and took him off so as to
save the other the trouble of going clear back to England!"

"No doubt that's it," agreed Jack. "But look!" he continued, "he's
discovered us! See him pointing toward us!"

"Better get ready to dive, then," cautioned Harry. "If he's able, he'll
get them to shoot at us. If they hit the 'U-13' it'll be a long way to
Tipperary for us! We don't know how thick this armor is!"

"Down we go!" shouted Jimmie, seizing the wheel. "Lively, now!"

Even as the boy spoke, a muffled roar was distinctly heard by the lads in
the submarine. A crash that reverberated through every portion of the
vessel told that they had been hit by a projectile.

With a quick, startled glance at his companions, Ned hastened aft to
examine the possible damage. He could discover no leak.

"I guess we're lucky, after all!" he stated presently. "We're not taking
in water, so I'm sure they didn't do very much damage."

"It might have been more serious, though!" commented Jack.

"Maybe the shot just carried away some of the light work like railings
and so on around the deck. I don't think the shot struck the hull, or
we'd have heard more racket," went on Ned.

"Let's keep below the surface for a while. Maybe we can get away from
those fellows far enough to be out of their sight while we change air.
They're not the least bit sociable!"

"Full speed ahead, Harry!" cried Frank. "Let's hurry on!"

"Better take it easy," cautioned Jimmie. "We may not be out of the woods
yet. Let's just go along slowly for a while."

"Aw, go on!" scorned Frank. "What's there out here to bother?"

"Sure!" chimed in Jack. "We're away out in the North Sea where we can
find nothing but warships and sailing vessels and such!"

"Maybe we might run into the real 'U-13'," countered Jimmie. "Then, what
would you do if you should meet that fellow?"

"Why, put on steam and run away from him, of course!"

"All right, go ahead if you want to," submitted Jimmie unwillingly, "but
I don't think it wise. It's taking considerable risk!"

Since the majority seemed to be in favor of more speed, the engines were
again urged to greater effort. Suddenly all were startled by a cry from
Jimmie. The boat swerved sharply to starboard, rolling until the deck was
at an acute angle. Harry reached for the levers, prepared to stand by the
engines for orders from the pilot.

Directly Jimmie rang a stop bell. The vessel came again to an even keel.
The boys were once mor