Heron wrote many books on mathematics, physics, geometry, and mechanics. The 'Pneumatica' describes mechanical devices operated by compressed air, water or steam, such as a fire engine, a water organ, and the aeolipile, which is the first steam-powered engine.

His device consisted of a sphere mounted on a boiler by an axial shaft and having two canted nozzles to produce a rotary motion from the escaping steam.