Hale Telescope
The Hale Telescope is a 200-inch (5.1 m), f/3.3 reflecting telescope at the Palomar Observatory in California, US, named after astronomer George Ellery Hale. With funding from the Rockefeller Foundation, he orchestrated the planning, design, and construction of the observatory, but did not live to see its commissioning. The Hale was groundbreaking for its time, with double the diameter of the next largest telescope and pioneering the use of many technologies such as vapor deposited aluminum and low thermal expansion glass. It is still in active use.
It was the largest optical telescope in the world from its completion in 1948 until the BTA-6 was built in 1976, and the second largest until the construction of the Keck 1 in 1993.
History
Hale supervised the building of the telescopes at the Mount Wilson Observatory with grants from the Carnegie Institution of Washington: the 60-inch (1.5 m) telescope in 1908 and the 100-inch (2.5 m) telescope in 1917. These telescopes were very successful, leading to the rapid advance in understanding of the scale of the Universe through the 1920s, and demonstrating to visionaries like Hale the need for even larger collectors.