Dear Claude, Those are fascinating pictures especially:
http://www.gallerydiabolus.com/gallery/upload/utisz/my%20sun%20and%20your%20s un3.jpg This is almost straight out of M.C. Escher! You ask: What's the declination of that wall? That's a fun question. As with many Escher drawings the whole thing is delightfully impossible so I would say that this is "an undeclining wall". Unfortunately, his high standard of draughtsmanship is not quite matched by his understanding of sundials: 1. He has horizontal gnomons which are fine if you are on the equator or if you have a traditional unequal-hours design but... 2. The hours go round clockwise which suggests north-facing dials but... 3. They should go from VI to VI not from 7:30 to 4:30 or... 4. If unequal-hours he should have VI at the bottom not XII. 5. The two dials show different times which is understandable for an impossible figure but, since they differ by about one hour, maybe one is for daylight saving time? I shall print it out and colour it in! Frank H. King Cambridge, UK --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
