Largest optical telescopes of the world

 World's
 largest     Aperture  Scope
 scope in     meters

 1580          ?       William Bourne's telescopic device with a lens as objective and a
                       concave mirror as eyepiece!  Didn't understand how it worked,
                       believed magnification depends on the diameter of the lens.
 1608          ?       Hans Lippershey, inventor of the telescope.
 1609         0.016    Galileo - first person to properly observe the skies with a telescope.
 1612         0.026    Galileo.
 1620         0.038    Galileo.
 1638         0.06     Hevelius - Scheiner's helioscope - the first equatorially mounted scope.
 1645         0.12     Hevelius, Danzig.
 1655         0.057    Christian Huygens 12 foot f.l. refractor; discovered Titan.
 1656         0.07     Christian Huygens 23 foot f.l. refractor, x100.
 1672         0.10     Newton (reflector).
 1675         0.13     Hooke (reflector).
 1680?        0.18     Robert Hooke's Gregorian reflector.
 1686         0.19     Constantin Huygens 7.5" 123 foot f.l. air telescope.
 1686         0.20     Constantin Huygens 8"   170 foot f.l. air telescope.
 1686         0.22     Constantin Huygens 8.5" 210 foot f.l. air telescope.
 1690         0.20     Cassini.
 1721         0.15     Halley (reflector).
 1734         0.38     Gregorian reflector by James Short.
 1750         0.50     Gregorian reflector by James Short.
 1752         0.46     Gregorian reflector by James Short, made for the king of Spain.
 1761         0.60     Father Noel (reflector).
 1780-1789    0.75     Rev J. Mitchell's Gregorian reflector,
                         bought, although broken, by Willian Herschel after Mitchell's death.
 1789-1815    1.22     William Herschel's 40 foot f.l. reflector, Bath, England.
                         Last used in 1815, destroyed in a gale 1839.  Frame dismantled by
                         John Herschel 1840 due to rot, then the tube lay in the garden and was
                         crushed by a falling tree in 1870.  Today the original mirror and a
                         quarter of the tube remains.
 1815-1826    0.47     William Herschel's 20 foot f.l. reflector, Bath, England, built in 1783.
                         Restored by William and John Herschel in 1820, then used by
                         John Herschel in South Africa 1834-1838.
 1826-1845    0.91     Lord Rosse's first reflector with 3 foot aperture.
 1845-1878    1.83     Lord Rosse's Leviathan, 6 foot aperture, Birr Castle, Ireland.
                         Last used in 1878, deteriorated rapidly from 1908, dismantled in 1914,
                         mirror moved to Science Museum.  Restored in 1998 with a mirror of
                         aluminium.  One of the original mirror remains at Science Museum,
                         the second original mirror is lost.
 1878-1889    1.22     Great Melbourne Telescope, 4 foot aperture, Melbourne, Australia.
                         Constructed in 1869, remained in Melbourne until the late 1940's. Its
                         building is still intact.  This was the last large reflector with a
                         speculum metal mirror.  It was constructed by, among others, Lord Rosse.
 1889-1908    1.52     A.A. Common's 60-inch reflector; purchased by Harvard University around 1900.
 1908-1917    1.52     60-inch reflector, Mt Wilson, California, USA.
 1917-1948    2.5      Hooker 100-inch reflector, Mt Wilson, California, USA.
 1948-1974    5.0      Hale 200-inch reflector, Palomar Mountain, California, USA.
 1974-1992    6.0      BTA-6, Mt Pashtoukov, Caucasus, Russia.
 1992-2005    9.8      Keck 1, Mauna Kea, Hawaii, USA - twin 9.8 m scopes in separate domes. Keck 2
                       finished in 1996.
 2005 Oct    11.9      LBT (Large Binocular Telescope), Mt Graham, Arizona, USA - 2 x 8.4 m
                       binocular scope.

 2027 ?      30   m    TMT (Thirty Meter Telescope), 492 mirrors 1.4 m each.
                         Delayed due to protests about its location on Mauna Kea, Hawaii
 2027 ?      39   m    E-ELT (European Extremely Large Telescope),
                         about 800 mirrors 1.4 m each, secondary mirror 4.2 m
 2029 ?      22   m    GMT (Giant Magellan Telescope, 7 mirrors 8.4 m each

