Ctesibius of Alexandria

Ctesibius of Alexandria was a Greek physicist and inventor who lived in the third century BC. He was the first to study the science of compressed air and its applications in various devices, such as pumps, catapults, and organs. He also improved the water clock, or clepsydra, by making it more accurate and adding a pointer to mark the hours. He wrote several treatises on pneumatics, but none of them have survived. He was the head of the Museum of Alexandria, a center of learning and research in the ancient world. He was also a barber by profession, and he invented a counterweight-adjustable mirror for his shop. He was considered the father of pneumatics by later writers, such as Vitruvius and Hero of Alexandria, who described his inventions and experiments. He was also praised by Proclus and Philo of Byzantium, who recognized his contributions to the engineering tradition of Alexandria.