Theatrum naturae et artis

or water injected by a syringe (e) pressing and extending itself again.

(a) To which, as it presses down, the water is forced to yield, so that the greater the pressure of the air, the greater the height to which the water also rises.

(b) In an intermittent fountain, from which only as much water flows down as air succeeds it, which, if the fallen water has been removed, finally rushes in and presses. From this principle they construct lamps, in which oil succeeds as much as is necessary, without any further care of ours. To this also belongs a small vessel, useful for irrigating more delicate plants, emitting as much water as we wish; and since it is divided into two parts, it is disposed in such a way that two different liquids, e.g., wine and water, can be contained in it, and wine is returned to the one asking from the place where the water seems to be.

(c) In a fountain, either divided into two parts or not divided, from which water is expelled by the incumbent air pressing upon it. Various figures can be imposed upon this fountain, through which the water is ejected not without pleasure, some of which are made of lead, others of thin sheets, others of other material and can be varied according to the genius and will of anyone.

(d) In the fountain of Hero a device that uses air pressure to create a self-sustaining water jet, consisting of an upper and lower vessel and reabsorbing the ejected water, which pushes the air contained in the lower vessel into the upper one, and there by its pressure expels the water. And this fountain has its own