This is simply due to its own rapid revolution, which, on the same principle that keeps the arrow and the rifle-ball straight on their course, prevents it from altering its position.
The very same principle acts on the boys’ Tops, and is shown in a really remarkable manner by the professional Japanese top-spinners, who will place several tops upon each other, as shown in the illustration, and make them sway backwards and forwards in the most extraordinary manner, sometimes being all upright, and sometimes leaning almost at right angles to each other.
A favourite mode of illustrating this power of Centrifugal Force is by the Gyroscope, a figure of which is given on the right hand of the illustration. The interior wheel is made to revolve rapidly, and the effect of the revolution is to enable the instrument to maintain a horizontal position, even when suspended on one side, as shown in the engraving.
The power of this revolution is quite wonderful, even in a small Gyroscope which can be purchased for a few shillings. It almost seems to be alive, and to insist on retaining its position, in spite of all efforts to the contrary.
This principle is used in the swinging cabin of the Bessemer ship, and is also employed by quoit-players in keeping their missile steady as it flies towards the mark. Even the now fashionable Bicycle is managed on the same principle.
As is well known to all bicycle riders, it is comparatively easy to maintain the balance when the pace is rapid and the wheels revolving quickly. The difficulty is, to do so when the pace is slow, and the rider is deprived of the centrifugal force which keeps him on his balance almost in spite of himself. It is just the same with a child’s hoop, which runs straight and upright when it is driven rapidly, or when, for example, it runs downhill. But, as soon as the centrifugal force is expended, it begins to waver, loses its direction, and soon falls to the ground.
USEFUL ARTS.
CHAPTER XVII.
OSCILLATION.—UNITED STRENGTH.—THE DOME.
Connection of Oscillation with Centrifugal Force.—Equality of Time in Oscillation.—The Spider.—The Stone and String.—Pendulum of the Clock, and its Effect on the Machinery.—Acceleration and Retardation.—Compensating Pendulums.—The Metronome, and its Use in Music.—A simple Metronome.—Value of the Instrument in War.—The Escapement, and its Connection with the Pendulum.—Mode of Action.—Larva of Burying-beetle.—Earthworms and Serpents.—Union is Strength.—The Hippopotamus Rope and its Structure.—The Spider-web.—Distinction between the Threads.—Principle of the Dome.—The Arch, and its Connection with the Dome.—Esquimaux Huts.—Receiver of the Air-pump, and its Power of Resistance.—The Human Skull and the Egg.—Accidental Resemblance.—The Salad-dressing Bottle.—The Medusa, Strobila, and Hydra.
A portion of our last chapter dealt of Centrifugal Force. We will now proceed to another well-known power, which seems to be a variation, or perhaps a division, of the same power. I mean the principle of Oscillation, which has done so much for the present state of the world. I mention the connection of the two principles because it is evident that, if Oscillation were continued in one direction, it would be converted into centrifugal force. In fact, it can only be considered as centrifugal force interrupted.