"And you do know, don't you?" asked Tom eagerly.

"Well, I have it pretty accurately charted out, if you will allow me that expression," was the calm answer. "I took pains to look it up at the request of Mr. Sharp."

"And he wanted to worm that information out of you?" inquired the youth excitedly.

"Yes, I'm afraid he did."

"Did you give him the location?"

"Well," remarked the captain, as he took another observation before closing up the telescope, "you see, while we were talking, I happened to drop a copy of a map I'd made, showing the location of the wreck. Mr. Berg picked it up to hand to me, and he looked at it."

"Oh!" cried Tom. "Then he knows just where the treasure is, and he may get to it ahead of us. It's too bad."

"Yes," continued the seaman calmly, "Mr. Berg picked up that map, and he looked very closely at the latitude and longitude I had marked as the location of the wreck."

"Then he won't have any trouble finding it," murmured our hero.

"Eh? What's that?" asked the captain, "if I may be permitted to request you to repeat what you said."

"I say he won't have any trouble locating the sunken Boldero," repeated Tom.

"Oh, but I think he will, if he depends on that map," was the unexpected reply. "You see," explained Mr. Weston, "I'm not so simple as I look. I sensed what Mr. Berg was after, the minute he began to talk to me. So I fixed up a little game on him. The map which I dropped on purpose, not accidentally, where he would see it, did have the location of the wreck marked. Only it didn't happen to be the right location. It was about five hundred miles out of the way, and I rather guess if Mr. Berg and his friends go there for treasure they'll find considerable depth of water and quite a lonesome spot. Oh, no, I'm not as easy as I look, if you don't mind me mentioning that fact; and when a scoundrel sets out to get the best of me, I generally try to turn the tables on him. I've seen such men as Mr. Berg before. I'm afraid, I'm very much afraid, the sight he had of the fake map I made won't do him much good. Well, I declare, it's past four bells. Let's go to breakfast, if you don't mind me asking you," and with that the captain started off up the beach, Tom following, his ideas all a whirl at the unlooked-for outcome of the interview.



Chapter Ten

Trial of the Submarine

Tom felt such a relief at hearing of Captain Weston's ruse that his appetite, sharpened by an early breakfast and the sea air, came to him with a rush, and he had a second morning meal with the odd sea captain, who chuckled heartily when he thought of how Mr Berg had been deceived.

"Yes," resumed Captain Weston, over his bacon and eggs, "I sized him up for a slick article as soon as I laid eyes on him. But he evidently misjudged me, if I may be permitted that term. Oh, well, we may meet again, after we secure the treasure, and then I can show him the real map of the location of the wreck."

"Then you have it?" inquired the lad eagerly.

Captain Weston nodded, before hiding his face behind a large cup of coffee; his third, by the way.

"Let me see it?" asked Tom quickly. The captain set down his cup. He looked carefully about the hotel dining-room. There were several guests, who, like himself, were having a late breakfast.

"It's a good plan," the sailor said slowly, "when you're going into unknown waters, and don't want to leave a wake for the other fellow to follow, to keep your charts locked up. If it's all the same to you," he added diffidently, "I'd rather wait until we get to where your father and Mr. Sharp are before displaying the real map. I've no objection to showing you the one Mr. Berg saw," and again he chuckled.

The young inventor blushed at his indiscretion. He felt that the news of the search for the treasure had leaked out through him, though he was the one to get on the trail of it by seeing the article in the paper. Now he had nearly been guilty of another break. He realized that he must be more cautious. The captain saw his confusion, and said:

"I know how it is. You're eager to get under way. I don't blame you. I was the same myself when I was your age. But we'll soon be at your place, and then I'll tell you all I know. Sufficient now, to say that I believe I have located the wreck within a few miles. I got on the track of a sailor who had met one of the shipwrecked crew of the Boldero, and he gave me valuable information. Now tell me about the craft we are going in. A good deal depends on that."

