David Rittenhouse may not be a household name like Thomas Jefferson and Benjamin Franklin, yet as a scientific and political figure, not only was he admired by these great men, he also had a hand in shaping the early United States as well as the scientific knowledge of the day.
Rittenhouse was born on April 8, 1732 near Philadelphia, Pennsylvania. Using books found at home and a set of tools he inherited, he taught himself science and math, as well as how to build clocks and scientific instruments.
Early in his career he built two orreries (models of the solar system) that showed solar and lunar eclipses and other astronomical phenomena for a period of 5,000 years, going either forward or backward in time. The first went to Princeton University (then the College of New Jersey), the second to the University of Pennsylvania.
He was one of the first in the U.S. to build a telescope, which he used to observe and record the transit of Venus across the Sun in 1769. In 1781 he became the first American to view the planet Uranus. He built his own observatory on his father's farm outside of Philadelphia.
In his early years Rittenhouse took up surveying, helping to define the borders of New Jersey, New York, Maryland and Pennsylvania. In 1784 he and a crew completed the survey of the Mason-Dixon Line to the southwest corner of Pennsylvania.
He was a member of the American Astronomical Society and the American Philosophical Society, becoming President of the latter after Benjamin Franklin's death. He was also a member of the Royal Society of London, a rare honor for an American.
Rittenhouse simultaneously had his hands in both science and politics. In 1775 he delivered a lecture to the American Philosophical Society on the history of astronomy. In this lecture, he linked nature to the rights of man, including liberty and the right to self-govern, and he also denounced slavery. The Society ordered his lecture to be printed and distributed at the Second Continental Congress in 1776.
From 1779—1782, Rittenhouse taught as a Professor of Astronomy at the University of Pennsylvania, also serving as Vice Provost and Trustee. During this time, he also served as the Treasurer of Pennsylvania, a position he held from 1779 to 1787. He was appointed the first director of the U.S. Mint, a position he held from1792-1795.
Rittenhouse was listed by Thomas Jefferson as an example of New World genius in Jefferson's book Notes on the State of Virginia, in company with Benjamin Franklin and George Washington. During his lifetime Rittenhouse published several works on astronomy, magnetism and mathematics.
Rittenhouse died in 1796. His two orreries are still on display today: one is in the library of the University of Pennsylvania and the other is in Peyton Hall at Princeton.