This list of largest optical telescopes in the 19th century includes what were large optical telescopes for their time. See List of largest optical telescopes in the 20th century for later telescopes. The list includes various refractors and reflectors that were active at some time between about 1799 to 1901.
The main material used early on for reflecting telescope mirrors was speculum metal, which reflected only about two-thirds of the incident light, and which tarnished, requiring maintenance. Two-element refracting telescopes were extensively used in 19th century observatories despite their smaller apertures than metal, and later glass, mirror telescopes.
The technology for silver-coating glass mirrors, more reflective than speculum metal and not subject to tarnishing, was developed in the mid-19th century but was slow to be adopted. A major technology advance of this time was the development of photography, permitting astrophotography, and some telescopes were tailored to this application. A wide variety of scientific instruments were developed for use with telescopes, such as for spectroscopy and various astronomical measurements.
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 ('Silver on glass') reflector telescopes proved more durable, for example the Crossley Reflector, which continued to be used and upgraded even into the 21st century. Refracting telescopes, with lenses, especially achromatic doublets, rather than mirrors were popular in the 19th century (see also great refractor).
Legend
Name/Observatory | Aperture cm (in) | Type | Location then (Original Site) | Extant* |
---|---|---|---|---|
Leviathan of Parsonstown | 183 cm (72") | reflector – metal | Birr Castle; Ireland | 1845–1908? |
A.A. Common 60-inch [1] | 152.4 cm (60") | reflector – glass | England, UK | 1891–1904 [1] |
Herschel 40-foot (1.26 m diam.) [2] | 126 cm (49½") | reflector – metal | Observatory House; England, UK | 1789–1815 |
Great Paris Exhibition Telescope of 1900 | 125 cm (49.21") | achromat – siderostat | Paris 1900 Exposition, France | 1900–1901 |
Great Melbourne Telescope [3] | 122 cm (48") | reflector – metal | Melbourne Observatory, Australia | 1878 |
William Lassell 48-inch [4] | 122 cm (48") | reflector – metal | Malta | 1861–1865 |
National Observatory, Paris | 1.2 m (47") | reflector-glass [5] | Paris, France | 1875–1943 [1] |
Yerkes Observatory [6] | 102 cm (40") | achromat | Williams Bay, Wisconsin, USA | 1897 |
Meudon Observatory 100 cm [7] | 100 cm (39.4") | reflector-glass | Meudon Observatory, France | 1891 [8] |
James Lick telescope, Lick Observatory | 91 cm (36") | achromat | Mount Hamilton, California, USA | 1888 |
Crossley Reflector [9] | 91.4 cm (36") | reflector – glass | Lick Observatory, USA | 1896 |
A. A. Common Reflector | 91.4 cm (36") | reflector – glass | Great Britain | 1880–1896 |
Rosse 36-inch Telescope (The 3-foot) | 91.4 cm (36") | reflector – metal | Birr Castle; Ireland | 1826 |
Grande Lunette, Paris Observatory | 83 cm + 62 cm (32.67" + 24.40") | achromat x2 | Meudon, France | 1891 |
83-cm Reflector, Toulouse Observatory | 83 cm (32.67") | reflector-glass | Toulouse, France | 1875 [10] [11] |
Potsdam Großer Refraktor Astrophysical Observatory Potsdam | 80 cm + 50 cm (31½" + 29½") | achromat x2 | Potsdam, Deutsches Kaiserreich | 1899 |
Focault 80 cm, Marseille Observatory [12] | 80 cm (31.5") | reflector-glass | Marseille, France | 1862–1965 [13] |
Grand Lunette Biscoffscheim, Nice Observatory | 77 cm (30.3") | achromat | Nice, France [14] [15] | 1886 |
