The most important steam machine of the ancient years is the “Aeolipile” (aeolosphere), a steam turbine that is preserved and described by Heron of Alexandria (1st century A.D.) in his “Pneumatica”. A sphere is placed over a closed boiler and communicates therewith. The boiler’s water is heated, becomes steam and emerges with speed from the two curved nozzles of the sphere, which rotates in a mad way (in accordance with the momentum conservation principle and the action-reaction law).
Given the ability of controlled transmission of movement during the Hellenistic period, if the socio-economic and political conditions allowed so, this admirable innovation would have resulted to the “Industrial revolution” with unforeseeable consequences for humanity.
The principle of jet propulsion (through the powerful discharge of a compressed gas) first appears in the flying pigeon, a magnificent flying machine, ancestral of the modern rocket-propelled technology, invented by Archytas of Tarentum (since the 5th century B.C.) and preserved by Favorinus in “Pantodape Historia” (Miscellaneous History) and by Aulus Gellius in “Noctes Atticae”.