nor the little scow would be seen far on the water
on a dark night. Sambo, when he got near enough, could take one of the
metal tubes, swim in under water to some point where no watchman was near,
and stick the tube fast into the wall. Then another tube, and
another---all under water where they would not show to a passing watchman.

"Then, when he had all in place, and while no patrolling watchman was too
near, Sambo could begin to attach the wires. That would take but a few
minutes. Whenever any one came too near Sambo had but to swim out a little
way and tread water until he could return to his job. When, at last, all
was complete, Sambo would attach a wire from the bombs to a wire moored at
a stated point under water, and then swim in, work his magneto, and touch
the whole thing off from a safe hiding place on shore. The explosion
itself would shatter the last length of wire. Oh, but it was all slick
and easy!"

Not increasing his speed, but keeping steadily at the jog-trot, Tom was at
last near enough to the wall to raise his voice and shout.

"Hullo!" came back the answer.

"This is Reade, the chief engineer," Tom answered, through the night.
"We've caught the fellow that has been blowing up the wall. A half a
dozen of you men hurry over here with your lanterns. Come on the run."

The man who had answered summoned several of his comrades as quickly as he
could. As the men had to come in from the wall, however, it took a little
time. Then six men reported, almost breathless, to Reade. Still behind
them came Corbett on the run, summoned from the boat.

"What's this I hear, Mr. Reade?" puffed the foreman. "You've solved the
mystery and caught the fellow who has been dynamiting the wall?"

"Got him and he's tied up, waiting for his ride to jail," Tom chuckled.

"How did it happen, sir?" asked Corbett, staring with his eyes very wide
open.

"I caught the fellow---a huge giant of a negro, the same fellow who got
Hazelton the other night," replied Tom. "But before the fight was over the
black 'got' me, instead, and had me tied up. Then Nicolas came along and
put the negro out of the fight, and---"

"Nicolas?" demanded Foreman Corbett incredulously.

"Yes. Nicolas proved himself to be the most fiery little bunch of fighting
material that I have ever seen," laughed Reade, as they walked rapidly
along.

"How could that Mexican wallop a giant?"

"I'll ask Nicolas to show you, to-morrow," Tom lau