into an air-tight room near
the bottom of the submarine, and, after the door had been securely
fastened, water was admitted. When the room was full, the diver opened a
door in the hull and stepped out of the boat, which had previously been
lowered until it rested on the Canal bottom.

From the porthole in the submarine's bow he could be seen slowly making
his way, following the luminous path made by the searchlight. In a short
time he reached the gate of the lock, and began to follow its course
toward the bank. He was soon out of the range of vision of those at the
porthole, but, in a few minutes, returned; and it could be seen, by the
way in which he still scanned the walls, that he had not yet found the
wires leading to the explosives.

He had traversed perhaps half the distance from the center to the other
bank, when he was seen to stop suddenly and carefully examine something
near the lock.

"I'll bet he's found the wires," exclaimed Bert, excitedly.

"Very likely he has," replied Mr. Warren. "I was beginning to be afraid
that the plotters had buried the wires so cunningly that it would be
almost impossible to get at them."

But here, all doubts on the subject were set at rest, as they saw the
sailor draw a pair of wire cutters from his belt and ply them on
something near the wall. Immediately afterward he straightened up and
waved his hand, as a signal that everything was all right.

"By Jove," cried the lieutenant, drawing a long breath, "I guess now
we've spoiled those fellows' plans for good. But, believe me, that was
rather ticklish work. I expected almost every minute to be wafted
heavenward by a charge of dynamite. None of us would have had the
slightest chance in the world, if that explosion had taken place."

"I rather think you're right," agreed Bert. "But why doesn't the man
come back? He seems to be continuing his search along the Lock gate."

"Oh, that's because the captain gave him orders before he went out to
examine the wall from end to end for traces of a second set of wires.
But I guess that the Japs had such confidence in their handiwork that
they had no doubt of the success of their one set. I must confess that I
haven't much doubt regarding them, either, if we hadn't happened along to
spoil the whole show for them."

"Yes, the whole country owes Mr. Wilson a debt of gratitude it can never
repay," broke in Captain Clendenin, who had come up and overheard the
lieutenant's las