Henry Augustus Rowland

Henry Augustus Rowland (1848 to 1901) was an American physicist who spent his career at Johns Hopkins University in Baltimore. Born in Honesdale, Pennsylvania, the son of a Presbyterian pastor, he graduated from Rensselaer Polytechnic Institute in 1870 and was first an assistant professor of physics there. His early papers found no outlet at home, but James Clerk Maxwell recognised their quality and had them printed in the Philosophical Magazine, and in 1876 Rowland became the first occupant of the chair of physics at Johns Hopkins. He is remembered for the high quality of the diffraction gratings he made and for the work he did with them on the solar spectrum, and he also redetermined the ohm and the mechanical equivalent of heat. He served as the first president of the American Physical Society from 1899 to 1901.