extremity with a valve that opens outwardly, and at its lower with one
that opens inwardly, be dipped into water and given a series of up and
down motions, the water will be seen to quickly rise therein and finally
spurt out at the top. The explanation of the phenomenon is very simple.
Upon immersing the tube in the water it fills as far as to the external
level of the liquid, and the air is expelled from the interior. If the
tube be suddenly raised without removing its lower extremity from the
water, the valve will close, the water will rise with the tube, and,
through the velocity it has acquired, will ascend far above its preceding
level. Now, upon repeating the up and down motion of the tube in the water
five or six times, the tube will be filled, and will expel the liquid
every time that the vertical motion occurs.

[Illustration: THE CHINESE PUMP.]

We speak here of a _glass_ tube, because with this the phenomenon may be
observed. Any tube, of course, would produce the same results.

The manufacture of the apparatus is very simple. The tube is closed above
or below, according to the system one desires to adopt, by means of a
perforated cork. The valve is made of a piece of kid skin, which is fixed
by means of a bent pin and a brass wire (Fig. 2). It is necessary to wet
the skin in order that it may work properly and form a hermetic valve. The
arrangement of the lower valve necessitates the use of a tube of
considerable diameter (Fig. 1). We would advise the adoption of the
arrangement shown in Fig. 2. Under such circumstances a tube half an inch
in diameter and about 3 feet in length will answer very well.

It is better yet to simply use one's forefinger. The tube is taken in the
right hand, as shown in Fig. 3, and the forefinger placed over the