Re: Stained Glass

[Brian Albinson]

Jack I have found you have to be careful when selecting stained glass for sundials.  The gnomon will not throw a shadow on transparent glass, but transparent glass will will project a coloured image on the floor.  When you look through transparent glass you can see objects behind it clearly. Translucent glass will accept a gnomon shadow but will project a black shadow on the floor.  When you try and look through translucent glass you will not see anything. Some glasses are a bit of both.  A black shadow on the floor usually means that the gnomon will throw a shadow on the glass face. If you have a transparent glass you particularly like for a dial, I have found grinding it with # 220 carborundum powder with water for a few minutes makes it useable. Brian Albinson Jack Aubert wrote: John, In your work with stained glass, have you found it possible to do anything useful or interesting using colored glass to project tinted shadows?  I know that sunlight coming into a church through a stained glass window can project colored images on the floor.    But from what I have been able to do with a couple of pieces of colored glass, it seems to me that a piece of colored glass in full sunlight just makes a shadow and the color is not noticeable.   I don't have a lot of different colors and shades of glass to experiment with, though.  Jack       --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial

---------------------------------------------------
https://lists.uni-koeln.de/mailman/listinfo/sundial