In 1948, the 200-inch (5.08 m) reflecting Hale telescope at the Palomar Mountain Observatory in California was dedicated. This was the first in the world with a 200-inch lens, which after casting was permitted to cool slowly over an 11 month period. The resulting 20-ton glass disk then required years years of careful grinding and polishing, interrupted by WW II. The telescope was officially named after Dr. George Ellery Hale who conceived, designed and promoted this telescope, though he died before it was completed. On 1 Feb 1949, studies first began with observations were first made of the constellation Coma Berenices. Explorer of the Universe: A Biography of George Ellery Hale, by Helen Wright. - book suggestion.