CHAUVENET, William, mathematician, born in Milford, Pennsylvania, 24 May, 1820; died in St. Paul, Minn., 13 December, 1870. After preliminary studies in Philadelphia, he was graduated at Yale in 1840. Soon after leaving College, he became assistant to Prof. Alexander died Bathe, and aided him in his meteorological observations at Girard College, Philadelphia. In 1841 he was appointed professor of mathematics in the navy, and for a few months served on the United States steamer " Mississippi," and a year later succeeded to the chair of mathematics at the naval asylum in Philadelphia. He was very active in the movement that led to the establishment of the United States naval academy at Annapolis. At first he was professor of mathematics and astronomy there, and later of astronomy, navigation, and surveying, and always the most prominent of the academic staff. In 1855 he was offered the professorship of mathematics, and in 1859 that of astronomy and natural philosophy at Yale, but both honors were declined. During the same year he was elected to the chair of mathematics in Washington University, St. Louis, No. Here he at once gained the esteem and confidence of those with whom he was associated, and in 1862 he was chosen chancellor of the university. In 1864 his health began to fail, and he spent some time in Wisconsin and Minnesota, but again resumed duties in 1865. He was obliged to resign the offices held by him in 1869, and then spent some time in travel, but without avaii. He was a member of numerous scientific societies, and in 1859 general secretary of the American association for the advancement of science, with which he had been connected since its first meeting. He was also one of the original members of the National academy of sciences, and at the time of his death its vice-president. Besides numerous contributions to the "American Journal of Science," " Proceedings of the American Association for the Advancement of Science." Gould's "Astronomical Journal," and the "Mathematical Monthly," he was the author of "Binomial Theorem and Logarithms for the Use of Midshipmen at the Naval School" (Philadelphia, 1843); "Treatise on Plane and Spherical Trigonometry" (1850); " Manual of Spherical and Practical Astronomy" (1863); and " Treatise of Elementary Geometry" (1870). See the "Memoir of William Chauvenet," with full bibliography, contained in the " Biographical Memoirs of the Academy" (Washington, 1877).--His son, Regis, chemist, born in Philadelphia, Pennsylvania, 7 October, 1842, was graduated at Washington University in 1862, and at Lawrence scientific school of Harvard in 1867, after which he settled in St. Louis, and, with Andrew A. Blair. established an analytical laboratory. In the practice of his profession he soon became distinguished, and was called to act as chemical expert to numerous corporations. From 1872 till 1875 he was chemist to the Missouri geological survey, and for some time held a similar relation to the City of St. Louis. In the year 1883 he became professor of chemistry and president of the Colorado state school of mines in Golden.