"Williamson is all right," nodded Jack, slowly. "But how about Truax?"

"I think he's going to be a useful man," Hal responded. "He seems familiar with our type of engines. Of course, he knows nothing about the apparatus for submerging the boat or making it dive. But he doesn't need to. Now, Jack, old fellow, we're going along all right. Why not let Eph help you back to your bunk, or one of the seats in the cabin, and have your sleep out?"

"I've had it out," Benson declared, with a laugh. "I'm ready, now, to take my trick at the wheel."

"Nonsense," retorted Hal Hastings. "I've been here a bare quarter of an hour, and I'm good for more work than that. Jack, you're nothing but a fifth wheel. You're not needed; won't be all day, and at night we anchor in some harbor down the coast. Go and rest, like a good fellow."

"Can't rest, when I know I'm doing nothing," Benson retorted, stubbornly.

"Besides, this is the first time I've ever found myself moving along in regular formation with the United States Navy. I feel almost as if I were a Navy officer myself, and I mean to make the most of the sensation. Say, Hal, wouldn't it be fine if we really _did_ belong to the Navy?"

"Gee-whiz!" murmured young Hastings, his cheeks glowing and his eyes snapping.

"If we only belonged to the old Flag for life, and knew that we were practising on a boat like this as a part of the preparation for real war when it came?"

"_Don't!_" begged Hal, tensely. "For you know, old fellow, it can't come true. Why, we haven't even a residence anywhere, from which a Congressman could appoint one of us to Annapolis!"

"_One_ of us?" muttered Jack, scornfully. "Then it would have to be you.

_I_ wouldn't go, even as a cadet at Annapolis, and leave you behind in just plain, ordinary life, Hal Hastings!"

"Well, it's no use thinking about it," sighed Hal, practically. "Neither one of us is in any danger of getting appointed to Annapolis, so there's no chance that either one of us ever will become an officer in the Navy.

Let's not talk about it, Jack. I've been contented enough, so far, but now it makes me almost blue, to think that we can only go on testing and handling submarine craft like these, while others will be their real officers in the Navy, and command them in any war that may come."

Though his head throbbed, and though a dizzy spell came over him every few minutes, Jack Benson stuck it out, up there beside his chum, for an hour.

Then, disdaining aid, he crept down the stairs, stretching himself out on one of the cabin seats. Eph brought him a pillow and a blanket. Jack soon slept, tossing uneasily whenever pain throbbed dully in his head.

"Guess I'll go out and have a little look at the young captain," proposed Sam Truax, an hour later.

"Try another guess," retorted Eph, curtly. "You'll stay here in the engine room. Jack Benson isn't going to be bothered in any way."

"I'm not going to bother him; just going to take a look at him," protested Truax, moving toward the door that separated the engine room from the cabin.

But young Somers caught the stranger by the sleeve of the oily jumper that Sam had donned on beginning his work.

"Do you know what folks say about me?" demanded Eph, with a significant glare.

"What do they say?"

"Folks have an idea that, at most times, I'm one of the best-natured fellows on earth," declared Eph, solemnly. "Yet they _do_ say that, when I'm crossed in anything my mind's made up to, I can be tarnation ugly. I just told you I don't want the captain disturbed. Do you know, Sam Truax, I feel a queer notion coming over me? I've an idea that that feeling is just plain ugliness coming to life!"

Truax came back from the door, a grin on his face. Yet, when he turned his head away, there was a queer, almost deadly flash in the fellow's eyes.

Jack slept, uneasily, until towards the middle of the afternoon. As soon as Eph found him awake, that young man brought the captain a plate of toast and a bowl of broth, both prepared at the little galley stove.

"Sit up and get away with these," urged Eph, placing the tray on the cabin table. "Wait a minute. I'll prop you up and put a pillow at your back."

"This boat isn't a bad place for a fellow when he's knocked out," smiled Jack.

"Any place ought to be good, where your friends are," came, curtly, from young Somers.

As Captain Jack ate the warm food he felt his strength coming back to him.

"Poor old Hal has been up there in the conning tower all these hours,"

muttered Captain Jack, uneasily. "He must have that cramped feeling in his hands."

"Humph!" retorted Eph. "Not so you could notice it much, I guess. It's a simpleton's job up in the conning tower to-day. All he has to do is to shift the wheel a little to port, or to starboard, just so as to keep the proper interval from the 'Dad' boat. Besides, I've been up there on relief, for an hour while you slept, and Hal came down and sat with the engines. Cheer up, Jack. No one misses you from the conning tower."

Benson laughed, though he said, warningly:

"I reckon we'll do as well to drop calling the gunboat the 'Dad boat'

instead of the 'parent vessel.'"

"Well, you needn't bother at all about the conning tower to-day," wound up Eph, glancing at his watch. "It's after half-past three at this moment and I understand we're to drop anchor about five o'clock."

So Skipper Jack settled back with a comfortable sigh. Truth to tell, it was pleasant not to have any immediate duty, for his head throbbed, every now and then, and he felt dizzy when he tried to walk.

"Who could have hit me in that fashion, last night, and for what earthly purpose?" wondered the boy. "I've had some enemies, in the past, but I don't know a single person about Dunhaven, now who has any reason for wishing me harm."

Never a thought crossed his mind of suspecting Sam Truax. That worthy had come with a note from David Pollard, the inventor of the boats. Sam, therefore, must be all right, the boy reasoned.

Jack lay back on the upholstered seat. He sat with his eyes closed most of the time, though he did not doze. At last, however, he heard the engine room bell sound for reduced speed. Getting up, the young captain made his way to the foot of the conning tower stairs.

"Making port, Hal?" he called.

"Yep," came the reply. "We'll be at anchor in five minutes more."

Jack made his way slowly to the door of the engine room.

"Eph," he called, "as soon as you've shut off speed, take Truax above and you two attend to the mooring."

"Take this other man up with you," urged Sam Truax. "I don't know anything about tying a boat up to moorings."

"Time you learned, then," returned Eph Somers, "if you're to stay aboard a submarine craft."

"Take this other man up with you," again urged Truax.

Eph Somers turned around to face him with a good deal of a glare.

"What ails you, Truax? You heard the captain's order. You'll go with me."

"Don't be too sure of that," uttered Sam Truax, defiantly.

"If you don't go above with me, and if you don't follow every order you get aboard this boat, I know where you _will_ go," muttered Eph, decisively.

"Where?" jeered Sam.

"Ash.o.r.e-in the first boat that can take you there."

"You seem to forget that I'm on board by David Pollard's order," sneered Truax.