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
Perkins Observatory instrument on site, interest in Perkins Observatory within the Ohio State University Astronomy Department declined. The on-site staff shrank until there was just a part-time secretary and a building superintendent who had only a small maintenance budget. Few of the observatory’s Directors (employees of OSU) spent much time at the observatory. There was not even enough money in the budget to maintain subscriptions to prominent astronomy magazines for the Observatory’s library. For some years a small dome detached and separated from the main observatory building housed a 0.6-meter f1.8 Schmidt telescope. In 1990 this instrument was moved to Lowell Observatory