Alvan Clark & Sons

Alvan Clark & Sons was an American maker of optics that became famous for crafting lenses for some of the largest refracting telescopes of the nineteenth and early twentieth centuries. Founded in 1846 in Cambridgeport, Massachusetts by Alvan Clark (1804–1887, a descendant of Cape Cod whalers who started as a portrait painter, and his sons George Bassett Clark (1827–1891) and Alvan 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 and Adler 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 observed Sirius B in 1862.

In 1873 they built the convert|26|in|mm|sing=on objective lens for the refractor at the United States Naval Observatory. In 1883, they build the convert|30|in|mm|sing=on telescope for the Pulkovo Observatory in Russia, the convert|36|in|mm|sing=on objective for the refractor at Lick Observatory was made in 1887, and the convert|40|in|mm|sing=on lens for the Yerkes Observatory refractor, in 1897, only ever exceeded in size by the lens made for Great 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 West Somerville, Massachusetts, where manufacturing continued in association with the Perkin-Elmer Corporation, another maker of precision instruments. Most of Clark's equipment was disposed of as scrap during World War II, and Sprague-Hathaway itself was liquidated in 1958.

Chabot Space and Science Center
Percival Lowell using the 24" Alvan Clark & Sons telescope at Lowell Observatory
United States Naval 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