Gravity Powered Pendulum Clock
Invented in 1656 by Christian Huygens, the physics properties of a swinging pendulum was the basis of all precision clocks until the 1940s. As noted by Galileo, the period of swing of a pendulum can be made very precise and stable depending only on its length.
This modern version is made faithfully in the original design powered only by gravity as the potential energy of the descending weight is transferred to the kinetic energy of the drive train gears and pendulum. The key feature of any pendulum clock is the anchor escapement mechanism- a curved piece attached to the pendulum with two prongs that only allows the escapement wheel to move forward one tooth per swing cycle, and producing the characteristic “tick-tock” sound.
The weight descends about 1 cm per hour, and when hanging from a wall the chain needs to be pulled once a week, raising the weight up about 2 m to keep the clock in operation. This beautiful clock, made by Hermle, features a chime that sounds upon the hour.