Square table alarm clock, German, c 1550.
© Science Museum / Science & Society Picture Library
This clock was probably made in the Augsburg area and is typical of timepiece work of the mid-16th century. It is almost wholly constructed of iron. The dial has a single hour-hand and two main sets of figures: numbered 1-12 twice over and 1-24, to allow for the use of the 24 hour clock in Italy up until the end of the 17th century. Raised touch-pins around the dial are for finding the time at night. Timekeeping is controlled by the usual verge escapement with a dumb-bell shaped balance. There is an internal bell, and the alarm sounds through a decorative grill in the side of the clock.