Hi Everyone, Does anybody know the name the device described below?
It looks like a glass sphere held in the center of a small equatorial sundial. The image of the sun focuses to a point at some short distance away from the surface of the glass sphere. Held in place at this distance away from the glass and following the curve of the sphere is a piece of waxpaper against a dark background. When the sun shines, the waxpaper is scorched. When the sun is behind the clouds, it is not scorched. The result is a recording of the amount of sunshine seen at that location on that day. At least this is how it appears to me from a picture I have seen. Anybody have a name and possibly a source to buy one? Thanks, Chuck.
