Hen'ry, Joseph

a celebrated physicist, was born in Albany, N. Y., 1797, received a common education and commenced life as a watchmaker in his native city. In 1826 he was profe or of mathematics in the Albany Academy, and in 1827 began making experiments in electricity. He invented the first machine moved by the agency of electro-magnetism, and was the first to demonstrate those principles by which intelligence is conveyed between distant points through the agency of the electric telegraph. In 1832 he was appointed profe or of Natural Philosophy in the College of New Jersey, at Princeton, and in 1837 visited England, where he imparted his knowledge to Profe or Wheat stone. In 1846 he was elected first secretary of the Smithsonian Institution at Washington, a post he held until his death, May 13, 1878. H. published, in 1839, Contributions to Electricity and Magnetism, and also contributed several scientific papers to The American Philosophical Society, to Silliman's Journal, and to the Journal of the Franklin Institute .