Timeline of telescope technology

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Timeline of telescope technology

c.2560 BC - c.860 BC - Egyptian artisans polish rock crystal, semi-precious stones, and latterly glass to produce facsimile eyes for statuary and mummy cases. The intent appears to be to produce an optical illusion. ^[1] ^[2] ^[3] ^[4]
c.470 BC - c.390 BC - Chinese philosopher Mozi writes on the use of concave mirrors to focus the sun's rays.
423 BC - Aristophanes writes about the use of a burning glass in his play The Clouds, first performed in this year.

Strepsiades: Have you ever seen this stone in the chemist's shops, the beautiful and transparent one, from which they kindle fire?

Socrates: Do you mean the burning-glass?

The Clouds translated by William James Hickie, available at Project Gutenberg.

5th century BC - Artifacts that could be lenses found in a sacred cave on Mount Ida, Crete date to this period.
c.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 - 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." ^[5]

I find it stated by medical men that the very best cautery for the human body is a ball of crystal acted upon by the rays of the sun.^[6]

984 - Ibn Sahl completes a treatise On Burning Mirrors and Lenses, describing plano-convex and biconvex lenses, and parabolic and ellipsoidal mirrors.
9th-11th century - 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 - 1021 - Ibn al-Haitham (Alhazen) writes treatise Kitab al-Manazir - "Book of Optics".
1230-1235 - Robert Grosseteste 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.^[7]
1266 - Roger Bacon apparently documents the use of a telescope in his treatise Opus Majus, using terms very similar to his mentor, Robert Grosseteste.
1270 (approx) - Witelo writes Perspectiva - "Optics" incorporating much of Kitab al-Manazir.
1520 - 1559 - English mathematician and surveyor Leonard Digges likely inventor of both reflecting and refracting telescopes.^[8]^[9]
1608 - Hans Lippershey, a Dutch lensmaker, applies for a patent for the design of a telescope. Several other people make similar claims around the same time, such as Jacob Metius and Zacharias Janssen.
1609 - Galileo Galilei makes his own improved version of Lippershey's telescope, calling it at first a "perspicillum," and then using the terms "telescopium" in Latin and "telescopio" in Italian. Telescopes using one convex and one concave lens are often termed 'Galilean'.
1611 - Johannes Kepler describes the optics of lenses (see his books Astronomiae Pars Optica and Dioptrice), including a new kind of astronomical telescope with two convex lenses (the 'Keplerian' telescope).
1616 - Niccolo Zucchi constructs a reflecting telescope.
1630 - Christoph Scheiner constructs a telescope to Kepler's design.
1650 - Christiaan Huygens produces his design for a compound eyepiece.
1663 - Scottish mathematician James Gregory designs a reflecting telescope with paraboloid primary mirror and ellipsoid secondary mirror. Construction techniques at the time could not make it, and a workable model was produced only about 60 years later. The design is known as 'Gregorian'.

A replica of Isaac Newton's reflecting telescope of 1672

1668 - Isaac Newton produces his own design of reflecting telescope using a paraboloid primary mirror and a flat diagonal secondary mirror. This design is termed the 'Newtonian'.
1672 - Laurent Cassegrain, produces a different design of reflecting telescope to Gregory, again, well ahead of manufacturing techniques of the time using a paraboloid primary mirror and a hyperboloid secondary mirror. The design, named 'Cassegrain', is still used in astronomical telescopes used in obervatories in 2006.
1674 - Robert Hooke produces an experimental model to the Gregorian design.
1721 - John Hadley constructs the first working telescope to the Gregorian design.
1730s - James Short succeeds in producing high-quality telescopes to the Gregorian design.
1733 - Chester Moore Hall invents the achromatic lens.
1758 - John Dollond re-invents and patents the achromatic lens.
1783 - Jesse Ramsden invents his eponymous eyepiece.
1849 - Carl Kellner designs and manufactures the first achromatic eyepiece, announced in his paper "Das orthoskopische Ocular".
1860 - Georg Simon Plössl produces his eponymous eyepiece.
1880 - Ernst Abbe designs the first orthoscopic eyepiece (Kellner's was solely achromatic rather than orthoscopic, despite his description).
1910s - George Willis Ritchey and Henri Chrétien co-invent the Ritchey-Chrétien telescope used in many, if not most of the largest astronomical telescopes.
1930 - Bernhard Schmidt invents the Schmidt Camera.^[10]
1944 - Dmitri Dmitrievich Maksutov invents the Maksutov telescope.