Telescope Timeline

• 500 BC - 1400: al-Haitham, Bacon

  470 BC Chinese mirrors: Chinese philosopher Mozi writes on the use of concave mirrors to focus the sun's rays.
  423 BC Aristophanes Burning Glass: Aristophanes writes about the use of a burning glass in his play The Clouds.
  500 BC Ancient lenses: 5th century BC - Artifacts that could be lenses found in a sacred cave on Mount Ida, Crete date to this period.
  212 BC Burning of the Roman Fleet: 212 B.C. This is the legend of the burning of the Roman fleet at Syracuse through the use of specially directed mirrors arranged by Archimedes.
  4 BC Seneca and Younger: 4 BC-65 - Seneca the Younger describes magnification by a globe filled with water: "Letters, however small and indistinct, are seen enlarged and more clearly through a globe of glass filled with water."
  23 Pliny the Elder: 23-79 - Pliny the Elder "And yet, we find that globular glass vessels, filled with water, when brought in contact with the rays of the sun, become heated to such a degree as to cause articles of clothing to ignite."
  984 Ibn Sahl: 984 - Ibn Sahl completes a treatise On Burning Mirrors and Lenses, describing plano-convex and biconvex lenses, and parabolic and ellipsoidal mirrors.
  800 Visby Lenses: 9th-11th centuries Visby lenses possibly used to make a telescope. The lenses may have been imported from the Middle-East via Viking trading routes, but there is also evidence of local manufacture of lenses.
  1015 Ibn al-Haitham: 1015-1021 - Ibn al-Haitham (Alhazen), a Muslim academic from what is now Iraq, writes treatise Kitab al-Manazir - "Book of Optics". Discusses the optics of lenses and mirrors and some say he even discovered the law of refraction (Snell's Law). Also discussed camera obscura as had the Greeks before him.
  1230 Robert Grosseteste: 1235 -Robert Grosseteste, an English bishop, describes the use of 'optics' to "...make small things placed at a distance appear any size we want, so that it may be possible for us to read the smallest letters at incredible distances..." in his work De Iride.
  1266 Roger Bacon: 1266 - Roger Bacon , an English Franciscan monk, apparently documents the use of a telescope in his treatise Opus Majus, using terms very similar to his mentor, Robert Grosseteste.
  1270 Witelo: 1270 (approx) - Witelo , a Polish monk, writes Perspectiva - "Optics" incorporating much of Kitab al-Manazir.
  1289 Florentine lensmakers: 1289-Florentine manuscript documents the use of lenses to correct the vision of the elderly. Florence becomes a dominant center for lens manufacture in Europe.
  1300 Reading Mirrors: Concave mirrors similar to makeup or shaving mirrors used to aid in reading as an alternate to lenses.
  

• 1450-1600: DaVinci, della Porta

  1450 Mass Production of Lenses: After the printing press was invented, lenses were produced in mass numbers in several areas of Europe (especially Florence, Lowlands, and Germany). In relative terms, spectacles could be bought for less than they would cost today (e.g. 1/2 days pay of a stone mason). Nobles would sometimes order hundreds at a time to give as presents.
  1450 Improved Glass Making: In latter half of 15 century, Venetian glassblowers develop a way of making very pure glass out of quartz sand and potash
  1450 Concave lenses: Some time in the latter half of the 15th century, lensmakers develop technique to produce concave lenses. By this point, everything was in place to create both Keplerian and Galilean telescopes.
  1490 da Vinci Refractor?: 1490 -Leonardo da Vinci in Codex Atlanticus mentions use of lenses to view the Moon.
  1513 da Vinci Reflector: 1513 -Leonardo da Vinci in Codex Arundul describes using a primitive reflecting astronomical device based on a concave mirror.
  1513 Pope Leo X?: Reports by contemporaries that Pope Leo used a tubeless lens-based viewing device to view birds at great distance in detail. Since Leo was severely myopic it is speculated he was using a combination of concave and convex lenses.
  1538 Girolamo Fracastoro: 1538-Girolamo Fracastoro, an Italian professor, poet and personal physician of the the pope suggests combining lenses to produce a telescopic effect in his work,Homocentricorum Seu de Stellis Liber Unus
  1539 Rucellai's Reflecting Microscope: In Le Api (1539), Giovanni Rucellai, Italian poet and cousin of the pope, describes the use of concave mirrors to magnify insects. This may have been the first dissecting microscope. This and da Vinci's reflector demonstrates that the practical application of mirrors for magnification was recognized well before the seventeenth century.
  1520 Leonard Digges: 1520-1559 - Thomas Digges has described how his father, English mathematician and surveyor Leonard Digges, had built a 'perspective glass' which enabled the user to see small objects from very far away.
  1538 Italian Optical Projectors: 1538-1600 - Various Italian scientists (Benedetti, Barbaro, della Porta) experiment with optical projection systems based on various combinations of camera obscura, biconvex lenses, and concave mirrors. This would have required skilled production of lenses and concave mirrors. .
  1589 della Porta-Natural Magic: 1589 - In Natural Magic, Giambattista della Porta discusses telescopic devices and a complicated optical projection device consisting of a camera obscura, a biconvex lense, and a concave mirror that could be used to project images. T
  1593 della Porta-De Refractione: 1593-In De Refractione, della Porta presents first theoretical analysis of lenses. Would shortly be superseded by Kepler's work.
  

