Perkins Observatory were both growing. Light pollution therefore became increasingly problematic. So in 1961 the Perkins Telescope was moved to Lowell Observatory in Flagstaff, Arizona. Lowell is the largest private observatory (non-university or government affiliated) in the world. Through the end of the 20th century, the Perkins Telescope was the observatory’s largest instrument. Observing time on this instrument was shared between Lowell astronomers and the Ohio State University. The telescope at Perkins was immediately replaced with a cassegrain reflector telescope. It was donated by Michael R. Schottland, an entrepreneur from Martinsville, Virginia. At that time it was the largest privately owned telescope
Chamberlin Observatory the observatory is heavily affected by light pollution, which limits its use in scientific research. Chamberlin Observatory Chamberlin Observatory is an astronomical observatory owned and operated by the University of Denver. It is located in Denver, Colorado (US) in Observatory Park. It is named for Humphrey B. Chamberlin, a Denver real estate magnate who pledged $50,000 in 1888 to build and equip the facility. The observatory building was designed by Robert S. Roeschlaub, with the astronomical aspects and functions designed by Professor Herbert Alonzo Howe after he visited many observatories in the east. It was modeled after the Goodsell Observatory