The Boy Volunteers with the Submarine Fleet

After hours more of interminable waiting, they heard a noise close at hand. With something like a snap the door opened and a flood of light streamed into their compartment from the electric bulbs without, and, looking up, they saw, at the ceiling of their room, a small electric bulb.

"Why is it we didn't hunt for that?" whispered Ralph, looking up.

"But I can't see any way to turn it on," said Alfred.

"That lights only from the outside," said the attendant. "Here is something to eat," he continued in English.

"What time is it?" asked the captain.

"Half past one o'clock," was the reply.

They had been in that cramped prison pen five hours.

"Did you torpedo another ship?" queried the captain.

"We tried to; but a torpedo boat destroyer came up too close," he answered.

"How many shots did it fire?" asked Ralph.

"Two," was the laconic reply.

"How long have we been submerged?"

"Two hours," answered the man. "As I came down the report from the periscope showed a clear sea, and we are now about to resume surface travel and repair one of the periscopes."

The boys glanced at each other and at the captain.

"Yes," remarked the captain, "that was a pretty close call."

The attendant left them without closing the door, and as the prisoners glanced about, nothing was to be seen of the stairway which led to the conning tower. Men were noticed at work, each being stationed at some particular machine or set of machinery. Then, with a bang, something like a trap door swung aside and the stairway was revealed, and a peculiar light streamed in through the hatch opening.

"It's the sun," said Ralph, in ecstacy.

"I never thought we'd see that again," said Alfred, almost overcome.

"May we walk around?" asked the captain, as he approached an under officer.

"There isn't much chance for exercising here," was the reply, "but I think you will be given top liberty after awhile," replied the man.

"Will they let us go?" asked Ralph eagerly.

"No; he didn't say that; he meant they would give us liberty to walk on the top deck for a short time," replied the captain.

Shortly thereafter the lieutenant in command of the submarine appeared at the foot of the hatchway and informed the captain that they were at liberty to ascend. Never did the sun appear to be more beautiful or inviting, although there was a perceptible chill in the atmosphere. The submarine was moving along at a speed of twelve knots an hour. Four men were engaged in taking down a bent and partially ruptured periscope tube.

The captain glanced at it and drew the attention of the boys to its structure. It was the tall periscope that received the shot, which struck it about four feet from the top.

"It must have been hit on the water line," said the captain, addressing the lieutenant.

The latter merely nodded, but made no remarks in response.

They were permitted to walk to and fro for an hour, when the order came to descend, and they again entered their prison. As before, they were subjected to total darkness, but there was no necessity for this deprivation, and it is not clear why an enemy should treat prisoners in this manner, for such actions necessarily leave only resentments and do no good whatever.

It was a long, long, dreary afternoon and night, which they tried to while away in sleeping, for conversation, under the circumstances, soon became irksome. When they awoke, or, rather, when all were again alert and felt as though the night must have passed, the captain was the first to break the silence, as he said:

"We have been resting quietly for more than an hour, I should say, probably lying in wait in one of the steamer lanes for new victims."

"Isn't it likely we are on the bottom of the ocean? Don't they go down sometimes and wait there?" asked Ralph.

"Yes; but not in deep water, such as is found in this bay. At no place is it less than 150 fathoms, and in the central portion, where our ship went down it is more than 2,000 fathoms."

"Why, that's two miles deep, or more," said Alfred.

"Yes, the Bay of Biscay is one of the deep holes in the Atlantic coast line of Europe. The average depth of the Irish Sea, St. George Channel, the English Channel and the North Sea is only about 250 feet, and there are thousands of places in the North Sea, particularly, like the Dogger Banks, where the water is not more than a hundred feet deep," remarked the captain.

"Then the submarines could easily rest on the bottom if the depth is not more than one hundred feet?" asked Alfred.

"Submarines have, in several cases, gone down as far as 200 feet below the surface, but it is at a great risk," said the captain.

"You mean risk from the pressure of the water?" said Ralph.

