Dear Willy, Tom, Chilian, and all. The gnomonic complex of Puerta de Toledo, Madrid, was build in 1988 commemorating the 200 anniversary of the king Charles III death.
Juan J. Caurcel made the calculations and Alberto Corazón the design. As I understands, the right moon dial corresponds to the previous week of full moon, and the left one to the week after. (The light on the other weeks before and after new moon is insufficient to be read). Knowing the day before or after full moon, you follow the curve until the intersection with the moon shadow. Where you read the time displayed on the external arc. As Chilan correctly points, moon dials can be very imprecise. If I am not wrong, a complete study by Rafael Soler about these dials, will be published in a coming BSS bulletin. Regards Miguel G. Arrando 39.53N 3.03E _____ De: [email protected] [mailto:[email protected]] En nombre de Chiu ?,Chi lian Enviado el: sábado, 13 de noviembre de 2010 7:56 Para: Tom Laidlaw CC: Sundial sundiallist Asunto: Re: sundial complex in Madrid By the way, those day lines are set on an assumption that at mid-night of full moon night the moon passes the maridian. However, this is not the way it goes. The full moon passes the maridian before or after the midnight. The deviation varies month by month and covers a range up to100 minutes. In all, a simple moon dial like this usually does not give correct solar time. ChiLian Chiu N25, 121 2010/11/13 Tom Laidlaw < <mailto:[email protected]> [email protected]> I found another picture of that sundial in Madrid. According to the description the complex contains four sundials and two moondials. It looks like it has a vertical, equatorial, two polars so the ones on the front must be moondials, but I don't know anything about how moondials work. It is still a fascinating work. The link is below. <http://commons.wikimedia.org/wiki/File:Plaza_de_la_Puerta_de_Toledo_(Madrid )_01.jpg#filehistory> http://commons.wikimedia.org/wiki/File:Plaza_de_la_Puerta_de_Toledo_(Madrid) _01.jpg#filehistory Tom Laidlaw -----Original Message----- From: Tom Laidlaw [mailto: <mailto:[email protected]> [email protected]] Sent: Friday, November 12, 2010 2:28 PM To: 'Tom Laidlaw'; 'Willy Leenders'; 'Sundial sundiallist' Subject: RE: sundial complex in Madrid That's the first time anybody try to make a "universal dial" like that. If I can figure out the angles, etc. I am going to try to make one. Anyone else know more about this dial? Who made it, etc.? Tom -----Original Message----- From: <mailto:[email protected]> [email protected] [mailto: <mailto:[email protected]> [email protected]] On Behalf Of Tom Laidlaw Sent: Friday, November 12, 2010 2:10 PM To: 'Willy Leenders'; 'Sundial sundiallist' Subject: RE: sundial complex in Madrid Hi there, Looks to me like it might be trying to incorporate time zones? Tom Laidlaw -----Original Message----- From: <mailto:[email protected]> [email protected] [mailto: <mailto:[email protected]> [email protected]] On Behalf Of Willy Leenders Sent: Friday, November 12, 2010 11:53 AM To: Sundial sundiallist Subject: sundial complex in Madrid Can anyone explain the sundials on the left and right corner columns on the sundial complex with image address below. The sundials consist of intersecting curves. The sundial complex stands in Madrid (Spain). <http://www.flickr.com/photos/leokoolhoven/3973477239/sizes/o/in/photostream /> http://www.flickr.com/photos/leokoolhoven/3973477239/sizes/o/in/photostream/ Willy Leenders Hasselt in Flanders (Belgium) Visit my website about the sundials in the province of Limburg (Flanders) with a section 'worth knowing about sundials' (in Dutch): <http://www.wijzerweb.be/> http://www.wijzerweb.be --------------------------------------------------- <https://lists.uni-koeln.de/mailman/listinfo/sundial> https://lists.uni-koeln.de/mailman/listinfo/sundial --------------------------------------------------- <https://lists.uni-koeln.de/mailman/listinfo/sundial> https://lists.uni-koeln.de/mailman/listinfo/sundial --------------------------------------------------- <https://lists.uni-koeln.de/mailman/listinfo/sundial> https://lists.uni-koeln.de/mailman/listinfo/sundial
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