Sources of Further Information
University of Illinois online meteorology guides including images and explanations of rainbows
Arizona State University Patterns in Nature site including explanations of rainbows and activities.
The Rainbow Bridge, Chapter 8, What are "all the colors of the rainbow"? including a history of explanations of rainbows.
Australian Severe Weather site including pictures of rainbows
AKM (German Halo Workgroup) site including pictures of halo forms
Atmospheric Optics site including explanations of halo forms.
Lee, R. L., Jr. and A. B. Fraser: The Rainbow Bridge: Rainbows in Art, Myth, and Science, Penn State Press, 2001.