The Water Clock
The first example of a feedback mechanism is believed to be the 3rd century BC work of Ctesibius who invented a mechanical water clock with an alarm. (Excerpt- Profitable Intelligence)
Description
Best reference work available about these little-known instruments of time measurement. A comprehensive history of each kind of timekeeper followed by an elaborately illustrated catalogue of 37 instruments. Full bibliography and index. 117 illustrations (40b/w, 55 full collor, 22 two-color drawings).
