Three Gallo-Roman bronze disks with astral inscriptions

This article concerns three archaeologically recovered circular bronze objects found at Gallo-Roman (first century BC–fourth century AD) sites in France. Through comparisons with other more or less contemporary objects of known function, it is argued that one of these disks definitely, and another likely, belonged to gearwork devices for keeping track of simple chronological cycles, while the third belonged to a clepsydra of a type recognized only recently.