• 1600-1699: Galileo, Newton

  1608 Telescope Patent Fight: 1608 - Hans Lippershey, a Dutch lensmaker, and other Dutch lensmakers (Jacob Metius and Zacharias Janssen) engage in patent fight over the Galilean telescope design (convex objective and concave ocular). Patent denied because the design was considered too simple to keep secret.
  1608 Binocular Telescope: 1608 - Hans Lippershey, a Dutch lensmaker submits a paired set of telescopes to the Dutch patent office at their request..the first primitive binocular telescope.
  1609 della Porta: 1609 - della Porta sends a letter to a correspondent with a diagram of a telescope. It is the first known illustration of a telescope.
  1609 Galileo: 1609 - Galileo Galilei creates an improved version of the telescope based only on reports of the Dutch instruments. He would quickly improve them from about 3 or 4 power to 20X. It was Galileo who made the telescope a key instrument of astronomy since he quickly started using the telescope for astronomical observation.
  1611 Kepler's Dioptrice: 1611 - Johannes Kepler, the great astronomer, describes the optics of lenses in Dioptrice which some believe represents the foundation of modern optics. He describes a new kind of astronomical telescope with a convex objective and a convex eyepiece (the 'Keplerian' telescope).
  1616 Zucchi Reflector: 1616 - Niccolo Zucchi, a Jesuit priest, constructs a reflecting telescope, using a borrowed mirror. It was more a proof of concept since his design was not thought to be very practical. See Jesuits and the Telescope.
  1613 Astronomical Telescope: 1613 - Christoph Scheiner, a Jesuit priest, constructs first modern astronomical telescope based on Kepler's design. See Jesuits and the Telescope.
  1613 Japan:First Telescope: 1613 - English captain of the Clove, John Saris, gives a telescope (a perspective glass) to Matsura Hoin, an important local official.
  1614 New World:First Telescope: Portugese mariners bring first telescope to new world. Use of the telescope was mentioned in records of the battle of Guaxanduba, Brazil between the French and Portugese.
  1617 Early Terrestrial Telescope: While in the service of Archduke Maximilian of Tyrol, Christoph Scheiner, the Jesuit scientist, builds first modern terrestrial telescope. Scheiner had presented Maximilian with a Keplerian telescope which inverted the final image. When Maximilian complained, Scheiner added a third lens to correct the image. Modern terrestrial telescopes based on this design use four lenses.See Jesuits and the Telescope.
  1620 Equatorial Mount: Christopher Scheiner builds and uses an equatorial mount. in his helioscope. Equatorial mounts allow changing the view of a telescope by altering position in a single axis (other mounts require altering position in two axes). . Equatorial mounts for telescopes would later be perfected by another Jesuit, Christopher Grienberger. See Jesuits and the Telescope.
  1621 Willebrord Snell: 1621- Willebrord Snell discovers the law of refraction, also known as Snell's law but does not publish his work. Some authors believe that the Muslim academic Ibn al-Haitham may have discussed the law 600 years before Snell.
  1621 China:First Telescope: 1621- Johannes Schreck, a Jesuit, brings first telescope to China. See Jesuits and the Telescope.
  1632 Bonaventura Cavalieri: 1632 - Bonaventura Cavalieri publishes Specchio Ustoria (On Burning mirrors) where he discusses the theory of parabolic mirrors and discusses configurations for a reflecting telescope similar to the Gregorian and Newtonian designs and a listening device similar to a Cassegrain telescope.
  1636 Marin Mersenne: 1636 - In Harmonie Universelle, Marin Mersenne, a Minim priest, presents diagrams for the construction of reflecting telescopes in configurations similar to the Gregorian and Cassegrain telescopes. See Reflecting on History
