ny instructions that might be necessary
in order to make the tests more conclusive.

"If you will come along with me, then, Mr. Benson," suggested Major
Woodruff, "I will put you ashore on the neck. On the way over I will
give you your instructions."

As the tug came alongside again Jack followed the major over the gang
plank to the deck of the other craft.

"Good-bye, Captain Somers," called Jack, laughingly. "Give a fine
account of yourself as an enemy of the United States!"

"Oh, you--" began Eph, flaring red, but wisely cutting his speech
short.

On the way over to the strip of land known as the "neck" Major Woodruff
managed to make his instructions wholly clear to young Benson.

"Now, you know what to watch for, and what observations, to report to
me," finished the major of engineers, as the tug came to a stop. A
small boat was lowered, and, in this, Captain Jack Benson was put on
the desolate shore.

Then the tug went back over by the fort. Jack grew tired of waiting,
for it was some two hours ere the tug finally left the ordinance wharf
at Fort Craven.

It was warm out there, on the low, sandy cliffs, provided one got into
a position sheltered from the ocean winds. So Jack, in the weariness
of his waiting, threw himself down in a sheltered hollow.

Finding that the sun shone disagreeably in his eyes, the submarine boy
pulled his cap forward over his face.

Then, in the course of a very few minutes, the inevitable happened. Jack
Benson drifted off into sleep.

He awoke with a fearful start, for he had no idea how long he had slept.
Yanking out his watch and noting the time, the submarine boy concluded
that he had not been asleep more than twenty or thirty minutes.

"But I might just as easily have slept for hours," Benson reproached
himself. "Then what a hero I'd have felt. Asleep on post!"

At that moment Jack Benson heard a faraway whistle, across the bay.
Showing just the top of his head above a ridge of sand, Captain Jack
saw the Army tug just pulling out from the dock across the bay.

But Jack saw something else, too, in that brief instant.

A slim, soldierly-looking man of perhaps thirty, tall and of naturally
good carriage, was skulking along in front of the submarine boy, yet
hidden from the bay by a sand ridge.

Under one arm the stranger carried a draughtsman's board and a book. A
strap over one shoulder held a field-glass case.

"Where in blazes have I seen that chap before