Rowland, Henry Augustus

Rowland, Henry Augustus (rō`lənd), 1848–1901, American physicist, b. Honesdale, Pa., grad. Rensselaer Polytechnic Institute, 1870. He was professor of physics at Johns Hopkins from 1875. Rowland is known especially for his invention of a dividing engine for ruling diffraction gratings on curved surfaces and for accurately determining the value of the ohm and the mechanical equivalent of heat. He also did important work in the field of electrical power.

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Rowland, Henry Augustus (1848–1901) physicist; born in Honesdale, Pa. A civil engineer, he did railroad surveys (1871), then taught at Wooster University (1871–72) and Rensselaer Polytechnic Institute (1872–75). After a year's study in Europe (1875–76), he became the first physics professor at the new Johns Hopkins University (1876–1901). Best known for his invention of the concave spectral grating (1882), he also discovered the magnetic effect of electrical convection (1876–78) and improved on James Joule's work on the mechanical equivalent of heat.