LESLEY, J. Peter, American geolo gist: b. Philadelphia, 17 Sept. 1819; d. Milton, Mass., June 1903. He was graduated at the University of Pennsylvania in 1838, for the next three years was engaged as assistant in the first geological survey of Pennsylvania. In 1844 he was graduated at the Princeton Theo logical Seminary and licensed as a minister. Visiting Europe, he made foot-journeys through several countries and for a while studied at the University of Halle. From 1845 to 1848 he labored for the American Tract Society among people in the mountain districts of Pennsylvania and then served two years as minister of a Congregational church at Milton, Mass., re signing on account of a change in his religious views. Returning to Philadelphia, he resumed his geological researches, extending his inves tigations throughout the coal, oil and iron re gions of this country and Canada. In 1855 he became secretary of the American Iron Asso ciation; in 1858 secretary and librarian of the American Philosophical Society; and State geologist of Pennsylvania in 1874. He was also
professor of geology at the University of Penn sylvania 1872-78 and there in 1886 was ap pointed emeritus professor. In 1863 he went to Europe to examine the Bessemer iron works for the Pennsylvania Railroad Company, and in 1867 was appointed by the United States Senate a commissioner to the Paris Exposition. He was president of the American Association for the Advancement of Science in 1884. He edited many works, published numerous scien tific papers in variousjournals and reports, and also wrote 'A Manual of Coal and Its Topog raphy' (1856) ; 'The Iron Manufacturer's Guide> (1858) 'Man's Origin and Destiny from the Platform of Sciences); 'Historical Sketch of Geological Explorations in Pennsyl vania' (1876) ; and 'Paul Dreifuss, His Holi day Abroad' (1882). Consult Ames, M. L., 'Life and Letters of Peter and Susan Lesley' (2 vols., New York 1909).