A hydrochronometer is a type of water clock. There are actually two of these extremely rare clocks located in Rome, the other is at Palazzo Berardi. Father Giovan Battista Embriaco was an inventor and professor at the College of St Thomas. Embriaco created this hydrochronometer in 1867, and after its completion, it was sent to the Paris Universal Exposition where it received several awards. The clock returned to Rome in 1873 and was placed on the Terrazza del Pincio in the Villa Borghese gardens. It was installed as part of a fountain…