List of largest optical telescopes in the 18th century

List of largest optical telescopes in the 18th century includes various refractors and reflectors that were active some time between about 1699 to 1801. It is oriented towards astronomy, not terrestrial telescopes (e.g., spyglasses).

Many of the largest were metal mirror reflectors, some of which had substational apertures even for the 20th century. One problem was that many instrument makers. including William Herschel, did not pass on their mirror-making craft, and by the next century reflectors had largely been passed over in favour of small achromats (2-lens refractors). It was not until the 20th century that really large reflectors would predominate once again.

The major breakthrough in the 18th century was the perfection of two and even three lens refractor telescopes, as well as the increased number of reflectors using polished metal mirrors rather than metal-coated glass, which was not developed until the mid-19th century.

Selected Reflectors & Refractors The main telescope technologies during this period were refractors with non-achromatic objectives (single lens), speculum metal reflectors, refractors with achromatic doublets objective (doublet lens), and apochromatic triplets (after 1760s) objectives. The list is inherently limited by what examples and records have survived.

Name(s)Aperture cm (in) Type Significance Location then/Original Site Extant* Herschel 40-foot (1.26 m diameter) 126 cm(49.5") Reflector World's largest 1789; Mimas & Enceladus discovery telescope Observatory House, Slough, England 1789–1815 Reverend John Michell's Gregorian reflector 75 cm (29.5") Reflector – Gregorian World's largest 1780 Yorkshire, Great Britain 1780–1789 Herschel "X Feet" or "Large 10 Feet" 61 cm (24") Reflector England 1800 Father Noel's Gregorian reflector 60 cm (23.5") Reflector – Gregorian World's largest 1761; 1796 Newtonian conversion Paris, France 1761-1841 James Short Gregorian reflector 50 cm (19.5") Reflector – Gregorian World's largest 1750 Scotland 1750 Schröter 27 foot Newtonian 47 cm (18.5") Reflector Lilienthal, Lower Saxony (Germany) 1793–1813 Herschel 20-foot 47 cm (18.5") Reflector Observatory House; England 1782 James Short Reflector for King of Spain 46 cm (18.1") Reflector – Gregorian Spain 1752 James Short's Gregorian reflector 38 cm (14") Reflector – Gregorian World's largest 1734 Scotland 1734 Huygens aerial for Royal Society of LondonPaul Schlyter, Largest optical telescopes of the world 19 cm (7.5") aerial London, England 1691–1786 William Herschel 7-foot 16 cm (6.3") Reflector Used to discover Georgium Sidus (Uranus) England 1776–1783 Hadley's Reflector 15 cm (6") Reflector First parabolic newtonian England 1721 Van Deyl of Amsterdam telescope 11.4 cm (4.5") achromat England 1781 James Short 4.5 inch reflector 11.4 cm (4.5") reflector England 1737 Shuckburgh telescope 10 cm (4.1") achromat First large equatorial Warwickshire, England 1791–1923 Dollond Apochromatic Triplet 9.53 cm (3.75") apochromat First apochromatic triplet England 1763 Dollond Triplet for Wollaston 9.02 cm triple lens RAS No. 16 England 1771 Francesco Bianchini's aerial telescope 6.6 cm (2.6") aerial Rome, Italy 1726 Chester Moore Hall's Doublet 6.4 cm (2.5") achromat First achromatic doublet England 1733 Troughton Equatorial Telescope 5.08 cm (2") achromat Equatorial mount Armagh Observatory, Ireland 1795 Newton's reflector (1st) 3.3 cm (1.3") Reflector First reflecting telescope England 1668–1704

* (First light or Build Completion to Inactive or Deconstruction)

Gallery

See also Lists of telescopes List of largest optical telescopes in the 19th century List of largest optical telescopes in the 20th century List of largest optical telescopes historically List of largest optical reflecting telescopes Peter Dollond

References

List of largest optical telescopes in the 18th century

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