During the Great Depression, people had to find entertainment
wherever they could. One spot was at the Corning Glass works in
New York. The company was casting the mirror for the 200-inch
telescope at Palomar Mountain, California. People were so
enamored of this "Giant Eye" that they bought tickets to watch
the mirror being cast. That process began 75 years ago today,
when workers at Corning Glass began melting 20 tons of glass. It
was a daunting task. Large telescope mirrors can sag under their
own weight. And glass expands and contracts as it heats and
cools. Both of these things can ruin the view of the night sky.
So after several failed attempts with conventional glass,
Palomar Observatory turned to Corning and its new material,
Pyrex -- the same type of glass used in cookware. It doesn't
expand and contract very much, making it a perfect material for
telescopes. The first casting failed. But a second -- which
started on December 2nd, 1934 -- was a success. After months of
work, the mirror was shipped cro