A Kleroteria

This is a Kleroteria, a device used in ancient Greek (read: Athens) to randomly select judges for trials.

IT was working as follows; Each slot was filled with a bronze ticket (pinakla) that was carried by citizens that were eligible for jury duty. Then on top right of the machine would a funnel be places with black and white balls - these would, in random order, fall down through a tube. They were then to be released one by one, a white one indicating that the row it represented would be serve as judges for the day, a black one that they wouldn't.