Dear Isabella and others, The double ring sundial on the indicated website has two errors.
1. The person as drawn must not stand with two feet on one side of the centerline, but with the feet on either side of the centerline. 2. The inner ring is always wrong. You better leave him out. He is supposed to indicate the clock time, but because the equation of time is not included in it - increasing to around plus or minus fifteen minutes - he may not be correct. A sundial is just as attractive because, as the only simple instrument, it indicates the natural time, adjusted to the position of the sun. For all kinds of other (mostly unnatural and artificial) time displays, we have plenty of other instruments: wristwatch, tower clock, computer, telephone, etc. Willy Leenders Hasselt in Flanders (Belgium) > Op 31 dec. 2019, om 13:55 heeft Frank King <[email protected]> het volgende > geschreven: > > Dear Isabella, > > There is nothing very special about the double ring design. It is (more or > less) two ordinary analemmatic sundials, one superimposed on the other. > > This version was popularised by Douglas Hunt and you should explore his > website... > > http://www.sunclocks.com <http://www.sunclocks.com/> > > Practically anyone who uses this mailing list can advise you! > > Frank King > Cambridge, U.K. > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial >
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