Re: Pin-hole projections on meridian lines in Italy.
Does anybody know what happened to the web pages that included Images of the solar eclipse of August 11, 1999 seen as pin-hole projections on various meridian lines in Italy. Bob, As I think you now, the Almanacco is still here http://tinyurl.com/yycey3 but they've deleted older stuff to make way for current. On a previous address for the site, however, the page was (inadvertently, I think) left undeleted, here: http://tinyurl.com/y3jc7m The photos aren't on it, but they can still be found here: http://tinyurl.com/u5rbn so that the page can be more or less reconstituted. -- Bill Thayer http://penelope.uchicago.edu/Thayer/E/home.html --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Pin-hole projections on meridian lines in Italy.
You can try this url: http://www.thebells.net/eclipse/ Bruno Caracciolo - Original Message - From: Robert Terwilliger To: 'Sundial Mailing List' Sent: Thursday, October 26, 2006 3:55 AM Subject: Pin-hole projections on meridian lines in Italy. Does anybody know what happened to the web pages that included Images of the solar eclipse of August 11, 1999 seen as pin-hole projections on various meridian lines in Italy. It was part of L'Almanacco Astronomico and the URL was: http://www.nauticoartiglio.lu.it/almanacco/Aa_ecli_13.htm The URL no longer works - it was a very interesting page and I'd like to have it backwith the NASS links. Bob ---https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Portable Dial Adjusted for EOT and DST
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
RE: Portable Dial Adjusted for EOT and DST
I wasn't aware that conventional Italian hours counted forward from sunset. Here's a new diagram showing Italian hours so defined. Brad -Original Message- From: Roger Bailey [mailto:[EMAIL PROTECTED] Sent: Thursday, October 26, 2006 1:29 PM To: Edley McKnight; Lufkin, Brad (Mission Systems); Sundial Mailing List Subject: RE: Portable Dial Adjusted for EOT and DST 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 babylonianItalian.png Description: babylonianItalian.png --- https://lists.uni-koeln.de/mailman/listinfo/sundial
date scale
Hello everyone! Thank you all for the help you gave mepreviously regarding "finding true north." I am now going to be pouring concrete for the date scale in my ananemmatic sundial. I am making the concrete pad 3 feet wide and 10 feet long. I have one question: do I lay out the center lineof the scale on the N-S axis, or do I lay it outon the 12:00 noon axis? The noon hour on the sundial is 10 inches off the N-S line.I appreciate your help. Thank you. Tracy --- https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Portable Dial Adjusted for EOT and DST
Hi Roger, Brad, I was just supposing that it was 9 hours before sunset, and guessing that I'd have to add 6 hours to the 3 shown. I AM interested in hours before sunset whatever one might call them locally. For instance, at exactly 45 degrees north latitude, when a vertical pole's shadow is pointing exactly west, it is 12 hours til sunset. Brad, Is it possible in your soda can model to have the hours before sunset actually calculated from true sunset, which does vary considerably at higher northern latitudes. I'd also be interested in being able to use a different size can, especially a taller one so that nearer the equator, summertime hours would all fit on the display. The soda can idea is certainly a great one, and the use of the gnomon that doesn't stick out to the side is also a neat idea. Hmmm, Chris Taylor's idea of duplicating the scales, showing AM hours on one set, PM hours on a separate set which would allow one color printing as well as reduce the clutter in winter months, sounds neat too! Yes, I'd like to try your java version as I run a number of operating systems. Thanks much! Edley McKnight From: Roger Bailey [EMAIL PROTECTED] To: Edley McKnight [EMAIL PROTECTED], Lufkin, Brad MMission Systems\ [EMAIL PROTECTED], Sundial Mailing List sundial@uni-koeln.de Subject:RE: Portable Dial Adjusted for EOT and DST Date sent: Thu, 26 Oct 2006 09:47:43 -0700 -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
Re: date scale
Hi Tracy, The date scale should be on the N-S centreline of the elliptical dial (i.e. the minor axis of the ellipse). The position of the 12 noon point is irrelevant. 3 feet by 10 feet is a big scale. How big is the dial? Regards Chris - Original Message - From: Tracy Paine To: sundial@uni-koeln.de Sent: Thursday, October 26, 2006 8:51 PM Subject: date scale Hello everyone! Thank you all for the help you gave mepreviously regarding "finding true north." I am now going to be pouring concrete for the date scale in my ananemmatic sundial. I am making the concrete pad 3 feet wide and 10 feet long. I have one question: do I lay out the center lineof the scale on the N-S axis, or do I lay it outon the 12:00 noon axis? The noon hour on the sundial is 10 inches off the N-S line.I appreciate your help. Thank you. Tracy ---https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
date scale
Hello Thank you Chris. In regards to your question, the major axis of my sundial is 33 feet. I used large basalt rocks for the hour marks. I tried to send a picture of it here, but the file was too big I guess. I plan to mosaic the top of the concrete date scale after it is cured. I would like to depict the analemma itself, colored according to the seasonswith the months marked around it. Tracy --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: date scale
Hi Roger Thanks for the info. I have HUGE rocks for the summer, spring/fall, and winter sunrises that lie just outside the sundial ellipse. However, after reading through the seasonal markers section of your website I now realize what the seasonal markers are. I placed the rocks so that the "line" from the sundial to the horizon, where the sun rises, passes through the center of the sundial! Oops! I am beginning to see now why this type of sundial is in an elliptical shape - I never fully understood that. I also have the seasonal sunrises marked further out on our property as well as the N-S and E-W lines. But they all line up with the center of the sundial. I am definitely going to add the "real" seasonal markers to the sundial. I have been working on this sundial project for quite sometime. I started a long time ago, and kept moving the location using portable hour marks. My shadow in the summer just about reaches the hour marks. I may make lines that radiate from the center out to the hour marks anyway. I really enjoy making this sundial. It is fascinating to me. I love learning new things about these sundials - some of it is over my head though and takes timeto figure out.I appreciate you all and the great information I have been getting. Thank you again. Tracy p.s. I have not seen the Shaha Lake analemmatic sundialyet. --- https://lists.uni-koeln.de/mailman/listinfo/sundial
