David Rittenhouse
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David Rittenhouse (April 8, 1732 – June 26, 1796) was a renowned American astronomer, inventor, mathematician, surveyor, scientific instrument craftsman, and public official. Rittenhouse was a member of the American Philosophical Society and the first director of the United States Mint.
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[edit] Biography
Rittenhouse was born near Germantown, Philadelphia, Pennsylvania, in a small village called Paper Mill Run, located along a stream of the same name, the stream itself a tiny tributary of the Wissahickon Creek. He was self-taught and from a young age showed great ability in science and mathematics. At nineteen years old, he started a scientific instrument shop at his father's farm in Norriton, Pennsylvania. His skill with instruments, particularly clocks, led him to construct two orreries, one of which is currently in the library of the University of Pennsylvania and the other is at Peyton Hall of Princeton University. Rittenhouse was one of the first to build a telescope used in the United States.
His telescope, which utilized natural spider webbing to form the reticle, he used to observe and record part of the transit of Venus across the sun on 1769-06-03, as well as the planet's atmosphere.
In 1785, he made perhaps the first diffraction grating using 50 hairs between two finely threaded screws, with an approximate spacing of about 100 lines per inch. This was roughly the same technique that Joseph von Fraunhofer used in 1821 for his wire diffraction grating.
In 1813, Rittenhouse's nephew (and American Philosophical Society member) William Barton published a biography, Memoirs of the life of David Rittenhouse. Former President of the United States Thomas Jefferson ordered six copies directly from the author.
[edit] Notable events
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, now known simply as the University 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 He was a founder of the Democratic-Republican Societies in Philadelphia.
[edit] Rittenhouse Square
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. The University of Pennsylvania houses its Physics and Mathematics departments in the David Rittenhouse Laboratory.
[edit] Trivia
His great excitement at observing the infrequently-occurring transit of Venus (for which he had prepared for a year) resulted in his fainting during the observation. His assistants were able to carry on where he left off.
[edit] References
- Greenslade, Thomas B., "Wire Diffraction Gratings," The Physics Teacher, February 2004. Volume 42 Issue 2, pp. 76-77. [1]
[edit] External links
- Biography and portrait at the University of Pennsylvania
- History of the University of Pennsylvania Orrery
- History of the Princeton Orrery
- O'Connor, John J., and Edmund F. Robertson. "David Rittenhouse". MacTutor History of Mathematics archive.
