The pendulum of Foucault which took its name from the French natural Léon Foucault, is a simple device created in 1851 to demonstrate the rotation of the Earth. Despite the fact that the Earth's rotation was a known fact that season, the introduction of the pendulum of Foucault was a proof of the rotation with a simple and understandable way. In most, the Foucault's pendulum became known from the homonymous novel by Umberto Eco.