David Rittenhouse (nonfiction)

David Rittenhouse.

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

When his uncle William Rittenhouse died, Rittenhouse inherited his uncle's set of carpentry tools and instructional books. Using his uncle's tools, he began a career as an inventor. Also at a young age, Rittenhouse showed a high level of intelligence by creating a working scale model of his great-grandfather William Rittenhouse's paper mill. He built other scale models in his youth, like a working waterwheel. He was self-taught from his family's books, never attended elementary school, and showed great ability in science and mathematics. When Rittenhouse was 13 years of age, he had mastered Isaac Newton's laws of motion and gravity.

When he was 19, he started a scientific instrument shop at his father's farm in what is now Valley Forge Medical Center & Hospital, located in East Norriton Township, Pennsylvania.

Astronomers who had been studying the planet Venus chose Rittenhouse to study the transit path of Venus in 1769 and its atmosphere. Rittenhouse was the perfect person to study the mysterious planet, as he had a personal observatory on his family farm. "His telescope, which he made himself, utilized grating intervals and spider threads on the focus of the telescope." His telescope is very similar to some modern-day telescopes.

During the first part of his career he was a surveyor for Great Britain, and later served in the Pennsylvania government. His 1763–1764 survey of the Delaware-Pennsylvania border was a 12-mile circle about the Court House in New Castle, Delaware, to define the northern border of Delaware. 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. When Rittenhouse's work as a surveyor ended, he resumed his scientific interests.

In 1768 he was elected to membership in the American Philosophical Society. He served as librarian, secretary, and after Benjamin Franklin's death in 1790, he became Vice president then served as president of the society until 1796. He was elected a Fellow of the American Academy of Arts and Sciences in 1782. He was a member of the Royal Society of London, which was rare for an American.

In 1768, Rittenhouse announced plans to observe a pending transit of Venus across the Sun from several locations. The transit of Venus occurred on 3 June 1769. Rittenhouse's 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. In addition to the work involved in the preparations, he had also been ill the week before the transit. 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.

Rittenhouse used the observations to calculate the distance from Earth to the Sun to be 93-million miles. (This is the approximate average distance between Earth and the Sun.) 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.

In 1768 he was elected to membership in the American Philosophical Society. He served as librarian, secretary, and after Benjamin Franklin's death in 1790, he became Vice president then served as president of the society until 1796.

After moving to Philadelphia in 1770, Rittenhouse used both astronomical and terrestrial observations to survey canals and rivers and to establish the boundaries between many of the Mid-Atlantic States. He held the post of city surveyor of Philadelphia in 1774.

His skill with instruments, particularly clocks, led him to construct two orreries (scale models of the solar system), the first for The College of New Jersey (now known as Princeton University), the second for the College of Philadelphia (now known as the University of Pennsylvania). Rittenhouse was prevailed upon to construct the second orrery by his friend, the Reverend William Smith, the first provost of the College of Philadelphia, who was upset that Rittenhouse would deliver such a device to a college located in the rural area of New Jersey, rather than in Philadelphia, which was seeking to be one of the important centers of the 18th century enlightenment and for the study of "natural philosophy" such as astronomy. Both of these orreries still exist, with each being held by their original recipients: one in the library of the University of Pennsylvania and the other at Peyton Hall of Princeton University.

In 1775 he was made Engineer of the Committee of Safety.

From 1779 to 1782 he was Professor of Astronomy in the University of the State of Pennsylvania, now known simply as the University of Pennsylvania.

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.

In 1781 Rittenhouse became the first American to sight Uranus.

In 1784 he complete the survey of the Mason-Dixon line.

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. This was roughly the same technique that Joseph von Fraunhofer used in 1821 for his wire diffraction grating.

He was a member of the Royal Society of London -- very rare for an American.

In 1786 Rittenhouse built a new Georgian-style house on the corner of 4th and Arch streets in Philadelphia, next to an octagonal observatory he had already built. At this house, he maintained a Wednesday evening salon meeting with Benjamin Franklin, Francis Hopkinson, Pierre Eugene du Simitiere and others. Thomas Jefferson wrote that he would rather attend one of these meetings "than spend a whole week in Paris."

On April 2, 1792, the United States Mint opened its doors, but would not produce coins for almost four months. Rittenhouse believed that the design of the coin made the coin a piece of artwork. The first coins were made from flatware that was provided by Washington himself on the morning of July 30, 1792. 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.

Much of Rittenhouse’s written work was lost after his death.

In the News

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  1756: Inventor, astronomer, mathematician, clockmaker, and alleged time-traveler David Rittenhouse constructs an exceptionally accurate orrery, which he will later use to create an early form of time crystals (nonfiction).

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  Orrery, modified for use as scrying engine, unexpectedly forecasts imminent math crime wave.

Fiction cross-reference

• Gnomon algorithm
• Gnomon Chronicles

Nonfiction cross-reference

• Henry Voigt (nonfiction)

External links

• David Rittenhouse @ Wikipedia