Clock Presented to Charlemagne
The French historians describe a clock sent to Charlemagne in the year 807, by the famous eastern caliph, Haroun-al-Raschid, which was evidently furnished with some kind of wheel-work, although the moving power appears to have been produced by the fall of water. In the dial of it were twelve small doors forming the divisions for the hours, each door opened at the hour marked by the index, and let out small brass balls which, falling on a bell, struck the hours—a great novelty at that time. The doors continued open until the hour of twelve, when twelve figures, representing knights on horseback, came out and paraded around the dial-plate.