"Yes," was the reply.

"What would be the pressure of the water on a submarine at that depth?" asked Alfred.

"Pressure is calculated on the square inch of surface; for every twenty-eight inches the pressure is equal to one pound. If, therefore, 200 is multiplied by 12 and then divided by 28, the quotient will represent the number of pounds on each square inch," answered the captain.

"Why multiply 200 by twelve?" asked Ralph.

"Because there are twelve inches in a foot," said the captain.

"Oh, yes; I didn't happen to think of it; well, 200 by 12,—that's 2,400, and divided by 28, is–"

"Eighty-five," interrupted Alfred. "Well, that's not very much."

"Quite true," rejoined the captain; "but how many square inches are there in a square foot?"

"One hundred and forty-four," replied Alfred.

"Then, eighty-five times one hundred and forty-four makes quite a sum," continued the captain.

"Whew,–" said Ralph with a half whistle in his tone, "why, if I have made it out right, it's over 12,000 pounds. No wonder it isn't safe to stay down very long, if at all, at that depth."

"I have often wondered how it is that the submarine could rest on the bottom or come up at will," said Alfred.

"All submarines are lighter than the water in which they float," answered the captain. "They are provided with tanks holding compressed air. Now, in order to submerge, the only thing necessary is to permit enough water to flow into special tanks within the submarine, until the combined weight of the water, hull and mechanism, is the same as the amount of water that the ship displaces. If an added quantity of water is now added, it will go down, and remain under water until the air in the compressed tanks is used to force out a quantity of water from the special tanks."

"But is that the only way they can go down?" asked Ralph.

"Oh, no; a submarine can submerge without doing that, but in such a case power must be used," answered the captain.

"What! push it down by power?" asked Alfred.

"Exactly; these vessels have fins, the same as fish, so arranged that if they are properly turned and the ship moves forward, it will dive, and continue to go down at an angle as long as the fins are properly set. If the vessel should stop moving the submarine would come to the top, because it is lighter than the water," responded the captain.

CHAPTER V

SOME OF THE MYSTERIES OF A SUBMARINE

With a click the door of their prison cabin opened and a seaman informed them that their breakfast was ready. They passed through the narrow door, and edged their way along a tortuous path that led to the rear, where they entered what might be called a miniature galley, on one side of which was a narrow shelf containing food of various descriptions.

There was room only for the attendant to pass while they were seated. An abundance of the best food was served, cereals, and even fruit, forming part of the menu. Each of these vessels carry from twenty-two to thirty men, but there were in sight in the dining room only ten, besides the cook and waiter.

After the meal, the captain inquired of the officer at the main hatch whether they would be permitted to go on deck.

"I have no orders," he replied.

Meanwhile, the boys had an opportunity to investigate the mysteries of the interior, for it was well lighted.

"What are those long drums ahead there?" asked Alfred.

"I think they are the casings which carry the torpedoes," replied the captain. "If you look beyond you will see the rear ends of the tubes which receive the torpedoes. The cylinders in sight hold the torpedoes until they are ready to be placed in the tubes and shot out of them."

"You have orders to go on deck," the under officer at the bottom of the hatch now informed them.

This was an invitation to which they quickly responded. They ascended, and found the sun hidden, and the sea about them calm. Glancing across the broad expanse of water, not a sail was in sight. It was a cold, gray morning, ordinarily uninviting weather, but after the house of confinement it was enjoyed to the fullest extent.

"Down below!" shouted a voice.

The boys looked around in surprise, for they had been on deck less than ten minutes.

"Clear the deck!" shouted the same voice. The boys, with the captain, were hustled forward into the conning tower, and the iron door closed with a bang. The boys were permitted to stop only long enough to see two men turn eight swinging bolts, which hung about the margins of the doors, and quickly screw them up against the jamb.

The lieutenant was leaning over a narrow table on which was a chart, and gazing through a crystal-covered port in the front of the conning tower. A bell tinkled, machinery began to turn and impart its vibration to the ship, and it was again a living thing. It glided forward with the same rhythmic noises for a half-hour, and then two bells were heard.

