Hi Anselmo &al, In the dusty corner of a mail folder I found an old message that I still wanted to respond to.
> From: Anselmo Pérez Serrada <[EMAIL PROTECTED]> > To: "Sundial, Mailinglist" <[email protected]> > Subject: Back again on thick gnomons > Date sent: Tue, 12 Feb 2002 15:44:33 +0100 > > Hi there, > > (This is a remark I passed to make two weeks ago and then I > forgot completely ) > > On 27th-JAN Rod Heil and Fer de Vries were discussing on > the thick-gnomon paradox, ie., the fact that sunrise hours and > sunset hours cross on the plate when the gnomon is thick so it > is not completely correct that these dials consist on two halves. > Do you remember? > > Well, my remark is as follows: of course Rod and Fer are right > and therefore Waugh is wrong in figure 5.4 of his book (page 41). > Anyway this is a mistake I have seen in many sundials and maybe > it is beause the error on the hour read is neglectible. > > Anselmo Pérez Serrada I don't understand why Waugh would be wrong in fig. 5.4. He is so smart as to include only hour lines from 6 am to 6 pm, and thereby avoids the common error that was correctly signalled by you, Fer and Rod. Kind regards, Frans ====================== Frans W. Maes 53.1°N, 6.5°E www.biol.rug.nl/maes/sundials/ -
