Pendulum plane of oscillation of a pendulum, like a gyroscope, tends to stay constant regardless of the motion of the pivot, and that this could be used to demonstrate the rotation of the Earth. He suspended a pendulum free to swing in two dimensions (later named the Foucault pendulum) from the dome of the Panthéon in Paris. The length of the cord was . Once the pendulum was set in motion, the plane of swing was observed to precess or rotate 360° clockwise in about 32 hours. This was the first demonstration of the Earth's rotation that didn't depend on celestial
Foucault pendulum transport. There are numerous Foucault pendulums at universities, science museums, and the like throughout the world. The United Nations headquarters in New York City has one; the largest is at the Oregon Convention Center. The experiment has also been carried out at the South Pole, where it was assumed that the rotation of the earth would have maximum effect at the Amundsen–Scott South Pole Station, in a six-story staircase of a new station under construction. The pendulum had a length of 33 m and the bob weighed 25 kg. The location was ideal: no moving air could disturb the pendulum,