Marvels of Modern Science | Page 7

hour, that any human being could resist the air pressure at such a velocity.
At any rate there can be no question as to the aeroplane attaining a much greater speed than at present. That it will be useful there can be little doubt. It is no longer a scientific toy in the hands of amateurs, but a practical machine which is bound to contribute much to the progress of the world. Of course, as a mode of transportation it is not in the same class with the dirigible, but it can be made to serve many other purposes. As an agent in time of war it would be more important than fort or warship.
The experiments of Curtiss, made a short time ago over Lake Keuka at Hammondsport, N.Y., prove what a mighty factor would have to be reckoned with in the martial aeroplane. Curtiss without any practice at all hit a mimic battle ship fifteen times out of twenty-two shots. His experiment has convinced the military and naval authorities of this country that the aeroplane and the aerial torpedo constitute a new danger against which there is no existing protection. Aerial offensive and defensive strategy is now a problem which demands the attention of nations.


CHAPTER II
WIRELESS TELEGRAPHY
Primitive Signalling--Principles of Wireless Telegraphy--Ether Vibrations--Wireless Apparatus--The Marconi System.
At a very early stage in the world's history, man found it necessary to be able to communicate with places at a distance by means of signals. Fire was the first agent employed for the purpose. On hill-tops or other eminences, what were known as beacon fires were kindled and owing to their elevation these could be seen for a considerable distance throughout the surrounding country. These primitive signals could be passed on from one point to another, until a large region could be covered and many people brought into communication with one another. These fires expressed a language of their own, which the observers could readily interpret. For a long time they were the only method used for signalling. Indeed in many backward localities and in some of the outlying islands and among savage tribes the custom still prevails. The bushmen of Australia at night time build fires outside their huts or kraals to attract the attention of their followers.
Even in enlightened Ireland the kindling of beacon fires is still observed among the people of backward districts especially on May Eve and the festival of mid-summer. On these occasions bonfires are lit on almost every hillside throughout that country. This custom has been handed down from the days of the Druids.
For a long time fires continued to be the mode of signalling, but as this way could only be used in the night, it was found necessary to adopt some method that would answer the purpose in daytime; hence signal towers were erected from which flags were waved and various devices displayed. Flags answered the purposes so very well that they came into general use. In course of time they were adopted by the army, navy and merchant marine and a regular code established, as at the present time.
The railroad introduced the semaphore as a signal, and field tactics the heliograph or reflecting mirror which, however, is only of service when there is a strong sunlight.
Then came the electric telegraph which not only revolutionized all forms of signalling but almost annihilated distance. Messages and all sorts of communications could be flashed over the wires in a few minutes and when a cable was laid under the ocean, continent could converse with continent as if they were next door neighbors.
The men who first enabled us to talk over a wire certainly deserve our gratitude, all succeeding generations are their debtors. To the man who enabled us to talk to long distances without a wire at all it would seem we owe a still greater debt. But who is this man around whose brow we should twine the laurel wreath, to the altar of whose genius we should carry frankincense and myrrh?
This is a question which does not admit of an answer, for to no one man alone do we owe wireless telegraphy, though Hertz was the first to discover the waves which make it possible. However, it is to the men whose indefatigable labors and genius made the electric telegraph a reality, that we also owe wireless telegraphy as we have it at present, for the latter may be considered in many respects the resultant of the former, though both are different in medium.
Radio or wireless telegraphy in principle is as old as mankind. Adam delivered the first wireless when on awakening in the Garden of Eden he discovered Eve and addressed her in the vernacular of Paradise in that famous sentence which translated in English reads both ways the same,--"Madam, I'm Adam." The oral words