40-foot telescope
English reflecting telescope, built 1785–1789William 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 48-inch (120 cm) diameter primary mirror with a 40-foot-long (12 m) 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 by Herschel's son John Herschel due to safety concerns; today the original mirror and a 10-foot (3.0 m) section of the tube remain.
Read article
Top Questions
AI generatedMore questions
Nearby Places
Observatory House
Municipal building in Slough, Berkshire, England
Municipal Borough of Slough
Former municipal borough
Heart of Slough
Urban redevelopment scheme in Slough, England
Slough rail accident
Collision at Slough, England in 1900
Chalvey Road
St Mary's Parish Church, Slough
Church in Slough, England
St Ethelbert's Church, Slough
Church in Slough, United Kingdom
Slough bus station
Bus station in Slough, United Kingdom