Kater's pendulum minutes per day slower than at Paris, or equivalently the length of a pendulum with a swing of one second there was 1¼ Paris "lines", or 2.6 mm, shorter than at Paris. It was realized by the scientists of the day, and proven by Isaac Newton in 1687, that this was due to the fact that the Earth was not a perfect sphere but slightly oblate; it was thicker at the equator because of the Earth's rotation. Since the surface was farther from the Earth's center at Cayenne than at Paris, gravity was weaker there. Since that time pendulums began
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,