Mechanical counter

They typically consist of a series of disks mounted on an axle, with the digits zero through nine marked on their edge.

Such counters have been used as odometers for bicycles and cars and in tape recorders and fuel dispensers and to control manufacturing processes.

It was based on chariot wheels turning 400 times in one Roman mile.

This engaged another gear with holes along the circumference, where pebbles (calculus) were located, that were to drop one by one into a box.

By the 3rd century (during the Three Kingdoms Period), the Chinese had termed the device as the 'jì lĭ gŭ chē' (記里鼓車), or 'li-recording drum carriage'[3] Chinese texts of the 3rd century tell of the mechanical carriage's functions, and as one li is traversed, a mechanical-driven wooden figure strikes a drum, and when ten li is traversed, another wooden figure would strike a gong or a bell with its mechanical-operated arm.