This is the central hall, about 12 meter high. On the left is visible a little model of the Foucault Pendulum mounted on a platform which can be rotated. This small exhibit is used to show to the visitors the property of invariance of the plane of oscillation. On the right there is the console containing the control electronics. This Foucault Pendulum is the greatest and the only permanently oscillating (entertained) pendulum in Sardinia and one of the few correctly working all over Europe. In fact, the permanently oscillating pendulums are rare, owing to the great difficulty of reducing all the errors and perturbations in the symmetry of the suspended mass, in the suspension “pivot”, in the positioning of the exciting magnet and so on: all these errors are cumulative in time, so obtaining a correct deviation is a very delicate task. ...continues