If I understand Mac Oglesby's recent Compendium article on shadow-plane dials properly, and if the gnomon is aligned with the earth's axis, then the hourlines will not change through the seasons, even though the ground is irregular. The declination would irrelevant.
Bill Gottesman Burlington, VT, USA lat 44.47583, long -73.202581 In a message dated 2/9/00 11:15:43 AM Eastern Standard Time, [EMAIL PROTECTED] writes: > Because the sun's declination changes during the year, changing the angle > that the sun strikes the style, will this technique produce the same shape > hour lines if it is done at any time of the year or is the declination > irrelevant? Will this technique produce the same shape hour lines at any > time of the year? I think it should. but I'm not sure. > > John Carmichael
