FIG. 2.—HERON’S WHIRLING EOLOPILE.
“Let Α Β be a hollow pedestal upon which there is an altar, Γ, in whose interior there is a large tube, Δ Ε, that descends from the fireplace into the pedestal and divides into three small tubes. One of the latter, Ε Ζ, runs to the serpent’s mouth; another, Ε Ζ Η, to a vessel, Κ Δ, suitable for containing wine, and the bottom of which should be above the figure, Μ, as this tube has to be connected with the cover of the vessel, Κ Λ, by a grating; and the third tube, Ε Ν Ξ, rises likewise to a vessel, Ο, suitable for receiving wine, and is connected in the same way with its cover. The two latter tubes are soldered to the bottoms of the vessels, and in each of these vessels there is a siphon, Ρ Σ and Τ Υ. One extremity of each of these tubes dips into the wine, while the other, which ends in the hand of the figure that is to make the libation, traverses the side of the wine vessel. When you wish to light the fire, you will first put a little water into the tubes so that they shall not be burst by the dryness of the fire, and you will stop up all the apertures so that the air shall not escape. Then the blast from the fire, mixed with the water, will rise through the tubes up to the gratings, and, passing through these, will press upon the wine and cause it to flow through the siphons, Ρ Σ and Τ Υ. The wine issuing thus from the hands of the figures, the latter will appear to make libations as long as the altar is burning. As for the other tube, which leads the blast to the serpent’s mouth, it causes the latter to hiss.”
FIG. 3.—HERON’S MARVELOUS ALTAR.
As regards the cock and the tubular boiler, we find these in a hot-water stove which Heron calls by the Græco-Latin name miliarion, because of its resemblance to a milestone.
[Fig. 4] shows us, in the center, the fireplace in the shape of a vertical cylinder, which should have beneath it an air vent that is not shown in the cut. All around this there is a boiler, likewise cylindrical, filled with water. A certain number of tubes, such as Ο Κ and Μ Ν, put its different parts in communication by passing through the fireplace, and thus increase the heating surface.