Alvan clark biography of william

American astronomer and telescope maker

Alvan Clark (March 8, 1804 – August 19, 1887), born in Ashfield, Massachusetts, was an American astronomer and telescope maker.

Biography

He started as a portrait painter and engraver (c.1830s–1850s), and at the age of 40 became involved in telescope making.

Using glass blanks made by Chance Brothers of Birmingham, England, and Feil-Mantois of Paris, France, his firm Alvan Clark & Sons ground lenses for refracting telescopes. Their lenses included the largest in the world at the time: the 18.5-inch (47 cm) at Dearborn Observatory at the Old University of Chicago (the lens originally intended for Ole Miss); also the two 26-inch (66 cm) telescopes at the United States Naval Observatory and McCormick Observatory, the 30-inch (76 cm) at Pulkovo Observatory, which was destroyed in the Siege of Leningrad (only the lens survives), the 36-inch (91 cm) telescope at Lick Observatory (still the third-largest