I know this isn't like your projection dials Thibaud, but one can have a sundial without any hour or date lines at all. I call these "Moment Dials" for lack better name. (Is there an official gnomonic name for these John Davis?). These are perhaps the simplest of all dials. They are simply a nodus whose shadow, or projected beam of light, indicates a specific time on a specific date. I saw a couple of them in old churches in Italy last year where there was a hole in the wall and a beam of light shined on a religious relic inside the church at a certain time on a certain date.
In this case of the odd stained glass structure in Venice, the entire round roof made of stained glass might cast its image centered on the circular floor at a certain date and time. So maybe it could be a "Moment Dial". I guess you're right that it isn't a true projection dial like the ones you and Fred came up with. Heck- it's probably just some sculpture that a crazed artist dreamed up! John From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Th. Taudin Chabot Sent: Saturday, September 26, 2009 12:45 PM To: sund...@rrz.uni-koeln.de Subject: Re: A stained glas projection dial? This is definitly no sundial, not even a projection dial. If it was the (shadow)lines should be curved. However the idea could be used to make a nice projection sundial. Thibaud At 18:54 26-9-2009, John Carmichael wrote: Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01CA3E8F.55EAD820" Content-Language: en-us Have any of you see this odd structure in the Giardini at the 2007 Venice Biennale? I'm trying to figure out how this might function as a sundial. If it is a sundial, it might be classified as a stained glass projection dial. My best guess is that when the colored projected image of the circle is centered on the white circular surface on the ground, that this is some significant time and date. Any ideas? See: http://www.flickr.com/photos/caranti/1405841967/in/pool-1207...@n23 John p.s. Photos of unusual existing and potential gnomons have been pouring into this pool. As of this morning there are 627 entries! http://www.flickr.com/groups/1207...@n23/ John L. Carmichael Sundial Sculptures 925 E. Foothills Dr. Tucson AZ 85718-4716 USA Tel: 520-6961709 Email: jlcarmich...@comcast.net My Websites: (business) Sundial Sculptures: http://www.sundialsculptures.com <http://www.sundialsculptures.com/> (educational) Chinook Trail Sundial: http://advanceassociates.com/Sundials/COSprings/ (educational) Earth & Sky Equatorial Sundial: http://advanceassociates.com/Sundials/Earth-Sky_Dial/ (educational) Gnomons, Styles & Nodi: http://www.flickr.com/groups/1207...@n23/ (educational) My Painted Wall Sundial: http://www.advanceassociates.com/WallDial (educational) Painted Wall Sundials: http://advanceassociates.com/WallDial/PWS_Home.html (educational) Stained Glass Sundials: http://www.stainedglasssundials.com <http://www.stainedglasssundials.com/> (educational) Sundial Cupolas, Towers & Chimneys: http://StainedGlassSundials.com/CupolaSundial/index.html --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial _____ Th. Taudin Chabot, . tcha...@dds.nl
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