gure arose, and appeared to be agitated, as he said: "Do
you mean to say that messages can be sent without wires?"

"Stations for that purpose are now in operation all over the world."

"That is as improbable to me as though you should tell me that it would
be possible to talk over a wire," he answered.

"But we do talk over wires, and it is possible to talk over distances
hundreds of miles apart, without wires even."

He glanced at those about him, and shook his head. He appeared to
hesitate about asking any more questions, and after shambling back and
forth a dozen times, or more, he stopped at the pile of debris, and
picked up a thick disk-like piece of metal, to one side of which was a
short broken tube attached.

"I have examined this many, many times. Perhaps you can tell me what it
is?" and he handed it to John.

"This is the disk of a phonograph."

"What is that?"

"An instrument which will reproduce the human voice, or any noise, or
the sound of music."

"I do not understand what you mean. If I talk to it will it talk back to
me?"

"No; it is so arranged that one form of the instrument receives the
sound of your voice, and impresses it on material in the form of a
cylinder, or a disk, and if this cylinder or disk is put into another
instrument, this little apparatus, which I hold in my hand will speak
the same words you uttered."

[Illustration: _Fig. 11. Phonograph Disk._]

"Then electricity must be a wonderful thing, to be able to be used by
men to talk to each other all over the world, and even to preserve what
they say."

"But the phonograph is not an electrical apparatus. The disk, here, with
the little stylus, or pointer on it, vibrates and gives forth the
sound."

"All this is most marvelous, and I would like to see some of those
wonderful things," he exclaimed.

"If you will come to the ship we will show you many of the things that
electricity does, as we have a phonograph there, and we have a search
light that operates by electricity, and which enables us to see many
miles," added Harry.

"Yes; I must see your ship, and I am ready to accompany you any time,
and I want my people to see those things, as well."

"But there are many other things that we now do with electricity. All
street railways are now operated by it; many boats are run by that
power; cooking is done by it, and its uses extend into almost everything
that man touches," remarked John.

"If this one branch of knowl