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List of largest optical refracting telescopes

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The Grande Cupole for the double refractor of Meudon, with roughly 83 cm (33 in) and 62 cm (24 in) aperture lenses on the same mounting, and making its debut in 1891.

Here is a list of the largest optical refracting telescopes sorted by lens diameter and focal length.

The largest practical functioning refracting telescope is the Yerkes Observatory 40 inch (102 cm) refractor, used for astronomical and scientific observation for over a century, and the next biggest is the James Lick telescope, and the Meudon Great Refractor.[1]

Most are classical Great refractors, which used achromatic doublets on an equatorial mount. However, other large refractors include a 21st-century Solar telescope which is not directly comparable because it uses a single element non-achromatic lens, and the short-lived Great Paris Exhibition Telescope of 1900. It used a 78-inch (200 cm) Focault siderostat for aiming light into the Image-forming optical system part of the telescope, which had a 125 cm diameter lens. Using a siderostat incurs a reflective loss. Larger meniscus lenses have been used in later catadioptric telescopes which mix refractors and reflectors in the image-forming part of the telescope. As with reflecting telescopes, there was an ongoing struggle to balance cost with size, quality, and usefulness.

This highly inclusive list includes some additional more eccentric examples include the Great Paris telescope, which also used a mirror, and also some Solar telescope that also pose some additional nuances. The SST has an optical aperture of 98 cm (39.37"), although the lens itself is 110 cm (43,31") which can sometimes, depending on the precise wording can be listed as one of the larger lenses used in a telescope although make a list of telescopes based on the physical size of the lenses rather than the aperture poses additional research issues as such information is not always available. Also, its a single element lens whereas most of this list are doublets, with a crown and flint lense elements.

