The Papers of Joseph Henry

Joseph Henry

JH as youth 1829

From a modest background, Joseph Henry (1797-1878) forged an identity as the most prominent scientist of mid-nineteenth-century America. He was born in Albany, New York, to Ann Alexander and William Henry, a teamster, and spent much of his childhood living with relatives in the nearby village of Galway. His father suffered from alcoholism and died when Henry was thirteen.
Henry described himself as "principally self educated." He devoured books at the village library, and a popular exposition of science seems to have inspired his interest in the field. He attended the Albany Academy in his twenties (between 1819 and 1822) and became a professor of mathematics and natural philosophy (physics) at the academy in 1826.
Despite a heavy teaching load, Henry managed to pursue original research on electromagnetic phenomena that brought him to the attention of the scientific world. He discovered (independently of Michael Faraday of England) mutual electromagnetic induction--the production of an electric current from a magnetic field--and electro-magnetic self-induction. In the course of his experiments during the early 1830s, he constructed the most powerful electromagnets of his day, a prototype telegraph, and the first electric motor. His electromagnetic telegraph proved it was possible to transmit an electric current with sufficient force to perform useful mechanical work at a distance.
In 1832 Henry was appointed professor of natural philosophy at the College of New Jersey (now Princeton University). While continuing his work in electromagnetism, Henry also investigated auroras, lightning, sunspots, ultraviolet light, and molecular cohesion. He often gave classroom demonstrations of his experiments, and surviving student accounts portray him as a popular, innovative, and even awe-inspiring teacher.
In 1846 Henry was elected secretary of the newly established Smithsonian Institution, a post he retained until his death. From his base at the Smithsonian, he aided scientific expeditions to the American West, the arctic, and the tropics. Through a publications program, a grants program, and an international exchange program at the Smithsonian, he fostered research in a variety of fields, including anthropology, archaeology, astronomy, botany, geophysics, and zoology. He also set up a national network of volunteer meteorological observers, which eventually evolved into a national weather service.
In addition to directing the Smithsonian for nearly thirty-two years, Henry served as president of the American Association for the Advancement of Science (1849-1850), an original member of the United States Light-House Board (1852-1878; chairman from 1871), and president of the National Academy of Sciences (1868-1878).
For more detailed biographical information, including articles on Henry's role in the development of the telegraph, the electric motor, and the telephone, please consult the home page of the Joseph Henry Papers Project at