A clarification Because of my bad English, I fear that the last sentence of my last Email can be misunderstood. Also a shepherd sundial with the cylinder surface developed on a plane is an altitude sundial and can not be fixed to a wall.
It must be drawn on a mobile plate which can be suspended vertically and rotated. Gianni Ferrari
--------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
