The discovery of the pendulum for grandfather clocks is probably the most important thing that ever happened in relation to clocks. Galileo Galilei was the scientist who invented this movement initially, followed up by the Dutchman Christiaan Huygens who succeeded in fully integrating the pendulum into clocks.

However, the simple origin of the pendulum dates back to 200 AD in China. It was nothing more that a rope with something heavy on the end of it. Gravity and its own motion, will swing the weight back and forth.

After Christiaan Huygens invention in the year 1650, the basic components of pendulums have not really changed. What you need is a weight or spring, and that's what powers the movement. A train of rods and gears transmit the movement to the clock's hands. The weight is attached to a chain that is wound around a drum. As the weight goes down, the unwinding of the cord transmits movement to the gears and from there to the hands.

The pendulum clock can run faster or slower by lengthening or shortening the pendulum. It is possible to make very precise adjustments to the speed at which the pendulum swings so the time is always accurate.