David Rittenhouse
Born	April 8, 1732(1732-04-08) Paper Mill Run, Pennsylvania
Died	June 26, 1796 (aged 64)
Occupation	Astronomer Inventor Mathematician

Home of David Rittenhouse as it appeared circa 1919

David Rittenhouse (April 8, 1732  – June 26, 1796) was a renowned American astronomer, inventor, clockmaker, mathematician, surveyor, scientific instrument craftsman, and public official. Rittenhouse was a member of the American Philosophical Society and the first director of the United States Mint.

[edit] Biography

Rittenhouse was born near Germantown, Philadelphia, Pennsylvania, in a small village called RittenhouseTown, located along a stream called Paper Mill Run, the stream itself a tiny tributary of the Wissahickon Creek. When his uncle, a carpenter in Philadelphia, died at a young age, he left young Rittenhouse a set of tools and instructional books. Rittenhouse used these tools and began a career as an inventor. At a young age, Rittenhouse showed a high level of intelligence by creating a working scale model of his grandfather's paper mill. He was self-taught and from a young age showed great ability in science and mathematics. At nineteen years old, he started a scientific instrument shop at his father's farm in West Norriton Township, Pennsylvania. His skill with instruments, particularly clocks, led him to construct two orreries, one of which is currently in the library of the University of Pennsylvania and the other is at Peyton Hall of Princeton University.

Rittenhouse was one of the first to build a telescope used in the United States. His telescope, which utilized natural spider silk to form the reticle, was used to observe and record part of the transit of Venus across the sun on June 3, 1769, as well as the planet's atmosphere.

In 1781, Rittenhouse became the first American to sight Uranus.^[1]

In 1784, David Rittenhouse and surveyor Andrew Ellicott and their crew completed the unfinished survey of the Mason Dixon line to the southwest corner of Pennsylvania, five degrees of longitude from the Delaware River.

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.

In 1813, Rittenhouse's nephew (and American Philosophical Society member) William Barton published a biography, Memoirs of the life of David Rittenhouse.^[2] Former President of the United States Thomas Jefferson ordered six copies directly from the author.

[edit] Clubs and Societies

After Galileo saw the first sign of Earth's neighbor, Venus, in 1610, astronomers who had been studying the planet, chose Rittenhouse as the person to study the transit path of Venus 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. Rittenhouse served on the American Astronomical Society, and this was another factor in being chosen to study Venus . Throughout his life, he had the honour to serve in many different clubs, committees, and much more.

In 1768, Rittenhouse was elected to membership in the American Philosophical Society. He served as a librarian, became secretary, and after Benjamin Franklin's death, he became Vice President.^[3] Following the death of Franklin in 1790, Rittenhouse served as President of the American Philosophical Society until 1796.^[4][5]

Another one of his interests was the Royal Society of London; this was very rare to see a foreign member of this exclusive society.

In 1786, Rittenhouse built a new Georgian style house on the corner of 4th and Arch street 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."^[6]

[edit] Family

David Rittenhouse had two wives. He married Eleanor Coulston February 20, 1766 and they had two daughters: Elizabeth (born 1767) and Ester (born 1769). David's first wife Eleanor died February 23, 1771 at age 35 from complications during the birth of their third baby, who died at birth. David married his second wife Hannah Jacobs December 31, 1772. They had an unnamed baby, who died at birth in late 1773. Hannah outlived David by more than three years, dying in late 1799. David's grandson (son of Ester) was named David Rittenhouse Waters.^[7]

[edit] Notable contributions to the United States

David Rittenhouse made many breakthroughs during his life, which were great contributions to the United States. During the first part of his career, he was a surveyor for Great Britain, but 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. Later Rittenhouse would help establish the boundaries of several other states and commonwealths both before and after Independence, including the boundaries between New Jersey, New York, and Pennsylvania. In 1763, Mason and Dixon began a survey of the Pennsylvania-Maryland border, but this work was interrupted in 1767. In 1784 Rittenhouse and Andrew Ellicott completed this survey of the Mason-Dixon line to the southwest corner of Pennsylvania. When Rittenhouse's work as a surveyor ended, he resumed his scientific interests.

When Rittenhousee was thirteen years of age, he had mastered Isaac Newton's Laws of Motion and Gravity. As a young boy he loved to build scale models, such as a working waterwheel and a paper mill. Rittenhouse never went to elementary school and was completely self-educated from family books. With his love of tools and his amazing ability to create things he crafted two orreries for Rutgers University in New Jersey. In return for the gift, the college gave him a scholarship to attend the college enabling him to obtain a degree in philosophy. At the age of twenty-eight, he published his first mathematical paper, one of many papers published throughout his life.