Name/Observatory Location at
debut 		Modern location name or fate Lens diameter Focal length Built Comments Image
Great Paris Exhibition Telescope of 1900[2] Paris 1900 Exposition Dismantled 1900 125 cm (49.21") 57 m (187 feet) 1900 Fixed lens, scrapped. Aimed via a 2m reflecting siderostat
Yerkes Observatory[3] Williams Bay, Wisconsin, USA - 102 cm (40″) 19.4 m (62′) 1897 Largest in current operation.[4]
Swedish 1-m Solar Telescope,
ORM		 La Palma,
Spain		 - 98 cm (39.37") 15 m 2002 Single element non-achromatic objective[5] combined with reflective Adaptive optics and a Schupmann corrector. The lens is 110 cm in diameter stopped down to 98 cm.
James Lick telescope
Lick Observatory		 Mount Hamilton, California, USA - 91 cm (36″) 17.6 m 1888[2]  
Grande Lunette
Paris Observatory		 Meudon, France - 83 cm + 62 cm (32.67"+24.41") 16.2 m 1891 Double telescope
Großer Refraktor
Astrophysical Observatory Potsdam		 Potsdam, Deutsches Kaiserreich Potsdam, Germany 80 cm + 50 cm (31.5"+19.5") 12.0 m 1899 Double telescope by Repsold and Sons, optics by Steinheil
Grande Lunette
Nice Observatory		 Nice, France since 1988 Côte d'Azur Observatory 77 cm (30.3″)[2][6] 17.9 m 1886 Bischoffscheim funded
William Thaw Telescope
Allegheny Observatory, University of Pittsburgh		 Pittsburgh, Pennsylvania, USA - 76 cm (30″) 14.1 m 1914 Brashear made, photographic[7]
Pulkovo observatory Saint Petersburg, Russian Empire Destroyed 76 cm (30″) 12.8 m (42 feet) 1885 Destroyed during WWII, only lens (made by Alvan Clark & Sons) survives.
28-inch Grubb Refractor
Royal Greenwich Observatory		 Greenwich, London, Great Britain - 71 cm (28″) 8.5 m 1894
Rolfscher Refraktor[8] Rathenow, Germany - 70 cm (27.6″) 20.8 m 1949 Single element non-achromatic objective with Schupmann corrector.
Großer Refraktor
Vienna Observatory		 Vienna, Austrian Empire Vienna, Austria 69 cm (27" ) 10.5 m 1880 Largest refractor in 1880, by Grubb[9]
Great Treptow Refractor
Treptow Observatory		 Berlin, Germany - 68 cm (26.77") 21 m 1896 renamed Archenhold Observatory 1946
Innes Telescope Observatory Johannesburg, South Africa Observatory Johannesburg, South Africa 67 cm (26.5") 11.6 m 1909-1925 Still in operation for educational purposes. By Grubb
Yale-Columbia Refractor
Yale Southern Station		 Johannesburg, Union of South Africa Relocated 1952 66 cm (26") 10.8 m 1925–1952 Yale-Columbia Refractor moved to Mount Stromlo Observatory in 1952, same telescope as following entry.
Yale-Columbia Refractor
Mount Stromlo Observatory		 Mount Stromlo, Australia Destroyed 2003 66 cm (26") 10.8 m 1952 Yale-Columbia Refractor - Previously located in South Africa. Relocated to Australia in 1952. Destroyed by bush fire on January 18, 2003.[10]
Leander McCormick Observatory Charlottesville, Virginia, USA - 66 cm (26" ) 9.9 m 1884 completed c. 1874, installed 1884
U.S. Naval Observatory Foggy Bottom Washington, DC, USA moved to Northwest, Washington, D.C., 1893 66 cm (26") 9.9 m 1873 Largest refractor in 1873. Alvan Clark & Sons mounting replaced with Warner & Swasey mounting in 1893.
Thompson 26-inch Refractor[11] Royal Observatory, Greenwich, Great Britain[11][12] Equatorial Group, Herstmonceux, Sussex[11] 66 cm (26")[11] 6.82 m[11] 1896 Manufactured by Sir Howard Grubb as a gift from Sir Henry Thompson; originally used at Greenwich on the same mount as a 30-inch reflector[12]
Llano del Hato National Astronomical Observatory Llano del Hato, Venezuela - 65 cm (25.6″) 10.6 m 1955
