On Wed, 26 Oct 2005, Tony Smith wrote: > Only 3 problems with front surface mirrors - expensive, hard to get, > and I don't think Archimedes had any. Make that two: he likely had ONLY front surface mirrors. Either bronze, silver, or mercury polished copper. Peter -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist