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
Craig telescope Craig telescope The Craig telescope was a large telescope built in the 1850s, and while much larger than previous refracting telescopes, it had some problems that hampered its use. Its unique design and potential caused a great deal of excitement about it in its day. The telescope was ready in August 1852 and was visited by the William Parsons (he was famous for the Leviathan of Parsonstown, the largest telescope overall of this age). It is known to been used to observe the planet Saturn. It was the largest refracting telescope (a telescope with a lens) in the world from