David Rittenhouse 1732-96, American astronomer and instrument maker, b. near Germantown, Pa., self-educated. A clockmaker by trade, he developed great skill in the making of mathematical instruments. He was called upon to determine, with his own instruments, the boundary lines of several states and also part of the boundary known as the Mason-Dixon Line . In 1769 he was asked by the American Philosophical Society to observe the transit of Venus. His contributions include the use of measured grating intervals and spider threads on the focus of the telescope. Active in public affairs, he was a member of the convention that framed Pennsylvania's constitution and was state treasurer (1777-89) and director of the U.S. mint (1792-95). After the Revolution he was an Anti-Federalist. He succeeded Benjamin Franklin as president (1791-96) of the American Philosophical Society; most of his writings appeared in its Transactions.

Bibliography: See biography by B. Hindle (1964).

David Rittenhouse (1732-1796)

Source

Astronomer, clockmaker, and president of the american philosophical society

Early Years. Benjamin Franklin’s successor as president of the American Philosophical Society was David Rittenhouse, America’s foremost scientist in the last part of the eighteenth century. Born near Germantown, Pennsylvania, in 1732, Rittenhouse showed remarkable mechanical and mathematical abilities as a child. At seventeen he built a clock shop at the family farm. Clockmaking was his principal occupation for twenty years, although he also worked as a surveyor, establishing the official boundary line between Pennsylvania and Maryland (1763) and between New York and New Jersey (1769). His success as a clockmaker led him to other kinds of mathematical instruments. As a member of the American Philosophical Society he built an observatory at his farm. Later, at his home in Philadelphia, he built another, the first permanent astronomical observatory in America. It is also believed that Rittenhouse made the first telescope in America to observe the transit of Venus (1769).

Revolutionary Patriot. During the Revolutionary War Rittenhouse was a military engineer, supervising the manufacture of weapons and ammunition. One of his more unusual ideas in collaboration with Thomas Paine was a flaming iron arrow, which they hoped to use to destroy British fortifications at Philadelphia. Rittenhouse also became more involved in public affairs as a member of the Pennsylvania Assembly and the state constitutional convention in 1776. The next year he served as the president of the Pennsylvania Council of Safety. After the war he continued his public career, serving as Pennsylvania state treasurer until 1789, and he also returned to surveying, “running the line” between Pennsylvania and New York (1786) and New York and Massachusetts (1787). Later he was appointed professor of astronomy at the University of Pennsylvania, where he made various discoveries in the fields of astronomy, optics, and magnetism. Among his many inventions was a thermometer made of two strips of different metals, as in modern bimetallic thermostats, and a collimating telescope. In 1791 Rittenhouse began a five-year tenure as president of the American Philosophical Society. Between 1792 and 1795 he also acted as first director of the U.S. Mint, where he organized the department and supervised the minting of the first U.S. coin, a silver five-cent piece.

The Orrery. Rittenhouse was most famous in his lifetime for his elaborate mechanical planetarium, called an “orrery,” that showed the movement and position of planets orbiting a sun. Originally built sometime around 1767, the mechanism was “so accurately adjusted,” he wrote, “as not to differ sensibly from the tables of Astronomy in some thousands of years.” His orrery also included “a most curious contrivance for exhibiting the appearance of a solar eclipse, at any particular place on the earth.” (One of Rittenhouse’s orreries is now at the Franklin Institute in Philadelphia, and another at Princeton University.) Jefferson was awestruck when he saw it. “He has not indeed made a world,” he wrote, “but he has by imitation approached nearer its Maker than any man who has lived from the creation to this day.” Rittenhouse died in 1796.

Source

Howard C. Rice Jr., The Rittenhouse Orrery (Princeton, N.J.: Princeton University Library, 1954).

David Rittenhouse

David Rittenhouse (1732-1796), American astronomer and instrument maker, was a noted amateur scientist who constructed the finest orrery made at that time.

David Rittenhouse was born on April 8, 1732, near Germantown, Pa., into a poor farming family. He was stimulated by some books and tools of his uncle's and evidently educated himself in mathematics and astronomy. With help and encouragement from an Episcopal clergyman, he continued to advance his mathematical knowledge. In 1763 his boundary survey for Pennsylvania was so accurate that it was later accepted by the English surveyors Charles Mason and Jeremiah Dixon.

In 1767 Rittenhouse began his masterwork, the finest and most accurate orrery of that period. This mechanical representation of the movement of the planets through the universe was used widely in teaching and demonstration in the 18th century and also served as a demonstration of the reasonableness of nature. Rittenhouse's first orrery was capable of reproducing the relations of the planets forward or backward 5,000 years and emitted music when in operation.

Rittenhouse was in demand over the next few years by colleges that wanted him to make orreries, and the Commonwealth of Pennsylvania awarded him £300 as an honor and £300 more to make an orrery "for the use of the public." The fame derived from his orrery guaranteed him support for his observations in 1769 of the transit of Venus, which was an opportunity to measure the solar parallax. Rittenhouse's observations, made in a specially constructed laboratory, with instruments of his own design, were highly accurate and were favorably considered by European scientists working on the same problem.

In 1770 Rittenhouse moved to Philadelphia, where he was able to pursue a more active scientific career. He became a member of the informal scientific circle presided over by Thomas Jefferson. With his own improved telescopes he continued to make astronomical observations and to produce scientific and surveying instruments for himself and others, while making his living as a clockmaker. There is some uncertainty as to whether he independently developed a system of calculus, but he did become mathematically sophisticated and made some contributions in this area.

During the Revolutionary War, Rittenhouse was an avid patriot, serving on councils and committees of public safety, devising harbor defenses and methods of saltpeter production for gunpowder, and substituting iron weights in pendulum clocks to get lead for bullets. His last public service was as director of the U.S. Mint from 1792 to 1795. He died of cholera on June 26, 1796. He is often cited as an example of the untutored genius springing from American soil.

Further Reading

The best biography is Brooke Hindle, David Rittenhouse (1964).Edward Ford, David Rittenhouse: Astronomer-Patriot, 1732-1796 (1946), is also useful. For general background relating to Rittenhouse and the Jeffersonian circle see Daniel J. Boorstin, The Lost World of Thomas Jefferson (1948), and Brooke Hindle, The Pursuit of Science in Revolutionary America, 1735-1789 (1956).

Additional Sources

Hindle, Brooke, David Rittenhouse, New York: Arno Press, 1980, 1964. □