Hale Telescope mirror.. It was completed in 1948 and is still in active use. The Hale Telescope represented the technological limit in building large optical telescopes for over 30 years. It was the largest telescope in the world until the Russian BTA-6 was built in 1976, and the second largest until the construction of the Keck Observatory Keck 1 in 1993. Hale supervised the building of the telescopes at the Mount Wilson Observatory with grants from the Carnegie Institution of Washington: the telescope in 1908 and the telescope in 1917. These telescopes were very successful, leading to the rapid advance in understanding
40-foot telescope of the funding deal with the telescope, Caroline Herschel was granted a pension of £50 per year to be William's assistant. As a result, she was the first woman in England to be paid to carry out astronomy. The telescope was a local tourist attraction, visited by rich and famous people on their way to the nearby Windsor Castle to visit the King, and was featured on Ordnance Survey maps. It was the largest telescope in the world for 50 years. It was called the "40-foot telescope" as at the time telescopes were referred to by the length of their