Now the ether of the atmosphere, estimated to be fifteen trillion times lighter than air, is the medium through which the electrical vibrations pass in travelling in their radial direction from a central point, corresponding to the ripples or wavelets formed when a pond or surface of still water is disturbed. Ether is so fine a substance that the organs of sense are not delicate enough to detect it, and it is of such a volatile and uneasy nature that it is continually in motion. It vibrates under certain conditions, and when disturbed (as by a dynamo) it undoubtedly forms the active principle of electricity and magnetism.
James Clark Maxwell believed that magnetism, electricity, and light are all transmitted by vibrations in one common ether, and he finally demonstrated his theory by proving that pulsations of light, electricity, and magnetism differed only in their wave lengths. In 1887 Professor Hertz succeeded in establishing proof positive that Maxwell’s theories were correct, and, after elaborate experiments, he proved that all these forces used ether as a common medium. Therefore, if it were not for the ether, wireless telegraphy, with all its wonders, would not be possible. We understand, then, that the waves of ether are set in motion from a central disturbing point, and this can be accomplished only by means of electrical impulse.
Suppose that we strike a bell held high in the air. The sound is the result of the vibrations of its mass sending its pulsating energy through the air. The length of the sound-waves is measured in the direction in which the waves are travelling, and if the air is quiet and not disturbed by wind the sound will travel equally in all directions. The sound of a bell will not travel so well against a wind as it will with it, just as the ripples on a pond would be checked by an adverse set of wavelets.
Now the ether can be made to vibrate in a similar manner to the air by a charge of electricity oscillating or surging to and fro on a wire several hundred thousand times in a second. These oscillations strike out and affect the surrounding ether, so that, according to the intensity of the disruptive charge at the starting-point, the ether waves may be made to reach near or distant points.
This is, perhaps, more clearly shown by the action of a pendulum. In [Fig. 9] the rod and ball are at rest, but if drawn to one side and released it swings over to the other side nearly as far away from its central position of rest as from the starting-point. If allowed to swing to and fro it will oscillate until at last it will come to rest in a vertical position. This same oscillation (oscillation being a form of vibration) takes place in the water when a stone has been flung into it, and in the ether when affected by the electrical discharge. In [Fig. 10] are shown the principal varieties of vibration—the oscillating, pulsating, and alternating.
It is known that if these oscillations are damped, so that the over-intense agitation of the central disturbance is lessened, a new series of vibrations, such as the pulsating or alternating, is set up, and these secondary vibrations possess the power to travel around the world—yes, and perhaps to other worlds in the planetary cosmos.
OSCILLATION AND VIBRATION
The study of ether disturbances, wave currents, oscillating currents, and the other phenomena dependant upon this invisible force is most interesting and fascinating, and were it possible to devote more space to this topic several chapters could be written on the scientific theory of wireless telegraphy.[2]