Aeolipile

An aeolipile is a simple bladeless radial steam turbine that spins when the water inside its central container is heated, producing torque from jets of escaping steam. It is usually credited to Hero of Alexandria, a Greek Egyptian mathematician and engineer of the first century CE, though at least one source suggests the Roman writer Vitruvius may have described a similar device slightly earlier, around 30 to 20 BCE. The device consists of a spherical or cylindrical vessel fitted with curved nozzles, and when pressurized steam escapes through the nozzles it produces thrust that combines into rotational torque, spinning the vessel until aerodynamic drag and friction bring it to a steady speed. Although it is often described as the earliest recorded steam engine or reaction turbine, the aeolipile was never used to do practical work and was not a direct ancestor of the steam engines of the Industrial Revolution.