David Rittenhouse

David Rittenhouse (1732-1796) was one of America's premier eighteenth-century scientists. Born in Germantown, Pennsylvania, he was largely self-taught and demonstrated an early aptitude for science and mathematics. In the early 1750s, he set up shop making clocks and other mechanical devices and, from there, his reputation spread. He was employed as a surveyor, became known for his work in astronomy, and experimented with magnetism and electricity.

Beginning in the colonial period, Rittenhouse surveyed the Pennsylvania boundaries with Delaware, Maryland, New York, and New Jersey. In 1774 he was the city surveyor of Philadelphia and in 1784 he extended the Mason Dixon Line to the southwestern corner of Pennsylvania. During the American Revolution, Rittenhouse used his skills in military engineering for the Committee of Safety. He was a member of the Pennsylvania Assembly, the Pennsylvania Constitutional Convention of 1776, and the Board of War.

Rittenhouse was elected as a member of the American Philosophical Society in 1768 (and would serve as its president from 1791 to 1796). He led the scientific community in the observance of the transits of Venus and Mercury in 1769. Rittenhouse gained further attention when he constructed orreries — mechanical models of the solar system — for Princeton and for the University of Pennsylvania in 1770-1771. From 1779 until his death in 1796, Rittenhouse was directly affiliated with the University of Pennsylvania, serving as professor of astronomy, vice provost, and trustee.

Rittenhouse and Thomas Jefferson shared the same interest in science and the two became friends. In an exchange from 1790, Jefferson called on Rittenhouse, "in aid of your private friendship to me," to help establish a plan for uniform weights, measures, and coins.¹ Jefferson would be instrumental in creating a U.S. mint and Rittenhouse would become the first director of the mint (1792-1795). 

On the occasion of Jefferson's departure from Philadelphia in 1793, David Rittenhouse wrote:

I shall ever remember with pleasure, whilst memory continues to perform its office, that I have counted the name of Mr: Jefferson in the very short list of my friends.²

More than fifteen years earlier, Jefferson met the American-born inventor and astronomer in Philadelphia, where both were attending the Continental Congress.³ Rittenhouse was a member of the Pennsylvania Assembly and President of the American Philosophical Society. Both Jefferson and Rittenhouse were devoted to science. Jefferson displayed a print of Rittenhouse in Monticello's Parlor with his collection of American worthies.⁴

Rittenhouse's reputation as a scientist was principally linked to his clockwork-driven orrery, a model that showed the solar system. In Notes on the State of Virginia, Jefferson used Rittenhouse's achievements to counter the Abbe Raynal's contention that America "has not yet produced ... one able mathematician, one man of genius in a single art or a single science."⁵

We have supposed Mr. Rittenhouse second to no astronomer living: that in genius he must be the first, because he is self-taught. As an artist he has exhibited as great a proof of mechanical genius as the world has ever produced. He has not indeed made a world; but he has by imitation approached nearer its Maker than any man who has lived from the creation to this day.⁶

Rittenhouse and Jefferson's correspondence centered on scientific pursuits and the instruments necessary for them. Jefferson sent Rittenhouse his report on the 1778 eclipse and requested an astronomical clock for future observations.⁷ Among the instruments that Jefferson bought from Rittenhouse were a universal equatorial, made by the Englishman Jesse Ramsden, an odometer, an orrery, and a camera obscura.⁸

After Rittenhouse's death in 1796, Jefferson was elected to succeed him as president of the American Philosophical Society. In his letter of acceptance to the Society, he praised the former president: "Genius, science, modesty, purity of morals, simplicity of manners, marked him as one of nature’s best samples of the perfection she can cover under the human form."⁹