The Secret Wireless Part 5

Captain Hardy studied it for an instant. "Take this at once to Chief Flynn," he said. "He may want to ask some questions about it. Willie will relieve you at the wireless."

Several hours pa.s.sed before Roy returned, and Captain Hardy began to fear lest, despite the training in the geography of the city, Roy had become confused and gotten lost. Then suddenly the door of the wireless apartment burst open and Roy flew in.

"Chief Flynn told me he thought his men could unravel that message and that I should wait a while," panted Roy, breathless from running up the stairs. "And they did get it. It's what they call a transposition cipher. Here is what it says."

He held out a sheet of paper. On it the letters Roy had picked out of the air were arranged in four lines, as follows:

S R P S T S N I A O L T M I X N R E H O N T S T F I R G

"Read down instead of across," explained Roy.

Captain Hardy studied the cipher a moment more, then read aloud: "Six transports left this morning."

CHAPTER VI

A NEW DANGER POINT

For a moment there was dead silence. Then Captain Hardy spoke. "You have done excellent work, Roy," he said. "Beyond doubt this is a message from a German spy. It is fortunate you caught this particular message, for it proves that, whether there is a leak in the navy department or not, the Germans are watching our s.h.i.+ps here in New York.

Did you catch the direction this came from, Roy?"

"Yes, sir. I marked the direction on the blotter beneath the detector."

"We'll take a look at it," said the leader, and the little band entered the wireless room, where Lew was now on duty.

On the white blotter they found a long black line, tipped with an angle mark like an arrow-head. Captain Hardy got a map of the city, and spreading it on the table true to the compa.s.s points, stretched a yardstick across it in the direction indicated by the arrow.

"Hoboken," he muttered. "The arrow points to Hoboken." For a moment he studied the map before him. "You will remember," he said, looking up, "that Hoboken is the point on the Jersey side of the Hudson where there are such great railroad freight yards and such huge piers. Many Atlantic liners sail from Hoboken. Evidently the Germans are watching there. Of course they would be. Their spies are informing other German agents every time a troop s.h.i.+p sails. And somehow they get that news to Germany. It's a terrible menace to our army, boys. We must put an end to it."

"We will," came the reply from four sober-faced boys.

"It's going to be a long task, boys," said Captain Hardy. "Get your hats and we'll take a look at Hoboken."

Leaving Lew at the wireless, the four others set out. They rode for a distance on a Ninth Avenue elevated train, then walked to the ferry, and in less than an hour of the time they left their headquarters found themselves in the great Jersey s.h.i.+pping point.

Never had the boys from Central City seen anything quite like the water-front at Hoboken. The level ground was one great maze of railroad tracks, freight depots, warehouses, and pier sheds. The wide thoroughfare running along the waterfront presented a scene of bewildering confusion. Trolley-cars, steam trains, motor trucks, horse-drawn vehicles, and other conveyances were moving this way and that. Whistles were tooting, motors honking, bells ringing, drivers swearing, policemen shouting orders. Pedestrians were dodging in and out, messenger boys were darting here and there. Porters were carrying bundles on their shoulders, laborers were wheeling materials in steel wheelbarrows, lines of heavily laden trucks were pa.s.sing into steams.h.i.+p piers, and guards and watchmen at every entrance were closely scrutinizing all who approached.

The four observers walked slowly along, studying every foot of the way.

High fences had been built here and there to hide what was going on behind them. Covered ways led from railway terminals to pier sheds so that none could see what had come by train. Even the gangways to the s.h.i.+ps were screened. Every precaution had been taken to baffle curious eyes.

"They've done their best," commented Captain Hardy, "but they can't screen a s.h.i.+p on the river, and the Germans know when our transports sail, even if they don't know what's in them. Any one with a good gla.s.s can look out from any house along the river front and see clearly every move made by a steamer. Let's take a stroll among these houses."

They left the bustling water-front and pa.s.sed to the higher ground where stood the city proper. It was like most other American munic.i.p.alities--dirty, dingy, and unattractive, a hotchpotch of buildings with no architectural unity. But it had one feature possessed by few cities--an outlook on a great and busy harbor.

As the boys stood looking at the rolling Hudson below them, watching the ferry-boats come and go, like huge shuttles in a giant loom, following the movements of steamers, and tugs and tow-boats, and tracing the circling flight of the gulls, they forgot entirely the errand that had brought them. Presently their leader broke the silence.

"We shall have to get to work," he said.