Belgrade Observatory[13] Belgrade, Kingdom of Serbia Belgrade, Serbia 65 cm (25.6″) 10.55 m 1932  Zeiss made lens, same as at Berlin Observatory
Hida Observatory Gifu, Japan - 65 cm (25.6″) 10.5 m 1972
65 cm Zeiss Refractor, Pulkovo observatory Germany[14] Saint Petersburg, Russia 65 cm (25.6″) 10.413 m 1954 War reparation from Germany[14] In Pulkovo since 1954.
Observatory History Museum Mitaka 65 cm Mitaka, Tokyo, Japan - 65 cm (25.6″) 10.21 m 1929 Carl Zeiss Jena
Berlin-Babelsberg Observatory
Berliner Sternwarte Babelsberg 		Berlin, Germany 65 cm (26 ") 10.12 m (33 ft) 1914 Berlin Observatory just moved to Potsdam-Babelsberg in 1913; Zeiss lens
Newall Refractor[15]
National Observatory of Athens		 UK Athens, Greece since 1957 62.5 cm (24.5″) 8.86 m (29 ft) 1869 Built by Thomas Cooke for Robert Stirling Newall. First located at his estate; donated and relocated to Cambridge Observatory in 1889; donated to Athens Observatory and relocated to Mt. Penteli in Greece in 1957. Currently used only for educational purposes as part of the visitor center.
Craig telescope Wandsworth Common, London Dismantled 1857 61 cm (24″) 24.5 m (80 feet) 1852 Problem with lens figuring[16]
Sproul Observatory Pennsylvania, USA Dismantled July 2017 61 cm (24″) 11.0 m (36 ft) 1911 Currently under restoration to be re-installed in Northwest Arkansas[17]
Lowell Observatory Arizona, USA - 61 cm (24″) 9.75 m (32 ft) 1894 Alvan Clark & Sons telescope
Einstein Tower[18] Potsdam, Germany - 60 cm (23.6″) 14 m 1924 Tower telescope, fixed lens fed by a heliostat
Zeiss Double Refractor
Bosscha Observatory		 Bandung, Dutch East Indies Bandung, Indonesia 60 cm (23.6″) 10.7 m 1928
Großer Refraktor (Great Refractor)[19]
Hamburg Observatory		 Bergedorf, Germany - 60 cm (23.6″) 9 m 1911 by Repsold and Sons, optics (visual + photographic lens) by Steinheil
Grubb Parsons Double Refractor Saltsjöbaden, Sweden - 60 + 50 cm
(23.6″+19.7")		 8.0 m 1930 Stockholm Observatory in Saltsjöbaden
Radcliffe Double Refractor
UCL Observatory		 Oxford, UK Mill Hill, London 60 + 45 cm
(23.6″ + 18")		 7.0 m 1901 Obtained from the Radcliffe Observatory and installed at UCLO (then known as "ULO") in 1938
Halstead Observatory Princeton, USA Roper Mountain Science Center,[20] Greenville, SC 58.4 cm (23″) 9.8 m (32 ft) 1881 by Alvan Clark & Sons
Chamberlin Observatory Colorado, USA - 50 cm (20″) 8.5 m (28 ft) 1891 First Light 1894
Chabot Observatory Oakland, California Oakland, California, USA (2000) 50 cm (20″) 8.5 m (28 ft) 1914 "Rachel", Warner & Swazey Company (Optics John A Brashear Company) Refurbished in 2000 and moved to present location.
Van Vleck Observatory Connecticut, USA - 50 cm (20″) 8.4 m (27.5 ft) 1922
Carnegie Double Astrograph
Lick Observatory		 Mount Hamilton, California, USA Retired? 50 cm (20″)x2 4.67 m (14 ft) 1941/1962 (2nd lens) F7.4
Imperial Observatory Straßburg, German Empire Strasbourg, France 48.5 cm (19.1″) 7 m (23 ft) 1880[21] Then largest in German Empire
18½-in Dearborn Observatory Refractor Chicago, USA Evanston, USA 47 cm (18.5″) 1862 by Alvan Clark & Sons
Luneta 46
Observatório Nacional		 Rio de Janeiro, Brazil - 46 cm (18,4″) 9,7 m 1921 T. Cooke & Sons[22][23]
Wilder Observatory Amherst College, Amherst, MA, USA - 46 cm (18″) (25 ft) 1903 by Alvan Clark & Sons
Flower Observatory Philadelphia, USA - 46 cm (18″) 6.7 m (22.6 ft) 1896
Royal Observatory Cape Colony, British Empire South Africa 46 cm (18″) 6.7 m (22.6 ft) 1897 [24]
