- Alvan Clark & Sons
Alvan Clark & Sons was an American maker of
optics that became famous for crafting lenses for some of the largestrefracting telescope s of the nineteenth and early twentieth centuries. Founded in 1846 inCambridgeport, Massachusetts byAlvan Clark (1804–1887, a descendant of Cape Cod whalers who started as a portrait painter, and his sonsGeorge Bassett Clark (1827–1891) andAlvan Graham Clark (1832–1897). Five times, the firm built the largest refracting telescopes in the world.The convert|18.5|in|mm|sing=on Dearborn telescope (housed successively at the
University of Chicago ,Northwestern University andAdler Planetarium ) was commissioned in 1856 by the University of Mississippi. The outbreak of civil war prevented them from ever taking ownership. As a result it was being tested in Cambridgeport when Alvan Graham observedSirius B in 1862.In 1873 they built the convert|26|in|mm|sing=on
objective lens for the refractor at theUnited States Naval Observatory . In 1883, they build the convert|30|in|mm|sing=on telescope for thePulkovo Observatory in Russia, the convert|36|in|mm|sing=on objective for the refractor atLick Observatory was made in 1887, and the convert|40|in|mm|sing=on lens for theYerkes Observatory refractor, in 1897, only ever exceeded in size by the lens made forGreat Paris Exhibition Telescope of 1900 .The company's assets were acquired by the
Sprague-Hathaway Manufacturing Company in 1933, but continued to operate under the Clark name. In 1936, Sprague-Hathaway moved the Clark shop to a new location in WestSomerville, Massachusetts , where manufacturing continued in association with thePerkin-Elmer Corporation , another maker of precision instruments. Most of Clark's equipment was disposed of as scrap duringWorld War II , and Sprague-Hathaway itself was liquidated in 1958.Chabot Space and Science Center Percival Lowell using the 24" Alvan Clark & Sons telescope atLowell Observatory United States Naval Observatory Yerkes Observatory"> convert|40|in|mm|sing=on Refractor Telescope-1897.jpg|1897
convert|40|in|mm|sing=on Refractor Telescope-2006.jpg|2006
ee also
*
Chabot Space & Science Center ,Oakland, California References
* Deborah Jean Warner and Robert B. Ariail, "Alvan Clark & Sons, artists in optics" (2nd English ed.) Richmond, VA. : Willmann-Bell, in association with National Museum of American History, Smithsonian Institution, 1995 (1996 printing), 298 p. ISBN 0-943396-46-8
* Timothy Ferris, "Seeing in the Dark" Simon & Schuster 2002; 117p. ISBN 0-684865-79-3
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