Starting at one end of the street, they walked slowly along its entire length, studying every house that fronted on the river. They saw at once that their task was hopeless. Square after square the houses stretched in unbroken blocks. A hundred spies might be living in those houses and no one be the wiser. A hundred wireless outfits might be flas.h.i.+ng messages among the clothes-lines on the roofs and only a roof to roof survey would reveal the fact. But it was not necessary to run even so slender a risk of discovery. As the wireless patrol knew only too well, an aerial would work with great efficiency even though it were strung in a chimney or erected entirely within doors. Yet the little party continued its investigation until dusk, scanning every window whence a gla.s.s might be directed toward the river, and threading alleys and scrutinizing the wires of roofs and yards. But nowhere did they see anything to arouse their suspicion.

"We may as well go back, boys," their leader said at last. "We shall have to depend upon our ears rather than our eyes if we are to catch these villains. But we have made progress. We know where they are.

We have limited our field of observation to one place. Now we shall have to do as we did at Elk City. We shall have to get two portable sets with compact detectors and begin a watch in Hoboken. We'll have to find this hidden wireless by triangulation, just as we caught the dynamiters. But we haven't enough of a force to maintain two watches.

We shall likely have to send for more of the boys to come on."

They recrossed the river and made their way back to their headquarters.

Lew had heard nothing. He was relieved by Henry.

The others went down to dinner, and food was sent up to the lone watcher. But when his trick was ended, he made the same report that Lew had rendered. He, too, had heard nothing.

"Doubtless," said Captain Hardy, "they use their wireless seldom for fear of discovery. Probably they send a message only when troop s.h.i.+ps have actually sailed. That is likely the reason it was such a long time before we caught the first message. And it may be just as long before we hear another. But when it comes, we must be ready with our two detectors. I'll see Chief Flynn about them in the morning. And I'll tell him what we have learned in addition to what the cipher message told us."

"I wonder," said Roy, "how the secret service men ever unraveled that cipher. I could never have done it. I was looking for something like the code message we caught at Camp Brady."

"It probably was not very difficult, Roy," replied Captain Hardy, "or it could not have been fathomed so soon. I believe that most cipher messages to-day are like the one you caught at Camp Brady. Apparently they are innocent messages but they have a hidden meaning. The most difficult cipher messages, I have heard, are of the subst.i.tution kind, where many alphabets are used. It is pretty difficult to decipher such messages unless you have the key word."

"Then why didn't the Germans use a subst.i.tution cipher when they sent this message about the transports?" asked Willie. "Then we might never have been able to tell what they said."

"It was hardly worth while, Willie. They know the authorities are listening for their messages. It made no particular difference if the contents of this message were known. But when they send out an order for a spy to do something, I have no doubt they use the most difficult code they can devise, or at least one that they believe only the spy will understand. So we may expect to catch messages in different codes before we are through with our work."

Captain Hardy rose and began to look along the shelves of books. "Here is a volume," he said presently, "that will tell us a great deal about cipher messages."

He had just laid open the book when Roy rushed in from the wireless room. "I've got another message," he said, holding out a paper on which was a long string of letters.

"I wasn't expecting another message so soon," said Captain Hardy in surprise. Slowly he read the letters on the paper Roy had given him:

"FTSt.i.tEIAFTDLLTNSYWTORPSLHVNRLEEYLIOTEIH UAOSEIEGGEVNCENDRRTERNRADSNLEEITOCGEOSHM."

"It looks like the same cipher used before," he went on. "If it is, we can unravel this message without bothering the secret service. At any rate we'll make a try at it. Where's that other message, Willie?"

The first message was brought. Captain Hardy spread it on the table and the group bent over it.

"The letters divide evenly into four lines, you notice," said the leader. "Let's see if this message will do the same."

He counted the letters with his pencil. "Eighty," he announced. "That would make four lines of twenty letters each. We'll try it."

Rapidly he copied the first twenty letters. Below them he made a second line of the next twenty letters. Then the third set of twenty was written down. As he began the fourth row the three boys at his side held their breath.

"He's got it," Willie Brown cried, as Captain Hardy wrote down the first letter. "He's got it. It spells four."

Rapidly Captain Hardy finished out his line. The letters he had written down read like this:

FTSt.i.tEIAFTDLLTNSYWT ORPSLHVNRLEEYLIOTEIH UAOSEIEGGEVNCENDRRTE RNRADSNLEEITOCGEOSHM

He picked up the paper and slowly spelled out the following message:

"Four--transports--sailed--this--evening-- Large--fleet--evidently--collecting-- No--destroyers--with--them."