science · 03 October 1947 · 77 years ago
In 1947, after 11 years of grinding and polishing a 200-inch diameter telescope lens for the Mount Palomar Observatory was completed at the California Institute of Technology. This lens, the first of its size made in the U.S., began when 20 tons of molten glass at 2,700 deg. Fahrenheit were poured into a ceramic mold at Corning Glass Works, N.Y. on 2 Dec 1934. The glass lens was allowed to cool only one or two degrees per day over the next eleven months, and then brought to room temperature. The telescope in which the lens was mounted was named the Hale Telescope in recognition of the late Dr. George E. Hale who had initiated the project. The completed telescope was first used on 1 Feb 1949 by taking pictures of a Milky Way constellation.
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