If now the glass be lowered again, the air which is compressed by so doing closes the central valve, whilst that above the oblique tube is opened. From this valve the smoke will ascend in clouds ([Fig. 4]).
In this way the glass may be made to smoke the whole cigarette.
Water Swinging
Nearly every one has seen, at the circus or elsewhere, an acrobat executing giddy circular movements with a glass of water, and doubtless has wondered how it is that none of the liquid is spilt. This is due to the action of centrifugal force.
Having placed the glass full of water on the table, it is only a matter of taking it properly with the hand, holding it at arm’s length, and, with the arm thus extended, describing a complete circle, after which it may be placed upon the table without the loss of a single drop.
To insure the success of the experiment, particular attention must be paid to the manner in which the glass is held. Instead of taking it as you would when drinking, hold it with the hand reversed, the palm being turned upwards, as shown in [Fig. 5].
Fig. 5.—Centrifugal force experiment. First position.
Without hesitation throw the arm in the air, and swing it, not too quickly, but without shaking it, in the direction of the arrows in the diagram ([Fig. 6]).
