CHAPTER XX

ON THE TRAIL

"I can see the lights from the camp!" Bob exclaimed. "Use your eyes,

fellows. A little to the left of us, through the trees."

"Well, it's about time," groaned Jimmy, as they all looked in the

direction indicated. "I was just getting ready to lie down and die

peacefully. I couldn't travel another mile if you paid me for it."

"Oh, buck up, Doughnuts, and get a move on!" exclaimed Bob. "You never

know what you can do until you try. Come on, let's take it on the

double."

He and Joe and Herbert broke into a lively trot, and rather than be left

behind Jimmy overcame his reluctance for further effort, and with much

puffing and blowing and fragmentary complaint managed to hold the pace

until they arrived at the mess house.

Luckily for them, supper had been delayed owing to the failure of some

supplies to arrive on time, and the lumbermen had just started eating

when the radio boys burst in through the door.

The lumbermen stopped eating long enough to welcome their arrival, and

they found their places set as usual.

"Glory be!" exclaimed Jimmy, as he slid into his chair. "If there were a

pie-eating contest on to-night, I could show you fellows some real

class. I feel empty right down to my toes."

"It's lucky we got a head start, Champ," remarked one of the men, with a

grin. "Pass everything down this way, you amateurs. There's a

professional here wants to show us some fancy eating."

By this time Jimmy was too busily occupied to make any answer, and the

other radio boys were also showing good appetites. The long trip and the

excitement of their discovery of the secret code had sharpened their

naturally keen appetites until for once they all felt on equal terms

with the lumbermen. Jimmy surpassed himself, and great was the

admiration expressed for his ability as a trencherman.

After supper the boys sought out Mr. Fennington and told him of their

discovery in the lonely cabin. Then Bob showed him the copy he had made

of the code, and Mr. Fennington studied this a long time with knit

brows.

"There seems little doubt that you boys have unearthed an important

clue, and one that may easily lead to the discovery of the crooks who

stole my merchandise," he said, at length. "I suppose I should put this

information in the hands of the police. And yet perhaps we had better

say nothing until we learn something further. With your radio outfit you

may be able to catch another code message that would give us more

definite information, and then it would be time enough to call in the

police."

"I think that would be the best thing to do, Dad," agreed Herb. "As soon

as we get back home we'll fix it so one of us will be at the set a good

part of every afternoon and evening, and we'll be almost certain to

catch some more messages like the last one."

His father nodded, and was still considering the matter when there came

a knock at the door. Herb crossed over and opened it, and he and his

friends uttered exclamations of astonishment and delight as they

recognized the visitor. He was none other than Frank Brandon, the

government radio inspector.

On his part, he was no less pleased to see them, and they all shook

hands heartily, with many questions and explanations, after which the

radio inspector was introduced to Mr. Fennington.

"I suppose you're all wondering what I'm doing up here," he said, after

the greetings were over.

"Yes, in a way," admitted Bob. "Although we know that your position

calls you all over, and we may expect to meet you almost any old place."

"Yes, that's a fact," replied Brandon. "I'm up here on the same old

business, too. Somewhere in this neighborhood there's an unauthorized

sending station, but in these thick woods it may prove a rather

difficult place to locate exactly. However, it will only be a matter of

time when we nail it."

The boys glanced at one another, and the same thought was in all their

minds. They remembered the radio apparatus they had seen in the lonely

cabin, and had little doubt that this would prove to be the unauthorized

station of which the radio man was in search.

He must have read something of this in their expression, for he looked

searchingly from one to another.

"Looks to me as though you fellows knew something," he remarked. "I

might have known if there was anything going on in the radio line within

fifty miles of where you are that you'd know something about it."

"Well, I've got a hunch that we could lead you right to the place you're

looking for," said Bob quietly.

"What?" shouted Brandon, leaping excitedly to his feet. "Do you really

mean that? Tell me all about it."

For the second time that evening Bob recounted the happenings of their

eventful excursion, while the radio inspector listened intently,

throwing in a question here and there. When Bob had finished he made no

comment for a few minutes.

Then he took the copy of the code and examined it intently, jotting down

phrases here and there in his own notebook.

"Well," he said at length, "this looks to be a much bigger thing than I

had supposed. Of course I heard of the robbery of the motor-truck, but I

never for a moment connected that with this sending station we've been

looking for. It seems fairly evident, though, that if we can lay our

hands on the operators of the unauthorized sending outfit, we'll also

have the perpetrators of that hold-up. This is a case where we'll have

to think out every move before we act."

