Perkins Observatory is an astronomical observatory in Delaware, Ohio. It is owned and operated by Ohio Wesleyan University. In 1931 it had the third largest telescope in the World; the 69 inch aperture Perkins telescope came online at this observatory. The mirror was the largest cast in the United States up to that time, and it was made by the United States National Bureau of Standards. In the 1930s this observatory also started periodic document release called The Telescope, featuring results from the telescope but grew to include other astronomical information.