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TOM SWIFT AND HIS PHOTO TELEPHONE
OR THE PICTURE THAT SAVED A FORTUNE
BY VICTOR APPLETON
AUTHOR OF "TOM SWIFT AND HIS MOTOR CYCLE," "TOM SWIFT AND HIS
GIANT CANNON," "THE MOVING PICTURE BOYS," "THE MOVING PICTURE BOYS
IN THE JUNGLE," "THE MOTION PICTURE CHUMS' FIRST VENTURE," ETC.
CONTENTS
I. A MAN ON THE ROOF
II. BAD NEWS
III. TOM'S FAILURE
IV. RUN DOWN
V. SHARP WORDS
VI. A WARNING
VII. SOFT WORDS
VIII. TOM IS BAFFLED
IX. A GLEAM OF HOPE
X. MIDNIGHT VISITORS
XI. THE AIRSHIP IS TAKEN
XII. A STRANGE DISAPPEARANCE
XIII. THE TELEPHONE PICTURE
XIV. MAKING IMPROVEMENTS
XV. THE AIRSHIP CLUE
XVI. SUCCESS
XVII. THE MYSTERIOUS MESSAGE
XVIII. ANOTHER CALL
XIX. THE BUZZING SOUND
XX. SETTING THE TRAP
XXI. THE PHOTO TELEPHONE
XXII. THE ESCAPE
XXIII. ON THE TRAIL
XXIV. THE LONELY HOUSE
XXV. THE AIRSHIP CAPTURE
TOM SWIFT AND HIS PHOTO TELEPHONE
CHAPTER I
A MAN ON THE ROOF
"Tom, I don't believe it can be done!"
"But, Dad, I'm sure it can!"
Tom Swift looked over at his father, who was seated in an easy
chair in the library. The elderly gentleman--his hair was quite
white now--slowly shook his head, as he murmured again:
"It can't be done, Tom! It can't be done! I admit that you've made
a lot of wonderful things--things I never dreamed of--but this is
too much. To transmit pictures over a telephone wire, so that
persons cannot only see to whom they are talking, as well as hear
them--well, to be frank with you, Tom, I should be sorry to see
you waste your time trying to invent such a thing."
"I don't agree with you. Not only do I think it can be done, but
I'm going to do it. In fact, I've already started on it. As for
wasting my time, well, I haven't anything in particular to do, now
that my giant cannon has been perfected, so I might as well be
working on my new photo telephone instead of sitting around idle."
"Yes, Tom, I agree with you there," said Mr. Swift. "Sitting
around idle isn't good for anyone--man or boy, young or old. So
don't think I'm finding fault because you're busy."
"It's only that I don't want to see you throw away your efforts,
only to be disappointed in the end. It can't be done, Tom, it
can't be done," and the aged inventor shook his head in pitying
doubt.
Tom only smiled confidently, and went on:
"Well, Dad, all you'll have to do will be to wait and see. It
isn't going to be easy--I grant that. In fact, I've run up against
more snags, the little way I've gone so far, than I like to admit.
But I'm going to stick at it, and before this year is out I'll
guarantee, Father, that you can be at one end of the telephone
wire, talking to me, at the other, and I'll see you and you'll see
me--if not as plainly as we see each other now, at least plainly
enough to make sure of each other."
Mr. Swift chuckled silently, gradually breaking into a louder
laugh. Instead of being angry, Tom only regarded his father with
an indulgent smile, and continued:
"All right, Dad. Go ahead, laugh!"
"Well, Tom, I'm not exactly laughing at YOU--it's more at the
idea than anything else. The idea of talking over a wire and, at
the same time, having light waves, as well as electrical waves
passing on the same conductor!"
"All right, Dad, go ahead and laugh. I don't mind," said Tom,
good-naturedly. "Folks laughed at Bell, when he said he could send
a human voice over a copper spring; but Bell went ahead and to-day
we can talk over a thousand miles by wire. That was the telephone."
"Folks laughed at Morse when he said he could send a message over
the wire. He let 'em laugh, but we have the telegraph. Folks
laughed at Edison, when he said he could take the human voice--or
any other sound--and fix it on a wax cylinder or a hard-rubber
plate--but he did it, and we have the phonograph. And folks
laughed at Santos Dumont, at the Wrights, and at all the other
fellows, who said they could take a heavier-than-air machine, and
skim above the clouds like a bird; but we do it--I've done it--you've
done it."
"Hold on, Tom!" protested Mr. Swift. "I give up! Don't rub it in
on your old dad. I admit that folks did laugh at those inventors,
with their seemingly impossible schemes, but they made good. And
you've made good lots of times where I thought you wouldn't. But
just stop to consider for a moment. This thing of sending a
picture over a telephone wire is totally out of the question, and
entirely opposed to all the principles of science."
"What do I care for principles of science?" cried Tom, and he
strode about the room so rapidly that Eradicate, the old colored
servant, who came in with the mail, skipped out of the library
with the remark:
"Deed, an' Massa Tom must be pow'fully preragitated dis mawnin'!"
"Some of the scientists said it was totally opposed to all natural
laws when I planned my electric rifle," went on Tom. "But I made
it, and it shot. They said my air glider would never stay up, but
she did."
"But, Tom, this is different. You are talking of sending light
waves--one of the most delicate forms of motion in the world--over
a material wire. It can't be done!"
"Look here, Dad!" exclaimed Tom, coming to a halt in front of his
parent. "What is light, anyhow? Merely another form of motion;
isn't it?"
"Well, yes, Tom, I suppose it is."