Pulkovo observatory | 76 cm (30") | achromat | Saint Petersburg, Russian Empire | 1885–1941/44 |
Royal Observatory, Greenwich | 76.2 cm (30") | reflector | Greenwich, England, UK | 1897 [1] |
28-inch Grubb Refractor – Royal Greenwich Observatory | 71 cm (28") | achromat | Greenwich, London, Great Britain | 1894 |
Harvard College Observatory | 71 cm (28") | reflector | United States | 1889 [1] |
Großer Refraktor, Vienna Observatory | 69 cm (26") | achromat | Vienna, Austrian Empire | 1880 [16] |
Great Treptow Refractor, Treptow Observatory | 68 cm (26.77") | achromat | Berlin, Germany | 1896 |
McCormick Observatory | 67 cm (26.37") | achromat | Charlottesville, Virginia, USA | 1883 |
U.S. Naval Observatory | 66 cm (26") | achromat | Washington, DC, USA | 1873 |
Royal Greenwich Observatory | 66 cm (26") | achromat | Herstmonceux, Great Britain | 1896 |
Newall Telescope | 62.5 cm (24.6") | refractor | Gateshead, England, UK | 1869 [17] |
Lowell Observatory | 61 cm (24") | achromat | Arizona, USA | 1896 |
Craig telescope | 61 cm (24") | achromat | Wandsworth Common, London, [18] UK | 1852–1857 |
William Lassell 24-inch [19] | 61 cm (24") | reflector – metal | Liverpool, England, UK | 1845 |
Royal Observatory, Edinburgh | 61 cm (24") | reflector | Edinburgh, Scotland, UK | 1872 [1] |
Daramona 24-inch reflector [20] | 61 cm (24") | reflector – glass | Streete, Ireland | 1881–1971 |
Radcliffe Double Refractor, Radcliffe Observatory | 60/45 cm (23.6″/18") | achromat x2 | Oxford, UK | 1901 |
Halstead Observatory | 58.4 cm (23") | achromat | Princeton, New Jersey, USA | 1881 |
Institut technomatique | 52 cm (20½") | refractor | Paris, France | 1857 [21] |
Chamberlin Observatory | 50 cm (20") | achromat | Colorado, USA | 1891 |
Nasymth 20-inch | 50 cm (20") | reflector – metal | United Kingdom [22] | 1842 |
Imperial Observatory (Straßburg) | 48.5 cm (19.1") | achromat | Straßburg/Strasbourg, German Empire/France | 1880 [23] |
Herschel 20-foot (0.475 m diam.) [24] [25] | 47.5 cm (18½") | reflector – metal | Observatory House; England, UK | 1782–? |
Schröter 27 foot Newtonian [26] | 47 cm (18½") | reflector – metal | Lilienthal, Lower Saxony (Germany) | 1793–1813? |
18½-inch Dearborn Observatory Refractor | 47 cm (18½") | achromat | Chicago (1862–1893), Evanston, Illinois (1893), USA | 1862 |
Flower Observatory | 46 cm (18") | achromat | Philadelphia, USA | 1896 |
Royal Observatory | 46 cm (18") | achromat | Cape Colony, South Africa, British Empire | 1897 [27] |
Merz & Mahler Refractor, Pulkovo observatory [28] | 38 cm (15") | achromat | Saint Petersburg, Russian Empire | 1839 |
Harvard Great Refractor, Harvard College Observatory [28] | 38 cm (15") | achromat | Cambridge, Massachusetts, USA | 1847 |
Armagh 15-inch Grubb Reflector [29] | 38 cm (15") | reflector – metal | Armagh Observatory, Northern Ireland | 1835 [30] |
Paris Observatory (Arago Telescope) 38 cm Brunner | 38 cm (15") | achromat | Paris, France | 1857 [31] |
Lunette coudée, Lyon Observatory | 36.6 cm | achromat | Saint-Genis-Laval, France | 1887 |
Markree Observatory 13.3-inch Grubb/Cauchoix [30] | 34 cm (13.3") | refractor | County Sligo, United Kingdom of Great Britain and Ireland | 1834 [30] |
The 12.8 Inch Merz refractor at Royal Greenwich Observatory [32] | 32.5 cm (12.8") | refractor | Greenwich, England | 1850s |
McMillin Observatory 12½-inch [33] | 31.75 cm (12½") | refractor | Ohio, USA | 1895; 1896–1968 |