Cooke-Zeiss Refractor,
Royal Observatory of Belgium[25]		 Uccle, Belgium - 45 cm (17.7″) 6.99 m 1891/1932 by Cooke & Sons, original 38 cm lens by Merz
replaced by 45 cm lens from Zeiss 1932
Gran Ecuatorial Gautier Telescope
La Plata Astronomical Observatory		 La Plata, Argentina - 43.3 cm (17″) 9,7 m 1894 Gautier
Brashear Refractor, Goodsell Observatory Northfield, Minnesota, USA - 41.15 cm (16.2″) 1890 by John Brashear
Herget Telescope
Cincinnati Observatory		 Cincinnati, Ohio - 40.64 cm (16″) 1904 by Alvan Clark & Sons
Vatican Observatory Castel Gandolfo, Italy - 40 cm (16″) 6.0 m 1881 by Zeiss
Dorides Refractor[26]
National Observatory of Athens		 Athens, Greece Athens, Greece 40 cm (16″) 5,08 m 1901 by Gautier[27]
Washburn Observatory Madison, Wisconsin, USA In regular use for education and general public. 39.5 cm (15.56″) 6.7 m (22.6 ft) 1881 by Alvan Clark & Sons
Dominion Observatory Refractor
Dominion Observatory		 Ottawa, Ontario, Canada Moved to Helen Sawyer-Hogg Observatory (Canada Science and Technology Museum, Ottawa) in 1974[28] 38.1 cm (15″) 571.5 cm 1905 Original achromat doublet by John Brashear replaced with apochomat triplet by Perkin-Elmer in 1958. Currently used for education and outreach.
Lunette Arago
Paris Observatory		 Paris, France - 38 cm (15") 9 m 1883 by Gautier and Henry brothers
Double Refractor
Fabra Observatory		 Barcelona, Spain - 38 cm + 38 cm (15" + 15″) 6 m + 4 m 1904 Double telescope
by Mailhat, Paris
Gran Ecuatorial Observatorio Astronómico Nacional Tacubaya, México - 38 cm (15") 4.8 m 1885 by Howard Grubb
Harvard Great Refractor
Harvard College Observatory[29]		 Cambridge, Massachusetts, USA - 38 cm (15″) 6.9 m 1847 largest telescope in America for 20 years[30]
Merz & Mahler Refractor, Pulkovo observatory Saint Petersburg, Russian Empire Rescued to Leningrad city in WWII (?) 38 cm (15″) 6.9 m 1839 (original) twin of the Harvard Great Refractor[29]
Telescopio Amici
Osservatorio Astrofisico di Arcetri		 Florence, Italy - 36 cm 5 m 1872 28 cm lens by G. B. Amici substituted by Zeiss lens in 1926. Currently used only for educational purposes.
Photographic Refractor
Leiden Observatory		 Leiden, Netherlands - 34 cm + 15  cm (13.4″ + 5.9") 524 cm 1897 Double telescope
by Gautier and Henry brothers
Astrograph
Vienna Observatory		 Vienna, Austrian Empire Vienna, Austria 34 cm + 26 cm (13.3″ + 10.2") 3.4 m + 3.4 m 1885 Double telescope
by Steinheil
Perth Astrograph, Perth Observatory[31] Old Perth Observatory, Mount Eliza, Western Australia Perth Observatory, Bickley, Western Australia. Used for public education and outreach 33 cm (13") 3.34 m 1897 Designed and built by Howard Grubb & Co. Relocated to Bickley ~1966. The original telescope (both camera and guide scopes), mount and dome were re-erected at Bickley
Fitz-Clark Refractor
Allegheny Observatory, University of Pittsburgh		 Pittsburgh, Pennsylvania, USA - 32.02 cm (13") 4.62 1861 Fitz made, visual/photographic. In 1895 established that Saturn's Rings are made up of particles and not solid.[7]
H. Fitz-H.G. Fitz Refractor
Henry Ruthurfurd, Private Observatory		 New York City, USA - 32.02 cm (13") 4.62 1864 Fitz made, visual/photographic. Started by Henry, finished by son Henry Giles
Bamberg Refractor
Urania Observatory (Berlin)		 Berlin-Moabit, Prussia Berlin, Germany 31.4 cm (12.36") 5 m 1889 then biggest in Prussia, moved to Insulaner Wilhelm-Foerster Observatory in 1963[32]
H. Fitz 12.6" refractor

