LOUIS LEONCE French geologist, was born at Canon, Calvados, on Sept. 25, 1798. In 1835 he was appointed professor of geology at the Ecole des Mines, in succession to Brochant de Villiers, whose assistant he had been in the duties of the chair since 1827. He held the office of engineer-in-chief of mines in France from 1833 until 1847, when he was appointed inspector-general; and in 1861 he became vice-president of the Conseil-General des Mines and a grand officer of the Legion of Honour. He was a member of the Academy of Berlin, of the Academy of Sciences of France and of the Royal Society of London, a senator of France from 1852, and, from 1853, perpetual secretary of the Academy of Sciences. Elie de Beaumont's theory of the origin of mountain ranges was propounded in a paper read to the Academy of Sciences in 1829, and afterwards elaborated in his Notice sur le systeme des montagnes (3 vols., 1852). According to his view, all mountain ranges parallel to the same great circle of the earth are of strictly contemporaneous origin, and between the great circles a relation of symmetry exists in the form of a pentagonal reseau (see criticism by W. Hopkins in Quart. Journ. Geol. Soc., 1853) . Probably the best service Elie de Beaumont rendered to science was in the preparation with Dufrenoy (q.v.) of the great geological map of France. After his superannuation at the Ecole des Mines he continued to super intend the issue of the detailed maps almost until his death at Canon on Sept. 21, 1874. His academic lectures for 1843-44 were published in 2 vols., 1845-49, under the title Lecons de geologie pratique.
A list of his works was published in the Ann. des Mines, vol. vii. 1875, p.