The character of the sounds from the machinery changed; they seemed to move forward with less effort, and as they felt the same inclination in the motion of the ship, all were now satisfied that she was again submerging. Fortunately, they were not confined to their room, and, although no verbal orders had been given for the various operations required to handle the vessel, the prisoners had an opportunity to judge of what was going on.

Thus, when the signal was given to change the motive power from the internal combustion engines to electricity, they could see the engine stop, and an attendant shift the clutch which engaged the electric motors. A dial swinging over a card alongside a pair of levers indicated the direction of movement, while another gave not only the inclination of the ship, but its speed as well.

These things were very fascinating to the boys, but their attention was now attracted to a still more interesting scene. A bell forward gave two short, quick snaps. Four men sprang forward and stood at attention, two on each side of the tube at the right of the hold.

"The indicator shows that the submarine is turning," said the captain. The boys watched the indicator; it had swung around almost half-way.

"There,—look at the inclinometer," said Ralph. "It is moving upward–"

"Ting! ting!" Two more sharp bells forward. The cylinder was off the torpedo, and it lay before them exposed.

Three bells more; and now there was feverish haste. An oval door in the wall ahead was swung open, revealing a round, black hole.

"That is the torpedo tube," said the captain quietly.

The torpedo was moved back three feet, and then again carried forward on its truck so that the end of the torpedo entered the tube.

One bell more. The torpedo moved into the tube, the breech block, which in this case was the oval door, closed, and the crew stood at attention. While thus waiting the boys glanced at the inclinometer and at the direction indicator.

"See it swing back and forth," said Alfred. "It seems to act queerly."

"Not at all," replied the captain. "Evidently we are chasing a ship which is zig-zagging, as we did, for the direction dial is constantly moving."

While thus conversing they were startled by the signal of four bells. One of the men, reaching forward, touched a button, and the signal could be heard in the conning tower. That was, evidently, to inform the commander there that all was in readiness. Everything was expectancy now. The ship still manoeuvered.

Then, without a warning of any kind, there was a singular dull sound, which seemed to shake the submarine from stem to stern.

"They have fired it," said Alfred.

"And they are putting in another one."

"If I am not mistaken it is the last one they have," suggested the captain.

"Why do you think so?" asked Alfred.

"I notice that all the cylinders with the open ends are without torpedoes, and you will notice that the one they are now putting in is the last one with the closed end," responded the captain.

"I am glad they haven't any more of them," said Ralph.

Three bells again sounded; the officer at the gun responded, and during the next two minutes of suspense, the boys were quiet, waiting for the next shot. It soon came; the ship shook as before, the breach block opened, the shell behind the torpedo was extracted, the door closed and the men stood at attention.

When the officer, who had handled the torpedoes, walked down the steps from the conning tower, the boys noticed him shake his head sadly.

"Did you notice that?" asked the captain.

"Do you mean the way he shook his head?" said Alfred.

"Yes; I am curious to get your views about that action of the officer," remarked the captain.

"That is, why he shook his head?" interjected Ralph.

"Yes," answered the captain. "Do you think he looked discouraged because the shot failed in its mission, or because it went home successfully? That is the problem."

The boys were quiet for a few moments. Ralph was the first to speak: "Well, I'll bet the torpedo didn't hit the ship, and he feels cut up over it, as it was the last one they had."

"I don't agree with you," rejoined Alfred. "It struck the ship and sunk it, and the fellow feels so badly about it that he shook his head the way he did when he thought of the suffering it caused. Don't you agree with me?" said Alfred, addressing the captain.

The captain could not repress a slight laugh as: he answered: "I must confess you advance good arguments in both directions; but really, I am of the opinion that either torpedo didn't get in its work."

"Why do you think the first one failed?"

"If the first one had succeeded, they would not have shot the second, would they?" replied the captain.

