Illustration of the core in the mold, which made it possible to reduce the thickness and weight of the final disk.
This guide provides historical, digital, and archival resources on the pouring of the 200" disk which was used in the Hale Telescope at Palomar Mountain in California. When the disk was cast, it was the largest single piece of glass ever made.
The mirror was made using Corning Glass Works' signature Pyrex®, a special glass designed to resist heat expansion. After many years of trial and error experimentation, as well as the advent of World War II, the disk was finally installed in 1948 in the Palomar Observatory.
This LibGuide is a selective list of resources on the topic. For more information, please search our library catalog or contact a reference librarian through our Ask a Librarian service.