The 200" Disk and the Hale Reflecting Telescope

A brief history of astronomy, from the use of constellations to determine the seasons, to the invention of the telescope, with a good explanation of refracting and reflecting telescopes. The film also presents the making of the mirror by Corning Glass Works for the Hale telescope at Mt. Palomar; the lens of the Kitt Peak National Observatory; and an introduction to high altitude telescopes. Briefly discusses Corning’s contribution for the uses of glass in space exploration.

Provides details of telescopes and their use, and the history of the building of the Hale telescope on Mt. Palomar, California. Although there is only a brief mention of the casting of the Pyrex 200" disk, there is much coverage of its grinding and polishing, its transportation to the observatory and its installation and use.

The film traces the story of the Chicago-born astronomer George Ellery Hale, considered the father of astrophysics, as he struggles personally and professionally to build the greatest telescopes of the 20th century at the Yerkes and Mount Wilson Observatories, and finally the 20-year effort to build the million-pound telescope on Palomar mountain beginning in the 1930s