This invention is described in his Pneumatics by Philo of Byzantium, an engineer of the 3rd century BC who lived in Alexandria. It is an automaton (robot) in the form of a maid (life-size) holding in her right hand an oinochoe. Inside the effigy were two containers, one with wine and one with water (as the Greeks drank the wine diluted), and a mechanism with tubes for transporting liquids and air. By placing a cup in the outstretched left hand of the therapist, one started the mechanism. With the pressure of the air, the liquids (first the wine and then the water) were channeled through the right hand to the oinochoe and from there to the cup, in the desired proportion. The automatic healer is the oldest known working robot.
The figure of Philon’s automatic healer on the obverse of the coin is based on a representation by the Kostas Kotsanas Museum of Ancient Greek Technology.