David Rittenhouse (61)

Elected to the American Society in 1767. Elected to the revived American Philosophical Society in 1768.

Secretary of the APS (1771-1772), curator of the APS (1772-1779), librarian of the APS (1775-1788), vice-president of the APS (1779-1783, 1787-1791), president of the APS (1791-1796)

David Rittenhouse (8 April 1732–26 June 1796) was an astronomer, instrument-maker, mathematician, and public official. He was also a prominent member of the American Philosophical Society, first elected to the American Society in 1767, and an agent of its revival following the American Revolution. Born near Germantown, Pennsylvania, he showed a precocious scientific and mechanical aptitude but lacked opportunities for formal education. Self-taught, with encouragement from his brother-in-law, APS member Thomas Barton, Rittenhouse opened a clock-making shop at age nineteen before expanding into the invention and manufacture of scientific instruments. He conducted numerous boundary surveys, including an extension of the Mason-Dixon Line, and played a pivotal role in observing the era’s most significant astronomical event: the 1769 Transit of Venus. The APS used Rittenhouse’s calculations to build three observatories; he constructed many of the instruments used therein, including the first telescope made in America; and his observations of the Transit were widely praised. In 1770, he relocated to Philadelphia, where he documented eclipses, comets, and the new planet Uranus and contributed ephemerides to dozens of almanacs. He also published extensively in the APS Transactions, solved famous mathematical equations, experimented with magnetism and electricity, and made improvements to the Franklin stove. In 1771 Rittenhouse constructed his most famous instrument: an orrery or mechanical model of the solar system in motion. His talents were in high demand during the American Revolution. As president of the Council of Safety, he oversaw the manufacture of cannons and gunpowder and surveyed positions for defensive works on the Delaware River. He was a member of the Pennsylvania Assembly, chaired the convention that produced Pennsylvania’s radical new state constitution, and served on the Board of War, the Loan Fund, and as state treasurer (1779-1789). He was also professor of astronomy at the University of Pennsylvania (1780–1781) and served on its board of trustees (1779-1796). Rittenhouse helped to organize the United States Bank and served as inaugural director of the U.S. Mint (1792-1795). Chief among his many honors was his 1795 election to the Royal Society of London. His brother Benjamin Rittenhouse, nephew Benjamin Smith Barton, brother-in-law Benjamin Jacobs, and sons-in-law Jonathan Dickinson Sergeant and Nicholas Waters were APS members. (PI, ANB, DNB, DAB)