1. An ancient device consisting of a hollow sphere or cylinder with bent tubes, rotated by steam jets escaping from the tubes; an early steam engine.
Usage: historical; also spelled aeolipile

Examples

• The eolipile, invented by Hero of Alexandria, is considered one of the first steam engines in history.
• Ancient engineers used the eolipile to demonstrate the power of steam pressure.
• The rotating sphere of an eolipile was driven by jets of steam escaping from small nozzles.
• Although the eolipile was a remarkable invention, it was not developed into a practical power source in antiquity.
• Modern museums display replicas of the eolipile to illustrate early mechanical engineering principles.