Читать книгу Famous Days in the Century of Invention - M. Grace Fickett - Страница 8

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Late one June afternoon Arthur Burton was leaning against a table in the eastern gallery of the main hall at the Philadelphia Exposition. It had been a wonderful day, but it was past dinner time, and he was hot, tired, and hungry. He had seen more wonders that day than he had witnessed in all his life before; but now his uncle and the other judges were in the midst of the Massachusetts educational exhibit, which wasn't half so interesting as the first electric light, or the first grain reaper, or the iceboats. So Arthur had moved away from the new-fashioned school desks and the slate blackboards, and was waiting rather wearily.

Suddenly he straightened up. Entering the door near by was the most distinguished visitor at the Centennial, the tall, handsome Dom Pedro, Emperor of Brazil, with the Empress and a bevy of courtiers. To Arthur's amazement, His Majesty walked directly up to the table against which he himself was standing; and looking beyond the little boy, he said with outstretched hand and a pleasant smile:

"How do you do, Mr. Bell? I am very glad to see you and your work."

Till then Arthur had scarcely noticed a sallow, dark-haired young man who had been sitting behind the little table, nor had he paid the slightest attention to some pieces of wood and iron with wire attached lying on the table. But now, the young man and his material had become decidedly interesting.

Dom Pedro II

"I remember very pleasantly," continued Dom Pedro, "my visit to your class in Boston University when you were teaching deaf mutes to speak by means of visible speech. You were working out a new method, I remember. I suppose this is apparatus that you have devised in that connection."

"I thank Your Majesty," stammered the surprised young man, who for a moment had been at a loss to recall who his royal visitor might be. "I shall be delighted to explain my apparatus. But it has nothing to do with teaching deaf mutes to speak. It is more wonderful than that. It speaks itself; that is, it reproduces sounds. It is the improvement on the telegraph that the world has awaited for years.

"You see, I found in my experiments that I could transmit spoken words by electric current through a telegraph wire so that those words could be reproduced by vibrations at the other end of the wire. I suppose my invention might be called a speaking telegraph."

By this time all the judges had joined the Emperor's party. Arthur fell back to his uncle's side, but he could still hear and see everything.

"Now, Your Majesty," continued Mr. Bell, "if you will press your ear against the lid of this iron box, I think in a moment you will have a surprise."

At these words, Mr. Bell's assistant, who had come up to the group during the conversation, went to another table several rods away and quite out of hearing. The Emperor bent down expectantly. The judges looked rather incredulous, but they were all interested.

"Is the man that went off going to talk over the wire so that the Emperor can hear?" whispered Arthur to his uncle.

"Mr. Bell says so," was the reply, "but we shall see."

Suddenly the Emperor gave a start, and a look of utter amazement came over his face.

"It talks! It talks!" he exclaimed excitedly.

It was quite true. Mr. Hubbard, Mr. Bell's assistant, had spoken in a low voice at the other end of the wire and his exact words had been reproduced. The Emperor's excitement was contagious. Everybody forgot how hot and hungry he was. One after another of the judges listened at the magic box to hear Mr. Hubbard or another of their number speak into the instrument at the other end.

"Oh, Uncle, do you suppose I can listen too after a while?" inquired Arthur, when he could no longer keep still.

Just then Mr. Bell himself interposed.

"Now it must be the little boy's turn."

The grateful little boy was not slow in stooping over to the receiver.

"What does he say, Arthur?" asked his uncle.

"Why, he says, 'To be or not to be,' whatever that means."

"You don't know your Hamlet very well yet, little boy."

"But I have heard a speaking telegraph, and that is better," replied Arthur.

By this time Mr. Hubbard was returning with the apparatus he had been using at the other end. It was time to see how the marvel had been wrought.

"Now tell us how it works, Mr. Bell," commanded Dom Pedro.

"It is very simple," Mr. Bell explained. "You know, of course, that for some years it has been possible to transmit articulate speech through India rubber tubes and stringed instruments for short distances; but I worked, as you see, to transmit spoken words by electric current through a telegraph wire.

"Here on the table before you is the instrument I call the transmitter, into which Mr. Hubbard spoke. This projecting part is only a mouth-piece. Inside is a piece of thin iron attached to a membrane, and this piece of iron vibrates whenever one speaks into the transmitter. For you know, gentlemen, that if you hold a piece of paper in front of your mouth and then sing or talk, the paper will vibrate as many times as the air does.

"Now, of course, if I could reproduce those sound or air waves at a distance, a person listening would hear the same sounds that caused the first vibration. I have accomplished that by making and breaking an electric current between two pieces of sheet iron. My assistant spoke into the cone-shaped mouth-piece. At the end of it, as you could see if I took off the cover, is the first thin plate of sheet iron. Near that iron, but not touching it, is a magnetized piece of iron wound around with a coil of wire.