id. "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 ships 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 compass 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 ship 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 shipping 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