Pictures by kind permission of
Smiths of Derby Group - Designers of the Ball Clock

 

HOW IT WORKS ?

The wheels to the right of the dial lift ball bearings up from a lower holding area and deposit them one by one on the main dial, one per minute, to show the number of minutes past the hour the time actually is.

On the hour the wheel of the
main dial turns one whole revolution thus spilling all the ball bearings into the receptacle directly below, and from there the balls run to the lower holding area and the sequence starts all over again.