"No; I don't think they would, seeing they had only one more left," remarked Ralph. "But why do you think the last one was no more successful?"

"I infer it from the following circumstances: It takes, on an average, a minute for a torpedo to reach its mark, after it leaves the torpedo tube. The officer in the tower is in a position where he can see the effect of the shot. If the torpedo struck, however favorable the blow, it would take at least fifteen or twenty minutes for the ship to go down. Sometimes the bulkheads will keep the ship afloat an hour or more. In fact, there are records of ships which have been torpedoed, that were actually towed into harbors and saved," answered the captain.

"But I do not see how that is any sign that the torpedo missed," replied Alfred inquiringly.

"Probably you did not notice the period that elapsed after the last shot, and the time the officer came down the tower hatch?" remarked the captain.

"No, I did not observe," replied Alfred.

"You remember, do you not, that as soon as the last torpedo was launched, the officer went up into the conning tower, and that within a minute, or not exceeding two minutes, he again came down the stairway, and shook his head in such a disconsolate manner?" continued the captain.

"Well, yes; you may be right in that," responded Alfred.

"Then, I inferred this," said the captain, "that the lieutenant had had ample opportunity to observe whether or not the shot went home, and, as it had not landed, he reported to the officer the failure. If the shot had struck he would have known it before the officer left the conning tower to come down. Do you get my idea?" asked the captain.

"That seems to answer the question, to my mind, that it wasn't a hit," said Ralph.

"Well, it doesn't quite satisfy me," replied Alfred. "The lieutenant might have told him that the shot hit the ship, and that it was going down, and that's what made him feel so badly about it."

The captain could not help feeling amused at Alfred's argument, as he replied: "I must admit that your view is logical, and I am also willing to assent that the question is one, which, in the absence of actual knowledge, could be settled in one way only."

"How is that?" asked Ralph.

"By knowing the mental condition and attitude of the officer who came down the hatchway. If he happened to be a humane person he would regret the loss of life, and show it, probably, by his actions. On the other hand, if he should be devoid of the finer feelings, and be a mere slave to duty, it is more than likely that he would shake his head discouragingly, to learn that the torpedo failed in its mission," was the captain's final word on the subject.

"Now that they are out of torpedoes, what do you suppose they will do?" asked Ralph.

"Go home; I suppose," replied Alfred.

"Unless they have a base somewhere on the coast," replied the captain.

"Where is the most likely place for such a base?" asked Ralph.

"That is the enigma, of course. It has been believed that the Germans have a base somewhere along the northern coast of Spain," said the captain.

"What are the reasons for thinking so?" asked Alfred.

"One of them is that some of the Spaniards are said to be more or less friendly to the Germans, and, furthermore, there are few ports or harbors on the north coast, hence the shipping to Spain in the southern waters of the Bay of Biscay is very small, a condition which would help to keep a base along the coast line at one or more points."

"But we ought to know in the next day or two whether they have such a base," said Ralph.

"Yes; it will be the opportunity now for us to make some observation which will tell us whether we are going to Germany, or not," said the captain with a grin.

Situated, as they were, below decks, with no instruments but the direction indicator, and the inclinometer in sight, it was impossible to judge of the direction they were going, for it was evident that the submarine was now moving ahead at full speed.

"It will be, probably, twenty-four hours before we are able to get any information as to our destination," said the captain.

"Do you intend to ask some of the men?" inquired Alfred.

"No; that would be fruitless. It is not at all likely they will venture any information upon a subject of that character," replied the captain.

"Then how would it be possible to learn anything about where we are going?" asked Ralph.

"We are now somewhere in the Bay of Biscay, and I infer that we must be about a hundred and fifty miles from the Spanish coast. To reach that at the rate we are going, would take at least ten hours, for I assume that the vessel is capable of at least ten miles an hour. Then, we must take into consideration the possible meeting with vessels, in which case we must submerge, and thus go much slower," said the captain.

"Then, if they have a base anywhere along the coast we ought to be there before tomorrow at this time?" ventured Alfred.

