The Ingenious and Curious Pneumatic Motions of Hero

ON DRAWING WATER OUT

From large pipes. Theorem V.

Having placed the bent pipe in the vessel A.B. with the inner leg submerged in the water, and fastened it in such a way that it cannot move, by piercing a rule that crosses the vessel like the diameter of a circle, we will have another small vessel, not very large, such as the C.D. shown below, the mouth of which is stopped very well with a lid. In this, let a hole be made in the middle, and into this a tube E. large enough that the outer leg of the pipe enters into it. But let another tube F.G. be invested fitted with leather and tied very well to E.. Let the vessel C.D. also be pierced in the bottom H.. Then fill the vessel with water, stopping the hole H., and let the leather tube F.G. be invested into the outer leg, tying it to it very well so that no air can enter. And wanting to draw the water from the vessel A.B., open the hole H. in the bottom of the vessel C.D.. As the water exits from it, the air that is in the pipe will descend in its place, and it will draw the water from the vessel A.B. little by little, in such a way that when the vessel C.D. is empty, the air that was in the pipe will have filled that vessel, and the water will have filled the pipe, which, for the reasons stated above, will immediately begin its effusion. Thus, having removed the vessel C.D., we will let the pipe flow, which, to operate well, is necessary to be straight and fastened very well with rules, as can be understood from the example described below.

An illustration of a hydraulic experiment. On the left is a large, ornate classical urn (A and B) filled with water. A siphon tube is submerged in the urn, rising up and then curving down into a smaller vessel on the right (C, D, E, F, G, and H). The smaller vessel sits on a decorative base.

ON THE HOLLOW COPPER BALL. Theorem VI.

Beyond what I have said up to this point, there is the hollow copper ball useful for watering, about which it is necessary to reason in order to be able to explain various constructions from what has been said so far, starting from these no less than Geometry is made from points, lines, and angles. And this copper structure