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 19th and early 20th centuries.

The Clark firm gained "worldwide fame and distribution", wrote one author on astronomy in 1899.

The company also built a number of smaller instruments, which are still highly prized among collectors and amateur astronomers.

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.

Alvan Clark & Sons made the 36-inch (910 mm) objective lens for the Lick Observatory refractor, shown here in an 1889 drawing. The telescope was designed and built by the Warner & Swasey Company
Portrait of Clark and sons, circa 1870s (photo by T.R. Burnham )