Foucault pendulum with a 67-m-long wire from the dome of the Panthéon, Paris. The plane of the pendulum's swing rotated clockwise approximately 11.3° per hour, making a full circle in approximately 31.8 hours. The original bob used in 1851 at the Panthéon was moved in 1855 to the Conservatoire des Arts et Métiers in Paris. A second temporary installation was made for the 50th anniversary in 1902. During museum reconstruction in the 1990s, the original pendulum was temporarily displayed at the Panthéon (1995), but was later returned to the Musée des Arts et Métiers before it reopened in 2000. On April 6,
Foucault pendulum vector diagrams would not be observable in relation to the pendulum swing with this type of connection. At the equator the rotation of the Earth is not observable in relation to the pendulum swing because the plane of the pendulum swing is moving along with the rotation of the Earth and no net change in relationship occurs. It is shown by the diagrams that the surface velocity vectors of the Earth underneath the swing of the pendulum are either balanced in the same direction or included within the same plane as the pendulum swing. For the equatorial pendulum with a swing in