Ctesibius facts for kids

Ctesibius' water clock, imagined by Claude Perrault

Ctesibius (also known as Ktesibios or Tesibius) was a brilliant Greek inventor and mathematician. He lived in Alexandria, Ptolemaic Egypt, a long time ago, between about 285 and 222 BCE. We don't know much about his personal life. But his amazing inventions were famous even when he was alive!

Ctesibius probably led the famous Museum of Alexandria. He wrote the first books about using compressed air. These books explained how to use air in pumps and even in a type of cannon. Because of his work on how air behaves, he is often called the "father of pneumatics." Sadly, none of his original writings have survived. His most famous invention today is the hydraulis, an early type of pipe organ. It was a very important step towards the modern church organ.

Ctesibius' Amazing Inventions

Ctesibius was born around 300 BCE. He was the son of a barber, and he likely grew up in Alexandria. He started his career by following in his father's footsteps as a barber.

Clever Barber Inventions

While working as a barber, Ctesibius invented a special counterweight-adjustable mirror. This mirror could be easily moved up and down. It was a very practical invention for his father's shop!

The First Keyboard Instrument

One of Ctesibius's most important inventions was the hydraulis. This was a water organ and is seen as the very first keyboard instrument. It was a predecessor to the modern pipe organ. People said that Ctesibius and his wife, Thais, were both very skilled at playing this instrument.

Improving the Water Clock

Ctesibius also made big improvements to the water clock. This clock was also called a clepsydra, which means 'water thief'. For over 1,800 years, Ctesibius's water clock was the most accurate clock ever made! It was only beaten when the pendulum clock was invented in 1656.

A reconstruction of Ctesibius's hydraulic clock

Pumps and Siphons

Ctesibius also designed one of the first force pumps. This pump could create a strong jet of water. It could also lift water from deep wells. Examples of these pumps have been found at ancient Roman sites. The idea of the siphon, which moves liquid using air pressure, is also thought to have come from him.

What People Thought of Ctesibius

Many important ancient writers mentioned Ctesibius and his work. These writers include Vitruvius, Athenaeus, Pliny the Elder, and Philo of Byzantium. They often said that early inventors like Ctesibius were lucky. This was because they lived under kings who loved new ideas and supported the arts.

The philosopher Arcesilaus once visited Ctesibius when he was sick. Seeing that Ctesibius was struggling, Arcesilaus secretly put his purse under Ctesibius's pillow. When Ctesibius found it, he said, "This is the fun of Arcesilaus." This story shows that Arcesilaus was very kind and generous.

Ctesibius in Space

• In 1976, a crater on the far side of the Moon was named Ctesibius. This was done by the International Astronomical Union. It's a way to remember his great contributions to science and invention!