Tom hardly knew what to answer. He recalled what Mr. Sharp had said about not wanting to tell Captain Weston, until the last moment, that they were going in a submarine, for fear the old seaman (for he was old in point of service though not in years) might not care to risk an under-water trip. Therefore Tom hesitated. Seeing it, Captain Weston remarked quietly:

"I mean, what type is your submarine? Does it go by compressed air, or water power?"

"How do you know it's a submarine?" asked the young inventor quickly, and in some confusion.

"Easy enough. When Mr. Berg thought he was pumping me, I was getting a lot of information from him. He told me about the submarine his firm was building, and, naturally, he mentioned yours. One thing led to another until I got a pretty good idea of your craft. What do you call it?"

"The Advance."

"Good name. I like it, if you don't mind speaking of it."

"We were afraid you wouldn't like it," commented Tom.

"What, the name?"

"No, the idea of going in a submarine."

"Oh," and Captain Weston laughed. "Well, it takes more than that to frighten me, if you'll excuse the expression. I've always had a hankering to go under the surface, after so many years spent on top. Once or twice I came near going under, whether I wanted to or not, in wrecks, but I think I prefer your way. Now, if you're all done, and don't mind me speaking of it, I think we'll start for your place. We must hustle, for Berg may yet get on our trail, even if he has got the wrong route," and he laughed again.

It was no small relief to Mr Swift and Mr. Sharp to learn that Captain Weston had no objections to a submarine, as they feared he might have. The captain, in his diffident manner, made friends at once with the treasure-hunters, and he and Mr. Damon struck up quite an acquaintance. Tom told of his meeting with the seaman, and the latter related, with much gusto, the story of how he had fooled Mr. Berg.

"Well, perhaps you'd like to come and take a look at the craft that is to be our home while we're beneath the water," suggested Mr. Swift and the sailor assenting, the aged inventor, with much pride, assisted by Tom, pointed out on the Advance the features of interest. Captain Weston gave hearty approval, making one or two minor suggestions, which were carried out.

"And so you launch her to-morrow," he concluded, when he had completed the inspection "Well, I hope it's a success, if I may be permitted to say so."

There were busy times around the machine shop next day. So much secrecy had been maintained that none of the residents, or visitors to the coast resort, were aware that in their midst was such a wonderful craft as the submarine. The last touches were put on the under-water ship; the ways, leading from the shop to the creek, were well greased, and all was in readiness for the launching. The tide would soon be at flood, and then the boat would slide down the timbers (at least, that was the hope of all), and would float in the element meant to receive her. It was decided that no one should be aboard when the launching took place, as there was an element of risk attached, since it was not known just how buoyant the craft was. It was expected she would float, until the filled tanks took her to the bottom, but there was no telling.

"It will be flood tide now in ten minutes," remarked Captain Weston quietly, looking at his watch. Then he took an observation through the telescope. "No hostile ships hanging in the offing," he reported. "All is favorable, if you don't mind me saying so," and he seemed afraid lest his remark might give offense.

"Get ready," ordered Mr. Swift. "Tom, see that the ropes are all clear," for it had been decided to ease the Advance down into the water by means of strong cables and windlasses, as the creek was so narrow that the submarine, if launched in the usual way, would poke her nose into the opposite mud bank and stick there.

"All clear," reported the young inventor.

"High tide!" exclaimed the captain a moment later, snapping shut his watch.

"Let go!" ordered Mr. Swift, and the various windlasses manned by the inventor, Tom and the others began to unwind their ropes. Slowly the ship slid along the greased ways. Slowly she approached the water. How anxiously they all watched her! Nearer and nearer her blunt nose, with the electric propulsion plate and the auxiliary propeller, came to the creek, the waters of which were quiet now, awaiting the turn of the tide.

Now little waves lapped the steel sides. It was the first contact of the Advance with her native element.

"Pay out the rope faster!" cried Mr. Swift.

The windlasses were turned more quickly Foot by foot the craft slid along until, with a final rush, the stern left the ways and the submarine was afloat. Now would come the test. Would she ride on an even keel, or sink out of sight, or turn turtle? They all ran to the water's edge, Tom in the lead.

