List of largest optical telescopes in the 19th century


List of largest optical telescopes in the 19th century, are listings of what were, for the time period of the 19th century large optical telescopes. See List of largest optical telescopes in the 20th century for the 1900s. The list includes various refractor and reflector that were active some time between about 1799 to 1901.
The main reflecting technology early on, speculum metal reflected some 2/3 of light, and also had higher maintenance due to tarnishing. Another technology were the 2-element refractors, which were extensively used in 19th century observatories despite their small apertures compared to the largest metal mirror, and later glass telescopes. The technology for silver-coated glass mirrors was developed in the mid-19th century, but was slow to catch on. A major technology advance of this time was the development of astrophotography, and some telescopes were tailored to this application. Also, a wide variety of scientific instruments were developed, such as for spectroscopy and various astronomical measurements.

Reflectors & refractors

Early reflectors using speculum metal had some of the record-breaking apertures of the day, but not necessarily high performance. Starting in the 1860s metal coated glass reflector telescopes proved more durable, for example the Crossley Reflector, which continued to be used and upgraded even into the 21st century. Telescopes with lenses, especially achromatic doublets were popular in the 19th century.


Legend



Name/ObservatoryAperture
cm 		TypeLocation then Extant*
Leviathan of Parsonstown183 cm reflector – metalBirr Castle; Ireland
1845–1908?
A.A. Common 60-inch152.4 cm reflector – glassEngland1891–1904
Herschel 40-foot 126 cmreflector – metalObservatory House; England1789–1815
Great Paris Exhibition Telescope of 1900125 cm achromat – siderostatParis 1900 Exposition, France1900–1901
Great Melbourne Telescope122 cmreflector – metalMelbourne Observatory, Australia1878
William Lassell 48-inch122 cmreflector – metalMalta1861–1865
National Observatory, Paris1.2 m reflector-glassParis, France1875–1943
Yerkes Observatory102 cm achromatWilliams Bay, Wisconsin, USA1897
Meudon Observatory 100 cm100 cm reflector-glassMeudon Observatory, France1891
James Lick telescope, Lick Observatory91 cm achromatMount Hamilton, California, USA1888
Crossley Reflector91.4 cmreflector – glassLick Observatory, USA1896
A.A. Common Reflector91.4 cmreflector – glassGreat Britain1880–1896
Rosse 36-inch Telescope 91.4 cmreflector – metalBirr Castle; Ireland1826
Grande Lunette, Paris Observatory83 cm + 62 cm
achromat x2Meudon, France1891
83-cm Reflector, Toulouse Observatory83cm reflector-glassToulouse, France1875
Potsdam Großer Refraktor
Astrophysical Observatory Potsdam		80 cm + 50 cm
achromat x2Potsdam, Deutsches Kaiserreich1899
Focault 80 cm, Marseille Observatory80 cm reflector-glassMarseille, France1862-1965
Grand Lunette Biscoffscheim, Nice Observatory77 cm achromatNice, France1886
Pulkovo observatory76 cm achromatSaint Petersburg, Russian Empire1885
Royal Observatory, Greenwich76.2 cm reflectorGreenwich, England1897
28-inch Grubb Refractor - Royal Greenwich Observatory71 cm achromatGreenwich, London, Great Britain1894
Harvard College Observatory71 cm reflectorUnited States1889
Großer Refraktor, Vienna Observatory69 cm achromatVienna, Austrian Empire1880
Great Treptow Refractor, Treptow Observatory68 cm achromatBerlin, Germany1896
