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 120 cm (48-inch) diameter primary mirror with a 12 m (40 foot) long focal length (hence its name "Forty-Foot"). 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 (3.0 m) section of the tube remain.
Read more about 40-foot Telescope: Construction, Use, Decommissioning, Reconstruction, See Also
Famous quotes containing the word telescope:
“The telescope at one end of his beat,
And at the other end the microscope....”
—Robert Frost (1874–1963)