Detroit Observatory in Ann Arbor

Ann Arbor, Michigan, USA 32 cm (12⅝") 508 cm (200") 1857 The telescopes were restored to functionality as part of the University of Michigan's 2009 International Year of Astronomy celebration. Viewing nights and open houses[33] have been running since then.
Grubb refractor, Keele Observatory[34] Oxford, England Keele University, England (since 1962),

in use for the public

31.0 cm

(12.25")

4.39 m 1874 Still awaiting the reunion with its 19th-century camera used in the Carte du Ciel project and to prove Einstein's general relativity theory during the 1919 solar eclipse.
Northumberland Telescope,[35] Institute of Astronomy, Cambridge University Cambridge, England Still in use by Cambridge University Astronomical Society and Cambridge Astronomical Association 30 cm (12") 5.95m 1833 Original lens 11.6" made by Cauchoix of Paris, replaced on 150th anniversary by 12" lens designed by R.V. Willstrop,[36] and made by A.E. Optics of Cambridge.[37]
Urania Sternwarte (Zurich) Zurich, Switzerland - 30 cm (12″) 5.05 m 1907 by Zeiss
Griffith Observatory Los Angeles - 30 cm (12″) 5.03 m 1931 by Zeiss
Clark-Refraktor[38]
Vienna Observatory		 Vienna, Austrian Empire Vienna, Austria 30 cm (12″) 5.06 m 1880 by Clark and Sons
Deutsches Museum Munich, Germany - 30 cm (12″) 5.0 m 1924 by Zeiss
Ladd Observatory,
Brown University		 Providence, Rhode Island, USA Still in use for instruction and public education 30 cm (12″) 12.0-inch (300 mm) 4.57 m (15 ft) 1891 Lens designed by Charles S. Hastings and made by John Brashear; telescope mount by George N. Saegmuller
Irving Porter Church Memorial Telescope
Fuertes Observatory
Cornell University		 Ithaca, New York Still used for instruction and public outreach. 30 cm (12″) 4.57 m (15 ft) 1922 Optics by John Brashear, mounting by Warner & Swasey.
Jewett Observatory Pullman, Washington, USA Used for instruction and pleasure 30 cm (12") 4.57 m (15') Assembled from older parts 1953[39] Alvan Clark & Sons
Silesian Planetarium and Astronomical Observatory Katowice/Chorzów, Silesia, Poland 30 cm (12")[40] 4.5 m 1955 Largest and oldest Planetarium and Astronomical Observatory in Poland.[41] The 3rd largest in Eastern Europe (east of Germany), after Pulkovo Observatory in Saint Petersburg, Russia and Belgrade Observatory in Belgrade, Serbia
University of Illinois Observatory Urbana, Illinois, USA Used for instruction and pleasure 30 cm (12″) 4.57 m (15 ft) 1896 by John Brashear, National Historic Landmark, still used for instruction
Mitchel Telescope
Cincinnati Observatory		 Cincinnati, Ohio, USA - 28 cm (11″) 1843 Merz & Mahler; Oldest professional telescope still used weekly by the public[42]
Brashear Refractor
Nicholas E. Wagman Observatory		 Pittsburgh, Pennsylvania, USA - 28 cm (11″) 1910 John Brashear, Amateur Astronomers Association of Pittsburgh[43]
Great Refractor
Kuffner Observatory		 Vienna, Austria - 27 cm + 15.6 cm
(10.6″ + 6.1")		 350 cm + 294 cm 1884 + 1890 Double telescope
by Repsold and Sons, optics by Steinheil
Repsold Refractor (10-duims)
Leiden Observatory		 Leiden, Netherlands - 26.6 cm (10.5″) 399,5 cm 1885 Repsold and Sons, optics by Alvan Clark & Sons
Äquatoreal (Equatorial)[44]
Hamburg Observatory		 Millerntor Observatory, Hamburg, Germany Hamburg Observatory, Bergedorf, Germany 26 cm (10.2″) 3 m 1867 Repsold and Sons, optics by G. & S. Merz
Hume Cronyn Memorial Observatory
Named in memory of Hume Blake Cronyn		 Western University
London, Ontario, Canada		 - 25.4 cm (10″) 4.386 m (172") 1940 Built by Perkin Elmer Corp.
Second largest refractor in Canada. Continues as Canada's oldest public astronomy venue.
Mills Observatory Dundee, Scotland (1951) 25 cm (10″)   1871 by T. Cooke & Sons. Training telescope at St. Andrews 1938-1951
Coats Observatory Paisley, Scotland (1898) 25 cm (10″)   1898 by Howard Grubb. Replaced 5" refractor by Thomas Cooke, installed in 1883.
Blackett Observatory Marlborough College
Wiltshire, England		 - 25 cm (10")   1860 by Thomas Cooke. -
Quito Astronomical Observatory Quito La Alameda park 24 cm 1875 An operational 1875 Merz telescope and one of the Oldest Observatories in South America, founded in 1873.
Fraunhofer Refractor, United States Naval Observatory (Foggy Bottom) Foggy Bottom, D.C., USA 24.4 cm (9.6″) 1844 [45]
Fraunhofer-Refraktor
Berlin Observatory		 Berlin-Kreuzberg, Deutsches Kaiserreich Moved 1913 to Munich, Germany 24 cm (9.6″) 4 m (13.4′) 1835 Used to discover Neptune; in Deutsches Museum, München since 1913[46]
Great Dorpat Refractor (Fraunhofer)
Dorpat/Tartu Observatory (Old Building)		 Dorpat, Governorate of Livonia Tartu, Estonia 24 cm (9.6″) 4 m (13.4′) 1824 "..the first modern, achromatic, refracting telescope."[47][48]

Under construction

Name/Observatory Location at
debut 		Modern location name or fate Lens diameter Focal length Built Comments Image
Large Synoptic Survey Telescope Cerro Pachón, Coquimbo Region, Chile (Under development) 157 cm (61.81") 9.9175 m (32.5 feet) 2019 World's largest optical lense delivered for camera assembly in 2019; LSST begins imaging in 2023 link

See also

References

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  17. ^ Large telescope moves to Northwest Arkansas to further STEM recruitment goals
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  45. ^ [1]
  46. ^ Daugherty, Brian. "Berlin - History of Astronomy in Berlin". bdaugherty.tripod.com.
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  48. ^ "Fraunhoferi refraktor". www.obs.ee.

Further reading

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