2.10 Biography: David Rittenhouse

Whitney Webb

Mr. Percival

Astronomy Honors

10 Oct. 2007

David Rittenhouse

As the leading astronomer of Revolutionary America, David Rittenhouse indelibly left his mark on the astronomy of America, helping to lay the science’s foundations in the new nation. The son of Matthias Rittenhouse, a farmer, and his wife Elizabeth, David Rittenhouse was born in 1732 in Germantown, Pennsylvania. Due to his humble beginnings, Rittenhouse was self-taught and from a very early age showed a remarkable aptitude for both mathematics and science, mastering a translation of Newton’s Principia as a teenager. When he was nineteen years old, Rittenhouse opened a scientific instrument shop at his father’s farm where he became celebrated for his skill with instruments, especially clocks. Over the next thirty to forty years, Rittenhouse made several important and well known instruments. The most significant of these instruments are the two orreries, or astronomical modeling devices, which he gave to Princeton University and the University of Pennsylvania, then the Colleges of New Jersey and Philadelphia respectively.

In 1766, Rittenhouse married Eleanor Coulston, who bore him two children soon after, but tragically died during childbirth only four years after their marriage. Rittenhouse moved to Philadelphia following her death and used his prowess in astronomical and terrestrial observation to survey canals and rivers as well as to establish boundaries between several of the Mid-Atlantic States. He soon became the official city surveyor of Philadelphia in 1774. His scientific thinking and experimentation led to gain an impressive reputation in America and also in Europe as a result of his detailed observations and important astronomical works. The most noteworthy work on Astronomy puts forth a solution of how to find the place of a planet on its orbit, which was published in 1799. Rittenhouse was voted into the American Philosophical Society in 1768, where plans were made to observe the transit of Venus across the Sun. For this purpose, Rittenhouse constructed an observatory on his father’ farm in Norriton where he constructed one of America’s very first telescopes. This telescope used spider-silk to form the reticle. In 1769, Rittenhouse pioneered the observation of the transit of Venus which won him international acclaim. During his observations, Rittenhouse was the first to discover the presence of an atmosphere on Venus, which was also discovered by a Russian astronomer independently and at different times. In 1772, Rittenhouse re-married, this time to Hannah Jacobs. She bore him a child who died in early infancy.

During the Revolutionary War, Rittenhouse was a member of the Pennsylvania General Assembly and the Pennsylvania Constitutional Convention. He also served on the Board of War and was state treasurer from 1779 to 1787. In 1779, he was appointed to the Board of Trustees of the University of Pennsylvania, which had granted him an honorary Master’s degree in 1767. Rittenhouse also taught Astronomy at the University from 1779 to 1782. After the war, Rittenhouse continued surveying Pennsylvania’s borders and completed the unfinished survey of the Mason-Dixon Line in 1784. A year later, Rittenhouse made the first diffraction grating using fifty hairs between two finely threaded screws with an average spacing of one hundred lines per inch. During this time, Rittenhouse also dealt with several mathematical concepts and published his first mathematical paper in 1792, an attempt to determine the period of a pendulum. His subsequent mathematical papers, although nothing ground-breaking, had great significance as Rittenhouse was the only important American mathematician of the eighteenth century besides Benjamin Franklin. Rittenhouse studied electricity and magnetism to some extent. From 1791 to 1796, Rittenhouse served as the President of the American Philosophical Society and from 1792 to 1795 was the first director of the U.S. Mint. At the end of 1795, he was named a fellow of the Royal Society of London. Rittenhouse suffered from poor health for much of his life and died peacefully at his home in 1796. In 1813, Rittenhouse’s nephew who was also a member of the American Philosophical Society published a biography on Rittenhouse’s life. Former President Thomas Jefferson ordered six copies directly from the author.

Works Cited

"David Rittenhouse." Penn in the 18th Century. University of Pennsylvania. 10 Jan. 2008 [http://www.archives.upenn.edu/histy/features/1700s/people/rittenhouse_ david.html].

Dodge, Russ. "David Rittenhouse." Find a Grave. 21 June 2001. 10 Jan. 2008 [http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=22735].

Leitch, Alexander. "The Rittenhouse Orrery." A Princeton Companion. Princeton University. 10 Jan. 2008 [http://etcweb.princeton.edu/CampusWWW/Companion/ rittenhouse_orrery.html].

O’Connor, J. J., and E. F. Robertson. "David Rittenhouse." 12 Aug. 2005. Dept. of Math and Statistics, St. Andrews. 10 Jan. 2008 [http://www-history.mcs.st-andrews.ac.uk/ Biographies/Rittenhouse.html].

Rittenhouse, David. "To Determine the True Place of a Planet, in an Elliptical Orbit, Directly From the Mean Anomaly, by Converging Series." Transactions of the American Philosophical Society os 4 (1799): 21-26. 10 Jan. 2008 [http://links.jstor.org/sici?sici=0065-9746 (1799)1%3A4%3 C21%3ATDTTPO%3E 2.0.CO%3B2-Z].