A CENTURY ago, on June 27, 1831, the eminent French woman mathematician, Sophie Ger-main, died in Paris at the age of fifty-five years, and a few days later was buried in the Pere Lachaise cemetery. Her great women contemporaries were Mary Somerville (1780–1872) and Caroline Herschel (1750–1848), to whose names might be added, perhaps, that of Mrs. Marcet (1769–1858), whose “Conversations on Chemistry” was the means of awaking the interest of Faraday in science. Of the careers of Caroline Herschel, the devoted assistant of Sir William Herschel, and of Mrs. Somerville, whose “Mechanism of the Heavens” and “The Connexion of the Physical Sciences” gave her a world-wide reputation, everyone has heard, but Sophie Ger-main's story is little known. Yet she and Mrs. Somerville had much in common, and their minds were cast in the same mould. When Mary Somerville, amidst the duties of her London home, was finding time to study the works of Lacroix, Biot, Euler, and Laplace, Sophie Germain was corresponding with Lagrange and Gauss, investigating the motion of the sand on Chladni's vibrating plates, and writing memoirs which gained for her the respect and admiration of both mathematicians and physicists. Her place in history is that of the foremost of all French women of science.