BIOGRAPHY

When his family moved from Angoulème to Paris, young Charles Augustin attended Collège Mazarin and the Collège de France. In 1757 he became an auxiliary member of the Montpellier Science Society and wrote various articles on astronomy and mathematics. Returning to Paris, he was admitted, in 1760, to the Mézières Engineering School, where he came into contact with Bossut. He got his engineering diploma in 1761 as a First Lieutenant. From 1764-1772 he was stationed in Martinique, where he supervised the construction of Fort Bourbon. This experience formed a basis for some of his work in mechanics.

Back in France in 1773, he wrote an important memorandum on the influence of friction on certain problems of statics; though this article was neglected by contemporary engineers. The following year he started work on an article about magnetic needles, which won him the Paris Academy’s First Prize in 1777. At the request of the then Minister for War, he took part in reorganising the Military Engineers. In 1778, he published a article about the problem of efficiency in human labour.

From 1779 he dedicated himself to experimental research on friction. This resulted in his again winning the Paris Academy’s First Prize in 1781 for an article. which gave him considerable success.

Coulomb is clearly one of the important precursors of applied mechanics: he studied the effect of a machine free from friction and shock, concluding that friction is always proportional to the quantity of real effort released by the agent that produced the effect. He also studied the difference between useful work and fatigue in human and animal labour, as he searched for the optimal conditions for effective work. He also suggested a unit of measure for the "amount of action".

Coulomb’s admission to the Académie in 1781 allowed him to reside in Paris, where he got married and was able to give himself to research in Physics. Most of his innovative contributions are in the field of electricity. Between 1781 and 1806 he published 15 articles, under the aegis of the Académie or the Institut de France, which replaced it after the Revolution.

Torque, electricity and magnetism are the main subjects dealt with in these articles.

His most important paper on torque was published in 1784. He presented a balance, which worked on torque and the elasticity of wires, and which was capable of measuring tiny forces very precisely. This instrument enabled him to study electricity and magnetism in a new way. Coulomb undoubtedly had a completely different approach from other scientists in the field, even from the Frenchmen, DuFay and Nollet. In a series of seven articles presented to the Academy between 1785 and 1791, Coulomb widened the Newtonian paradigm about instantaneous action at a distance to the new fields of electricity and magnetism. Although Coulomb could prove experimentally that the inverse square law was valid, he never managed to prove it was proportional in electrical charges and the intensity of magnetic poles. In practice, he discovered in the law the denominator and not the numerator. Moreover he never defined electrical charge nor magnetic pole intensity.

His research led him to isolate two types of substance: conductors and dielectrics. He managed to show how the distribution of charge depends only on the mutual repulsion of like sign charges and the shape and position of bodies. He established that static charge is distributed solely on a conducting body’s surface, whatever its shape and material. He also showed that the theories utilising one or two electrical fluids are mathematically entirely equivalent.

In 1791, as a result of reforms made to the Académie and the Corps of Engineers, Coulomb left his post with the rank of Lieutenant General but went on working with the Committee for Standardising Weights and Measures in the Academy, until it was abolished on 8th August 1793. In December of that year he was "purged" and retired to one of his properties, La Justinière. However, her came back to Paris in 1795, where he was elected to the Institut de France as Member for Experimental Physics. In 1802, he became a General Inspector of Schools and concerned himself mainly with "lycées".

In 1806, an illness he had contracted as a young man in Martinique got worse and caused his death.