The New International Encyclopædia/Rittenhouse, David

RIT'TENHOUSE, David (1732-96). An American astronomer and maker of astronomical instruments, born in Pennsylvania. When 13 years old, he inherited a small library containing a few works on mathematics and among them Newton's Principia. In 1751 he adopted clock-making as a profession. He soon established a reputation as an astronomer and instrument-maker of unusual ability, and in 1763 was engaged to determine the boundary line since known as Mason and Dixon's line, for which he used instruments of his own construction. He was subsequently called upon to settle the boundaries between New York, New Jersey, Pennsylvania, and several other States. Soon after he made two orreries, one for Princeton College and one for the University of Pennsylvania. Rittenhouse was appointed by the American Philosophical Society to observe the transit of Venus, June 3, 1769. After 1770 he lived in Philadelphia, and was a member of the convention that framed the first State Constitution. He also served as the first State Treasurer (1777-89) and director of the Philadelphia mint (1792-95). He was professor of astronomy in the University of Pennsylvania (1779-82), and was a member of many learned societies, including the American Academy of Arts and Sciences, the Royal Society of London, and the American Philosophical Society, of which he was president after Franklin's death (1791). Most of his scientific papers appeared in the Transactions of the American Philosophical Society. Consult the Memoir by William Barton (1813).