Hi Frans and Martha: That's a fine sundial and a great webpage. I also like the terminator maps, but I particularly like the time correction feature on the date line. This built-in table of correction values solves in a simple neat way the problem of showing the Daylight Savings Time correction (or legal time in Mexico) as well as the correction for The Equation of Time, without the use of a confusing analemma on the date line.
I noticed that the date divisions are at ten day intervals so that the correction numbers don't look crowded. If one week divisions were used, the dateline might get pretty busy. Looks great the way it is. I also noticed that this dial is located very close to the Tropic of Cancer, making the dateline almost reach the time line. So this dial is about as close to the Equator as you can make an analemmatic and still have it work ok. There are also problems with analemmatic gnomons being too short in the tropics (Does anybody even know of any analemmatics located in the tropics? I doubt there are any.) John p.s. Is it correct to say that an analemmatic face collapses into a polar dial at the equator? John L. Carmichael Jr. Sundial Sculptures 925 E. Foothills Dr. Tucson Arizona 85718 USA Tel: 520-696-1709 Email: [EMAIL PROTECTED] Website: <http://www.sundialsculptures.com> ----- Original Message ----- From: "Frans W. Maes" <[EMAIL PROTECTED]> To: "Sundial List" <sundial@rrz.uni-koeln.de> Cc: "Villegas, Martha" <[EMAIL PROTECTED]> Sent: Monday, February 10, 2003 7:12 AM Subject: Analemmatic sundial in Torreón, Mexico > Hi all, > > An enthousiastic group, headed by Martha Villegas, has established a > beautiful analemmatic sundial in Torreón, Mexico, probably the first one in > the country. > > Read all about it at: http://www.biol.rug.nl/maes/torreon/welcome-e.htm > > A special addition here are the terminator maps, depicting the twilight line > across the Mexican Republic at local sunrise and sunset on three dates. > > Regards, > Frans Maes > 53.1N, 6.5E > > > > - > -
