1. An ancient device consisting of a hollow sphere or cylinder with bent tubes that rotates when steam or hot air escapes through the tubes; an early steam engine.
Usage: Also spelled 'aeolipile' or 'eolipile'; Historical; attributed to Hero of Alexandria (1st century CE); Primarily used in historical and scientific contexts

Examples

• The eolopile is considered one of the earliest examples of a steam-powered device in history.
• Ancient engineers demonstrated the eolopile by mounting it on a pivot so it would spin when heated.
• The principle behind the eolopile relies on the reaction force of escaping steam.
• Museums often display replicas of the eolopile to illustrate early mechanical engineering.
• The eolopile never became a practical power source in antiquity, remaining largely a curiosity.