A Hydrochronometer is a kind of a water clock.
In 1867, Fr. Giovan Battista Embriaco created a Hydrochronometer, and sent it to the Paris Universal Expo of 1867, where it received many prizes. The Hydrochronometer has the shape of a wooden pinnacle made of cast iron fused as tree trunks, while its four dials are visible from every direction.
In 1873, the Water clock was in Rome and was placed in Villa Borghese gardens into a fountain realized by the architect Gioacchino Ersoch. It's still placed there and works 24/7.
In June 2007, after two years of restoration at ELIS School, it was restarted by the Town Major of Rome.