THE UNDER-SEA WIRELESS
As soon as Rawlins was out of sight the boys commenced to talk, Tom
speaking through the transmitter while Frank wrote down what he said,
for of course they could not know if Rawlins heard them, and the only
means of determining if he had received all the words was to keep a
record for comparison when he came up. They were busily engaged at this
and tremendously interested and excited, when the telephone bell rang.
Telling Rawlins to wait a moment, and explaining the reason, Tom ceased
speaking while Frank answered the call.
“Hello, Frank,” came Henry’s voice. “I just rang up to be sure you were
there. How’s everything going?”
“Fine!” replied Frank, “come on down, we’re just testing it out for the
first time. When did you get back?”
“Last evening—but didn’t have a chance to run around to see you. I
called up, but the maid said you were out with Tom. Didn’t she tell you?
I’ll be right down, you bet. Say, I’ve some news for you. So long.”
“I’m glad he’s back from that trip with his father and is coming down,”
said Tom, “Won’t he be interested and surprised if this works? Wonder
what the news is.”
Then, turning to his set, he continued his interrupted talk, or attempt
to talk, with Rawlins until, five minutes later, Henry was pounding at
the door.
“Gee, but you’ve a fine place here!” he cried as he glanced about the
little laboratory, “and you’ve diving suits and helmets and everything.
Say, I was just crazy to get back when I got your letter telling about
your experiments and everything. Where’s the diver fellow? Oh say,
you’re not really talking to him under water! Crickety! Isn’t that
wonderful to think he can hear you down under the river!”
Tom laughed. “Don’t know if he can,” he replied. “We’ll have to wait for
him to come up and tell. You see we haven’t got an under-sea sending set
rigged up yet and the one he’s got is just a sort of makeshift for
experimenting.”
“Have you fellows heard anything more of that mystery chap?” cried
Henry, suddenly changing the subject.
“Not a word,” Tom assured him.
“Well, I have then,” declared Henry triumphantly. “I heard him last
night and I got him again to-day just before I called you fellows. He
was in the same old place, too.”
“Honest? Say, that _is_ funny!” exclaimed Frank. “What was he saying?”
“Don’t know,” replied Henry, “He was talking some foreign lingo that I
couldn’t make out, but I got one word. Bet you couldn’t guess what
’twas—another flower—Oleander this time.”
The boys were so interested in Henry’s news that they had temporarily
forgotten their under-water companion until Henry uttered a half
surprised exclamation and jumped away from the square opening in the
floor over the river.
“Gosh, there he comes!” he cried, as overcoming his first surprise at a
gurgling splash he glanced through the trapdoor and saw the diver’s
helmet appearing. “Don’t he look like a regular sea monster?”
A moment later, Rawlins was removing his suit and helmet.
“Did you hear us?” cried Tom the moment Rawlins’ face was visible.
“Did I!” exclaimed the diver. “Did I! Let me tell you I wished I had
cotton stuffed in my ears. You must think I’m deaf,—yelling like that.
Did you think you had to shout loud enough to have your voice go through
the water? And I’ll tell you I thought a tornado’d struck the place when
your friend here arrived. I even heard the telephone bell.”
Tom and Frank fairly danced with delight. “Hurrah! It works! It’s a
success! We’ve solved it! It’s under-sea radio!” shouted the excited
boys.
“I’ll say it works!” declared Rawlins. “But what the deuce were you
trying to talk Dutch for?”
“Talk Dutch?” cried Tom in a puzzled tone. “We weren’t talking Dutch or
anything but United States.”
It was Rawlins’ turn to be amazed. “Well, who in thunder was then?” he
asked. “I heard some one jabbering Dutch or some other foreign
language—don’t know what ’twas except it wasn’t French or Spanish.”
Henry gave a whoop. “It was that other fellow!” he cried excitedly.
“I’ll bet ’twas. He was talking just before I rang up as I told you.
Jehoshaphat! Mr. Rawlins must have heard him under water.”
“I guess that’s it,” agreed Tom. “Funny it didn’t occur to me. Of course
there’s no reason why he shouldn’t have been heard under water. We’re
using a tiny little wave length and so’s he, and he’s close to here, you
know. Did you hear him loudly, Mr. Rawlins?”
“Well, not so as to deafen me the way you did,” replied the diver with a
grin, “but if I’d understood his lingo I could have told what he was
talking about. The only word that sounded like sense to me was something
like Oleander.”
“Then ’twas him!” fairly yelled Henry ungrammatically. “That’s the name
he was using when I heard him.”
“Well, it just proves this new thing is a peacherino,” declared Tom.
“Now let’s get busy and fix it up in good shape and make a sending set
to try out.”
