464. Hero’s fountain. Water being poured into upper vessel descends tube on right into lower; intermediate vessel being also filled and more water poured into upper, confined air in cavities over water in lower and intermediate vessels and in communication tube on left, being compressed, drives by its elastic force a jet up central tube.
Notes:
Brown is referring to “Hero of Alexandria.” In this description it was spelled “Hiero” but in 474 he spells it “Hero” which is more commonly used at present, so we have made the correction.