 1844         0.61 m   William Lassell's 24-inch reflector
 1859-1865    1.22 m   William Lassell's 48-inch reflector (Liverpool, England)
                         While Lassell's reflectors were smaller than Lord Rosse's
                         they were more modern in their design, and had an
                         equatorial mounting.  Lassell moved the 48" to Malta in
                         1861, and never re-erected it upon returning to England
                         in 1865
 1873         0.66 m   26-inch equatorial, USNO, Washington DC, USA
                         Completed in 1873; moved to present site 1893
 1880         0.67 m   Grosse Refractor, Vienna Observatory, Austria
 1886         0.74 m   Lunette Biscoffscheim, Cote d'Azur Observatory, Nice, France
 1888         0.90 m   36-inch Refractor, Lick Observatory, Mt Hamilton, USA
 1889-1999    0.83 m   Grande Lunette, Meudon 33-inch, France.  Europe's largest
                         refractor.  Double refractor: 0.83 m visual, 0.62 m
                         photographic lens.  Out of service since the dome
                         was severely damaged in the great December 1999 storm:
                         now the dome cannot be moved.  It is currently being
                         repaired and renovated and is expected to again become
                         operational in 2004.
 1896         0.68 m   Berlin's big refractor, planned as 1.38 m aperture with 35 m
                         focal length.  The refractor actually built was of 0.68 m
                         aperture and 21 m focal length making it the 8'th biggest
                         refractor in the world, but it is still the longest telescope
                         tube in the world.  It survived WWII.
 1897         1.02 m   Yerkes 40-inch refractor (still the world's largest refractor)
                         with 20 m focal length, Williams Bay, Wisconsin, USA.
 1898         1.57 m   John Peate's 62-inch mirror for the American University
                         Observatory; never mounted in a telescope
 1900         1.25 m   "The great Paris telescope fiasko": 1.25 m lens of
                         57 meter focal length, mounted horizontally with a
                         sidereostat mirror 2 meters large in front of the lens.
                         Disassembled after the Paris exhibition in Nov 1900;
                         the parts were stored at the Paris observatory.
 1917         1.83 m   72-inch Plaskett reflector, Dominion Astrophysical
                         Observatory, Victoria, British Columbia, Canada
                         (first light some months after the Hooker telescope).

 1999         8.2 m    Subaru, a japanese telescope built on Mauna Kea, Hawaii, USA.
                         The word "subaru" is "The Pleiades" in japanese.
 1999         8.2 m    Very Large Telescope, Cerra Paranal, Chile.  Four 8.2 m telescopes.
                         First scope operational in 1999, all four operational in 2000.
 1999         8   m    Gemini North, Mauna Kea, Hawaii, USA.
 2000         6.5 m    MMT (Multiple Mirror Telescope), Mt Hopkins, Arizona, USA.
                         The original MMT had six mirrors 1.8 meters each, creating
                         a total aperture equivalent to a 4.5 meter mirror.  In 2000
                         they were replaced by one single 6.5 meter mirror, but despite
                         this, the telescope kept its original name.
 2002         8   m    Gemini South, the Andes, Chile.
 2005, late  10.4 m    GTC (Gran Telescopio Canarias), La Palma, Canary Islands, Spain
 2006 Aug    11.0 m    SALT (Southern African Large Telescope), Sutherland, South Africa

 1616         ?        The very first reflector by Nicolo Zucchi. No secondary mirror
 1663         ?        Gregory's reflector, with a concave secondary mirror
 1671         0.025 m  Newton's reflector, with a flat secondary mirror
 1672         ?        Laurent Cassegrain's reflector, with a convex seconday mirror
 1684         0.10? m  Roemer's transit instrument
 1733         0.064 m  The first achromatic refractor by Chester Moore Hall
 1738         0.15 m   Hadley's f/10 reflector; first modern Newtonian
 1765         ?        The first refractor with a triplet lens, by John Dollond
 1776-1783    0.16 m   William Herschel's 7 foot f.l. reflector; discovered Uranus
 1866         0.45 m   The first large refractor

Radio telescopes
 1931                  Karl Jansky discovers radio emission from the Milky Way
 1937         9.6 m    First radio telescope with a dish, by Grote Reber
 1957         76  m    Jodrell Bank radio telescope
 1962         91  m    Green Bank radio telescope
 1963        305  m    Arecibo radio telescope - non-steerable
 1971        100  m    Effelsberg radio telescope

IR telescopes
 1979         3.8  m   UKIRT, the world's largest dedicated IR telescope
 1983         0.60     Liquid helium cooled IR telescope onboard the IRAS satellite

UV and X-ray telescopes
 1952                  Hans Wolter outlined grazing incidence telescopes for X-rays
 1962                  First far UV telescope in OSO-1
 1973                  Wolter telescope onboard Skylab studied the solar corona
 1978         0.45 m   UV telescope on the International Ultraviolet Explorer
 1978         0.56     NASA's Einstein Observatory, with a Wolter X-ray telescope
 1983         0.17     ESA's Exosat, with a Wolter X-ray telescope
 1992                  Extreme Ultraviolet Explorer with a Wolter-like telescope
 1999                  Chandra satellite launched, having a Wolter telescope with 0.5" resolution