  1637 Rene Descartes: In various works in the 1630's, such as Dioptrique (1637) and Traite du monde ou de la lumiere (1634), Descartes provides major advances in telescope optics, including the first European publication of Snell's Law and the complete theory for the elimination of spherical aberration.
  1640 Keplerian Dominance: Keplerian design used by Scheiner and others replaces Galilean design as dominant design used in the larger astronomical telescopes. The Galilean design had very restrictive fields of view at higher powers. The dominance of the Keplerian design would continue until about 1900 when reflecting telescopes would start to dominate. See Jesuits and the Telescope.
  1645 Anton Schyrle (Rheita): In Oculus Enoch, Anton Schyrle, a Capuchin monk from Rheita (modern day Czech Republic) describes the design of keplerian telescopes with erector lenses. Schyrle also describes a more sophisticated design for binocular telescopes that would become the standard way to produce binocular telescopes in the next century.
  1646 North America:First Telescope: Jesuits bring first telescope to North America as a gift to Jean Bourdon, an engineer in New France. This telescope may have been used for surveying purposes instead of astronomy. The first telescope in the American colonies was brought over in 1660. See Jesuits and the Telescope.
  1650 Compound Eyepiece: 1650 - Christiaan Huygens designs an eyepiece that uses more than one lens, known as a compound eyepiece.
  1651 India:First Telescope: An Englishman, Jeremiah Shakerley, makes first known use of a telescope in India to observe the Transit of Mercury that occured on November 3, 1651.
  1660 Campani Brothers: The two Campani brothers, Giuseppe and Matteo (a parish priest), are widely considered to have produced the best telescopes of the 17th century. These were Keplerian refracting telescopes. Cassini used their telescopes to make several important discoveries. Some believe that the Campani lenses were comparable in quality to the lenses of the 19th century.
  1663 Gregorian Design: 1663 - Scottish mathematician, James Gregory, describes a reflecting telescope with a perforated concave main mirror and convex secondary mirror.
  1665 Francesco Grimaldi: 1665- Physicomathesis de lumine by the Jesuit,Francesco Grimaldi, is published. In the book, Grimaldi concludes that light has wave-like properties.
  1666 Newton's Prism Experiment: 1666- Isaac Newton discovers that white light is composed of different colors through his prism experiment. Partially as a result of this experiment, Newton gives up hope in refracting telescopes and concentrates on reflecting telescopes.
  1668 Newtonian Reflector: Isaac Newton - Isaac Newton produces a design of reflecting telescope using a paraboloid primary mirror and a flat diagonal secondary mirror. Perhaps the most practical of the designs from the time. Reflecting telescopes were not very practical in the seventeenth century because the mirrors, being made of metal, would tarnish, and the more stringent tolerances required for proper manufacture of paraboloid and spherical mirrors.
  1672 Cassegrain Design: 1672 - Laurent Cassegrain, a French priest, proposes a design using a paraboloid primary mirror and a hyperboloid secondary mirror. Like the Gregorian design the main mirror was perforated. Both the Cassegrainian and Gregorian design were anticipated by Mersenne. The design, named 'Cassegrain', is probably the most commonly used design in large research telescopes even today.
  1674 Clock Driven Equatorial Mount: Robert Hooke publishes diagram of clock-driven equatorial mount for telescopes in Animadversions. This type of drive can automatically track stars.
  1692 Russia:First Telescope: Archbishop Athanasius of Kholmogory builds an observatory where he designs and builds first Russian-made telescope. Foreign telescopes may have been used in Russia before this time (no data).
  

