David Rittenhouse (April 8, 1732 – June 26, 1796) was an American astronomer, inventor, clockmaker, mathematician, surveyor, scientific instrument craftsman, and public official.

Rittenhouse was born on April 8, 1732,[2] in Rittenhousetown, in Germantown, along Paper Mill Run, a small tributary of the Wissahickon Creek.

At a young age, David showed a high level of intelligence by creating a working scale model of his great-grandfather William Rittenhouse's paper mill.

[2][4][5] At the age of 19, he started a scientific instrument shop at his father's farm in what is now Valley Forge Medical Center and Hospital, located in East Norriton Township, Pennsylvania.

At this house, he maintained a Wednesday evening salon meeting with Benjamin Franklin, Francis Hopkinson, Pierre Eugene du Simitiere and others.

Rittenhouse's work was so precise and well-documented that it was incorporated without modification into Charles Mason and Jeremiah Dixon's survey of the Pennsylvania–Maryland border.

In 1768, the same year that he became a member of the American Philosophical Society, Rittenhouse announced plans to observe a pending transit of Venus across the Sun from several locations.

Lying on his back beneath the telescope, trained at the afternoon sun, he regained consciousness after a few minutes and continued his observations.

His account of the transit, published in the American Philosophical Society's Transactions, does not mention his fainting, though it is otherwise meticulous in its record and documented.

The published report of the transit was hailed by European scientists, and Rittenhouse would correspond with famous contemporary astronomers, such as Jérôme Lalande and Franz Xaver von Zach.

David Rittenhouse was treasurer of Pennsylvania from 1777 to 1789, and with these skills and the help of George Washington, he became the first director of the United States Mint.

The coins were hand-struck by Rittenhouse, to test the new equipment, and were given to Washington as a token of appreciation for his contributions to making the United States Mint a reality.

[13] In 1785 Rittenhouse made perhaps the first diffraction grating using 50 hairs between two finely threaded screws, with an approximate spacing of about 100 lines per inch.

Other notable events in Rittenhouse's life include: In his book Notes on the State of Virginia, Thomas Jefferson listed Rittenhouse alongside Benjamin Franklin and George Washington as examples of New World genius when disputing French naturalist Georges-Louis Leclerc, Comte de Buffon's claim that the environment and climate of North America had stunted the intellect of peoples living there both native and European.

[21] A fictionalized version of David Rittenhouse, portrayed by Armin Shimerman, appeared in the tenth episode of the first season of the NBC television series Timeless (2016–2018).