"Hurrah!" suddenly yelled the lad, trying to stand on his head. "She floats! She's a success! Come on! Let's get aboard!"

For, true enough, the Advance was riding like a duck on the water. She had been proportioned just right, and her lines were perfect. She rode as majestically as did any ship destined to sail on the surface, and not intended to do double duty.

"Come on, we must moor her to the pier," directed Mr. Sharp. "The tide will turn in a few minutes and take her out to sea."

He and Tom entered a small boat, and soon the submarine was tied to a small dock that had been built for the purpose.

"Now to try the engine," suggested Mr. Swift, who was almost trembling with eagerness; for the completion of the ship meant much to him.

"One moment," begged Captain Weston. "If you don't mind, I'll take an observation," he went on, and he swept the horizon with his telescope. "All clear," he reported. "I think we may go aboard and make a trial trip."

Little time was lost in entering the cabin and engine-room, Garret Jackson accompanying the party to aid with the machinery. It did not take long to start the motors, dynamos and the big gasolene engine that was the vital part of the craft. A little water was admitted to the tanks for ballast, since the food and other supplies were not yet on board. The Advance now floated with the deck aft of the conning tower showing about two feet above the surface of the creek. Mr. Swift and Tom entered the pilot house.

"Start the engines," ordered the aged inventor, "and we'll try my new system of positive and negative electrical propulsion."

There was a hum and whir in the body of the ship beneath the feet of Tom and his father. Captain Weston stood on the little deck near the conning tower.

"All ready?" asked the youth through the speaking tube to Mr. Sharp and Mr. Jackson in the engine-room.

"All ready," came the answer.

Tom threw over the connecting lever, while his father grasped the steering wheel. The Advance shot forward, moving swiftly along, about half submerged.

"She goes! She goes!" cried Tom

"She certainly does, if I may be permitted to say so," was the calm contribution of Captain Weston. "I congratulate you."

Faster and faster went the new craft. Mr. Swift headed her toward the open sea, but stopped just before passing out of the creek, as he was not yet ready to venture into deep water.

"I want to test the auxiliary propellers," he said. After a little longer trial of the electric propulsion plates, which were found to work satisfactorily, sending the submarine up and down the creek at a fast rate, the screws, such as are used on most submarines, were put into gear. They did well, but were not equal to the plates, nor was so much expected of them.

"I am perfectly satisfied," announced Mr. Swift as he once more headed the boat to sea. "I think, Captain Weston, you had better go below now."

"Why so?"

"Because I am going to completely submerge the craft. Tom, close the conning tower door. Perhaps you will come in here with us, Captain Weston, though it will be rather a tight fit."

"Thank you, I will. I want to see how it feels to be in a pilot house under water."

Tom closed the water-tight door of the conning tower. Word was sent through the tube to the engine-room that a more severe test of the ship was about to be made. The craft was now outside the line of breakers and in the open sea.

"Is everything ready, Tom?" asked his father in a quiet voice.

"Everything," replied the lad nervously, for the anticipation of being about to sink below the surface was telling on them all, even on the calm, old sea captain.

"Then open the tanks and admit the water," ordered Mr. Swift.

His son turned a valve and adjusted some levers. There was a hissing sound, and the Advance began sinking. She was about to dive beneath the surface of the ocean, and those aboard her were destined to go through a terrible experience before she rose again.



Chapter Eleven

On the Ocean Bed

Lower and lower sank the submarine. There was a swirling and foaming of the water as she went down, caused by the air bubbles which the craft carried with her in her descent. Only the top of the conning tower was out of water now, the ocean having closed over the deck and the rounded back of the boat. Had any one been watching they would have imagined that an accident was taking place.

In the pilot house, with its thick glass windows, Tom, his father and Captain Weston looked over the surface of the ocean, which every minute was coming nearer and nearer to them.

"We'll be all under in a few seconds," spoke Tom in a solemn voice, as he listened to the water hissing into the tanks.

"Yes, and then we can see what sort of progress we will make," added Mr. Swift. "Everything is going fine, though," he went on cheerfully. "I believe I have a good boat."

