AMPERE' FiN'par', ANDRE MARIE (1775 1830). A distinguished French physicist, ematician, and naturalist, born at Lyons. The death of his father under the guillotine in 1793 made a deep and melancholy impression on the. mind of the young man, and he sought solace in the study of nature and the Latin poets. In 1,801, after be had been engaged for some time as private mathematical tutor at Lyons, he be came professor of physics in the Central School of the department of Ain at Bourg. He was afterwards professor of mathematics at Lyons. He was called to Paris, where he distinguished himself as an able teacher in the Polytechnic. School. He began his career as an author by the essay ou the mathematical theory of chances, Sur la theorie mathematique du jeu (Lyons, 1802). In 1814 he was elected a member of the Academy of Sciences, and in 1824 was appointed professor of experimental physics in the College dc France. Science is largely indebted to Am pere, especially for his electrodynamic theory and his original views of the identity of electri city and magnetism, as given in his Recueil d'ob screat ions electro-dyna iqucs (Paris, 1822), and his Theorie dcs phenomenes elcct ro-d yna miqucs (Paris, 1820). Ampere was the inventor
of the astatic needle (q.v.), which made possible time modern astatic galvanometer (q.v.). He was the first to show that two parallel conductors carrying currents traveling in the same direction attract each other, while if traveling in opposite directions they repel each other. Ampere also formulated the theory that there were currents. of electricity circulating in the earth in the direc tion of its diurnal revolution which attracted the magnetic needle. The ampere (q.v.), or unit of the strength of an electrical current, is named after him. Ampere's scientific papers are largely contained in the Annales de Physique et de Chimie. A eulogy by Arago, delivered shortly after his death, which contains an account of his life, will be found translated into English in the annual report of the Smithsonian Institu tion for 1872 (Washington, 1872).