Great refractor (English Wikipedia)

John Woodruff (2003). Firefly Astronomy Dictionary. Firefly Books. p. 71. ISBN 978-1-55297-837-5.
Physics Demystified By Stan Gibilisco, ISBN 0-07-138201-1, page 515 Since a lens can only be held in place by its edge, the center of a large lens will sag due to gravity, distorting the image it produces. The largest practical lens size in a refracting telescope is around 1 meter,

bbc.co.uk (Global: 8^th place; English: 10^th place)

"History – British History in depth: The Airy Transit Circle". BBC. Retrieved 2014-03-01.

books.google.com (Global: 3^rd place; English: 3^rd place)

A.H. Batten (1988). Resolute and Undertaking Characters: The Lives of Wilhelm and Otto Struve. Springer Science & Business Media. p. 45. ISBN 978-90-277-2652-0.
Lee, Sir Sidney (1903). Dictionary of National Biography: Index and Epitome. Smith, Elder & Company.
Edgar Sanderson; John Porter Lamberton; Charles Morris (1910). Six Thousand Years of History: Achievements of the nineteenth century. T. Nolan. p. 286.
The Massachusetts Teacher. 1848. p. 367.
English, Neil (2018-10-31). Chronicling the Golden Age of Astronomy: A History of Visual Observing from Harriot to Moore. Springer. ISBN 9783319977072.
King, Henry C. (2003-01-01). The History of the Telescope. Courier Corporation. ISBN 9780486432656.
Reed Business Information (1982). New Scientist. Reed Business Information. p. 573. {{cite book}}: |author= has generic name (help)^{[permanent dead link]}
Reed Business Information (1982). "The Refracting Telescopes of the 19th Century". New Scientist. Reed Business Information. p. 573. {{cite magazine}}: |author= has generic name (help)^{[permanent dead link]}
Fred Watson (2006). Stargazer: The Life and Times of the Telescope. Perseus Books Group. p. 200. ISBN 978-0-306-81483-9.
The Observatory. Editors of the Observatory. 1881. p. 192.
Peter L. Manly (1995). Unusual Telescopes. Cambridge University Press. p. 181. ISBN 978-0-521-48393-3.

cam.ac.uk (Global: 670^th place; English: 480^th place)

ast.cam.ac.uk

"Northumberland Telescope | Institute of Astronomy". www.ast.cam.ac.uk. Archived from the original on 2019-07-22. Retrieved 2019-10-05.
"Institute of Astronomy: Northumberland". www.ast.cam.ac.uk. Archived from the original on March 25, 2010.

kicc.cam.ac.uk

"Kavli Institute for Cosmology". www.kicc.cam.ac.uk. Archived from the original on March 16, 2010.

craig-telescope.co.uk (Global: low place; English: low place)

"the lens". The Craig Telescope. Retrieved 2014-03-01.
Craig, John; Gravatt, William; Slater, Thomas; Rennie, George. "The Craig Telescope". craig-telescope.co.uk. Retrieved 3 January 2011.
"Welcome to the Online Museum of the Craig Telescope". Craig-telescope.co.uk. Retrieved 2014-03-01.
"How it was constructed". The Craig Telescope. Retrieved 2014-03-01.

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https://docs.google.com/viewer?a=v&q=cache:DqLUutQdc2gJ:www.astrosurf.com/re/building_large_telescopes_refractors.pdf ^{[bare URL PDF]}

doi.org (Global: 2^nd place; English: 2^nd place)

Drew, J. (1851). "Report of the Council to the Thirty-first Annual General Meeting". Monthly Notices of the Royal Astronomical Society. 11 (4). Royal Astronomical Society: 104–105. Bibcode:1851MNRAS..11..104D. doi:10.1093/mnras/11.4.67a.
Waaland, J. Robert (1967). "Fraunhofer and the Great Dorpat Refractor". American Journal of Physics. 35 (4): 344. Bibcode:1967AmJPh..35..344W. doi:10.1119/1.1974076.
Lequeux, James (2009). "The great nineteenth century refractors". Experimental Astronomy. 25 (1–3): 43–61 [43]. Bibcode:2009ExA....25...43L. doi:10.1007/s10686-009-9154-9. S2CID 119885380.
Barnard, E. E. (1917). "Focal length of the 40-inch telescope of the Yerkes Observatory". The Astronomical Journal. 31: 24. Bibcode:1917AJ.....31...24B. doi:10.1086/104239.

europa.com (Global: low place; English: low place)

"History of the Cauchoix objective". Archived from the original on 2019-09-10. Retrieved 2010-09-06.
"BARDOU : Established in Paris in 1818 by D.F. Bardou, then run by his son P.G. Bardou, and grandson, Albert D. Bardou". Europa.com. Archived from the original on 2019-09-10. Retrieved 2014-02-28.

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"World's Biggest Refractors". Archived from the original on 2006-10-03. Retrieved 2009-08-14.

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"Zeiss Telescopes - Griffith Observatory - Southern California's gateway to the cosmos!".