"There is no doubt of it in my mind," remarked Captain Weston, and Tom felt a little disappointed that the sailor did not shout out some such expression as "Shiver my timbers!" or "Keel-haul the main braces, there, you lubber!" But Captain Weston was not that kind of a sailor, though his usually quiet demeanor could be quickly dropped on necessity, as Tom learned later.

A few minutes more and the waters closed over the top of the conning tower. The Advance was completely submerged. Through the thick glass windows of the pilot house the occupants looked out into the greenish water that swirled about them; but it could not enter. Then, as the boat went lower, the light from above gradually died out, and the semi-darkness gave place to gloom.

"Turn on the electrics and the searchlight, Tom," directed his father.

There was the click of a switch, and the conning tower was flooded with light. But as this had the effect of preventing the three from peering out into the water, just as one in a lighted room cannot look out into the night, Tom shut them off and switched on the great searchlight. This projected its powerful beams straight ahead and there, under the ocean, was a pathway of illumination for the treasure-seekers.

"Fine!" cried Captain Weston, with more enthusiasm than he had yet manifested. "That's great, if you don't mind me mentioning it. How deep are we?"

Tom glanced at a gage on the side of the pilot tower.

"Only about sixty feet," he answered.

"Then don't go any deeper!" cried the captain hastily. "I know these waters around here, and that's about all the depth you've got. You'll be on the bottom in a minute."

"I intend to get on the bottom after a while," said Mr. Swift, "but not here. I want to try for a greater distance under water before I come to rest on the ocean's bed. But I think we are deep enough for a test. Tom, close the tank intake pipes and we'll see how the Advance will progress when fully submerged."

The hissing stopped, and then, wishing to see how the motors and other machinery would work, the aged inventor and his son, accompanied by Captain Weston, descended from the conning tower, by means of an inner stairway, to the interior of the ship. The submarine could be steered and managed from below or above. She was now floating about sixty-five feet below the surface of the bay.

"Well, how do you like it?" asked Tom of Mr. Damon, as he saw his friend in an easy chair in the living-room or main cabin of the craft, looking out of one of the plate-glass windows on the side.

"Bless my spectacles, it's the most wonderful thing I ever dreamed of!" cried the queer character, as he peered at the mass of water before him. "To think that I'm away down under the surface, and yet as dry as a bone. Bless my necktie, but it's great! What are we going to do now?"

"Go forward," replied the young inventor.

"Perhaps I had better make an observation," suggested Captain Weston, taking his telescope from under his arm, where he had carried it since entering the craft, and opening it. "We may run afoul of something, if you don't mind me mentioning such a disagreeable subject." Then, as he thought of the impossibility of using his glass under water, he closed it.

"I shall have little use for this here, I'm afraid," he remarked with a smile. "Well, there's some consolation. We're not likely to meet many ships in this part of the ocean. Other vessels are fond enough of remaining on the surface. I fancy we shall have the depths to ourselves, unless we meet a Government submarine, and they are hardly able to go as deep as we can. No, I guess we won't run into anything and I can put this glass away."

"Unless we run into Berg and his crowd," suggested Tom in a low voice.

"Ha! ha!" laughed Captain Weston, for he did not want Mr. Swift to worry over the unscrupulous agent. "No, I don't believe we'll meet them, Tom. I guess Berg is trying to work out the longitude and latitude I gave him. I wish I could see his face when he realizes that he's been deceived by that fake map."

"Well, I hope he doesn't discover it too soon and trail us," went on the lad. "But they're going to start the machinery now. I suppose you and I had better take charge of the steering of the craft. Dad will want to be in the engine-room."

"All right," replied the captain, and he moved forward with the lad to a small compartment, shut off from the living-room, that served as a pilot house when the conning tower was not used. The same levers, wheels and valves were there as up above, and the submarine could be managed as well from there as from the other place.

"Is everything all right?" asked Mr Swift as he went into the engine-room, where Garret Jackson and Mr. Sharp were busy with oil cans.

"Everything," replied the balloonist. "Are you going to start now?"

