“Honestly now,” Jack said, when the subject arose between the two chums, “I believe the old man means to stick it out on the bridge until we arrive in port. I take off my cap to him. If that’s the stubborn sort these British naval men are, I don’t much wonder Britannia Rules the Waves.”

Did, you ought to say, Jack,” corrected Tom, with a chuckle; “for since the submarine came along it’s anybody’s fight now as to who is mistress of the sea. Great Britain has Germany’s Grand Fleet cooped up in the Kiel Canal; at the same time the subs roam the ocean as they please. One rules the surface, and the other seems to have control of the undersea part.”

From that starting point the boys began to speak of the remarkable changes that had occurred in many things since the great world war broke out. Fleets of airplanes were serving as the eyes of each army and raining down tons upon tons of explosives on ammunition dumps, reserves, trains, railway stations where troops were gathered; and an endless number of other astonishing feats were of daily occurrence that a short time ago would have been looked on as wild dreams.

Suddenly came a warning from the crow’s-nest of the steamer, “Periscope off the weather bow!”

This time it was no false alarm. The experienced seaman who spent his watch aloft in the crow’s-nest with a glass glued to his eyes would not be apt to make a mistake.

The greatest excitement followed. Every one sprang to his feet. Faces turned white. Hands that gripped glasses trembled as with sudden palsy. Excited voices were heard. There was a sudden quiver throughout the great vessel, as the watchful commander on the bridge gave the order to change instantly her course.

All glasses were pointed in one direction. Some of the most sanguine declared they could make out a slender moving object that came and went as the billows rolled onward, and which could be only the dreaded periscope of the waiting submarine pirate.

Then again loud cries were heard. This time they carried an even more terrible menace. It was bad enough to be told that a periscope had been sighted off the weather bow, but when many quivering fingers pointed to the near-by water, and the import of the fresh alarm could be understood, the sudden dread caused every heart, for the moment, to cease beating.

“A torpedo coming!”

“Look! You can see the bubbles swinging out on either side as it heads this way!”