Now that the boys’ first experiment had been such a huge success they
were more enthusiastic and excited than ever. They had been confident
that the diver would be able to hear sounds or that he might even
distinguish words under water, but they had not dared to hope that their
very first efforts would result in the sound being carried to the ears
of the man beneath the water as clearly and loudly as though he had been
present in the same room with the speaker.
“I’ll bet water carries electromagnetic waves better than air,” declared
Tom. “Why, if this little set can respond to these short five watt waves
in this way, think what it would mean to a submarine with big amplified
sets and getting messages sent with hundreds of watts. Why a fellow
could sit in Washington and talk to submarines and divers all over the
Atlantic.”
“You’ve hit on a wonderful possibility,” Rawlins assured him. “Of course
I was pretty close—I didn’t go over a hundred yards from the dock and
it’s shoal water. I’m anxious to try it down a hundred feet or so and a
mile or two from the sender. We’ll do that after we get things right—go
down to my hangout in the Bahamas and give it a real honest-to-goodness
tryout.”
“It’s all in that new amplifying arrangement and that single control
tuner Frank hit upon,” said Tom. “And we’re not really responsible for
either. Mr. Henderson gave us the idea for the tuner and a friend of
Dad’s invented the tube, but couldn’t get any one interested. You see,
Henry, this tube is just about 400 times as much of an amplifier as the
other tubes, and we get a detector and amplifier all in one. Look
here—it’s the smallest bulb you ever saw—about the size of a peanut and
we operate it on a flashlight battery with a special little dry cell for
the filament. Of course they don’t last long, but a fellow can’t stay
down more than an hour or two anyway and the batteries will run the set
steadily for five hours. For under-sea work the cost don’t count. What
we’re up against now is to make the sending set to go with it. The
receiver was easy. That fits in this special helmet all right and don’t
have to be waterproof, but the sending set’ll have to be outside and
it’ll be an awful job to keep the water from short circuiting it.”
As he talked, Tom was showing Henry the set and pointing out its many
novel features.
“This single tuner is great,” he continued. “It’s fixed so it’s set at a
certain spot for the normal wave lengths sent from the diver’s home
station. See, here in the middle at zero. Then, if he wants to get a
shorter wave he turns it to the left which gives him a range down to
half his normal wave length, or for longer waves he turns it to the
right and gets twice his normal length. If he wants to go to long wave
lengths—for example, if he was a spy or something and wanted to get the
big sending stations—he’d turn the knob clear to the left and then back
to the right and around to opposite the zero point. Then he’d be on
about 2500 meters and that being his utmost length he just has to tune
slowly towards zero again. And the rheostat works automatically with it
and so does the variable condenser and it’s not very complicated
either.”
“But what does he do for an aërial?” queried Henry.
“Doesn’t use one,” replied Tom. “Just has this sort of wire cage
sticking from his helmet, like a loop, but made of two grids set at
right angles to each other. But gosh! I never thought about there being
interferences under water.”
“I suppose Henry understands all that,” interrupted Rawlins laughingly,
“but it means about as much to me as that Dutch talk I heard. Somehow or
other I can’t get on to this radio a little bit. When you get that
sending outfit rigged you’ll have to go down and test it. I’d probably
bungle something. I didn’t even dare meddle with this gadget for tuning.
I tried it once and when your voice stopped I just shoved her back and
let it go at that. That’s when I heard that Dutchman.”
“Then he’s on a different wave length and it proves _we_ can tune out
under water,” declared Tom gleefully. “That’s another feather in our
caps.”
Henry quickly grasped the boys’ ideas and together the three worked
diligently until sundown while Rawlins busied himself devising the
fittings for his suit to accommodate the sending apparatus and helped
the boys tremendously with suggestions for rendering a set watertight
and with advice as to mechanical and other details.
By the time they were obliged to stop their work the plans for the
under-sea transmission set were well worked out and, with high hopes and
flushed with the success of their achievements, they locked up the
workshop and walked up town discussing plans for the morrow.
The following day they went to the dock right after breakfast, for
school was over for the season and they had all their time to
themselves. Rawlins was already there and before they left that night
they had the set nearly completed and Tom declared they would be able to
give it a test the next day.
Mr. Pauling was of course deeply interested and enthusiastic over the
boys’ work and promised to go down himself as soon as the instruments
were perfected. He listened to the boys’ glowing accounts of their work
and their success and later, when Mr. Henderson called, he too became
most optimistic regarding their under-sea radio.
