The Ingenious and Curious Pneumatic Motions of Hero

ON THE FLOW THAT IS ALWAYS EQUAL,

Let there be a vessel A.B. filled with water up to the surface H.K., inside which floats a small bowl C.D., the mouth of which is stopped very well with its lid C.D.. In this lid, and in the bottom of the bowl, a hole is made through which one

A woodcut illustration shows an ornate, classical vessel with two handles featuring sculpted faces. Inside the vessel, a small bowl (catino) floats. A bent siphon tube, labeled E.F.G., passes through the center of this bowl and exits through the side of the main vessel. The water level in the main vessel is marked with H and K. The vessel itself is marked A and B.

leg of the bent tube E.F.G. passes, as in the following example. These holes should be excellently sealed with stagno tin/solder around this tube, assuming that we make the vessel of copper or a similar metal. The other leg of it is placed outside the vessel, the mouth of which is lower than the surface of the water in the vessel, as above. If, through the mouth of the tube that is outside the vessel, we draw the air with our mouth, the water will likewise follow it. Because there cannot be a vacuum in the tube, the flow will take its beginning from it and will continue until all the water that is in the vessel has exited. This flow will be equal, because as the surface of the water descends, the bowl with the tube fixed into it will also descend; and the greater the excess of the tube on the outside, the faster the flow of the water will be, even though it is always equal by its own nature.

ON THE FLOW THROUGH THE BENT PIPE,

The flow, sometimes equal and sometimes unequal, will likewise be produced through the bent pipe according to our will, and sometimes, if we so please, equal by its own nature, or faster or slower than the first flow. Let there be, for example, the vessel full of water A.B. and the bowl C.D. covered as stated above. Through the middle of it, both the bottom and the lid, a tube is inserted that is wider than the inner leg of the bent pipe; in the following example, this is E.F., sealed very well around the hole in the bottom and lid of the bowl with solder, assuming, as was said above, that the vessel is of copper. But on each side of the vessel, two rules are placed; on the inside of each of these a channel is hollowed out, and at the top of these, another rule is placed, fastening these side rules within the vessel. The two rules with the channels hollowed into them will be G.H.I.K.