The Ingenious and Curious Pneumatic Motions of Hero

is of copper and brass, and on the lathe of the potters, which we commonly call boccalari jug-makers. The example is A.B., in the lower part of which thick and minute holes are bored,

A woodcut illustration shows a spherical vessel (A and B) with an ornamental handle at the top and a small tube (C, D) protruding from the upper surface. The bottom of the sphere is perforated with many small holes, and it sits upon a rectangular pedestal.

but in the upper part a mouth is made, and on each side handles to support it. In it, there is a small tube C.D.. And when one wants to use it, immerse it in water, so that it will enter into it through the perforations, and the air, forced, will exit through the tube C.D.. If we stop the mouth of this at C. with our thumb while pulling the ball out of the water, it will not exit out at all, because the air cannot enter from any place, since the opening C., which is stopped with the finger, is closed. But if we want to scatter the water, lift the finger from the mouth C., and the water will immediately exit, with the air succeeding in its place. The flow will stop if we again close the mouth C. with our finger, until, lifting it, we again open the way for the air. There will be no difference between the tube C.D. and the bent pipe; indeed, this will be rendered more convenient than that, being able to be closed with such ease with the finger.

THAT ONE CAN FILL THE CONCAVE BALL

with hot and cold water, one separated from the other, and send them out, when one, when the other; and both together. Theorem VII.

A woodcut illustration of a spherical vessel similar to the one above, but with an internal vertical divider (diaphragm) labeled C and D. The top has a neck labeled E, and the bottom is perforated. The sphere is labeled A and B.

With the above-mentioned method, the ball is filled with hot and cold water, and with water and wine, one separated from the other, and it is made to exit, now one, now the other; and both together at our will in this way. The ball having been manufactured in two parts, place the diaphragm, that is, a thin partition original: "cartilagine", closed and soldered into one of these half-parts all around. Then, let one half of the ball be soldered to the other. The ball will be A.B. and the partition C.D. which divides one part of the ball from the other. And this ball, in the manner of a Criuello sieve, should be perforated in the bottom. And in the top, a neck E.F. should be made, pierced with two tubes, one of which goes into one part of the ball, the other into the other, and they join together at G.. And when we want to fill half the ball with hot water, we will stop one of the holes that is in the neck with a finger.