Bamberg Refractor, Wilhelm Foerster Observatory (since 1963) in Berlin | 31.4 cm (12.36") | achromat | Urania Observatory, Berlin-Moabit, Prussia / Berlin, Germany | 1889–1945 [34] |
Grubb refractor, Keele Observatory | 31 cm (12.25") | achromat | Oxford, England, UK | 1874 |
University of Illinois Observatory | 30 cm (12") | achromat | Urbana, Illinois, USA | 1896 |
Great refractor of Amici (Amici I), Florence Observatory La Specola | 28.4 cm (11.2") | achromat | Florence, Italy | 1841 |
Merz und Mahler (Mitchell cupola), Cincinnati Observatory | 28 cm (11") | achromat | Cincinnati, Ohio, USA | 1843 |
Repsold Refractor (10-duims), Leiden Observatory | 26.6 cm (10½") | achromat | Leiden, The Netherlands | 1885 |
Mills Observatory | 25 cm (10") | achromat | United Kingdom | 1871 |
Fraunhofer Refractor, United States Naval Observatory (Foggy Bottom) | 24.4 cm (9.6") | achromat | Foggy Bottom, D.C., USA | 1844 [35] |
Quito Astronomical Observatory [36] | 24 cm (9½") | Great refractor | Quito, Ecuador | 1875 |
Fraunhofer-Refraktor, Berlin Observatory | 24 cm (9.6") | achromat | Berlin-Kreuzberg, Deutsches Kaiserreich (1835–1913) [37] | 1835 |
Great Dorpat Refractor (Fraunhofer) Dorpat/Tartu Observatory | 24 cm (9.6") | achromat | Dorpat, Governorate of Livonia, Russian Empire / now Tartu, Estonia | 1824 [38] [39] |
Van Monckhoven Telescope | 23 cm | refractor | Ghent, Belgium, UGENT Observatory Armand Pien | 1880 |
Sheepshanks Equatorial of Royal Greenwich Observatory [32] | 17 cm (6.7") | achromat | Greenwich, England, UK | 1838 |
Merz Refractor (6-duims), Leiden Observatory | 16.6 cm (6½") | achromat | Leiden, The Netherlands | 1838 |
Wesleyan University 6-inch Lerebours refractor [40] | 15.24 cm (6") | achromat | Connecticut, USA | 1836 [40] [41] |
Shuckburgh telescope | 10 cm (4.1") | achromat | Warwickshire, England, UK | 1791–1923 |
Utzschneider & Fraunhofer Comet Seeker [42] | 10.2 cm (4") | acrhomat | Foggy Bottom, D.C., USA | 1843 |
Ertel Comet Seeker Markree Observatory | 7.62 (3") | achromat | Markree, Ireland | 1842–1873 [43] |
* (First light or Build Completion to Inactive (Retired) or Deconstruction)
A primary mirror is the principal light-gathering surface of a reflecting telescope.
Yerkes Observatory is an astronomical observatory located in Williams Bay, Wisconsin, United States. The observatory was operated by the University of Chicago Department of Astronomy and Astrophysics from its founding in 1897 until 2018. Ownership was transferred to the non-profit Yerkes Future Foundation (YFF) in May 2020, which began millions of dollars of restoration and renovation of the historic building and grounds. Yerkes re-opened for public tours and programming in May 2022. The April 2024 issue of National Geographic magazine featured a story about the Observatory and ongoing work to restore it to relevance for astronomy, public science engagement and exploring big ideas through art, science, culture and landscape. The observatory offers tickets to programs and tours on its website.
A refracting 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 spyglasses and astronomical telescopes but is also used for long-focus camera lenses. Although large refracting telescopes were very popular in the second half of the 19th century, for most research purposes, the refracting telescope has been superseded by the reflecting telescope, which allows larger apertures. A refractor's magnification is calculated by dividing the focal length of the objective lens by that of the eyepiece.
