The Pneumatics of Hero of Alexandria

and that which is along the diameter of the vessel will be made as a frame like the letter H. But let another crossbeam be placed in the upper part, like N. O. Through the crossbeam of the vessel placed along the diameter, and through this one of the pegmatio frame/scaffolding, the interior leg of the pipe must pass and enter into the tube inserted and soldered into the basin. Similarly, a coclea screw or screw R. must pass through these, and the helix of it must be fixed into the nut, which will be in the track N. O. and in L. M. And this screw, which will pass through L. M. and N. O., shall extend outside in R. as much as we like. In R. there should be a handle, similar to those of drills, with which the screw can be turned so that the basin at times is lifted up and at other times descends downward. Remembering to ensure that the interior leg of the pipe remains submerged in the water. If, therefore, we draw the air with our mouth through the exterior hole, and consequently the water, the flow of it

A technical diagram of a hydraulic vessel mechanism. An ornate urn-like vessel labeled A and B contains an internal frame (telaro) marked with letters N, O, L, M, and K. A vertical screw (coclea) marked R with a handle at the top passes through the frame. A curved siphon pipe (canna) is positioned with its internal leg submerged in the vessel's liquid, passing through the frame structure.

through the pipe will be equal until all the water that is in the vessel has exited. But when we want the flow to be faster, but still equal in itself, we will turn the screw, and pressing the water with the basin by virtue of the frame N. O. L. M., the exit of the water will become faster than before, and the flow will be equal in itself. If we want that flow to be more forceful, the screw should be turned by lowering the crossbeam L. M. of the frame, and consequently the basin. If we want it slower, by turning the screw in the opposite direction, we will raise the basin. In this way, the flow through the bent pipe will be partly equal and partly unequal. But because drawing the water with our mouth does not work in large conduits, as it does in small ones, when wishing to draw water through large channels, we will do as in the following theorem, so that what has been said above is understood clearly in the figure below.

OF DRAWING WATER OUT OF

With the bent pipe placed in the vessel A. B. with its interior leg submerged in the water and fixed in such a way that it cannot move, and by piercing a track that crosses the vessel like the diameter of a circle, we will have another small vessel, not very large, like the one below, C. D., the mouth of which is sealed very well with a lid. In the middle of this, a hole is made, and in this, a tube E. so large that the exterior leg of the pipe enters into it. But inside it, another tube made of leather must be fitted and tied very well to E., which is F. G. The vessel C. D. must also be pierced at the bottom H. Then, fill the vessel with water, plugging the hole H., and the leather tube F. G. must be fitted onto the exterior leg, tying it to it very well so that no air can enter. And wishing 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, air will descend in its place, which is in the pipe, and will draw the water from the vessel A. B. little by little,

A technical diagram for Theorem V showing two connected vessels. On the left is a larger ornate vessel (A, B) with a curved siphon pipe emerging from it. This pipe is connected to a smaller vessel on the right (C, D) by a leather-sleeved joint (F, G, E). Water is shown flowing out of the bottom of the smaller vessel at point H into a basin, creating the suction necessary to prime the siphon in the larger vessel.

so 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. Therefore, having removed the vessel C. D., we will let the pipe flow, which, to operate well, must be upright and fixed with tracks very well, as can be understood from the example below.

OF THE HOLLOW COPPER BALL.

Beyond what I have said up to here, there is the hollow Copper Ball useful for watering, of which it is necessary to speak in order to be able to explain various constructions from what has been said so far, starting from these no less than geometry does from points, lines, and angles. And this is made of copper.