McCormick Observatory67 cm achromatCharlottesville, Virginia, USA1883
U.S. Naval Observatory66 cm achromatWashington, DC, USA1873
Quito Astronomical Observatory24 cm Great refractorQuito, Ecuador1875
Royal Greenwich Observatory66 cm achromatHerstmonceux, Great Britain1896
Lowell Observatory61 cm achromatArizona, USA1896
Craig telescope61 cm achromatWandsworth Common, London1852–1857
William Lassell 24-inch61 cmreflector – metalLiverpool, England1845
Royal Observatory, Edinburgh61 cm reflectorGreenwich, England1872
Daramona 24″ reflector61 cm reflector – glassStreete, Ireland1881–1971
Radcliffe Double Refractor, Radcliffe Observatory60/45 cm
achromat x2Oxford, UK1901
Halstead Observatory58.4 cm achromatPrinceton, USA1881
Institut technomatique52 cm refractorParis1857
Chamberlin Observatory50 cm achromatColorado, USA1891
Nasymth 20″50 cm reflector – metalUnited Kingdom1842
Imperial Observatory 48.5 cm achromatStraßburg/Strasbourg, German Empire/France1880
Herschel 20-foot 47.5 cm reflector – metalObservatory House; England1782-?
Schröter 27 foot Newtonian47 cm reflector – metalLilienthal, Lower Saxony 1793-1813?
18½-in Dearborn Observatory Refractor47 cm achromatChicago, Evanston, Illinois, USA1862
Flower Observatory46 cm achromatPhiladelphia, USA1896
Royal Observatory46 cm achromatCape Colony, British Empire 1897
Merz & Mahler Refractor, Pulkovo observatory38 cm achromatSaint Petersburg, Russian Empire1839
Harvard Great Refractor, Harvard College Observatory38 cm achromatCambridge, Massachusetts, USA1847
Armagh 15- inch Grubb Reflector38 cm reflector – metalArmagh Observatory, Northern Ireland1835
Paris Observatory 38 cm Brunner38 cm achromatParis, France1857
Lunette coudée, Lyon Observatory36.6 cmachromatSaint-Genis-Laval, France1887
Markree Observatory 13.3″ Grubb/Cauchoix34 cm refractorCounty Sligo, United Kingdom of Great Britain and Ireland1834
The 12.8 Inch Merz refractor at Royal Greenwich Observatory32.5 cm refractorGreenwich, England1850s
McMillin Observatory 12.5″31.75 cmrefractorOhio, USA1895; 1896-1968
Bamberg Refractor Urania Observatory 31.4 cm achromatBerlin-Moabit, Prussia / Berlin, Germany1889–1963
Grubb refractor at 31 cm achromatOxford, England1874
University of Illinois Observatory30 cm achromatUrbana, Illinois, USA1896
Great refractor of Amici, Florence Observatory La Specola28.4 cm achromatFlorence, Italy1841
Merz und Mahler, Cincinnati Observatory28 cm achromatCincinnati, Ohio, USA1843
Repsold Refractor, Leiden Observatory26.6 cm achromatLeiden, The Netherlands1885
Mills Observatory25 cm achromatUnited Kingdom1871
Fraunhofer Refractor, United States Naval Observatory 24.4 cm achromatFoggy Bottom, D.C., USA1844
Fraunhofer-Refraktor Berlin Observatory24 cm achromatBerlin-Kreuzberg, Deutsches Kaiserreich 1835
Great Dorpat Refractor Dorpat/Tartu Observatory24 cm achromatDorpat, Governorate of Livonia/ Tartu, Estonia1824
Van Monckhoven Telescope23 cmrefractorBelgium, Ghent, UGENT Observatory Armand Pien1880
Sheepshanks Equatorial of Royal Greenwich Observatory17 cm achromatGreenwich, England1838
Merz Refractor, Leiden Observatory16.6 cm achromatLeiden, The Netherlands1838
Wesleyan University 6-inch Lerebours refractor15.24 cm achromatConnecticut1836
Shuckburgh telescope10 cm achromatWarwickshire, England1791–1923
Utzschneider & Fraunhofer Comet Seeker10.2 cm acrhomatFoggy Bottom, D.C., USA1843
Ertel Comet Seeker
Markree Observatory		7.62 achromatMarkree, Ireland1842-1873

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