"Yes, we're deep enough for a speed trial. We'll go out to sea, however, and try for a lower depth record, as soon as there's enough water. Start the engine."

A moment later the powerful electric currents were flowing into the forward and aft plates, and the Advance began to gather way, forging through the water.

"Straight ahead, out to sea, Tom," called his father to him.

"Aye, aye, sir," responded the youth.

"Ha! Quite seaman-like, if you don't mind a reference to it," commented Captain Weston with a smile. "Mind your helm, boy, for you don't want to poke her nose into a mud bank, or run up on a shoal."

"Suppose you steer?" suggested the lad. "I'd rather take lessons for a while."

"All right. Perhaps it will be safer. I know these waters from the top, though I can't say as much for the bottom. However, I know where the shoals are."

The powerful searchlight was turned, so as to send its beams along the path which the submarine was to follow, and then, as she gathered speed, she shot ahead, gliding through the waters like a fish.

Mr. Damon divided his time between the forward pilot-room, the living-apartment, and the place where Mr. Swift, Garret Jackson and Mr. Sharp were working over the engines. Every few minutes he would bless some part of himself, his clothing, or the ship. Finally the old man settled down to look through the plate-glass windows in the main apartment.

On and on went the submarine. She behaved perfectly, and was under excellent control. Some times Tom, at the request of his father, would send her toward the surface by means of the deflecting rudder. Then she would dive to the bottom again. Once, as a test, she was sent obliquely to the surface, her tower just emerging, and then she darted downward again, like a porpoise that had come up to roll over, and suddenly concluded to seek the depths. In fact, had any one seen the maneuver they would have imagined the craft was a big fish disporting itself.

Captain Weston remained at Tom's side, giving him instructions, and watching the compass in order to direct the steering so as to avoid collisions. For an hour or more the craft was sent almost straight ahead at medium speed. Then Mr. Swift, joining his son and the captain, remarked:

"How about depth of water here, Captain Weston?"

"You've got more than a mile."

"Good! Then I'm going down to the bottom of the sea! Tom, fill the tanks still more.

"Aye, aye, sir," answered the lad gaily. "Now for a new experience!"

"And use the deflecting rudder, also," advised his father. "That will hasten matters."

Five minutes later there was a slight jar noticeable.

"Bless my soul! What's that?" cried Mr. Damon. "Have we hit something?"

"Yes," answered Tom with a smile.

"What, for gracious sake?"

"The bottom of the sea. We're on the bed of the ocean."



Chapter Twelve

For a Breath of Air

They could hardly realize it, yet the depth-gage told the story. It registered a distance below the surface of the ocean of five thousand seven hundred feet—a little over a mile. The Advance had actually come to rest on the bottom of the Atlantic.

"Hurrah!" cried Tom. "Let's get on the diving suits, dad, and walk about on land under water for a change."

"No," said Mr. Swift soberly. "We will hardly have time for that now. Besides, the suits are not yet fitted with the automatic air-tanks, and we can't use them. There are still some things to do before we start on our treasure cruise. But I want to see how the plates are standing this pressure."

The Advance was made with a triple hull, the spaces between the layers of plates being filled with a secret material, capable of withstanding enormous pressure, as were also the plates themselves. Mr. Swift, aided by Mr. Jackson and Captain Weston, made a thorough examination, and found that not a drop of water had leaked in, nor was there the least sign that any of the plates had given way under the terrific strain.

"She's as tight as a drum, if you will allow me to make that comparison," remarked Captain Weston modestly. "I couldn't ask for a dryer ship."

"Well, let's take a look around by means the searchlight and the observation windows, and then we'll go back," suggested Mr. Swift. "It will take about two days to get the stores and provisions aboard and rig up the diving suits; then we will start for the sunken treasure."

There were several powerful searchlights on the Advance, so arranged that the bow, stern or either side could be illuminated independently. There were also observation windows near each light.

In turn the powerful rays were cast first at the bow and then aft. In the gleams could be seen the sandy bed of the ocean, covered with shells of various kinds. Great crabs walked around on their long, jointed legs, and Tom saw some lobsters that would have brought joy to the heart of a fisherman.

