Τhe sub-divided wheel of Philon

A variation of “tympanon”

It was a machine for pumping water of small differences in height. It consisted of a rotating narrow construction “tympanon” internally divided into eight radial triangular parts. An opening corresponded to each triangular part in its circumference for the inflow of water when it was at the lower point in its course and a hole at the top for the outflow of trapped water when it was at the higher point. A built-in treadmill on the “tympanon” or radial water – driven wings were used to initiate the pump. There was also the possibility of a reverse use of the mechanism as a generator.

SOURCES: Philon of Byzantium, Pneumatics, 61, Vitruvius, On architecture, X 4.