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ui.adsabs.harvard.edu

Drew, J. (1851). "Report of the Council to the Thirty-first Annual General Meeting". Monthly Notices of the Royal Astronomical Society. 11 (4). Royal Astronomical Society: 104–105. Bibcode:1851MNRAS..11..104D. doi:10.1093/mnras/11.4.67a.
Waaland, J. Robert (1967). "Fraunhofer and the Great Dorpat Refractor". American Journal of Physics. 35 (4): 344. Bibcode:1967AmJPh..35..344W. doi:10.1119/1.1974076.
Lequeux, James (2009). "The great nineteenth century refractors". Experimental Astronomy. 25 (1–3): 43–61 [43]. Bibcode:2009ExA....25...43L. doi:10.1007/s10686-009-9154-9. S2CID 119885380.
Andrews, A. D. (2000). "2000IrAJ...27..150A Page 150". Irish Astronomical Journal. 27: 150. Bibcode:2000IrAJ...27..150A. Retrieved 2019-10-24.
Flammarion, Camille (August 1877). "The Companion of Sirius". The Astronomical Register. 15 (176): 186–189. Bibcode:1877AReg...15..186F.
Pettit, Edison (1956). "1956ASPL 7..249P Page 253". Astronomical Society of the Pacific Leaflets. 7 (331). Articles.adsabs.harvard.edu: 249. Bibcode:1956ASPL....7..249P.
Pettit, Edison (1956). "1956ASPL 7..249P Page 255". Astronomical Society of the Pacific Leaflets. 7 (331). Articles.adsabs.harvard.edu: 249. Bibcode:1956ASPL....7..249P.
Barnard, E. E. (1917). "Focal length of the 40-inch telescope of the Yerkes Observatory". The Astronomical Journal. 31: 24. Bibcode:1917AJ.....31...24B. doi:10.1086/104239.

cfa.harvard.edu

"Harvard College Observatory: Great Refractor". Cfa.harvard.edu. 2012-11-21. Retrieved 2014-03-01.
"Harvard College Observatory: Great Refractor". www.cfa.harvard.edu. Retrieved 2019-10-25.

adsabs.harvard.edu

Waaland, J. Robert (1967). "Fraunhofer and the Great Dorpat Refractor". American Journal of Physics. 35 (4): 344. Bibcode:1967AmJPh..35..344W. doi:10.1119/1.1974076.
Andrews, A. D. (2000). "2000IrAJ...27..150A Page 150". Irish Astronomical Journal. 27: 150. Bibcode:2000IrAJ...27..150A. Retrieved 2019-10-24.

articles.adsabs.harvard.edu

"1914Obs 37..245H Page 248". Articles.adsabs.harvard.edu. Retrieved 2014-03-01.

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"Newall Refractor | The Hellenic Archives of Scientific Instruments". www.hasi.gr. Retrieved 2019-10-24.

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http://www.mbgrg.org/newsletters/newsletter20_July13.pdf ^{[bare URL PDF]}

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Stimson, Thomas (2018-05-04). "This week in art history: The Great Exhibition of 1851". Medium. Retrieved 2019-10-24.

nationalarchives.gov.uk (Global: 744^th place; English: 547^th place)

webarchive.nationalarchives.gov.uk

"28-inch telescope : Scenic attractions : Visit the museum : NMM". webarchive.nationalarchives.gov.uk. Archived from the original on 2008-11-14. Retrieved 2019-10-25.

nmm.ac.uk (Global: low place; English: low place)

"28-inch telescope : Scenic attractions : Visit the museum : NMM". webarchive.nationalarchives.gov.uk. Archived from the original on 2008-11-14. Retrieved 2019-10-25.
"The 28-inch photo-visual refractor : : RMG". Nmm.ac.uk. 1944-07-15. Archived from the original on 2011-10-24. Retrieved 2014-03-01.

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"Fraunhoferi refraktor". Obs.ee. Retrieved 2014-03-01.

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Lequeux, James (2009). "The great nineteenth century refractors". Experimental Astronomy. 25 (1–3): 43–61 [43]. Bibcode:2009ExA....25...43L. doi:10.1007/s10686-009-9154-9. S2CID 119885380.

stsci.edu (Global: low place; English: low place)

amazing-space.stsci.edu

"Era: Great Refractors". Amazing-space.stsci.edu. Retrieved 2014-03-01.
"Telescope: Yerkes 40-inch Refractor". Amazing-space.stsci.edu. Retrieved 2014-03-01.

tripod.com (Global: 549^th place; English: 491^st place)

bdaugherty.tripod.com

Brian Daugherty. "Berlin – History of Astronomy in Berlin". Bdaugherty.tripod.com. Archived from the original on 2011-07-19. Retrieved 2014-03-01.

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mthamilton.ucolick.org

Misch, Tony; Remington Stone (1998). "The Building of Lick Observatory". Lick Observatory. Univ. of California. Retrieved 2008-06-30.

web.archive.org (Global: 1^st place; English: 1^st place)

"History of the Cauchoix objective". Archived from the original on 2019-09-10. Retrieved 2010-09-06.
"Northumberland Telescope | Institute of Astronomy". www.ast.cam.ac.uk. Archived from the original on 2019-07-22. Retrieved 2019-10-05.
Brian Daugherty. "Berlin – History of Astronomy in Berlin". Bdaugherty.tripod.com. Archived from the original on 2011-07-19. Retrieved 2014-03-01.
"World's Biggest Refractors". Archived from the original on 2006-10-03. Retrieved 2009-08-14.
"BARDOU : Established in Paris in 1818 by D.F. Bardou, then run by his son P.G. Bardou, and grandson, Albert D. Bardou". Europa.com. Archived from the original on 2019-09-10. Retrieved 2014-02-28.
"Kavli Institute for Cosmology". www.kicc.cam.ac.uk. Archived from the original on March 16, 2010.
"Institute of Astronomy: Northumberland". www.ast.cam.ac.uk. Archived from the original on March 25, 2010.
"The 28-inch photo-visual refractor : : RMG". Nmm.ac.uk. 1944-07-15. Archived from the original on 2011-10-24. Retrieved 2014-03-01.

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Dictionary of National Biography, 1885–1900, Volume 53, "South, James", by Agnes Mary Clerke (WikiSource 2010)

Great refractor (English Wikipedia)

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