Ctesibius

Ktesibios from Alexandria ( Egypt), ancient Greek Κτησίβιος ὁ Ἀλεξανδρεύς, was a Greek engineer, inventor and mathematician who lived in the first half of the 3rd century BC.

Ktesibios worked under Ptolemy I and Ptolemy II in the library of Alexandria. He is regarded as one of the first engineers at all. His pupil was probably Philo of Byzantium. His designs are known from Alexandria and Vitruvius Heron. In his father's barber shop Ktesibios should have installed an adjustable mirror and have thereby discovered the physicality and ability to work the air. His work " Περὶ τῶν πνευματικῶν " ( pneumatics) was groundbreaking.

The most important inventions shall apply:

• Spring catapult (air release): In ( two) Bronze cylinders compressed air and thus biased bronze leaf springs. When opening the valves of the leaf springs were thrown objects such as a lever, for example stones through the relaxation.
• Fire hose (suction and pressure pump ): The most important invention of the Ktesibios represented the combined suction and pressure pump, which was used later with attached hose for extinguishing fires.
• Water meter with gear drive: using a pointer attached to a cork floats (vertical hour scale ) was measured by the time the water supply in a closed vessel. By gears on racks figures were also rotated. Another version moving through gears on a rotatable cylinder calculated for any time of day hour display. A replica is now in the Deutsches Museum in Munich.
• Water organ: The water organ of Ktesibios ( organon hydraulikon ) as compressed at the pressure pump air to produce sounds. This invention was frequent dissemination especially in ancient Rome.
• Water Level Controller: A kind of self-closing valve and thus an anticipation of the principle of control theory