The Ingenious and Curious Pneumatic Motions of Hero

it will breathe, as the air succeeds into the evacuated place, and it will no longer pull the material. And if anyone were to say universally that there is nothing that is entirely empty, one could find many arguments to demonstrate this, and perhaps persuade with words, since they bring forward no sensible demonstration. But in those things that appear clear, and that fall under the senses, if they were to demonstrate a certain vacuum collected and made outside of its Nature, and being disseminated in small parts, and that bodies by compression fill those disseminated Vacua, to those who labor to bring forward probable reasons for this, it is certainly not to be lent an ear. For, having constructed a sphere—the thickness of which is of sheet metal so that it cannot easily be broken—but well-made, and excellently sealed on all sides, then having perforated it, and having placed a copper pipe in the hole, such that the perforated place opposite according to the diameter to the opposed hole does not iron original: "non ferri"; likely a typo for "non si ferri" or similar, meaning "does not close off"; so that the water can flow, and making the other part of the pipe extend about three fingers outside the sphere, and with tin sealing the perimeter of the hole through which the pipe is placed, then if we close this pipe and the external surface of the sphere, so that We, wanting to blow into it with the mouth, the spirit refers to air or vapor cannot in any way escape.

We will see what is contained within it, which is certainly nothing else but the air existing in it in the same way as happens in those other vessels that are called empty, which, being all full, and by a certain continuity applied to their perimeter, since there can ultimately be no sort of vacuum in it, water cannot be placed in it, nor other air, since the one that was inside before does not depart. Rather, it will happen that by doing violence to place it inside, the vessel will break before it can receive any of it, because it is full, as the bodies of air cannot be contracted into a smaller size. Because it would be necessary that certain intervals be made between them, in which the compressed bodies would be of smaller mass. This is not possible, as there is no vacuum at all. And when, according to all surfaces, the bodies are applied together, similarly within the perimeter of the vessel, being violated, they cannot give place to other bodies, there being no vacuum. And for this reason, in no way can any of those bodies that are outside be placed into the proposed sphere if some part of the air first contained in it does not depart. That is, if all the place is costive and continuous, as is thought. But if someone comes to inflate the sphere through the mouth of the pipe, they will certainly introduce much spirit, yet the air that is in it will not depart. That this is always so is clearly demonstrated: that within the sphere, a contraction of those bodies that are implicated in the vacua comes to be made. But in this, the contraction is made because Nature is here violated by the violent admission of the spirit. Therefore, if by blowing through that mouth we place our hand there, and with the finger immediately stop the hole, the costive air will always remain in the sphere. But if we open that mouth, the air introduced therein will erupt again and escape with a very great noise and clamor. For as we have proposed, it is driven out by the dilation of the persistent air, made with a certain impetus. Again, if anyone wants to draw out with the mouth through the pipe the air that is in the proposed sphere, they will pull out a very large quantity, yet no other substance will succeed into the sphere, as was said above regarding the Medical Egg A common term for a glass vessel used in experiments on vacuum or distillation.. Wherefore it is clearly demonstrated that in the vacuum of the sphere a very great coacervation had been made; for...