72. _A Lamp in which the Oil is raised by blowing Air into it._

[Illustration: Diagram of apparatus as described in text]

The same effect can be produced with the same general construction,

more readily [than] by constructing the pedestal in which the water is.

Let the rest be as before, with the exception of the pedestal and the

water in it; the extremity M of the tube M N, (fig. 72), being fitted

air-tight into an orifice in the surface of the shaft, so as to be

visible outside. Then apply the mouth and blow into the outer orifice;

the breath will pass into the cup and force out the oil through the

tube X O. Thus the same will take place as before; for as often as we

blow into the tube oil will flow into the lamp. It will be necessary

that the extremity of the handle should be bent at right angles to the

orifice of the lamp, that the oil may not be driven outside.

The pneumatics of Hero of Alexandria · 第 100 / 110 题