The following article is a reprint from the Journal of the AAVSO, Vol. 7, No. 2. We acknowledge and thank the editor of the Journal of the AAVSO for graciously allowing us to reprint this article for the benefit of our observers and readers.
Peter L. Collins
Mt. Hopkins Observatory
Tucson, AZ 85721
The following article is a reprint from the Journal of the AAVSO, Vol. 10, No. 1, 25, 1981. We acknowledge and thank the editor of the Journal of the AAVSO for graciously allowing us to reprint this article for the benefit of our observers and readers. Kenneth C. Beckmann
201 West Springfield
Union, Missouri 63084