Joseph Henry

Joseph Henry 1797-1878, American physicist, b. Albany, N.Y., educated at Albany Academy. He taught (1826-32) mathematics and natural philosophy at Albany Academy and was professor of natural philosophy (1832-46) at Princeton (then the College of New Jersey). From 1846 he served as the first secretary and director of the newly founded Smithsonian Institution; he introduced and developed many of its activities and established its general policies. Before assuming his responsibilities at the Smithsonian, he had made notable contributions to the physical sciences, especially in electromagnetism. Henry improved the electromagnet, increasing its strength and fitting it for practical use. He invented and operated the first electromagnetic telegraph, which formed the basis for the commercial telegraphic system. He discovered self-inductance, and the unit of inductance is often called the henry in his honor. Independently of Michael Faraday , he discovered the principle of the induced current, basic to the dynamo, transformer, and many other devices. Henry invented a small electromagnetic motor, and extended the work on induced currents to show that an induced current can be used to induce another current in a nearby circuit and that resulting currents in turn can induce others. His numerous other contributions include the institution of the weather report system.

Bibliography: See his Papers, ed. by N. Reingold et al. (15 vol., 1972-); biographies by S. R. Riedman (1961) and A. E. Moyer (1997).

Henry, Joseph (1797–1878), physicist and first director of the Smithsonian Institution.Born in Albany, New York, Joseph Henry attended the Albany Academy between 1818 and 1822. He taught physics and mathematics at the Albany Academy (1826–1832) and physics at the College of New Jersey, now Princeton University (1832–1846), before being elected secretary (director) of the Smithsonian in 1846.

Henry was the first American since Benjamin Franklin to gain an international reputation in experimental physics, especially electromagnetic induction. His pioneering work on the nature of electricity, magnetism, and the interaction between the two was valued both for its own sake and because it demonstrated how understanding nature could lead to technological advancement. His research proved essential for the development of the telegraph. Among his other discoveries were the concept of the transformer and the oscillatory nature of the discharge of a capacitor. In recognition of his discoveries in electromagnetic induction, the unit of inductance, the “henry,” was named after him.

As director of the Smithsonian, he set aside his personal research program to become an administrator and spokesperson for the importance of basic scientific research. At the Smithsonian, Henry established a program of direct support of research, scholarly publication, and international exchange. He supported research not only in the natural sciences, but also in anthropology and ethnography.

Often compared to Franklin, Henry became a larger‐than‐life symbol of American accomplishment in science and the acclaimed father of modern electrical technology, including the electric motor and the telephone. The premier American physicist of the mid–nineteenth century and an able institution builder, Henry, as a leader of American science, sought to establish rigorous standards for the scientific community and to increase the level of public support for research. His early accomplishments in the laboratory and his important discoveries accorded him the prestige and respect necessary for his success as a science administrator and spokesperson.
See also American Association for the Advancement of Science; Coast and Geodetic Survey, U.S.; Electrical Industry; Mathematics and Statistics; Physical Sciences; Science: Revolutionary War to World War I.

Bibliography

Robert V. Bruce , The Launching of Modern American Science 1846–1876, 1987.
Albert E. Moyer , Joseph Henry: The Rise of an American Scientist, 1997.

Marc Rothenberg

Henry, Joseph (1797–1878), New York physicist whose electromagnetic experiments and discoveries, independent of and evidently slightly prior to those of Faraday, were the foundation of the development of the telegraph, telephone, radio, and electric motor. He was a professor at the College of New Jersey (1832–46), and director of the Smithsonian Institution (1846–78), which published his Scientific Writings (1886).