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
Lowell, Massachusetts is River Meadow, or Hale's Brook. This brook flows largely in a man-made channel, as the Lowell Connector was built along it. Both of these minor streams have limited industrial histories as well. The bordering towns (clockwise from north) are Dracut, Tewksbury, Billerica, Chelmsford, and Tyngsborough. The border with Billerica is a point in the middle of the Concord River where Lowell and Billerica meet Tewksbury and Chelmsford. The ten communities designated part of the Lowell Metropolitan area by the 2000 US Census are Billerica, Chelmsford, Dracut, Dunstable, Groton, Lowell, Pepperell, Tewksbury, Tyngsborough, and Westford, and Pelham, NH. See Greater