|Legendary characters used the power of mythology to fly through
the heavens. About 100 BC a Greek inventor known as Hero of Alexandria came
up with a new invention that depended more on the mechanical interaction
of heat and water. He invented a rocket-like device called an aeolipile.
It used steam for propulsion. Hero mounted a sphere on top of a water kettle.
A fire below the kettle turned the water into steam, and the gas traveled
through the pipes to the sphere. Two L-shaped tubes on opposite sides of
the sphere allowed the gas to escape, and in doing so gave a thrust to the
sphere that caused it to rotate.