| Pendulums
Pendulums are available for most types of clocks and the correct length is often stamped on the back-plate of mass produced clocks. American clocks are in inches, German in mm, and French in lignes. The length is from the uppermost flexible part of the suspension to the centre of mass of the bob. In practice, this is the centre of the bob, but in theory it is a fraction higher. French clocks usually have the movement serial number stamped on the pendulum. If there is any discrepancy in this number and the number on the backplate, and the clock cannot be regulated, it may not be the original pendulum. Pendulums for French clocks vary in weight and size, and there are three standard types available. There is no specific rule on how to identify the type needed, but generally speaking: |