Hero's Fountain

Device constructed by Hero, which depends for its action on the elasticity of the air. It consists of two closed ve els, one above the other, the upper partly filled with water. They are so joined by a system of vertical tubes that, if water be poured into the lower globe through one of these tubes, the water in the upper one will be forced out through a vertical pipe and will rise to a height depending upon the dimensions of the instrument. Hero stratus. Victim of vain ambition, who fired the temple of Artemis at Ephesus 356 B.C.