David Rittenhouse.

David Rittenhouse (1732 - June 26, 1796) was an astronomer, mathematician, and the first director of the United States Mint. He retired in 1795 and died of cholera on June 26, 1796.

Rittenhouse was born in Paper Mill Run (now Germantown) Philadelphia. He was self-taught and from a young age showed great ability in science and mathematics. At 19 he started a scientific instrument shop on his father's farm in Norriton. He was a skilled clock-mender. This led him to construct two orreries, one of which is in the library of the University of Pennsylvania and one which is Peyton Hall at Princeton University. Rittenhouse invented the diffraction grading and was one of the first to build a telescope used in the United States.

Other notable events in Rittenhouse's life include:

• 1763-1764 Worked on the boundary survey of Pennsylvania and Maryland
• 1767 Granted an honorary master's degree from the College of Philadelphia (later University of Pennsylvania)
• 1768 Discovered the atmosphere of Venus (independent of the earlier discovery by Mikhail Lomonosov in 1761)
• 1769 Observed the transit of Venus
• 1770 Came to Philadelphia
• 1775 Engineer of the Committee of Safety
• 1779-1782 Professor of Astronomy in the University of the State of Pennsylvania
  • 1780-1782 Vice-Provost
  • 1782-1796 Trustee
• 1791-1796 President of the American Philosophical Society
• 1792-1795 First Director of the United States Mint
• 1793 Discovered a planet

In 1825 one of William Penn's original squares in Philadelphia, called 'Southwest Square' (being in the southwest quadrant of the original city plan) was renamed Rittenhouse Square in David Rittenhouse's honor.

External links

• History of the University of Pennsylvania Orrery
• History of the Princeton Orrery