The aeolipile and the power gap

This watch point answers the familiar question of why ancient steam did not immediately become naval propulsion. The aeolipile was an impressive demonstration rather than a practical engine. An Egyptian altar mechanism could use heated water to open doors and create theatrical motion, but neither device supplied the pressure and power needed to drive a wheel or propeller. Savery, Newcomen, and Watt came after a long accumulation of better materials, engineering practice, and operating skill. The gap did not reflect a lack of intelligence in earlier societies. It separated the display of an effect from dependable machinery built around it.