Hero of Alexandria (lived AD 62)

Greek mathematician and engineer, the greatest experimentalist of antiquity. Among his many inventions was an automatic fountain and a kind of stationary steam engine. His books have survived mainly in Arabic.

Hero was also a teacher and in Alexandria founded a technical school with one section devoted entirely to research.

He regarded air as a substance that could be compressed and expanded, and explained the phenomenon of suction and associated apparatus, such as the pipette. His assumption that air is composed of minute particles was 1,500 years ahead of its time.

In mechanics, he devised a system of gear wheels which could lift a mass of 1,000 kg/2,200 lb by means of a mere 5 kg/11 lb. His work Mechanics contains the parallelogram of velocity and the laws of levers, and his construction of a variable ratio via a friction disc has been used to build a motor vehicle with a semi-automatic transmission.

Hero's book Metrica explains the measurement of geometrical figures. Pneumatica describes numerous mechanical devices operated by gas, water, steam, or atmospheric pressure, and siphons, pumps, and working automata in the likeness of animals or birds.