Quite a number of people seem to be imbued with the idea that no one ever thought of sending messages by wireless before Mr. Marconi—in fact that he just put together a few old electrical instruments and forthwith sent and received messages over space without any connecting wires.
Of course the basis for these erroneous impressions is that Mr. Marconi is said to be, and rightly, the inventor of the wireless telegraph. Now I want to put those young fellows who are reading this account straight on the matter. Many men may work on a device and none of them hit upon the thing that is needed to make it practical; then some fine day a genius will happen along and see just what the device lacks and add it to the general collection, or he will put something to it, perhaps accidentally, that does the business, and this last touch which enables it to be used gives the man who does it the right to be called its inventor.
Now, dozens of men, including Morse, Edison and Tesla in this country, and Hughes, Pierce and Lodge in England, worked on the scheme of sending messages without wires; but they either experimented along the wrong line, or the few who worked on the right line did not push far enough ahead to get anywhere. The result was that by the time Mr. Marconi tackled it all the instruments that were needed for telegraphing without wires were at hand but no one had quite caught on how to use them.
Nearly every one thinks, too, that it is far more wonderful to send wireless messages than it is to send messages over a wire; but this is not the case at all, though both, I trow, are wonderful enough. When we say a message is sent by wireless we do not mean, by a long shot, that it goes from the place where it is sent to the place where it is received without anything between them to carry it. Nor again do we mean that it goes to a single receiver and nowhere else.
For instance, when you talk to a person ordinarily you convey to him your message without wires, but it is the air between your mouth and his ear that carries the message, that is, waves are set up in the air and these are called sound waves. Naturally since the air is everywhere on the surface of the earth the sounds you make travel in every direction.
A better example of wireless is a lighted lamp and your eye, for in this case the lighted lamp acts as a transmitter and sets up very short waves in the ether, which are called light waves and these likewise travel in every direction. The ether is a substance that is 15 trillion times lighter than the air and it fills the whole universe, and when the electric waves set up by a light in it strike your eye the optic nerve carries the sensation of them to your brain and you see the light.
The next thing to know is that light waves and wireless waves are exactly the same kind of waves, that is, both are caused by electric stresses and magnetic whirls in the ether, but while light waves are in the neighborhood of the ten-millionth of an inch in length, wireless waves are so long they make no impression at all on the eye.
That light is electric waves in the ether has been known for the last couple of hundred years and later on scientific sharks believed there were other and longer electric waves but they didn’t know how to produce them or to receive them until 1888.
In that year Heinrich Hertz, a young German college professor, discovered that when an electric spark was made by any kind of an apparatus the positive and negative electric charges in uniting together would not only break down the air to make the spark, but would form an oscillating current, that is, a current which surges to and fro hundreds of thousands of times a second, and that this high frequency current, as it is called, sets up waves in the ether just as the vibrations of a bell set up waves in the air.
Hertz made an apparatus by which he could produce electric waves of different lengths and this he called an oscillator. It consisted of a couple of wires fixed to the balls of the spark-gap of an induction coil, on the other and free end of which were soldered a couple of sheets of copper. (See the accompanying picture.)