PLATT, Franklin, geologist, born in Philadelphia, Pennsylvania, 19 November, 1844. He was educated at the University of Pennsylvania, but left in 1862, before graduation, and in 1863 served in the 32d Pennsylvania Gray reserve regiment. In 1864 he was appointed to the United States coast survey, and assigned to surveying work with the North Atlantic squadron during that year. He then was appointed on the staff of General Orlando M. Poe, chief engineer of the military division of the Mississippi, and was engaged in this duty until the surrender of General Joseph E. Johnston's army in April, 1865. Subsequently. in July, 1874, he was appointed assistant geologist of Pennsylvania, which post he held until Nay, 1881, after which he became president of the Rochester and Pittsburg coal and iron company. Mr. Platt is a member of scientific societies, to whose transactions he has contributed frequent papers on geology and kindred subjects. He prepared nine volumes of the reports of the geological survey of Pennsylvania. Those that were his exclusive work are " On Clearfield and Jefferson Counties" (Harrisburg, 187,5); "Coke Manufacture" (1876) ; "On Blair County "(1880) ; and" The Causes, Kinds, and Amount of Waste in Mining Anthracite " (1881).