Helios watch is crafty and interesting. The dial is a representation of the sun, with its rays forming the conventional display. An inner display called the moon shows the minutes and makes a full rotation every hour. At noon, the dial shines brightly to indicate the sun, while at midnight, the sunbeams make way for the moonbeams with darkening segments. Helios watch by F. Jouvenot is a remarkable piece, by all standards possible.
Via: Tuvie
