Ctesibius of Alexandria

or Ktesibios of Alexandria

flourished с 270 BC

Greek physicist and inventor.

He was the first great figure of the ancient engineering tradition of Alexandria, Egypt, which culminated with Heron of Alexandria and Philo of Byzantium. He discovered the elasticity of air and invented several devices using compressed air, including force pumps and an air-powered catapult; an improvement of the water clock, in which water dripping at a constant rate raised a float with a pointer; and a hydraulus (water organ), in which the weight of water forced air through the organ pipes. His writings have not survived, and his inventions are known only from references to them.

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▪ Greek physicist and inventor

Ctesibius also spelled  Ktesibios  

flourished c. 270 BC

      Greek physicist and inventor, the first great figure of the ancient engineering tradition of Alexandria, Egypt.

      Ctesibius was the son of a barber. The discovery of the elasticity of air is attributed to Ctesibius, as is the invention of several devices using compressed air, including force pumps and an air-powered catapult. His most famous invention, however, was an improvement of the clepsydra, or water clock, in which water dripping at a constant rate raised a float that held a pointer to mark the passage of the hours. Another notable invention was a hydraulis, or water organ, in which air was forced through the organ pipes by the weight of water rather than by falling lead weights. Ctesibius' writings have not survived, and his inventions are known only from references to them by Vitruvius and Hero of Alexandria, but he laid the foundations for the engineering tradition that culminated in the works of Hero of Alexandria and of Philo of Byzantium.

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