A celebrated French mathematician, born at Beaumont-en-Auge, Normandy; the son of a farmer; after teaching in his native place went to Paris, where he became professor in the Royal Military School; becoming member of the Académie des Sciences in 1785, he attained a position among mathematicians and astronomers almost equal to Newton's; his "Three Laws" demonstrated the stability of the solar system; he published many treatises on lunar and planetary problems, electricity, magnetism, and a Nebula-hypothesis; his "Mécanique Céleste" is unrivalled in that class of work; surviving the Revolution he became implicated in politics without success or credit; he received his marquisate from Louis XVIII. in 1817, when he became President of the French Academy; "Lagrange (q. v .) has proved that on Newton's theory of gravitation the planetary system would endure for ever; Laplace, still more cunningly, even guessed that it could not have been made on any other scheme" (1749-1827).