WADSWORTH, Marshman Edward, geologist, born in Livermore Falls, Maine, 6 May, 1847. He was graduated at Bowdoin in 1869, and then taught in Minnesota and Wisconsin. In 1873 he was elected professor of chemistry in the Boston dental college, and in 1874 he became instructor in mathematics and mineralogy in Harvard. He held an assistantship in lithology at the Museum of comparative zoology, Cambridge, Massachusetts, in 1877-'85, and was professor of mineralogy and geology in Colby university in 1885-'7. Professor Wadsworth was called in 1887 to the directorship of the Michigan mining-school, with the chair of mineralogy, petrography, and geology, and in 1888 he was appointed state geologist of Michigan. The degree of Ph.D. was conferred on him by Harvard in 1879 for post-graduate studies, and he is a fellow of the American association for the advancement of science, and a member of the Boston society of natural history and other scientific bodies. His bibliography embraces nearly 100 titles of papers on geology, lithology, and similar subjects, including the following books, "Geology of the Iron and Copper Districts of Lake Superior" (Cambridge, 1880); "The Azoid System and its proposed Subdivisions," with Josiah D. Whitney (1884); "Lithological Studies" (1884) ; and "Preliminary Description of the Peridotytes, Gabbros, Diabases, and Andesites of Minnesota" (St. Paul, 1887).