Probably part of the endowment of instruments sent to the Physics Laboratory by Charles Emmanuel III and received by Father Cossu (1764); indeed, in the accompanying note we also see "una fontana di Erone di vetro".
Hero's fountain takes its name from the person considered its inventor: Hero of Alexandria (50-120 AD) who is famous not only as a great mathematician, but also as an inventor and builder of fountains and ingenious and astonishing machines, not only of the hydraulic kind. With such machines, Hero made water rise above towers and, exploiting the powerful jets of steam of his aeolipiles, produced rotatory and translating motion, thus anticipating by two millennia modern steam turbines and jet engines. Unfortunately the Aristotelians of the time considered his inventions simply as curious and extravagant toys.
The fountain is made of a round brass recipient (diameter 25 cm, height 6 cm) and two glass balls (diameter 17 cm) one of which placed immediately underneath the recipient and the other some 60 cm below the other. ...continues