CHARLES AUGUSTIN COULOMB (1736-1806), a distinguished French natural philosopher, was born at Angoulême, June 14, 1736), and belonged to a noble family of Montpellier. He chose the profession of military engineer, spent three years, to the decided injury of his health, at Fort Bourbon, Martinique, and was employed on his return at Aix, Rochelle, and Cheibourg. He gained great distinction in 1773 by his Statical Problems Applied to Architecture, which he presented to the Academy of Sciences in 1779 ; he shared with Van Swinden the prize for improvements in the construction of compasses, and two years later he obtained the prize of the Academy by his Theory of Simple Machines, comprehending the Effects of Friction and the Stiffness of Ropes. In 1781 he was stationed permanently at Paris. There being a proposal for the construction of a system of canals in Brittany, Coulomb was sent as ioyal commissioner to the estates of that province. He expressed decided disapproval of the scheme, and his opinion caused him to be thiown into prison. He remained firm, however, and refused to give any other verdict, and at length he succeeded in convincing the estates, who showed their appreciation of his candour by making him handsome offers, and presenting him with a seconds watch, adapted for scientific experiments. Coulomb was also appointed intendant-general of waters and fountains, chevalier of St Louis, member of the legion of honour, and member of the Academy of Sciences. On the outbreak of the revolution he gave up his offices, and retired from Paris to a small estate which he possessed at Blois. He was recalled to Paris for a time in order to take part in the new determination of weights and measures, which had been decreed by the Revolutionary Government. Of the National Institute he was one of the first members ; and he was appointed inspector of public instruction in 1802. But his health was already very feeble, and four years later he died of slow fever. His fame rests chiefly on his most elaborate and important investigations in electricity and magnetism, and on his invention of the torsion balance.

Coulomb's chief works, besides those already mentioned, are— Methods of executing without Water all Kinds of Hydraulic Works; Observations cm the Daily Labour of Men ; On Heat ; Experiments on tlie Circulation of Sap ; On tlie Cohesion of Fluids, and their Resistance to Slow Motions; Theoretical and Experimental Researches on the Force of Torsion ; and several treatises on electricity and magnetism.