"Of course it is," said Tom. "With vibrations of a certain length
and rapidity we get sound--the faster the vibration per second the
higher the sound note. Now, then, we have sound waves, or
vibrations, traveling at the rate of a mile in a little less than
five seconds; that is, with the air at a temperature of sixty
degrees. With each increase of a degree of temperature we get an
increase of about a foot per second in the rapidity with which
sound travels."
"Now, then, light shoots along at the rate of 186,000,000 miles a
second. That is more than many times around the earth in a second
of time. So we have sound, one kind of wave motion, or energy; we
have light, a higher degree of vibration or wave motion, and then
we come to electricity--and nobody has ever yet exactly measured
the intensity or speed of the electric vibrations."
"But what I'm getting at is this--that electricity must travel
pretty nearly as fast as light--if not faster. So I believe that
electricity and light have about the same kind of vibrations, or
wave motion."
"Now, then, if they do have--and I admit it's up to me to prove
it," went on Tom, earnestly--"why can't I send light-waves over a
wire, as well as electrical waves?"
Mr. Swift was silent for a moment. Then he said, slowly:
"Well, Tom, I never heard it argued just that way before. Maybe
there's something in your photo telephone after all. But it never
has been done. You can't deny that!"
He looked at his son triumphantly. It was not because he wanted to
get the better of him in argument, that Mr. Swift held to his own
views; but he wanted to bring out the best that was in his
offspring. Tom accepted the challenge instantly.
"Yes, Dad, it has been done, in a way!" he said, earnestly. "No
one has sent a picture over a telephone wire, as far as I know,
but during the recent hydroplane tests at Monte Carlo, photographs
taken of some of the events in the morning, and afternoon, were
developed in the evening, and transmitted over five hundred miles
of wire to Paris, and those same photographs were published in the
Paris newspapers the next morning."
"Is that right, Tom?"
"It certainly is. The photographs weren't so very clear, but you
could make out what they were. Of course that is a different
system than the one I'm thinking of. In that case they took a
photograph, and made a copper plate of it, as they would for a
half-tone illustration. This gave them a picture with ridges and
depressions in copper, little hills and valleys, so to speak,
according to whether there were light or dark tints in the
picture. The dark places meant that the copper lines stood up
higher there than where there were light colors."
"Now, by putting this copper plate on a wooden drum, and revolving
this drum, with an electrical needle pressing lightly on the
ridges of copper, they got a varying degree of electrical current.
Where the needle touched a high place in the copper plate the
contact was good, and there was a strong current. When the needle
got to a light place in the copper--a depression, so to speak--the
contact was not so good, and there was only a weak current."
"At the receiving end of the apparatus there was a sensitized film
placed on a similar wooden drum. This was to receive the image
that came over the five hundred miles of wire. Now then, as the
electrical needle, moving across the copper plate, made electrical
contacts of different degrees of strength, it worked a delicate
galvanometer on the receiving end. The galvanometer caused a beam
of light to vary--to grow brighter or dimmer, according as the
electrical current was stronger or weaker. And this light, falling
on the sensitive plate, made a picture, just like the one on the
copper plate in Monte Carlo."
"In other words, where the copper plate was black, showing that
considerable printing ink was needed, the negative on the other
end was made light. Then when that negative was printed it would
come out black, because more light comes through the light places
on a photograph negative than through the dark places. And so,
with the galvanometer making light flashes on the sensitive plate,
the galvanometer being governed by the electrical contacts five
hundred miles away, they transmitted a photograph by wire."
"But not a telephone wire, Tom."
"That doesn't make any difference, Dad. It was a wire just the
same. But I'm not going into that just now, though later I may
want to send photographs by wire. What I'm aiming at is to make an
apparatus so that when you go into a telephone booth to talk to a
friend, you can see him and he can see you, on a specially
prepared plate that will be attached to the telephone."
"You mean see him as in a looking-glass, Tom?"
"Somewhat, yes. Though I shall probably use a metal plate instead
of glass. It will be just as if you were talking over a telephone
in an open field, where you could see the other party and he could
see you."
"But how are you going to do it, Tom?"
"Well, I haven't quite decided. I shall probably have to use the
metal called selenium, which is very sensitive to light, and which
makes a good or a poor electrical conductor according as more or
less light falls on it. After all, a photograph is only lights and
shadows, fixed on sensitive paper or films."
"Well, Tom, maybe you can do it, and maybe you can't. I admit
you've used some good arguments," said Mr. Swift. "But then, it
all comes down to this: What good will it be if you can succeed in
sending a picture over a telephone wire?"
"What good, Dad? Why, lots of good. Just think how important it
will be in business, if you can make sure that you are talking to
the party you think you are. As it is now, unless you know the
person's voice, you can't tell that the man on the other end of
the wire is the person he says he is. And even a voice can be
imitated."
"But if you know the person yourself, he can't be imitated. If you
see him, as well as hear his voice, you are sure of what you are
doing. Why, think of the big business deals that could be made
over the telephone if the two parties could not only hear but see
each other. It would be a dead sure thing then. And Mr. Brown
wouldn't have to take Mr. Smith's word that it was he who was
talking. He could even get witnesses to look at the wire-image if
he wanted to, and so clinch the thing. It will prevent a lot of
frauds."
"Well, Tom, maybe you're right. Go ahead. I'll say no more against
your plans. I wish you all success, and if I can help you, call on
me."
"Thanks, Dad. I knew you'd feel that way when you understood. Now
I'm going--"
But what Tom Swift was going to do he did not say just then, for
above the heads of father and son sounded a rattling, crashing
noise, and the whole house seemed to shake. Then the voice of
Eradicate was heard yelling:
"Good land! Good land ob massy! Come out yeah, Massa Tom! Come
right out yeah! Dere's a man on de roof an' he am all tangled up
suthin' scandalous! Come right out yeah befo' he falls and
translocates his neck! Come on!"