Device for determination of the hours of sunshine on a given date at a given location has an arrangement of two rings on which date, and time are set with latitude set by angling one of the rings at a corresponding latitude angle

摘要

Device comprises a ring (7) with a vernier scale (8) representing 24 hours of a day over 360 degrees and a second ring (9), with the same rotation axis as the first, arranged in a vertical plane along a North-South direction with the twelve months of the year represented around its scale. The axis of this ring is set at an angle corresponding to the latitude in the location under consideration.