Abstract:
The horizontal pendulums of the Grotta Gigante have a long history dating back to 1959. In the past the instruments have been revised several times. The main instrumental characteristics are exposed, including the noise spectrum calculated over about 30 years. A review on the main results obtained with the pendulums is made, results which cover the topics of Earth tides and loading effects, free oscillations of the earth, preseismic effects and regional deformations.