A reflecting telescope is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century by Isaac Newton as an alternative to the refracting telescope which, at that time, was a design that suffered from severe chromatic aberration. Although reflecting telescopes produce other types of optical aberrations, it is a design that allows for very large diameter objectives. Almost all of the major telescopes used in astronomy research are reflectors. Many variant forms are in use and some employ extra optical elements to improve image quality or place the image in a mechanically advantageous position. Since reflecting telescopes use mirrors, the design is sometimes referred to as a catoptric telescope.
The Paris Observatory, a research institution of the Paris Sciences et Lettres University, is the foremost astronomical observatory of France, and one of the largest astronomical centers in the world. Its historic building is on the Left Bank of the Seine in central Paris, but most of the staff work on a satellite campus in Meudon, a suburb southwest of Paris.
Markree Observatory was an astronomical observatory in County Sligo, Ireland. The asteroid 9 Metis was discovered from this observatory in 1848 by Cooper's assistant Andrew Graham using a comet seeker telescope. The observatory was also home to the largest refractor of the early 1830s, which had a 13.3-inch (340 mm) aperture Cauchoix of Paris lens; the largest in the world at that time. The observatory also housed a number of instruments and was operated to varying degrees throughout the 19th century.
Marseille Observatory is an astronomical observatory located in Marseille, France, with a history that goes back to the early 18th century. In its 1877 incarnation, it was the discovery site of a group of galaxies known as Stephan's Quintet, discovered by its director Édouard Stephan. Marseille Observatory is now run as a joint research unit by Aix-Marseille University and the French National Center for Scientific Research (CNRS).
Hamburg Observatory is an astronomical observatory located in the Bergedorf borough of the city of Hamburg in northern Germany. It is owned and operated by the University of Hamburg, Germany since 1968, although it was founded in 1825 by the City of Hamburg and moved to its present location in 1912. It has operated telescopes at Bergedorf, at two previous locations in Hamburg, at other observatories around the world, and it has also supported space missions.
Grubb Parsons was a historic manufacturer of telescopes, active in the 19th and 20th centuries. They built numerous large research telescopes, including several that were the largest in the world of their type.
The Crossley telescope is a 36-inch (910 mm) reflecting telescope located at Lick Observatory in the U.S. state of California. It was used between 1895 and 2010, and was donated to the observatory by Edward Crossley, its namesake.
The Toulouse Observatory is located in Toulouse, France and was established in 1733.
Great refractor refers to a large telescope with a lens, usually the largest refractor at an observatory with an equatorial mount. The preeminence and success of this style in observational astronomy defines an era in modern telescopy in the 19th and early 20th century. Great refractors were large refracting telescopes using achromatic lenses. They were often the largest in the world, or largest in a region. Despite typical designs having smaller apertures than reflectors, great refractors offered a number of advantages and were popular for astronomy. It was also popular to exhibit large refractors at international exhibits, and examples of this include the Trophy Telescope at the 1851 Great Exhibition, and the Yerkes Great Refractor at the 1893 World's Fair in Chicago.
The Great Melbourne Telescope was built by the Grubb Telescope Company in Dublin, Ireland in 1868, and installed at the Melbourne Observatory in Melbourne, Australia in 1869. In 1945 that Observatory closed and the telescope was sold and moved to the Mount Stromlo Observatory near Canberra. It was rebuilt in the late 1950s. In 2003 the telescope, still in use as an observatory, was severely damaged in a bushfire. About 70% of the components were salvageable; a project to restore the telescope to working condition started in 2013.
Yerkes 41-inch reflector is a 40-inch aperture (101.6 cm) reflecting telescope at the Yerkes Observatory, that was completed in 1968. It is known as the 41 inch to avoid confusion with a 40 inch refractor at the observatory. Optically it is a Ritchey–Chrétien design, and the main mirror uses low expansion glass. The telescope was used as a testbed for an adaptive optics system in the 1990s.