>Hi Mac, > >It seems to me, since the position of the lines on the dial plate are >determined in part by the length of the gnomon, the length of the gnomon >must be know first. > >For example if you are designing a dial which is to have a 6 inch gnomon, >AND you wish to take advantage of a ball tip, it seems to me you would >measure six inches to the ball center and use the center of the ball's >shadow as the indicator. > >Does this make sense? > >Charles
Hello Charles, Yes, that makes sense. I do wonder, however, if under certain conditions it'll be tough to see where the center of the ball's shadow is. For example, when the sun is at a small angle to the dial won't the ball's shadow be elongated (maybe VERY elongated) and the center hard to pin point? Mac
