The Submarine Boys' Trial Trip Part 4

"Pardon me, sir," replied Jack, courteously, though firmly.

"Do you refuse to answer my question, boy?"

Again the irritating, half-contemptuous use of "boy" made Jack's cheeks flush, though he answered merely:

"I think, sir, Mr. Farnum has a right to the first information."

"Do you understand, boy, that I am about to take a large interest in this business?"

"I have heard so, sir. But I hope you won't mind my saying that this little surprise was thought out by my comrades and myself. It seems to me, therefore, that we have some rights in the disclosing of the secret."

"Humph!" broke in Don Melville. "It's all some deception--some cheap trick, anyway."

Captain Jack held up one hand to signal the sh.o.r.e boat, which, with two workmen in it, was hovering near. As the boat came in, the submarine boy announced:

"Now, I will show you the rest of the principle that my mates and I are demonstrating. Mr. Farnum, by the way, has just spoken of the humane side of this discovery, the making possible the rescue of a crew of a boat that can't be made to rise. Gentlemen, there's still another side to it. Under actual war conditions, with a submarine boat guarding a coast or harbor entrance, if the commander of the boat brought the conning tower above the surface, the presence of the boat would be detected on a clear day. But the head of a swimmer rising from the boat could not be observed at any very great distance. Yet the swimmer could make out the hull or masts of a hostile vessel some miles away.

This new trick is likely to make submarine boats much more valuable to the countries owning them. Now, I want to try something else, and see whether I can do it."

The sh.o.r.e boat put in when called. In the bow was a hundred-pound anchor, with plenty of cable to pay out after it. Captain Jack entered the boat, looked over the anchor tackle, then returned to sh.o.r.e.

"Come to me where I stop," he directed the men in the boat. With that, after getting his bearings fully, he swam out, counting his strokes as he went.

"It's about here that I came up," he called, pausing and treading water easily. "Bring the boat here."

Clambering aboard, he directed the casting of the anchor overboard. Then, poising himself at the bow, he made a strong dive, vanishing under the water.

"What's he going to do now?" asked Mr. Melville, curiously.

"I'd rather wait than guess," smiled Mr. Farnum.

For just an instant Don Melville looked, as he felt, green with envy.

Some moments pa.s.sed. Then, not far from the spot where the "Pollard" had gone down, her conning tower appeared once more. That was followed by the emergence of the platform deck and upper hull above the water. In another moment the tower manhole was opened, and Jack Benson, with a wave of the hand, stepped out, his bathing suit changed for his uniform. He lifted his cap in a joyous salute to those on sh.o.r.e.

"By Jove, Jack, but you're a wonder!" shouted Mr. Farnum across the water.

"I'll have Dave Pollard excited when I write him about this thing. But you have me guessing how the trick was done."

Once more Benson signaled the small boat in close, after the anchor had been lifted. Now, the young submarine captain came in to sh.o.r.e.

"You come on board with me, Mr. Farnum?" invited Jack.

"Are you going to show him how you worked the trick?" demanded Mr.

Melville, quickly.

"Yes, sir."

"Then I believe we'll all come on board."

"I--I am sorry, sir." Jack hesitated. "If anyone but Mr. Farnum comes aboard I shall show nothing. Later on, when Mr. Farnum and I have talked this matter over--"

"Are you going to stand for this boy's nonsense, Farnum?" broke in the capitalist, angrily.

"I guess I shall have to," responded the builder, with the p.r.o.nounced drawl which, with him, was a sign that he was close to inward anger.

"Mr. Melville, I must beg you to remember that the secret, whatever it is, belongs, so far, to Captain Benson. You may not approve, but I think he is wholly right in this instance."

The capitalist bowed stiffly. He and his son remained on the sh.o.r.e as Farnum embarked with his young employe. They were soon on board the "Pollard," which was not long in sinking. Then, after a few minutes, Jack's head once more shot above the water. The sh.o.r.e boat was waiting, and again dropped the anchor close to where the boy had come up. Jack stood in the boat for a few minutes, taking in deep breaths and sunning his wet skin. Then, for the second time, he dived below the surface.

Five minutes afterward the "Pollard" was at the surface and moving back to her moorings. Mr. Farnum and Captain Jack returned to the sh.o.r.e.

The boatbuilder's face was glowing with delight.

"You saw our young captain come up while I was with the 'Pollard' down on the bottom, didn't you?" inquired the yard's owner.

"Yes," admitted Mr. Melville, grudgingly, while Don half scowled, then turned his head away. "But how is the thing done?"

"That," replied Jacob Farnum, courteously, "at the request of Captain John Benson, must remain a secret for the present."

"Oh!" said the capitalist, but his tone was ominous.

CHAPTER III

MR. MELVILLE HURLS THE CRASH

It was really a wonderful, even if a very simple, revolution in the handling of submarine boats that Jack Benson had thought out.

Up to that time many scores of lives had been lost, in different parts of the world, when the crews of submarine boats had found, for one reason or another, that they could not raise their craft from the bottom of the depths. Formerly, when crews found themselves placed in that predicament, death followed.

Jack's solution was wonderfully simple. In brief, when the "Pollard" lay on the bottom of the little harbor at Dunhaven, the young captain had crawled into the long tube through which torpedoes were to be discharged in war time.

One end of this torpedo tube projects slightly into the water, at the bow of the submarine boat. The other end of the tube is well inside the craft. Two doors, or "ports," as they are called, close the tube at the ends. Ordinarily the forward port is closed, to keep water from entering the boat. When a torpedo is placed in the tube for firing, the outer or forward port is opened automatically just at the instant of discharging the torpedo. Enough compressed air is turned into the tube to force the torpedo out, after which the torpedo goes on its deadly journey propelled by its own motor. The presence of the air thus turned into the tube at the instant of firing keeps out the water until the tube's forward port is once more closed. Then the rear port of the tube, inside the submarine boat, may be opened whenever it is desired.

Captain Jack Benson, when he reached bottom with the "Pollard," and had donned his bathing suit, crawled into the tube through the rear port.

This port was then closed. Hal Hastings simultaneously opened the outer port and discharged compressed air into the tube. Thus Jack forced his way out into the water, and, with the aid of his natural buoyancy, made a quick swim for the surface.

In returning, he had dived down, close to the anchor cable. Nearer the bottom he seized the cable, thus hauling himself down to the outer port of the torpedo tube. He had quickly crawled into the tube, where the presence of air still kept the water out. As he knocked heavily at the rear port with both hands, Hal swiftly turned in a moderate discharge of compressed air, while Eph, controlling mechanism inside, swung the forward port shut. Then the rear port was swung back, Captain Jack crawling back into the forward compartment of the boat.

"The whole trick is rather easy," Jack informed Mr. Farnum, as they walked that night in the village and discussed the matter in undertones.

"But you were in not more than seventy feet of water there," suggested the builder. "You couldn't do it at much greater depth."

"At eighty feet of water I could do it," replied Benson, thoughtfully.

"But at a greater depth than eighty feet--?"

"Of course, the deeper one gets, the more tremendous the pressure of the water is," answered the young captain. "At a depth of a hundred feet, say, the pressure of the water would be enough to crowd me back into the tube, crushing my body."