specially to Gianni Ferrari for his thorough analysis of the question. In middle latitudes we've got +/- 30 deg around the EW line to 'place' our gaps. This is enough to see with a certain frequence alignments like that described by John Carmichael. And I suppose as well this is the reason why many burial monuments and temples from all ages have got EW oriented 'windows'.
As this kind of things are so appealing to the public, I am considering including a collection of pictures on this topic in our web, so please, send me more like these by Jean-Paul Cornec. As regards to conical gnomons I must say that they're a gold mine: they've got thousands of nice properties and can be used for everything (azimuthal, babilonical-italian or sidereal hours, shadow-plane sundials, and so on) as you can see in Fabio's web www.nonvedolora.it And, talking about the past, F. Menendez Pidal discovered that the old Spanish village of Castil de Peones (42º28'58''N 3º23'2''W) has got a sundial in his coat of arms (see attachment). We do not know much about heraldics and ignore how, when and why could the sundial arrive there. Any hint? Do you know of any other old sundial-logos? In these tragic days we're living, best wishes for all. Anselmo Perez Serrada Attachment converted: Macintosh HD:CastilDPeones.jpg (JPEG/JVWR) (0006D97C)
