like Los Angeles. The Corning Glass Works was assigned the task of making a primary mirror. Construction of the observatory facilities and dome started in 1936, but because of interruptions caused by World War II, the telescope was not completed until 1948 when it was dedicated. Due to slight distortions of images, corrections were made to the telescope throughout 1949. It became available for research in 1950. A functioning one tenth scale model of the telescope was also made at Corning. The telescope saw first light on January 26, 1949, at 10:06pm PST under the direction of American astronomer Edwin Powell Hubble, targeting NGC 2261, an object also known as Hubble's Variable Nebula. The photographs made then were published in the astronomical literature and in the May 7, 1949 issue of Collier's Magazine. The telescope continues to be used every clear night for scientific research by astronomers from Caltech and their operating partners, Cornell University, the University of California, and the Jet Propulsion Laboratory. It is equipped with modern optical and infrared array imagers, spectrographs, and an adaptive optics system. It has also used lucky cam imaging, which in combination with adaptive optics pushed the mirror close to its theoretical resolution for certain types of viewing. One of the Corning Labs' glass test blanks for the Hale was used for the C. Donald Shane telescope's primary mirror. The collecting area of the mirror is about 31,000 square inches (20 square meters). Components The Hale was not just big, it was better: it combined breakthrough technologies including a new lower expansion glass from Corning, a newly invented Serrurier truss, and vapor deposited aluminum. Mounting structures The Hale Telescope uses a special type of equatorial mount called a "horseshoe mount", a modified yoke mount that replaces the polar bearing with an open "horseshoe" structure that gives the telescope full access to the entire sky, including Polaris and stars near it. The optical tube assembly (OTA) uses a Serrurier truss, then newly invented by Mark U. Serrurier of Caltech in Pasadena in 1935, designed to flex in such a way as to keep all of the optics in alignment. Theodore von Karman designed the lubrication system to avoid potential issues with turbulence during tracking. 200-inch mirror Originally, the Hale Telescope was going to use a primary mirror of fused quartz manufactured by General Electric, but instead the primary mirror was cast in 1934