William Herschel 40 Foot Telescope, 1880s

William Herschel's 40 foot telescope, also known as the Great Forty Foot telescope, was a reflecting telescope constructed between 1785 and 1789 at Observatory House in Slough, England. It used a 47 inch diameter primary mirror with a 1, 200 cm focal length. It was the largest telescope in the world for 50 years. It may have been used to discover Enceladus and Mimas, the 6th and 7th moons of Saturn. It was dismantled in 1840; today the original mirror and a 10 foot section of the tube remain

Restrictions Only for Ireland and United Kingdom

Diagram Forty German-anglo German-british Herschel Reflecting Reflector Seolink-scientists-01-2020 Telescope

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