eolopile
/iˈɑləˌpaɪl/
noun
- A simple device that spins when heated, consisting of a hollow metal ball with bent tubes that release steam, used to show how steam power works.
- In science class, we built a small eolopile to see how steam can make a ball spin.
- The museum had a working model of an eolopile that rotated when water inside was boiled.
- The ancient Greek inventor Hero designed the eolopile, which is considered an early steam engine.