Foucault’s pendulum is a device to demonstrate the Earth’s rotation. The pendulum in the Flower Garden was conceived in 1908 by an astronomer, physicist, and a gymnasium secondary school teacher, František Nábělek, as a copy of the original device presented in 1851 by Léon Foucault. Since 1995, the exact copy of the original pendulum has been operating under the dome of the Panthéon, Paris. The swinging pendulum is a 20-kilogram bob suspended from a 22.35-metre-long wire. While swinging, the spike on the bob makes a print into the sand below, which demonstrates the Earth’s rotation. The pendulum placed in the Rotunda in the Flower Garden is one of four pendulums of its kind in the world.