"That is exactly what I mean," answered the captain.

CHAPTER VI

GROPING THROUGH THE ENGLISH CHANNEL

There was a steady pulsation of the engines during the entire afternoon without cessation until five o'clock, when the submarine submerged and continued under water for an hour. The three captives had now learned a great many of the manoeuvers incident to the diving operations, the signals accompanying each action, and studied with the greatest diligence and care the direction indicator and inclinometer.

"I have been noticing the indicator for the last hour," said Ralph, "and it didn't change once. Are we going due north?"

"The indicator that you see is not for the purpose of showing the points of the compass, but to tell whether or not there is a turning movement in the ship. If, for instance, the rudder should be turned to starboard or to port, the dial would swing in such a position as to show how much of a turn has been made, and no more," responded the captain.

"Suppose then, that after making a quarter turn, the ship should again go ahead on a straight line, what would happen to the dial?" asked Alfred.

"In that case the dial would again indicate that by coming back to its original position,—or, in other words, the dial would show that the ship had then assumed a new direction of sailing, and if it again changed to the right or to the left the indicator would reveal this to the observer," remarked the captain.

"I wish we had a compass," said Ralph.

"Unfortunately, they have taken our watches and pocket compasses," said the captain. "We may contrive, later on, to get a glimpse of the steering compass."

"Do you know where it is?" eagerly inquired Alfred.

"The navigating officer's instrument is in the conning tower, but it is usual, too, to have a similar instrument below, and I am sure it is located to the left of the cook's galley. It would not be safe, however, for either of us to be spying around in that quarter," responded the captain.

That night they were again locked in their narrow apartment. As they had been provided with a good meal it was not such an unpleasant experience, and they were also comforted by the feeling that the submarine was now engaged in a no more perilous duty than trying to reach some port.

That night was followed by a trying day of waiting. Singularly, they had not been permitted to ascend the hatchway stairs since the first day of their capture.

"A glance at the sun would be enough to tell us the direction," remarked the captain after they left the table at the lunch hour.

"I suppose they are keeping us down here for that purpose," suggested Alfred.

"I have thought," replied the captain, "that the very fact of keeping us in ignorance of the direction they are going is the best indication that we are making for a concealed base."

When they retired the second night the captain remarked: "It is now plain to my mind that we are on the way to Germany, or, possibly, to a base somewhere at a greater distance than Spain."

"How long would it take to make the trip to Germany?" asked Alfred.

"If we circled the British Isles and came in by way of Norway, it would mean a run of 1,400 miles. To go by way of the Channel would be about 800 miles. It would make but little difference in point of time," answered the captain.

"Why wouldn't it take longer to travel 1,400 miles?" asked Ralph.

"Because on the long route we would be able to travel four-fifths of the way on the surface, and would not have to avoid mines and nets. The Channel route is a dangerous one, requiring the utmost caution," said the captain.

The second morning Alfred was outside, as usual, consulting the instruments, when a voice remarked in response to an inquiry: "48, 10." He paid no attention to it at the time, but later on, in a conversation, remarked to the captain:

"Some one in the conning tower, this morning, said '48, 10.' What do you suppose he meant by that?"

"Glad you remembered that. Are you sure the figures you give are correct?" asked the captain eagerly.

"Sure of it," was Alfred's reply.

"Then we are near the English Channel. Good; I am glad to know that. Did you hear them refer to any other figures?" asked the captain.

"What would the other figures be?" asked Ralph.

"Of course, I can only guess. The figures you have given me unquestionably represent forty-eight degrees and ten minutes north latitude. What interests me most is to get our position east and west," said the captain.

"About what longitude are we in?" asked Ralph.

"If we are less than five degrees west we must be in the English Channel, and it would appear that they are taking the shortest route. If we should be seven or eight degrees west I should regard it as a pretty sure symptom that we are going to encircle the British Isles," remarked the captain.

Late that afternoon Ralph rushed into their little cabin and said: