No. 6. A vessel for retaining or discharging a Liquid at pleasure.
LET us now proceed to construct the necessary instruments, beginning with the less important, as from the elements. The following is a contrivance of use in pouring out wine. A hollow globe of bronze is provided, such as A B (fig. 6) pierced in the lower part with numerous small holes like a sieve. At the top let there he a tube, C the upper extremity of which is open, communicating with and soldered into the globe. When it is desired to pour out wine, with one hand grasp the tube C D near the mouth C, and plunge the globe into the wine until it is wholly immersed. The wine enters through the holes, and the air within, being driven out, passes through the tube C D: and if, pressing the thumb on the aperture c, you lift the globe out of the wine, the wine contained in the globe will not flow out, as no air can enter to supply the vacuum, for the only entrance is through the mouth C, which is closed by the thumb. When, when, we desire to let the wine flow, we remove the finger, and the air, rushing in, fills the vacuum produced. If we again press the finger on the air-hole C, there will be no discharge until we once more remove finger from the vent. We may, in like manner, dlip the globe into hot or cold water, and then retain or let out the contents at pleasure, until all the water within is exhausted. If the extremity C of the tube C D is bent, the action will be the same, and it is then easier to stop the orifice with the finger.