Carl wrote, > This would also apply to a nodus. I would guess John that your > sundial at > the Colorado school might be experiencing this. I believe its gnomon > ends > at a tip. I believe the shadow of this tip may be lost in the shadows at > this time of year.
There IS a way of locating the tip of a rod gnomon to better than 0.2mm which I demonstrated at the recent NASS McLean conference when talking about the latest version of my Precision Declinometer which utilises a principle suggested by the late Bill Maddux. This will appear in a forthcoming article in Compendium. The whole PowerPoint presentation was distributed with the electronic version. Tony Moss --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
