Dear Chris, Bill & all, I can add some information, based on my article on the Genk cone dial in the Bulletin of the Dutch Sundial Society, May 2005.
Javier Moreno Bores mentioned the relationship between conventional hour lines and Bab. & Ital. hour lines already in his article in the NASS Compendium 5(2), June 1998. The beautiful minimalistic sundial Chris mentioned is located in the Spanish sundial town of Otos (some 70 km south of Valencia). It was made by Joan Olivares (gnomonics) and Andreu Alfaro (artwork). A picture can be found at: http://www.ruralotos.com/ruta_rellotges.htm. Although it might look like an equatorial dial, it is in fact a horizontal dial. The hours are indicated on the concrete base: numbers for the even hours, points for the odd ones. The circle was mainly meant as an artistic addition. It does serve a calendrical function, though: at the equinox its shadow becomes a straight line. By adding hour and half-hour lines, and Bab. & Ital. hour numbers, this nice sculpture could be converted into a triple sundial! Best regards, Frans Chris Lusby Taylor wrote: > > Thank you, Bill, for your very kind words. I'm glad my article hit the > spot for you. I'm very fond of Italian Hours - one thing a sundial does > a whole lot better than a watch is to tell you how long it is to sunset. > > The originator of the cone gnomon is, I believe, Javier Moreno Bores. > I'd seen pictures of his dial at Genk. While working out how it must > work, I realised (as he surely knows) that its hour lines are exactly > the same as the half-hour lines of a conventional sundial. I also > spotted that you don't need the whole cone - any conic section would be > just as good. So a circular disk or ring surrounding a conventional > gnomon would tell Italian and Babylonian hours on the existing hour lines. > > At that point, I remembered seeing somewhere a picture of a sundial with > a gnomon consisting of a shiny metal tube that was bent to form both a > polar gnomon and an equatorial circle. So, someone else seems to have > had the idea of combining both gnomons on one dial before I did. Very > sorry, but I don't know who. > > While thinking of other ways to realise the gnomon physically, I thought > of using a CD. It turns out to be ideal, except for the hole in the > middle, as its silvering helps you hold it at the correct angle. > > If anyone reading this is not a member of the BSS and would like a > picture of my "Universal Italian and Babylonian Hours Accessory" > consisting of nothing more than 3/4 of a CD, please email me off list. > Please be careful not to email the whole list. > > Chris Lusby Taylor > 51.4N 1.3W > > > > > ----- Original Message ----- > *From:* Bill CS.Com <mailto:[EMAIL PROTECTED]> > *To:* sundial@uni-koeln.de <mailto:sundial@uni-koeln.de> > *Sent:* Thursday, March 29, 2007 7:31 PM > *Subject:* Article in March BSS bulletin > > I want to recommend Chris Lusby Taylor's article in the March BSS > Bulletin > on Italian/Babylonian hours and how they relate to the horizontal > sundial. > I had never really been interested in these hours much before, and > did not > understand the geometric principles involved. Chris's article took > a little > work for me to understand, but it was worth it, as the illustrations and > text were right-on. I now understand how cone gnomons can naturally > display > these hours. > > Best of all, he describes a method for easily telling hours from > sunrise, or > hours to sunset, from a horizontal sundial, using just a (destroyed) > round > Music CD. Very clever. Chris, did you discover this method > yourself, or is > a modern day adaptation of a previously known method? > > Bill Gottesman > Burlington > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > > ------------------------------------------------------------------------ > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
