Hi John, Since you are in a very dry climate with clear weather you may not notice that with hazy light the cone image is quite forshortened and points to an incorrect point. Yes, the cone points out a line very clearly and yes, it does look quite like a clock hand, but the very shadow tip position is quite a way off from what it should be. The spherical nodus and other symetrical ones, although not so attractive, give a much more accurate spot. The area of untruth may be mostly in declination rather than hour angle with most dials, such as your neat painted dial. You could try letting the light shine through some thin plastic to simulate haziness, or come visit us on the coast where hazy is very common. Of course, too hazy and nothing works.
for an azimuth dial it might work very well, where for a pillar dial, not so well. Thanks for the interesting ideas! Edley. --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
