The Story in a Telegram
How Man Learned to Send Messages
From the time when man had learned to protect himself from the beasts of the forest, and thus was able to move about more freely, and live by himself rather than remain with the tribe, he has found it necessary to send messages.
One of the most interesting of the early methods for sending messages was the Indian way of smoke signalling with the simple equipment of a fire with its rising column of smoke and a blanket or shield. Messages were sent, relayed, received and answered, at points hundreds of miles apart. Among savages still found in remote parts of the earth this and other primitive methods are still in use. In the wilds of Africa to-day at points where the electric telegraph service has not yet penetrated, the natives by the simple method of beating drums, which can be heard from one relay point to another, are able to send the “news of the day” across the country with marvellous rapidity. In some parts of South America, the natives long ago discovered that the ground is a good conductor of sound and send their messages almost at will, making their signals by tapping against poles which they have planted in the ground at various points and which constitute both their sending and receiving instruments.
The Signal Corps in the army uses flags for sending messages, where the telegraph is not available, the flags being of different colors, and the signals are produced by waving the flags in different ways. The army heliograph is also used as a telegraph line—a mirror which reflects the sun’s rays in a manner understood by a prearranged code. These and other similar methods are merely elaborations of devices developed and used by the savages as a solution of the ever present need of sending a message to some other point.
THE FIRST MESSENGER BOY
THE GREEK RUNNER.
In this picture we see the Greek Runner on the last leg of his journey and the man to whom he is to deliver the message waiting for him. This method of sending messages was not very fast, although the runners were picked because of their speed and endurance.
THE PONY TELEGRAPH.
Here we see the fast riders of the Pony Telegraph, which increased the speed of delivering messages quite a good deal, but, of course, there was danger of losing the message to enemies or through accident, so that it might be difficult under such circumstances to send a secret message or to even be certain that it would arrive at destination.
The great Marathon runner was nothing more or less than a telegraph messenger hastening with his written message, from the man who delivered it to him, to its destination, and his work was harder than that of the messenger boy to-day, for he not only had to deliver the message himself to its destination, but had to run fast all the way or lose his job.
The messenger on foot finally gave way to the Pony Telegraph, which not only shortened the time necessary to deliver a message, but marked the beginning of a system.
How Does a Telegram Get There?
The next time your daddy takes you down to the office, ask him to show you the telegraph call box. When you see it, you will perhaps not think that by merely pulling down the little lever you can so start things going that, if you wish, you can cause men who are on the other side of the earth to work for you in a few minutes, and to make little instruments all along the way which, with their other equipment, have cost millions of dollars, click, click, click at your will.
Sooner or later during the day your father will be wanting to send a telegram. He steps to the call box, pulls the little lever and goes back to his desk. In a few minutes, sometimes before you realize it, the little blue-coated messenger appears and says “Call?” Father hands him a telegraph blank on which he has written the message, the messenger takes off his cap, puts the message inside and the cap back on his head and away he goes on his bicycle as fast as his legs can pedal, to the central office, to which point you follow him to see what he does with the message.
If you had been at the telegraph office instead of your father’s office, you would have seen one of these boys start off on his wheel to get the message your father wished to send. When the little lever on the call box is pulled down, it is pulled back by a spring which sets some clock work going which sends a signal over the wire on a circuit which runs out from a register at the main office. The register has a paper tape running through it, and the signal from the call box appears as a series of dots on the tape. The clerk knows from the number and spacing of the dots that it was your father that called and not some other business man whose box might be on the same circuit.
The operators you have seen working in these pictures are Morse operators. They send the message by Morse Code in dots and dashes which are sent over the wire as electric impulses. At the other end the message is read by listening to the clicks the sounder makes as it receives these same electric impulses. This is the simplest way of telegraphing.
The number of messages sent between two big cities in a day is tremendous—many more than could be transmitted over one Morse wire. Many wires would be needed. But wire costs money, so ingenious men set to work to find some way to send more than one message over a single wire at the same time. They succeeded. There is now the duplex telegraph, which sends a message each way simultaneously over a single wire, the quadruplex, which sends two messages each way simultaneously over a single wire. Last but not least there is the multiplex, which sends four messages each way simultaneously over a single wire. This seems almost unbelievable, but it is done. In the case of the duplex and quadruplex, the different messages are sent by currents of different strength, and by changing the direction of the current. Receiving instruments are designed so as to separate the messages by being affected only by the currents of certain strength or polarity, as the direction of flow is termed. It can easily be seen that by these ingenious devices, the telegraph company saves many thousands of dollars in the miles and miles of wire, and hundreds of telegraph poles which would be required if all the messages had to be sent over a simple Morse wire, one message only upon the wire at a time.
THE WONDERFUL ELECTRIC TELEGRAPH SYSTEM...
In this picture we see the interior of a telegraph office along the line of a railroad. The operator has her hand on the “key” or sending instrument. At her left in a stand called the resonator, is the receiving instrument called the “sounder” which clicks off the message. In front of her is an instrument called the “relay.” Current from two of the batteries goes through the key when it is pressed down, through the relay and out on to the wires of the pole line, then through the relay of the receiving operator at the other end, (see picture on opposite page) through his key and through two more batteries to the ground. The earth forms the return wire of an electric circuit when both keys are “closed” or pressed down. You know all electricity has to flow in a closed circuit. The “sounder” has to make good strong clicks to be understood, and the current after it has gone through miles of wire and ground may not be strong enough so the sounder is put on a local circuit of its own, with a special battery. In this circuit is a contact maker which is part of the relay. When the key is pressed down and current flows over the wires on the poles and through the relays, the magnets of the relay pull on a little piece of metal called the “armature,” which makes a contact and closes the local sounder circuit, so current from the single local battery can flow up through the magnets of the sounder and back to the battery. This makes the sounder click. When the key is released, the relay armature is pulled back by a spring and breaks the circuit of sounder, which then emits another click. By the number and duration of the clicks and the time between them, the receiving operator knows the meaning of the signal. The Morse Code, which is used throughout the United States, is shown on next page.
...SENDS MESSAGES THOUSANDS OF MILES INSTANTANEOUSLY