David Rittenhouse (1732-1796) was one of America's premier eighteenth-century scientists. Born in Germantown, Pennsylvania, he was largely self-taught and demonstrated an early aptitude for science and mathematics. In the early 1750s, he set up shop making clocks and other mechanical devices and, from there, his reputation spread. He was employed as a surveyor, became known for his work in astronomy, and experimented with magnetism and electricity.
Beginning in the colonial period, Rittenhouse surveyed the Pennsylvania boundaries with Delaware, Maryland, New York, and New Jersey. In 1774 he was the city surveyor of Philadelphia and in 1784 he extended the Mason Dixon Line to the southwestern corner of Pennsylvania. During the American Revolution, Rittenhouse used his skills in military engineering for the Committee of Safety. He was a member of the Pennsylvania Assembly, the Pennsylvania Constitutional Convention of 1776, and the Board of War.
Rittenhouse was elected as a member of the American Philosophical Society in 1768 (and would serve as its president from 1791 to 1796). He led the scientific community in the observance of the transits of Venus and Mercury in 1769. Rittenhouse gained further attention when he constructed orreries — mechanical models of the solar system — for Princeton and for the University of Pennsylvania in 1770-1771. From 1779 until his death in 1796, Rittenhouse was directly affiliated with the University of Pennsylvania, serving as professor of astronomy, vice provost, and trustee.
Rittenhouse and Thomas Jefferson shared the same interest in science and the two became friends. In an exchange from 1790, Jefferson called on Rittenhouse, "in aid of your private friendship to me," to help establish a plan for uniform weights, measures, and coins.1 Jefferson would be instrumental in creating a U.S. mint and Rittenhouse would become the first director of the mint (1792-1795). Over the years, Jefferson purchased instruments such as an orrery and an odometer from Rittenhouse.
Primary Source References
1781. (Notes on the State of Virginia). "We have supposed Mr. Rittenhouse second to no astronomer living: that in genius he must be the first, because he is self-taught. As an artist he has exhibited as great a proof of mechanical genius as the world has ever produced."2
Jefferson-Rittenhouse Correspondence. Transcriptions available at Founders Online.