was an inventor and mathematician in Alexandria, Ptolemaic Egypt. He wrote the first treatises on the science of compressed air and its uses in pumps. Vitruvius's description Vitruvius (c. 80 BCE – c. 15 BCE) mentions aeolipiles by name: Hero's description Hero (c. 10–70 CE) takes a more practical approach, in that he gives instructions how to make one: Practical usage It is not known whether the aeolipile was put to any practical use in ancient times, and if it was seen as a pragmatic device, a whimsical novelty, an object of reverence, or some other thing. A source described it as a mere curiosity for the ancient Greeks, or a "party trick". Hero's drawing shows a standalone device, and was presumably intended as a "temple wonder", like many of the other devices described in Pneumatica. Vitruvius, on the other hand, mentions use of the aeolipile for demonstrating the physical properties of the weather. He describes them as: After describing the device's construction (see above) he concludes: In 1543, Blasco de Garay, a scientist and a captain in the Spanish navy, allegedly demonstrated before the Holy Roman Emperor, Charles V and a committee of high officials an invention he claimed could propel large ships in the absence of wind using an apparatus consisted of copper boiler and moving wheels on either side of the ship. This account was preserved by the royal Spanish archives at Simancas. It is proposed that de Garay used Hero's aeolipile and combined it with the technology used in Roman boats and late medieval galleys. Here, de Garay's invention introduced an innovation where the aeolipile had practical usage, which was to generate motion to the paddlewheels, demonstrating the feasibility of steam-driven boats. This claim was denied by Spanish authorities. See also Catherine wheel (firework) Rocket engine Segner wheel Steam engine Steam locomotive Steam rocket Tip jet References Further reading History of thermodynamics Steam engines Rocket engines Industrial design Hellenistic engineering Early rocketry Ancient inventions Ancient Egyptian technology Egyptian inventions History of technology