American geologist: b. Windsor, Conn., 22 Dec. 1822; d. New Haven, 7 Dec. 1892.
His early life was passed chiefly in the Western Reserve, Ohio, and he was graduated at the Western Reserve College in 1846 and at the Cleveland Medical School in 1848. From 1851 to 1855 he practised medicine in Cleveland. He was assistant surgeon and geologist to the government expedition that explored the country between San Francisco and the Columbia River; also accompanied Lieutenant Ives in his exploration of the Colorado River, and the expedition under Captain Macomb in its exploration from the Sania Fé to the junction of the Grand and Green rivers.
His reports upon the scientific results of these expeditions brought him great credit in the scientific world. At the beginning of the Civil War he became attached to the Sanitary Commission, and later secretary of its Western department. He was afterward connected with the Smithsonian Institution, and with the Columbian (now George Washington) University, Washington, and in 1866 was appointed professor of geology and palæontology at the Columbia College School of Mines, which post he retained till his death.
Besides many special reports and parts of general reports, his writings include: ‘The Rock Oils of Ohio’ (1859); ‘Catalogue of the Plants of Ohio’ (1860); ‘Iron Resources of the United States’ (1874); ‘The Structure and Relations of Dinichthys’ (1875); ‘Palæozoic Fishes of North America’ (1889); ‘Later Extinct Floras’ (1898); etc. He was especially conversant with the palæontology of the Carboniferous Era in America, and particularly with extinct fishes; and as a teacher he had great popularity and influence. He was among the early members of the National Academy of Sciences. The most interesting portions of the ‘Report on the Colorado River of the West, Explored in 1857-58’ (Washington 1861) were written by him and relate to the geology, physiography and Indians of that region.
Encyclopedia Americana, 1920