XV.—TRICKS WITH WIND AND AIR.
INFLAMMABLE AIR.
Put a sponge saturated with ether in a bladder. Let some one inflate this apparently empty vessel with common air with a bellows. On applying a lighted match to a nozzle tied in the mouth of the bladder the gas will take fire and burn, and the spectators will be compelled to believe you rendered common air inflammable.
CURIOUS VIVIFICATION.
Take any number of two-inch tubes, ten inches long, and close the bottom except one small hole. Place a piston in each, as in a syringe. In the bottom place a worm spring under a figure of a man or woman, each one different and in a different attitude, and of such a size as to fill up the hollow cylinders.
Set them all in a circular wooden frame, and create a vacuum under each piston by pushing them down, stopping the hole, and drawing them up to any height you please.
On placing the frame in the receiver, and exhausting the air, the force of the spring being greater than the friction of the piston and the weight of the figure, they will rise up gradually in their proper attitudes. On admitting the air into the receiver they will retire.
If the tubes be inflated with air, they will be extended when the pressure of that in the receiver is taken.
Fig. 111.
What is the difference between this subject and a young widow? The latter is a widdy girl, while the above is a giddy whirl.
FIERY SHOWER.
Bore out a small reservoir in a piece of hard wood, in the shape of a cup or inverted cone, and fill it with quicksilver in the upper aperture of the receiver of an air-pump. On exhausting the air, the atmospherical pressure will force the mercury through the wood so that it will fall in a luminous shower.
THE COIN AND WINE-GLASS PUZZLE.
Place a half-crown in a wine-glass over a sixpence. To remove the latter without touching the glass, blow down into it, when the larger coin will turn and let the other pass up out over the other side.
Fig. 112.
THE WEATHER PROPHETS.
Suspend a small circular plate by its centre of gravity, by a fine string or piece of catgut, and attach the other end to a hook. As the air is more or less moist, the plate will turn. A bell-glass may cover it to prevent the wind deranging it, but the air must have access to the string.
Make a box, representing with one side a housefront with two doors, and mount on one side of the turning-plate a man with an umbrella, and on the other a lady with a fan. When the man comes out it indicates damp, whilst the appearance of the lady foretels dry weather. Unfortunately, as the atmospherical changes affect it but by degrees, these weather prophets are unreliable.
THE DANCER ON AN INVISIBLE MOUNTAIN.
Mr. Panky’s friends, invited to his country seat, having admired a beautiful little dancer on the summit of a fountain-jet (page 137), he no sooner has led them into the house than he points to a figure, much of the same appearance, which waltzes a few inches above the surface of his glass table. There is no visible cause.
Explanation.—The figure is made of a cone of silver-foil, the dress of silver-paper, and the head of the seed-vessel of the antirrhinum, which is extremely light and properly shaped. The base can be weighted with lead pellets to keep the head uppermost, and the whole dances on a current of air. A funnel of pasteboard, with the small end encircling the hole in the table, will catch the figure so that it must roll down into the proper place for an ascension again.