CROSS, Charles Robert, physicist, born in Troy, New York, 29 March 1848. He was graduated at the Massachusetts institute of technology in 1870, and has since been connected with the physical department of that institution as student assistant in 1869-'70, instructor in 1870-'i, assistant professor in 1871-'5, and as professor in 1875-'87. In addition to holding the chair of physics, he is director of the Rogers laboratory, and is also at the head of the department of electrical engineering. The developing and superintending of this latter course, one of the first to be introduced in a College in this country, has occupied his attention for several years, and its success under his administration is his just reward. Professor Cross is a member of the Appalachian mountain club, and was its president in 1880. He was a delegate to the International congress of Alpine clubs held in Geneva in 1879, and was elected one of its vice-presidents. Besides numerous papers contributed to "Proceedings of the American Academy of Sciences and Arts." "American Journal of Otology," he has published "Course in Elementary Physics" (Boston, 1873) and "Lecture Notes on Mechanics and Optics" (1884).