News & Updates:

Like the website?
Recommend Us To a Friend

Clocks, Watches, Musical Boxes - Part 1

The earliest clocks with movements driven by the power from a falling weight had neither hands nor dial, and marked the hours by striking a bell. Eventually, a face to show the hours was added, and at a later date the hours were divided into minutes and a further hand affixed to indicate them. These clocks were heavy iron-framed affairs, usually placed high inside a tower within which the weight had a good distance to travel before it needed rewinding.

Regulation to prevent the weight crashing down from top to bottom of the tower was achieved by a device known as a Foliot balance. In this, the final wheel in the train was set on a hori­zontal spindle. The wheel, called the crown wheel because of its appearance, was cut with comparatively long angled teeth into which fitted alternately two flat plates (or pallets) on an upright spindle. At the top of this latter spindle was a shaped arm with adjustable weights at either end for regulating the speed of the clock. For smaller indoor clocks the swinging arm was replaced by a wheel, and the speed was controlled by making the weight lighter or heavier.

Early in the sixteenth century appeared the first clocks using a coiled spring instead of a weight. The fact that the power exerted by a spring grows less as it uncoils was the subject of much research, and a device known as the fusee was the successful outcome. It takes the form of a cone-shaped drum with grooves on to which the gut or chain from the mainspring drum is wound. As the spring is uncoiled it reaches the larger circumference and this equalizes the weakened pull. The use of springs and fusees encouraged the making of portable clocks and these, first made in Germany, soon became popular. Their time-keeping, like that of all other clocks, was erratic and the sundial remained an essential standby.

Fig. 8. The Foliot.

Related terms include mckeown's price guide to antique & classic cameras and jewelry collecting.