Physicist; born in
Baltimore, Md., Nov. 13, 1836; left college and entered the draughtingroom of a mechanical engineer.
Later he took a laboratory course and made a specialty of chemistry.
He was appointed
Professor of Physics and Chemistry in the
University of
Maryland in 1856, and three years later accepted the similar chair in Westminster College,
Fulton, Mo., where he remained two years. In 1867-71 he was
Professor of Astronomy in Lehigh University, and from 1871 till his death
Professor of Physics in Stevens Institute of Technology,
Hoboken, N. J. In 1869 he had charge of a party sent to
Burlington,
Ia., to observe the solar eclipse of Aug. 7, for the
United States Nautical almanac.
During this eclipse he took forty-one successful photographs.
In 1871-75 he contributed a series of investigations entitled
Researches in Acoustics to the
American journal of Science.
Later these investigations led to his inventions of the topophone and the acoustic pyrometer.
He was the author of many valuable papers, including
The effect of Magnetization in changing the dimensions of iron and steel bars;
Experiments with floating magnets;
A New Spherometer;
Measures of absolute radiation;
Simultaneous contrast color;
Researches on the Rontgen Rays;
Equilibrium of forces acting in the Flotation of Disks and rings of metal, with determinations of surface Tension, and many others.
His larger works include
Lecture notes on Physics;
The earth a Great magnet;
Light; and
Sound.
He died in
Maplewood, N. J., July 13, 1897.
