Man has arranged a little lever with an iron end-piece immediately above the electro-magnet, so that the magnet may attract it. Of course you are aware that it is the electrons within the soft-iron core of the electro-magnet who produce the magnetic effect. Every time we electrons in the surrounding wire make a forward move, the electro-magnet pulls down the end of the little lever referred to. As long as we keep marching, so long will the end of the lever remain down, but the moment we halt, the lever is free to be pulled up by a spring attached to it. The movements of the lever indicate the length of our long and short marches, and it is by means of these that man sends signals. All that he does is to control our march, by means of an electric push and a battery at one end of the wire, and it is we who produce the signals at the distant end of the wire. Each time man presses the push we move the distant lever. When we pull the lever down it is so arranged that it makes a sound like "click," and when we let it spring up against a stop it makes another sound not unlike "clack." Our long and short marches are therefore converted into long and short "click-clacks." Man has made a simple code of signals representing his alphabet, and right merrily do we rap out the signals for which we receive orders at the distant end of the wire, while some one at the other end listens to the sounds we cause to be made. I have told you enough of our duties to let you see how we are able to carry man's news from one part of the earth to any other part. By far the greatest part of our signalling work is done with this simple Morse sounder. It may interest you to note that we can produce those signals far faster than man can read them. When man found this out he took advantage of our powers. He made an automatic transmitter which could manipulate the make-and-break of the battery current far more rapidly than any human fingers could do. Then as we rapped off the signals with lightning speed at the distant end, he attached a little ink-wheel to the end of the moving lever, so that it could mark short and long strokes on a ribbon of paper passing close to it. Although man could not distinguish the signals by his ear he was able to read the record of those we caused to be left upon the paper ribbon. We have been made to work many other forms of telegraph instruments. In some of these we control type-letters, while in others we imitate handwriting, but all these are merely adaptations of our powers of marching. We are proud of our achievements in rapid signalling, which all right-thinking people have not been slow to acknowledge. CHAPTER X HOW WE COMMUNICATE WITH DISTANT SHIPS _THE SCRIBE'S NOTE ON CHAPTER TEN_ In this chapter the electron deals with that modern marvel--_Wireless Telegraphy_. Here the æther of space plays a very prominent part.