Back again on thick gnomons

[Anselmo P�rez Serrada]

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