“To cause the revolution of a sphere on a pivot by means of a boiler placed over a fire.
“Let Α Β ([Fig. 2][10]) be a boiler containing water and placed over a fire. It is closed by means of a cover, Γ Λ, which is traversed by a bent tube, Ε Ζ Η, whose extremity, Η, enters the hollow sphere, Θ Κ, in the direction of the latter’s diameter. At the other extremity is placed the pivot, Α Μ Ν, which is fixed upon the cover, Γ Λ. There are added to the sphere, at the two extremities of one of its diameters, two tubes bent at right angles and perpendicular to the line, Η Ν. When the boiler is heated, the steam will pass through the tube, Ε Ζ Η, into the small sphere, and, issuing through the bent tubes into the atmosphere, will cause it to revolve in situ.”
[10] This [figure], likewise borrowed from a MS. of the Renaissance, is sufficiently clear to allow letters to be dispensed with.
The following apparatus, likewise described by Heron, but not so well known as those that preceded, shows that the ancients employed steam (mixed with hot air, it is true) for causing liquids to rise. According to Father Kircher, who reports it on the faith of an author named Bitho, there was at Saïs, Egypt, a temple dedicated to Minerva in which there was an altar upon which, when a fire was lighted, Dionysius and Artemis (Bacchus and Diana) poured, one of them wine, and the other milk.
The miracle was performed as follows:
“On lighting a fire upon an altar, figures make libations and serpents hiss ([Fig. 3]).[11]
[11] The letters on the engraving are again dispensed with.
FIG. 1.—HERON’S EOLIPILE.