Saturn is the Roman name of the Greek god Kronos, a vengeful god and father of the chief god of the Greek Pantheon, Zeus. Chronos (Time) was another god who was depicted as a nubile lad. However, by the time of the Renaissance, Chronos began to take on the attributes of vengeful Kronos in depictions of Father Time. Thus, the Saturn dial may have a confused mythology behind it.
This dial is placed on a flat surface and automatically inclines to a 45 degree angle. The dial is turned so that the number XII points to true north. A bead of light on the glass gives the approximate local time.