The Oxford History Of The Classical World

The Furniture Of Democracy, fifth to fourth century B.C. The bronze wheels are public ballots: Aristotle tells us that those with solid axles
were for acquittal, the hollow for condemnation, and the voter could conceal his vote by holding the axle between his fingertips. These were
found in a building at the north-east corner of the Agora in Athens, near a clay bin, which might be a ballot box, and a water-clock
(klepsydra) for timing speakers in the law court. The fragmentary inscribed plaque is an identity card for a juror; the bronze ball for use in a
machine by which jurors were allotted at random to serve in different courts.