Hi Anselmo, Have you considered a couple of modern innovations, seasonal markers and split analemmas? The seasonal markers show where and when the sun rises and sets through the year. These would work well at your latitude. The split analemmatic dial has separate ellipses for morning and afternoon and separate zodiac lines with analemma like corrections for the equation of time. Fred Sawyer provided the original mathematics in his analysis of the Longwood Gardens dial. See http://www.longwoodgardens.org/Sundial/Analemma.html.
Brian Albinson continued the development and built a simple split dial with Len Berggren at Simon Fraser University to test the ideas. See http://www.math.sfu.ca/~berggren/Dials_Examples.htm Helmut Sonderegger's article "Analemmatic Sundials and Mean Time" in the NASS Compendium Sept 2003, and reprinted in the NASS Sourcebook, is an excel review and explanation of these concepts that are built into his latest program "Alemma". See http://web.utanet.at/sondereh/sun.htm The print version of the Analemmatic Sundial Sourcebook is out of print but the digital version is available for US$30. See http://sundials.org/publications/sourcebook.pdf For practical construction advice and other interesting ideas check Steve Irvine's site on Keppel Henge. http://www.steveirvine.com/sundial.html Roger Bailey walking Shadow Designs N 48.6 W 123.6 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of anselmo Sent: April 9, 2005 3:45 PM To: sundial@rrz.uni-koeln.de Subject: On the greatest size of an analemmatic and more Dear all, Needles to say, this mailing-list is wonderful! Thanks for all your contributions on the greatest feasible size of an analemmatic. I have been making tests with the spreadsheet written by Roger and Helmut and simulations with POV-RAY, and so far I do believe that 6 meter (18 ft) wide could be a good upper bound, as Frans Maes suggested in his web (hartelijk bedankt voor uw web, Frans!). With that size the shadow of a common person does not reach the ellipse in the four central hours of summer days, which seems quite reasonable. Now my doubts lie in materials: I have been talking to people hwo knows about road construction and things like these and every one of them tells me a different thing about laying the numbers and the decorations. Any suggestion from you? Best regards, Anselmo - -
