Hi Richard,
It seems you have reinvented Piet Hein's helical dial. See the home page of
Egeskov Castle, http://www.egeskov.dk/english/sightseeing/index.htm
and click nr. 25 on the map or in the list below it.
John Moir showed already that the dial does not function well outside the
equinoxes in BSS Bulletin 95.1.
I give an explanation of this ill-behavior in my website:
www.fransmaes.nl/sundials, choose Index and goto Kvaerndrup.
Regards,
Frans Maes
53.1N 6.5E
----- Original Message -----
From: "Richard Hollands" <[EMAIL PROTECTED]>
To: <sundial@rrz.uni-koeln.de>
Sent: 30 November, 2003 6:34 PM
Subject: RE: Dial design
I've just realized, thinking about it again, that the simplest
realization of a 'helical' dial is a single sheet of metal given a
half-twist of 180 degrees. So long as the edges are straight and the twist
is distributed uniformly then the desired "line o'light" effect will be
achieved.
[Richard Hollands] Reflection on your question suggests that you're right
and that the helical dial will only be accurate at the equinoxes. This is
the fallacy of treating mathematical abstractions as equivalent to
real-world objects.
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