The Boy Inventors' Diving Torpedo Boat

That night in the library of the Chadwick home, two boys and a dignified looking man, who wore a nut-brown beard slightly tinged with gray, sat poring over a pile of books and papers, their work illumined by a strong electric reading lamp.

The eldest of the party was, of course, Mr. Chester Chadwick, and the two lads, his son and nephew. Tom’s father, Mr. Jesson, was absent in the Northwest, making a collection of the flora of the region.

“It is plain enough,” Mr. Chadwick was saying, “that your friend’s craft, owing to its construction, cannot be equipped with the usual tanks employed in submarine designing. What we have to do, is to find out some other way of forcing it beneath the surface and keeping it there, if necessary.”

Jack, who had been busy with a sheet of paper for the last twenty minutes, looked up.

“I think I’ve got an idea,” he said; “of course, although it looks all right on paper, it might not work out in practice.”

“Let’s see it, my boy,” said Mr. Chadwick.

The rough sketch that Jack had made showed the White Shark equipped with peculiar looking paddle-wheels of spiral design instead of the ordinary type.

“My idea is,” he said modestly, “that of the Archimedian screw. When on the surface these spirals could be set level, but a slight tilt would drive the White Shark down toward the bed of the sea. To rise, you would simply have to reverse the process.”

Mr. Chadwick nodded thoughtfully.

“Your idea sounds by no means impossible of being put into practice,” he said after a moment’s consideration and a swift scrutiny of Jack’s rough sketch.

“We would have to test it out with a model, of course,” said Tom.

“Of course. But the engines in the White Shark are not so placed that they would drive propellers of this character, for, you know, there would be one on each side, on the principle of paddles instead of stern propellers.”

“That was my idea,” said Jack; “but I think it would be a simple matter to alter the position of the motors and install all the necessary driving shafts and gears.”

The subject was discussed till late and they parted for the night determined to put Jack’s idea to a test in the morning. There was much apparatus of various character about the workshops attached to High Towers, and they anticipated that the work of constructing a rough model would not take long. As readers of the other volumes of this series know, High Towers was a big estate embracing a lake and surrounded by a high fence, insuring privacy.

Mr. Chadwick had grown rich from his many inventions and could afford to indulge in the luxuries of his science. But, in spite of the idea of the young enthusiasts that it would not take long to construct a model, it consumed more than a week. The work of installing the Archimedian screws, so that they would be worked properly, was especially tedious.

But at last it was done. The complicated model of the White Shark was very like its original, only it was built on a scale of an inch and a half to the foot. It was an odd looking thing, with its two screw-like fins attached to the sides. Inside it were electric motors, and Jack had devised a system of controlling it from the shore with electric wiring; for it had been previously decided to test it in the lake at High Towers. To sum up its appearance in a homely simile, the White Shark looked like a cigar-shaped bottle with corkscrews on each side.

It was an excited group that on the morning of the test emerged from the workshop in which the young inventors had wrought out their ideas. Mr. Dancer was one of the group, for, during the construction of the model, he had been a constant visitor at High Towers and had displayed much interest in the work. He had almost recovered from the cut on his head, which proved to be only a flesh wound probably inflicted with a blackjack. Nothing more had been heard of Duke, although the police had been notified and a hunt was on for the inventor’s assailant.

The united efforts of the party were required to place the model on a hand truck preparatory to wheeling it down to the lake, where a sort of launching platform had been built. The eyes of all were bright with anticipation, though, and in the general excitement and enthusiasm there was no complaint of the work, which was really hard.

High Towers Lake was a body of water partly artificial and partly natural. Thick brush grew round its edges and it was indented by many small bays or coves.

When they reached the water’s edge, they found the electric apparatus which was to control the diving model already in place and the wires ready to be connected. This did not take long, and then came a momentary pause before the ceremony of launching.

“We ought to give it a name,” declared Jack before he cut the cord which held the model in place.

“By all means,” said Mr. Chadwick; “come, Tom, think up one.”

“I have already thought of one,” was the reply.

“The Mister T. Jesson, I suppose,” scoffed Jack.

“No, not that, nor the J. Chadwick, either,” retorted Tom; “my name was White Shark, Jr.”

“Very good, indeed,” said Mr. Chadwick with a laugh, “the White Shark, Jr., it shall be.”

“Let’s hope it proves a good example to its parent,” chimed in Jack.

“Well, the child is father to the man, as they say in the copy books,” smiled Mr. Dancer, “so let’s hope that the rule will work out in the case of a submarine.”

“Oughtn’t we to christen it?” asked Tom.

“In what way?” demanded Jack.

“By breaking a bottle of wine over the bow, of course.”

This came from Tom.

“Well, we have none of that sort of stuff here,” said Mr. Chadwick, “so I would propose that, as the native element of the model is to be under the water, we let her ‘christen’ herself as she dives into it.”

All agreed that this was a good plan, and then as everything was ready Jack drew his knife across the cord. The little craft slid down the ways just like what Tom called “a regular ship.”

It struck the water in a cloud of spray and Mr. Chadwick shouted:

“I hereby christen thee White Shark, Jr.”

“Hurrah!” shouted Tom, furnishing the applause proper on such occasions.

“Don’t holler till you see how it works,” remarked Mr. Dancer, cautiously; “put on the power, Jack.”

As the model submarine rose to the surface after its dive, Jack pressed the button that started the motors going. The spark flashed along the wire and the tiny craft’s propellers flew round with a whirring sound.

“Now for the real test,” said Mr. Dancer after a breathless pause, during which the White Shark, Jr., sped around in a circle, for Jack had set the rudder so that the craft could not get too far from shore.

The boy obeyed and at the same instant everyone uttered an undignified yell of triumph. As the concealed machinery tilted the screws downward, the White Shark, Jr., vanished from sight! Five seconds later Jack brought the little craft to the surface again, and then put it through a series of diving and rising evolutions that showed that his invention worked perfectly.

“If my dream is ever realized it will be solely owing to you!” cried Mr. Dancer, glowing with the fire of success and warmly clasping the boy inventor’s hand.