Aha, reverse Italian hours! The blue lines on Brad's drawing showing Babylonian hours, the time from sunrise, also would show reversed Italian hours, the time until sunset. Although the normal convention is for Italian hours to start at sunset and count forward through the night and following day, a few old dials use this reversed Italian system. The old dial on the Hotel Ruze, a 1586 Jesuit College in Cesky Krumlov, is one example showing Babylonian and reversed Italian hour lines. (Timelines slide 25, 26) http://www.ckrumlov.cz/uk/mesto/histor/t_sluhod.htm
It is interesting to think these things through! Roger Bailey -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Roger Bailey Sent: October 26, 2006 9:48 AM To: Edley McKnight; Lufkin, Brad MMission Systems"; Sundial Mailing List Subject: RE: Portable Dial Adjusted for EOT and DST -----Original Message----- <On the Babylonian and Italian hours you add 6 if necessary? <Edley McKnight Hello Edley, Italian and Babylonian hours are 6 hours from local time only on the equinox. Italian hours start at sunset; Babylonian hours start at sunrise. Both involve 24 equal hours per day. Since sunrise and sunset times vary through the year, the difference from local time varies as well. See my "Timelines.ppt" presentation, a 16.5 MB file at http://www3.telus.net/public/ormerod/NASSVanRTB/ On Brad's "sodaCan.png", I only see the blue lines for Babylonian hours, with black AM and red PM civil times and no Italian hours. It is interesting how these Babylonian hour lines are fairly flat through much of the year and much of the day, diverging most around the summer solstice and noon. Not surprising when you think about it, the altitude of the sun being fairly constant at a given time after sunrise. This is the benefit of concepts like this. They get you to "think about it". Thanks Brad, for the challenge. Roger Bailey Walking Shadow Designs N 48.7 W 123.4 --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