[edit] Transit of Venus

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. The American Philosophical Society persuaded the legislature to grant £100 towards the purchase of new telescopes, and members volunteered to man half of the twenty-two telescope stations when the event arrived.^[8][1]

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. Rittenhouse used the observations to calculate the distance from Earth to the Sun to be 93 million miles.^[1] (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.^[1]

[edit] Orrery

In 1770, Rittenhouse completed an advanced orrery. In recognition of the achievement, the College of New Jersey granted Rittenhouse an honorary degree.^[9] The college then acquired ownership of the orrery, and Rittenhouse made a new, even more advanced model to remain in Philadelphia. The State of Pennsylvania paid Rittenhouse £300 as a tribute for his achievement.^[10]

Rittenhouse was admired by many colonial Americans and scientists, including Dr. Benjamin Franklin, Thomas Jefferson,^[10] and John Adams.^[9] On February 24, 1775, Rittenhouse delivered a lecture on the history of astronomy to the American Philosophical Society, in which he linked the structure of nature to the rights of man, liberty, and self-government.^[10][11] Rittenhouse also used the occasion to decry slavery.^[12] So impressed were those in attendance that the American Philosophical Society commissioned the speech to be printed and distributed to delegates of the Second Continental Congress when they arrived in 1776.^[12][13]

[edit] United States Mint

The 1783 Nova Constellatio coin was first minted in Philadelphia. David Rittenhouse was consulted on the design.^[12]

David Rittenhouse was treasurer of Pennsylvania from 1777-1789, and with these skills and the help of George Washington, he became the first director of the United States Mint.^[14] 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 where made from flatware that was provided by Washington himself on the morning of July 30, 1792. The coins where 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. The coin design had not been approved by Congress. Coin production on a large scale did not begin until 1793. Rittenhouse resigned from the Mint on June 30, 1795, due to poor health. In 1871, the Congress approved a commemorative coin in his honor.

[edit] Notable events

Grave of David Rittenhouse at Laurel Hill Cemetery in Philadelphia, Pennsylvania.

Other notable events in Rittenhouse's life include:

• 1763-1764 Worked on the boundary survey of Pennsylvania and Maryland
• 1767 Granted an honorary master's degree from the College of Philadelphia (later University of Pennsylvania)
• 1768 Discovered the atmosphere of Venus
• 1769 Observed the transit of Venus
• 1770 Came to Philadelphia
• 1775 Engineer of the Committee of Safety
• 1779-1782 Professor of Astronomy in the University of the State of Pennsylvania, now known simply as the University of Pennsylvania
  • 1780-1782 Vice-Provost
  • 1782-1796 Trustee
• 1779-1787 Treasurer of Pennsylvania
• 1784 Completed the survey of the Mason-Dixon line
• 1791-1796 President of the American Philosophical Society
• 1792-1795 First Director of the United States Mint
• 1793 He was a founder of the Democratic-Republican Societies in Philadelphia.

[edit] Tributes to David Rittenhouse

• Rittenhouse Crater is a lunar crater named for David Rittenhouse.

The blue field of stars in the American flag may be a tribute to the work of David Rittenhouse

• In 1825, one of William Penn's original squares in Philadelphia, called 'Southwest Square' (being in the southwest quadrant of the original city plan) was renamed Rittenhouse Square in David Rittenhouse's honor.

• To the west of Rittenhouse Square, on Walnut Street, the University of Pennsylvania houses its Physics and Mathematics departments in the David Rittenhouse Laboratory.

• One admirer and colleague of Rittenhouse, Francis Hopkinson, was on the Navy Board that wrote the Flag Act of 1777, which defined the Flag of the United States of America and explained the blue field of stars as a representation of "a new constellation." This is thought by some to be a direct tribute to Rittenhouse. Biographer Brooke Hindle wrote, "Few admired Rittenhouse more unrestrainedly than Francis Hopkinson."^[6]

[edit] References

• Greenslade, Thomas B., "Wire Diffraction Gratings," The Physics Teacher, February 2004. Volume 42 Issue 2, pp. 76–77. [1]

• Keim, Kevin; Keim, Peter (2007). A Grand Old Flag. A History of the United States through Its Flags. New York, New York: Dorling Kindersley Ltd. ISBN 978-0-7566-8247-5. 

• Purvis, Thomas L. (1995). Revolutionary America, 1763-1800. New York: Facts On File, Inc. ISBN 0-8160-2528-2. 

[edit] External links

Wikiquote has a collection of quotations related to: David Rittenhouse

• Historic RittenhouseTown, Birthplace of N. American Paper & David Rittenhouse
• Biography and portrait at the University of Pennsylvania
• History of the University of Pennsylvania Orrery
• History of the Princeton Orrery
• The Rittenhouse Astronomical Society
• O'Connor, John J.; Robertson, Edmund F., "David Rittenhouse", MacTutor History of Mathematics archive, http://www-history.mcs.st-andrews.ac.uk/Biographies/Rittenhouse.html .
• David Rittenhouse at Find a Grave
•  "Rittenhouse, David". Encyclopædia Britannica (11th ed.). 1911. 
• David Rittenhouse