"Just before you arrived I was considering the advisability of putting

the matter into the hands of the police," said Mr. Fennington. "What

would you do?"

"Keep the whole thing to ourselves for the present," said Mr. Brandon

decisively. "I'll send for a couple of good men to come up here and help

me, and we'll keep a watch on that cabin for a few days. If this thing

got into the papers, it would put the crooks on their guard, and

probably spoil our chances of catching them and getting back the loot.

I've got a small but extremely efficient receiving and sending set in my

car, and if any more code messages are sent out we'll catch them."

His confidence was contagious, and the boys felt almost as though the

capture of the criminals had already been accomplished.

"What puzzles me, though," remarked Mr. Fennington, "is how you knew

that there was an unauthorized radio sending station in this

neighborhood, Mr. Brandon. I should think it would be almost impossible

to locate such a station, even approximately."

"On the contrary," replied Frank Brandon, "it is little more than a

matter of routine. Probably any of these radio fiends here could explain

the method as well as I can, but I'll try to make it plain to you.

"There is a certain type of aerial that has what we call 'directional'

properties, that is, when it is shifted around, the incoming signals

will be loudest when this loop aerial, as it is called, is directly in

line with the sending station. The receiving antenna is wound on a

square frame, and when the signals are received at their maximum

strength, we know that the frame is in a practically straight line with

the sending station we're after."

"Yes, but that still leaves you in the dark as to whether the station is

one mile away or a hundred miles," observed Mr. Fennington, as Brandon

paused.

"That's very true," answered the other. "And for that reason we can't

stop at using just one loop aerial. What we actually do is to have three

stations, each one equipped with a loop. These three stations are

located a good many miles apart. Now, with these three loops, we have

three lines of direction. We lay out these lines on a chart of the

territory, and where they intersect, is the place where the unlicensed

station is located. Is that clear?"

"Perfectly," said Mr. Fennington. "But what looks like a point on the

map may be a large space on the actual territory."

"Oh, yes, our work isn't done by any means after we have got our first

rough bearings," continued Brandon. "Having determined the approximate

position, we take the loops and receivers to what we know is a place

quite near the station we're after, and then we repeat the former

process. This time it is much more accurate. Gradually we draw the net

tighter until we find the antenna belonging to the offender, and

then--well, we make him wish he hadn't tried to fool the government."

"You certainly have it reduced to an exact science," acknowledged Mr.

Fennington. "I don't wonder that everybody interested in radio gets to

be a fanatic."

"We'll make a 'bug' out of you before we get through, Dad," declared

Herb, grinning.

"If my load of silk is recovered through the agency of radio, I'll be

enthusiastic enough over it to suit even you fellows," said his father.

"It will mean the best set that money can buy for you if I get it back."

"We'll hold you to that promise," threatened Herb. "Radio can do

anything," he added, with the conviction of a devotee.

"Well, pretty nearly everything," qualified Mr. Brandon. "A little while

ago it was considered marvelous that we could transmit the voice by

radio, and now the transmission of photographs by radio has been

successfully accomplished."

"What!" exclaimed Mr. Fennington incredulously. "Do you mean to say that

an actual recognizable photograph has been sent through the air by

radio? That seems almost too much to believe."

"Nevertheless, it has been done," insisted Frank Brandon. "I saw the

actual reproduction of one that had been sent from Italy to New York by

the wireless route, and while I can't claim that it was perfect, still

it was as plain as the average newspaper picture. And don't forget that

this is a new phase of the game, and is not past the experimental stage

yet."

"Well, after that, I am inclined to agree with Herbert that 'radio can

do anything,'" admitted Mr. Fennington.

"I don't think we'll have much trouble making a convert of you," laughed

the radio inspector. "No doubt the quickest way, though, will be to

recover your stolen shipment, so we'll start working in that direction

the first thing in the morning."

And in this he was as good as his word. He was up betimes, getting in

touch with headquarters by means of his compact portable outfit. He kept

at work until he had received the promise of two trustworthy men, who

were to report to him at the lumber camp as soon as they could get

there. Then he routed out the radio boys, and after a hasty breakfast

they all set out to locate the cabin where the boys had found the code

key.

The Radio Boys Trailing a Voice; Or, Solving a Wireless Mystery · 第 20 / 25 章