Earliest Clocks.
The first clock which appeared in Europe was probably that which Eginhard (Secretary to Charlemagne) describes as sent to his royal master by Abdallah, King of Persia. "A horologe of brass, wonderfully constructed, for the course of the twelve hours, while as many little brazen balls dropped upon bells underneath, and sounded each other." The Venetians had clocks in 872, and sent a specimen of them that year to Constantinople.