“It’s merely a question of experimenting, boys,” he declared. “We were
on the right track during the war, but radio’s jumped ahead a lot since
then and whatever the government experts accomplish is kept mighty
quiet. I’m glad that single control works out so well. We’ll have to
thank the Huns for that. We found one on a captured U-boat, but as far
as I know the government never took it up seriously—don’t know why
unless it was because there was no particular need of it. We never did
find out what the Germans used it for—for all we know they may have been
experimenting along under-sea lines too. And if that new tube of
Michelson’s proves good he’ll make a fortune and have you boys to thank
for it. I’m coming down to see your outfit just as soon as we get a
breathing space. We’re rushed to death just now.”
With nothing else to do the boys amused themselves listening at their
sets which, with so many other interests, had been sadly neglected of
late, and, out of pure curiosity and never expecting to hear anything,
Tom turned his loop aërial to the southeast and tuned for the short wave
lengths used by the mysterious talker they had once followed and tried
to locate so persistently. To his surprise, the sound of words came
clearly over the set.
“There he is again!” Tom exclaimed to Frank who was listening to a
broadcasted speech. “Get him and we’ll see what he says.”
But despite the fact that the boys could both hear the man plainly his
words were meaningless, for he was speaking some guttural,
harsh-sounding tongue.
“Oh, pshaw!” ejaculated Tom disgustedly after a few minutes of this.
“Who cares what he’s saying. I guess it’s some crazy foreigner.”
So saying, he again picked up the broadcasting station and forgot all
about the incident in his interest as he listened to a lecture on new
developments in radio.
“Some night we’ll be listening to that fellow talking about the new
under-sea radio,” chuckled Frank as the talk ceased and the boys laid
aside their receivers. “Say, won’t it be sport to hear him telling about
us and know all the fellows are listening to it?”
“Well, we won’t count our chickens just yet,” declared Tom sagely. “Just
because that receiving set works isn’t any proof the sending set will.
And without being able to talk back a diver isn’t any better off—or at
least much better off—if he can hear what’s going on in the air.”
But Tom might have been far more confident, for the following day when
the test was made it worked much better than their most sanguine
expectations had led them to think possible. To be sure, their
experiments came to an abrupt ending right in the midst of the test, for
the sending set on Tom’s suit leaked and, with a feeble buzz and
sputter, his words trailed off to nothingness.
But when, upon reaching the surface, Rawlins reported that he had heard
everything Tom had said and Frank and Henry in the shop had also heard
him, the boys knew that their plans and the principles of the outfit
were all right and that only the question of making the set absolutely
watertight remained to be solved.
“I don’t see why it should not be inside the suit,“ declared Rawlins, as
the boys were discussing the matter and were at a loss to know how to
accomplish their aims. “You say these wireless waves go through
everything and we get them through the suit in the receiving set so why
shouldn’t they go out through everything just as well. Look here, I was
thinking over this last night and here’s my idea.”
As the boys gathered about, the diver rapidly sketched his plan of a new
suit in which the sending set could be placed within a receptacle full
of compressed air.
“I believe that _would_ work,” cried Tom when he grasped Rawlins’
scheme. “I don’t see why compressed air should affect the outfit any and
it’s easy enough to make watertight fittings where the wires come out
and there’s no tuning to do, We can always use a special wave length and
if several men were talking under water each one could have his own wave
length. Yes. I’ll bet you’ve solved the puzzle, Mr. Rawlins.”
Keen on the new plan the boys started a new set, or rather two new sets,
for they wished to make a test to determine if two men under water could
converse, while Rawlins busied himself on the special suits and air
pockets to be used.
“We’ll have to balance the weight of the set against the increased
buoyancy of this compressed air,” he remarked as he worked. “But I see
where that’s an advantage. One of your troubles has been the weight of
batteries and by this air caisson arrangement weight won’t cut any
figure under water.”
“But suppose the air pocket springs a leak?” queried Frank. “We’d be
just as badly off as before.”
“Well, I don’t calculate to have it leak,” replied Rawlins, “but if you
make the sets as near watertight as you can, they’d still go on working
for some time before they got soaked. And if I can’t make a little
caisson that’ll hold a hundred pounds of air for ten or twelve hours
I’ll give up diving and drive a taxi.”
Several days, however, were required to get the set and the air pocket
suits ready and when, after a test in the workshop, everything seemed in
perfect working order, Tom and Rawlins donned their suits and prepared
to descend the ladder through the trapdoor.
Just before his head dipped beneath the surface of the water Tom spoke
into his mouthpiece and Frank, listening at his instruments, gave a
start as his chum’s voice came clearly to his ears.
“So long, old man,” came Tom’s cheery voice, which somehow Frank had
expected would sound muffled. “Keep your ear glued to the set and be
ready for great news. I’ll bet we give you a surprise.”
The next instant only a few bubbles marked the spot where Tom had sunk
beneath the surface of the water, and little did he or the others dream
how much truth was in his parting words or what an amazing surprise was
awaiting not only Frank but himself.