Named in memory of André-Marie Ampère (1775–1836), French physicist who founded the science of electromagnetism. In 1820 he formulated a law that mathematically describes the phenomenon of deflection of a magnetic needle near a current-carrying wire. A full account of his theories has been given in his Mémoire sur la théorie mathématique des phénomènes electrodynamique (1827). (M 35494) _ _.