Since the 13th century, a few special public clocks have included the movement of the sun, moon, earth and other planets, and from those early days Jacks were devised as human figures which actually "struck" the hours. Soon thereafter, automata appeared as mechanical figures that performed many and various acts, such as the four knights on horseback who joust on the hour at the Wells Cathedral in England. Over 300 clocks, for buildings or tabletops,...