Binet, JACQUES-PHILIPPE-MARIE, French mathematician and astronomer, b. at Rennes, in Brittany, February 2, 1786; d. in Paris, May 12, 1856. After two years of study at the Ecole Polytechnique, he was appointed, in 1806, student-engineer in the government department of bridges and roads. Teaching, however, soon attracted him. For some time, he was professor of mathematics at the Lycee Napoleon. He then became, at the Ecole Polytechnique, successively, repetiteur of descriptive geometry, examiner, professor of mechanics, and inspecteur-general of studies. In 1823, he succeeded Delambre in the chair of astronomy at the College de France. Because of his intense devotion to the cause of Charles X, the Government of July, 1830, removed him from the Ecole Polytechnique, although it allowed him to retain his professorship at the College de France. He had been made a member of the Societe Philomathique, in 1812. In 1843, he was elected to succeed Lacroix in the Academie des Sciences, of which he was a most active member and had become president at the time of his death. Binet was a man of modest manner and a devout Catholic.
To mathematics, mechanics, and astronomy, Binet contributed many valuable articles on a great variety of topics. These articles were published in the “Bulletins de la Societe philomathique”, in the “Comptes rendus de l’Academie des sciences”, in the “Journal des Mathematiques” (Liouville) and, chiefly, in the “Journal de l’Ecole polytechnique.” He also rewrote, to a large extent, the second volume of the “Mecanique analytique” of Lagrange for the edition of 1816. A few of his principal articles are: “Memoire sur la theorie des axes conjugues et des moments d’inertie des corps”, enunciating the principle sometimes called Binet’s Theorem (Journ. de l’Ec. pol., IX, 1813; “Memoire sur la determination analytique d’une sphere tangente a quatre autres spheres” (ibid., X, 1815); “Memoire sur la determination des orbites des planetes et des cometes” (ibid., XIII, 1831); “Me-moire sur les integrales definies euleriennes et sur leur applicationla theorie des suites ainsi qu’a revaluation des fonctions des grands nombres” (ibid., XVI, 1839; Paris, 1840); “Memoire sur les inegalites seculaires du mouvement des planetes” (Journal de Math., V, 1840); “Memoire sur la formation d’une classe tres etendue d’equations reciproques renfermant un nombre quelconque de variables” (Paris, 1843).
PAUL H. LINEHAN