Angelo Brazzi wrote: > > I have to calculate a large orizzontal sundial (8-10 m stylus) and I need > to know how to > calculate, with a good accuracy, the sun declination for April 18 1693. The > formulae reported by > the sources that I have go back to 1900 but not further. Can anyone help me? > Thanks. > I found out about sundials mailing list from Sundials on the Internet. > > Angelo Brazzi
Angelo, I used the program Dialist Companion of the North American Sundial Society and the answer is 11.16 degrees at noon UT. See part of the output of this program. The Dialist's Companion Version 1.0 Latitude 51.5° N Date Sat Apr 18 1693 Longitude 0° Julian Day 2339524.00000000 Greenwich 12:00:00 pm Equation of Time + 01:00 Longitude Correction + 00:00 Total Correction + 01:00 Sun DIAL TIME 12:01:00 pm Altitude 49.661051° Azimuth 0.378911° W Declination 11.161565° Fer J. de Vries Netherlands.
