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Craig telescope

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Craig telescope
An illustration of the Craig Telescope
Location(s)Wandsworth Common, London Borough of Wandsworth, Greater London, London, England
BuiltApril 1852–August 1852 (April 1852–August 1852) Edit this at Wikidata
First light1852 Edit this on Wikidata
Decommissioned1857 Edit this on Wikidata
Telescope stylelens
optical telescope
refracting telescope Edit this on Wikidata
Diameter61 cm (2 ft 0 in) Edit this at Wikidata
Websitewww.craig-telescope.co.uk Edit this at Wikidata
  Related media on Commons

The Craig telescope was a large telescope built in the 1850s, and while much larger than previous refracting telescopes, it had some problems that hampered its use.[1] Its unique design and potential caused a great deal of excitement about it in its day.[1] The telescope was ready in August 1852 and was visited by the William Parsons (he was famous for the Leviathan of Parsonstown, the largest telescope overall of this age).[2] It is known to been used to observe the planet Saturn.[2]

Telescope

It was the largest refracting telescope (a telescope with a lens) in the world from 1852 to 1857, erected near London, England.[3][4] It was a great refractor, a large refracting telescope with an achromatic doublet with an aperture of 61 cm (2 feet (24 inches)) and that was completed in 1852 in Wandsworth Common and dismantled around 1857 (although the brick tower probably survived until 1870).[3][4] It had a focal length of 76–83 feet.[5] Its namesake, the Rev. John Craig, spent a small fortune to produce a uniquely designed telescope with nearly double the aperture of the next largest refracting telescopes, making it the largest refracting telescope in the World for the better part of a decade.[3][4] However, it had problem with its lens figuring starting from its first light in the summer of 1852.[3][6] It soon fell into disuse as that same year Craig lost his only son, then his wife in 1854, and lost his brother and was put in jail for 6 weeks in 1856.[3]

Craig did not have the lens re-figured and the telescope struggled to achieve his modest goals, which included observations of Earth's Moon and Saturn.[3] It was eventually demolished and Craig moved on to other projects, including opening one of the first indoor skating rinks.[3]

The doublet was made with flint glass by Chance Brothers and a plate glass by Thames Plate Glass Company.[4] The mounting was designed by William Gravatt, and featured a 19.5 meter tall brick tower with a 24.5 m long cigar shaped telescope tube (built by Messrs Rennie) slung from the side.[4][7]

The next largest refractors were two 15 inch (38 cm) refractors built by Merz and Mahler of Münich (Joseph Fraunhofer's firm), one at Pulkovo Observatory in Europe and one at Harvard College Observatory in America. The largest telescope at the time was in Ireland, a 6-foot (183 cm) aperture metal mirror by William Parsons, 3rd Earl of Rosse. (see "Leviathan of Parsonstown")

One of the goals for the telescope was to look for a Moon for Venus and to confirm the third (Crepe) ring of saturn[2] Some of the reported issues were with the overall lens quality and troubles in the personal life of Craig.[2]

See also

References

  1. ^ a b Information, Reed Business (1982-12-02). New Scientist. Reed Business Information. {{cite book}}: |first= has generic name (help)
  2. ^ a b c d [1]
  3. ^ a b c d e f g The Online Museum of the Craig Telescope (www.craig-telescope.co.uk)
  4. ^ a b c d e New Scientist: Dec 2, 1982 "The Monster Telescope at Wandworth"
  5. ^ ANNUAL OF SCIENTIFIC DISCOVERY:1854, Page 156 (Google Books 2010)
  6. ^ The Mechanics' magazine, museum, register, journal, and gazette, Volume 57, Page 354. (Google Books 2010)
  7. ^ "The geography of the heavens: and class-book of astronomy: accompanied by a ..." By Elijah Hinsdale Burritt, Henry Whitall, Page 324. Google Books 2010

Further reading