The 60-inch telescope on the Mount Wilson Observatory near Los Angeles. Its "first light" was December 8, 1908 when it was the largest operational telescope in the world. A reflector telescope of Cassegrain design, it became one of the most productive and successful telescopes in astronomical history, including the pioneering of spectroscopic analysis, parallax measurements, nebula photography, and photometric photography. Today it is one of the world's largest telescopes available to the general public.