EXHIBITS > The automatics of Heron >
Heron's (automatic) magic fountain
It was a most brilliant fountain which shot water higher than the available level of its reservoir defying ostensibly the beginnings of hydrostatic pressure.
It consisted of one open and two airtight containers placed one above the other. The middle airtight container was full with water and a pipette began a little above its bottom and led to a nozzle above the upper open container. When water was poured into the upper open container, this, through a pipe, flowed into the lower airtight container. The confined air in this was pressed and through another pipe it displaced the water of the middle container, forcing it to rise to the nozzle and to shape a small spurt. The spurt of water supplemented the water of the upper container (maintaining the level constant). Thus this process was self-supporting and it continued automatically until all the water from the middle container emptied.
SOURCES: "Heron of Alexandria, Pneumatics"