Marie-Alfred Cornu, For.Mem.R.S. (1841–1902)

Abstract

ON March 6 occurs the centenary of the birth of the distinguished French physicist, Marie-Alfred Cornu, who for thirty-five years held the chair of physics at the Ecole Polytechnique and who in 1896 was elected president of the Paris Academy of Sciences. Born at Chateauneuf, near Orleans, he had a brilliant career as a student at the Ecole Polytechnique and the Ecole des Mines, and was made a professor at the former at the age of twenty-six. His investigations carried out in the next ten or fifteen years raised him to the highest rank of experimentalists. Using Fizeau's methods he re-determined the velocity of light; with Baille, in the cellar of the Ecole Polytechnique, he re-determined the density of the earth, and among his memoirs of this time were some on the theory of electrostatics in which he explained the potential theory of Gauss and Green, then little known in France. His later work included valuable researches in spectroscopy. He was admitted a member of the Paris Academy of Sciences in 1878 as successor to A. C. Becquerel, and in the same year received the Lacaze Medal, and also the Rumford Medal of the Royal Society. In his own country he served on the Bureau des Longitudes, and as president of the International Commission of Weights and Measures. He was a foreign member of the Royal Society, and an associate of the Royal Astronomical Society. As Rede Lecturer at Cambridge in 1899, he discussed “The Wave Theory of Light and Its Influence on Modern Physics”. He was not only a successful experimentalist and a leader in scientific thought, but also a great teacher. He died on April 11, 1902. Three years later the French Physical Society struck a medal in his honour.