Pendulum and Weights

The pendulum and weights represent the heart of the Ptuj tower clock – acting as the motor that drives the entire mechanism. Every part of the clock construction has its own specific function, contributing to the operation of this magnificent device.

This cleverly designed mechanism allows the clock to function without the need for external energy sources, such as electricity or batteries. It is a simple yet effective system that utilizes the basic physical principles of gravity and oscillation to measure time.

Throughout the centuries, such a clock represented the peak of technological development and remains an admirable example of human innovation and skill to this day.

In addition to the pendulum, the four stone weights are a key part of the clock. During the day, they can be observed at different heights as they slowly descend. Each weight is equipped with a pulley, which is clamped into the stone using a special zinc casting method. The zinc spreads through the pores of the stone, ensuring a strong attachment of the pulley to the weight.

A steel cable is run over the pulley and attached to a drum in the clock mechanism at the top. As the weights slowly fall due to gravity, they rotate the drums and thereby drive the gears in the mechanism. This movement is the energy source for the clock’s operation, similar to a battery in a modern clock.

Since the weights are constantly falling, they would eventually reach the bottom of the tower. To prevent this, the weights must be regularly wound up – raised back to the top. In the past, this task was the daily duty of the clockmaker or the town guard.