788) ; (Theorie des fonctions analytiques' (1797) ;