• 1700-1899: Dollond, Liebeg

  1730 James Short: 1730s - James Short , a Scottish optician and astronomer produces the first practical high-quality Gregorian reflector.
  1733 Chester Moore Hall: 1733 - Chester Moore Hall invents the achromatic lens which combines two different types of glass (e.g. crown glass and flint glass) in a lens to reduce optical distortions.
  1758 John Dollond: 1758 - patents the achromatic lens and begins a successful company building telescopes using these achromatic lenses.
  1783 Jesse Ramsden: 1783 - Jesse Ramsden, an English instrument maker, develops an compound eyepiece composed of two elements of crown glass which reduces various types of aberrations. Ramsden also discovered that the Cassegrain design of reflecting telescope, which had fallen out of favour, had practical advantages of other types (less blurring of the image).
  1840 First Astro-Photograph: 1840- John William Draper takes first astrophotograph by photographing the moon.
  1845 Birr Castle-72-inch: 1845- William Parsons makes first use of his 72 -inch (183 cm) reflecting telescope at the Birr Castle in Ireland. It was the largest optical telescope until 1917 (the 100-inch Hooker Telescope)
  1850 Capocci-Liquid Mirror Telescope: 1850- Ernesto Capocci, Naples Observatory, suggests building telescopes using the paraboloid shapes produced by rotating reflective liquids (e.g. mercury).
  1856 Silvered-Glass Mirrors: 1856-1857. In 1856 Justus von Liebeg develops a technique to apply a very thin layer of silver to glass. Carl von Steinheil would build a telescope using this technology in 1856 and Foucalt would build one in 1857
  1872 Skey-Liquid Mirror Telescope: 1872 - Henry Skey, at Dunedin Observatory, New Zealand, constructs first working Liquid Mirror Telescope. This is a telescope made by rotating a reflective liquid (e.g. mercury) to produce a paraboloid shape.
  1878 Vienna Observatory: 1878 - A 68 -cm (26.8 in) refracting telescope is completed at the Vienna Observatory. It was the largest refracting telescope of its time. .
  1888 Lick Observatory: 1888 - A 36 -inch (91.4 cm) refracting telescope is commissiioned at the LickObservatory on top of Mt. Hamilton. It was the largest refracting telescope of its time. .
  1897 Yerkes Observatory: 1897 - A 40 -inch refracting (101.6 cm) telescope is commissiioned at the Yerkes Observatory, associated with the University of Chicago. It would be the largest refracting telescope ever built. From 1897 most large telescopes were designed as reflectors.
  

• 1900-Present: Large Reflectors

  1917 Mt. Wilson 100-in: 1917 - A 100 -inch (254 cm) reflecting telescope is commissiioned at the Mr. WIlson , in California. It was the largest optical telescope of its time.
  1930 Schmidt-Cassegrain: 1930 - Bernard Schmidt, an Estonian telescope maker, adds a corrector plate (a complex corrective lens) to a Cassegrain reflector to correct for spherical aberration.
  1931 Vacuum-Coated Mirrors: 1931 - John Strong , an American astronomer, develops a method for depositing aluminum on an astronomical mirror in a vacuum.
  1941 Maksutov-Cassegrain: 1941 - A. Bouwers, a Dutch telescope designer, and Dimitri Maksutov, a Soviet telescope designer, independently develop a Cassegrain reflector that used a simpler corrector plate (a simple curved lense). Was easier to manufacture than the Schmidt.
  1949 Palomar Observatory 200-in: 1949 - First use of the 200 -inch (508 cm) reflecting telescope at the Palomar Observatory. Mirrors made of pyrex glass.
  1959 Vanguard II: Vanguard II Satellite launched with optical telescopes to measure reflection of light from land and clouds. May have been first satellite using optical telescopes. This is difficult to confirm (i.e. lack of knowledge on spy satellites).
  1967 Automated Telescopes: 1967 -University of Wisconsin develops configuration to fully automate an optical telescope with light sensors and a small minicomputer ( a DEC PDP-8).
  1976 Bolshoi Telescope 6-m: 1976 - The 6 metre (236 in) Bolshoi Teleskop Azimutalnyi is commissioned atop Mount Pastukhov in the Caucasus (Russia). It was the largest optical telescope at this time.
  1982 Borra-Liquid Mirror Telescopes: 1982- Ermanno Borra, University of Laval, Quebec, Canada presents re-evaluation of the use of Liquid Mirror Telescopes using modern technology. Practical application of work include several large working telescopes, built at a fraction of the cost of a more traditional reflecting telescope.
  1990 Hubble Space Telescope: Hubble Space Telescope is launched. First large space based observatory. Telescope was a Cassegrainian reflector with a 2.4 metre primary mirror and a 0.3 metre secondary mirror.
  1993 Keck 1: 1993- First use of the Keck 1's 10 metre reflecting telescope on the dormant Mauna Kea volcano in Hawaii.
  1998 Klevtsov: 1998 - Klevtsov proposes Cassegrain design that uses a smaller corrector than the Maksutov and that only requires spherical mirrors (making it easier to manufacture).
  2007 Large Binocular Telescope: November, 2007- The Large Binocular Telescope, on Mount Graham in Arizona, USA, achieves first binocular light. Although the telescope is composed of the two 8.4 m circular mirrors placed side-by-side it has the equivalent light-gathering capability as an 11.8 metre reflecting telescope.
  

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