PEARSE, John Barnard, chemist, born in Philadelphia, Pennsylvania, 19 April, 1842. He was graduated at Yale in 1861, studied chemistry in Philadelphia for the next three years, and was in charge of the chemical division of the United States army laboratory there in 1863-'5. He spent the next two years in the School of mines in Freiberg, Saxony, and Leoben, Styria, made a specialty of iron and steel metallurgy, and worked in the German mines. He connected himself with the Pennsylvania steel company in Harrisburg, Pennsylvania, in 1868, and became its general manager in 1870. In June, 1874, he was a commissioner and secretary of the second geological survey of Pennsylvania. He has made various inventions in connection with steel manufacture, improved the design and product of the Bessemer steel plant, and was instrumental in making Bessemer pig-iron from native New Jersey and Pennsylvania ores. He has published " A Concise History of the Iron Manufacture of the American Colonies up to the Revolution, and of Pennsylvania till the Present Time " (Philadelphia, 1876).