There generally are two ways to go with a telescope: distance or width. Early telescopes focused primarily on magnification of distant stars, but the section of the sky they captured was tiny. By contrast, George Hale wanted his telescopes larger — way larger. He supervised the installation of the 60-inch telescope at the Mount Wilson observatory in 1907, and then a 100-inch one eleven years later. Then he began work on his own that would be larger than the first two put together.

On this day, June 3, in 1948 in a ceremony at the Palomar observatory near Los Angeles, Hale dedicated his new 200-inch telescope, the largest in the world.

Creating the 200-inch lens would be no easy feat. Not only did the glass have to be twenty-six inches thick and weigh 20 tons, but the function for which it would be used required it also be almost completely free of imperfections. Hale turned to a New York company, Coring Glass — the same one that today makes the glass on the iPhone and other touchscreen phones.