Alvan Clark born in Ashfield

Ashfield, Massachusetts

Ashfield is a town in Franklin County, Massachusetts, United States. The population was 1,737 at the 2010 census. It is part of the Springfield, Massachusetts Metropolitan Statistical Area.- History :...

, Massachusetts

Massachusetts

The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...

, the descendant of a Cape Cod whaling family of English

English people

The English are a nation and ethnic group native to England, who speak English. The English identity is of early mediaeval origin, when they were known in Old English as the Anglecynn. England is now a country of the United Kingdom, and the majority of English people in England are British Citizens...

 ancestry,http://www.nndb.com/people/702/000167201/ was an American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 astronomer

Astronomy

Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

 and telescope

Telescope

A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...

 maker. He was a portrait painter and engraver (ca.1830s-1850s), and at the age of 40 became involved in telescope making. Using glass blanks made by Chance Brothers

Chance Brothers

Chance Brothers and Company was a glassworks originally based in Spon Lane, Smethwick, West Midlands , in England. It was a leading glass manufacturer and a pioneer of British glassmaking technology....

 of Birmingham and Feil-Mantois of Paris, his firm Alvan Clark & Sons

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...

ground lenses for refracting telescope

Refracting telescope

A refracting or refractor telescope is a type of optical telescope that uses a lens as its objective to form an image . The refracting telescope design was originally used in spy glasses and astronomical telescopes but is also used for long focus camera lenses...

s, including the largest in the world at the time: the 18.5 inches (469.9 mm) at Dearborn Observatory

Dearborn Observatory

The Dearborn Observatory is an astronomical observatory located on the Evanston campus of Northwestern University. The observatory was originally constructed in 1888...

 at the Old University of Chicago

Old University of Chicago

The University of Chicago, now known as the Old University of Chicago , was a school founded by Baptists in Chicago in 1857...

 (the lens was originally intended for Ole Miss), the two 26 inches (660.4 mm) telescopes at the United States Naval Observatory

United States Naval Observatory

The United States Naval Observatory is one of the oldest scientific agencies in the United States, with a primary mission to produce Positioning, Navigation, and Timing for the U.S. Navy and the U.S. Department of Defense...

 and McCormick Observatory

McCormick Observatory

The McCormick Observatory is one of the astronomical observatories operated by the Department of Astronomy of the University of Virginia and is situated just outside of Charlottesville, Virginia in Albemarle County on the summit of Mount Jefferson . It is named for Leander J...

, the 30 inches (762 mm) at Pulkovo Observatory

Pulkovo Observatory

The Pulkovo Astronomical Observatory астрономи́ческая обсервато́рия Росси́йской акаде́мии нау́к), the principal astronomical observatory of the Russian Academy of Sciences, located 19 km south of Saint Petersburg on Pulkovo Heights...

 (destroyed in the Siege of Leningrad

Siege of Leningrad

The Siege of Leningrad, also known as the Leningrad Blockade was a prolonged military operation resulting from the failure of the German Army Group North to capture Leningrad, now known as Saint Petersburg, in the Eastern Front theatre of World War II. It started on 8 September 1941, when the last...

; only the lens survives), the 36 inches (914.4 mm) telescope at Lick Observatory

Lick Observatory

The Lick Observatory is an astronomical observatory, owned and operated by the University of California. It is situated on the summit of Mount Hamilton, in the Diablo Range just east of San Jose, California, USA...

 (still third-largest) and later the 40 inches (1,016 mm) at Yerkes Observatory

Yerkes Observatory

Yerkes Observatory is an astronomical observatory operated by the University of Chicago in Williams Bay, Wisconsin. The observatory, which calls itself "the birthplace of modern astrophysics," was founded in 1897 by George Ellery Hale and financed by Charles T. Yerkes...

, which remains the largest successful refracting telescope in the world. One of Clark's sons, Alvan Graham Clark

Alvan Graham Clark

Alvan Graham Clark , born in Fall River, Massachusetts, was an American astronomer and telescope-maker. He was the son of Alvan Clark, founder of Alvan Clark & Sons....

, discovered the dim companion of Sirius

Sirius

Sirius is the brightest star in the night sky. With a visual apparent magnitude of −1.46, it is almost twice as bright as Canopus, the next brightest star. The name "Sirius" is derived from the Ancient Greek: Seirios . The star has the Bayer designation Alpha Canis Majoris...

. His other son was George Bassett Clark

George Bassett Clark

George Bassett Clark was an American instrument maker and astronomer.Born in Lowell, Massachusetts and educated at Phillips Academy, Andover, he was the son of Alvan Clark, part of a family of refracting telescope makers in the 19th century...

; both sons were partners in the firm.

Two craters

Impact crater

In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...

 bear his name. The Clark

Clark (lunar crater)

Clark is a lunar crater that lies in the southern hemisphere of the Moon's far side. It is located midway between the larger walled plain Van der Waals to the south and the similar-sized crater Pizzetti to the north. It is named for American astronomer and telescope maker Alvan Clark and his son...

 on the Moon

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 is joinly named for him and his son, Alvan Graham Clark, and one on Mars

Mars

Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

 is named in his honor.

See also

• Alvan Clark & Sons
  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...
  
  
• List of astronomical instrument makers
• List of largest optical refracting telescopes

Further reading

• "Recent Deaths. Alvan Clark." Boston Daily Evening Transcript, 19 August 1887.
• "Autobiography of Alvan Clark." New-England Historical and Genealogical Register 43 (January 1889): 52-58.
• Warner, Deborah Jean. Alvan Clark & Sons, Artists in Optics. Washington, 1968.

External links

• National Gallery of Art has works by Clark