|
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. ==Biography== Rittenhouse was born in a small village within Philadelphia called Rittenhousetown. This village is located near Germantown, along the stream Paper Mill Run, which is a tiny tributary of the Wissahickon Creek. When his uncle 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 grandfather's paper mill. He was self-taught 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. 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. 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. His skill with instruments, particularly clocks, led him to construct two orreries (scale models of the solar system) 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. One of the orreries is currently in the library of the University of Pennsylvania and the other is at Peyton Hall of Princeton University. At the age of 28, he published his first mathematical paper; this is one of many papers published throughout his life. Rittenhouse was one of the first to build a telescope 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. In 1784 Rittenhouse, surveyor Andrew Ellicott and their crew completed the unfinished survey of the Mason–Dixon line to the southwest corner of Pennsylvania, 5 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.〔See: * ("An optical problem, proposed by Mr. Hopkinson, and solved by Mr. Rittenhouse," ) ''Transactions of the American Philosophical Society'', vol. 2, pp. 201–206 (1786). * Thomas D. Cope (1932) ("The Rittenhouse diffraction grating" ). Reprinted in: David Rittenhouse, ''The Scientific Writings of David Rittenhouse'', Brooke Hindle, ed. (New York, New York: Arno Press, 1980), pp. 377–382. (A reproduction of Rittenhouse's letter re his diffraction grating appears on pages 369–374.)〕 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''.〔Available online at (Google Books )〕 Former president Thomas Jefferson ordered six copies directly from the author. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「David Rittenhouse」の詳細全文を読む スポンサード リンク
|