Dear Frank, I am confused. Not so much about the term Heliodrom - which I never heard up to now - but about your sundial design / drawing. Could you please elaborate a little bit about it? Thank you and kind regards Siegfried
Siegfried Netzband Hebelstr. 12 75233 Tiefenbronn Tel: 07234 2802 Fax: 07234 942909 E-Post: [email protected] Skype: siegfried75233 www.ferienhaus-frieseneck.de -----Original-Nachricht----- Betreff: Re: Heliodrome Datum: 2019-03-18T14:20:41+0100 Von: "Frank King" <[email protected]> An: "[email protected]" <[email protected]> Dear Fabio, Many thanks for your photograph and explanation. This is just what I needed. I see that the heliodrome is 'the region of the celestial sphere bounded by the two tropics and the local horizon'. I now appreciate that I have been designing heliodromes for 40 years without knowing it! When I first read your message I had two thoughts: 1. For a sundial to show a heliodrome it must have a nodus. 2. A sundial can never show the whole heliodrome because any real sundial has edges. Both thoughts are WRONG. I attach an image of a paper sundial that I designed last year and you can see: 1. There is no nodus. 2. The surrounding circle is the projection of the horizon so you can see the WHOLE heliodrome. I think I shall use this word more frequently! Frank Frank King Cambridge, U.K. --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