"Look at the big fish!" cried Mr. Damon suddenly, and he pointed to some dark, shadowy forms that swam up to the glass windows, evidently puzzled by the light.

"Porpoises," declared Captain Weston briefly, "a whole school of them."

The fish seemed suddenly to multiply, and soon those in the submarine felt curious tremors running through the whole craft.

"The fish are rubbing up against it," cried Tom. "They must think we came down here to allow them to scratch their backs on the steel plates."

For some time they remained on the bottom, watching the wonderful sight of the fishes that swam all about them.

"Well, I think we may as well rise," announced Mr. Swift, after they had been on the bottom about an hour, moving here and there. "We didn't bring any provisions, and I'm getting hungry, though I don't know how the others of you feel about it."

"Bless my dinner-plate, I could eat, too!" cried Mr. Damon. "Go up, by all means. We'll get enough of under-water travel once we start for the treasure."

"Send her up, Tom," called his father. "I Want to make a few notes on some needed changes and improvements."

Tom entered the lower pilot house, and turned the valve that opened the tanks. He also pulled the lever that started the pumps, so that the water ballast would be more quickly emptied, as that would render the submarine buoyant, and she would quickly shoot to the surface. To the surprise of the lad, however, there followed no outrushing of the water. The Advance remained stationary on the ocean bed. Mr. Swift looked up from his notes.

"Didn't you hear me ask you to send her up, Tom?" he inquired mildly.

"I did, dad, but something seems to be the matter," was the reply.

"Matter? What do you mean?" and the aged inventor hastened to where his son and Captain Weston were at the wheels, valves and levers.

"Why, the tanks won't empty, and the pumps don't seem to work."

"Let me try," suggested Mr. Swift, and he pulled the various handles. There was no corresponding action of the machinery.

"That's odd," he remarked in a curious voice "Perhaps something has gone wrong with the connections. Go look in the engine-room, and ask Mr. Sharp if everything is all right there."

Tom made a quick trip, returning to report that the dynamos, motors and gas engine were running perfectly.

"Try to work the tank levers and pumps from the conning tower," suggested Captain Weston. "Sometimes I've known the steam steering gear to play tricks like that."

Tom hurried up the circular stairway into the tower. He pulled the levers and shifted the valves and wheels there. But there was no emptying of the water tanks. The weight and pressure of water in them still held the submarine on the bottom of the sea, more than a mile from the surface. The pumps in the engine-room were working at top speed, but there was evidently something wrong in the connections. Mr. Swift quickly came to this conclusion.

"We must repair it at once," he said. "Tom, come to the engine-room. You and I, with Mr. Jackson and Mr. Sharp, will soon have it in shape again."

"Is there any danger?" asked Mr. Damon in a perturbed voice. "Bless my soul, it's unlucky to have an accident on our trial trip."

"Oh, we must expect accidents," declared Mr. Swift with a smile. "This is nothing."

But it proved to be more difficult than he had imagined to re-establish the connection between the pumps and the tanks. The valves, too, had clogged or jammed, and as the pressure outside the ship was so great, the water would not run out of itself. It must be forced.

For an hour or more the inventor, his son and the others, worked away. They could accomplish nothing. Tom looked anxiously at his parent when the latter paused in his efforts.

"Don't worry," advised the aged inventor. "It's got to come right sooner or later."

Just then Mr. Damon, who had been wandering about the ship, entered the engine-room.

"Do you know," he said, "you ought to open a window, or something."

"Why, what's the matter?" asked Tom quickly, looking to see if the odd man was joking.

"Well, of course I don't exactly mean a window," explained Mr. Damon, "but we need fresh air."

"Fresh air!" There was a startled note in Mr. Swift's voice as he repeated the words.

"Yes, I can hardly breathe in the living-room, and it's not much better here."

"Why, there ought to be plenty of fresh air," went on the inventor. "It is renewed automatically."

Tom jumped up and looked at an indicator. He uttered a startled cry.

"The air hasn't been changed in the last hour!" he exclaimed. "It is bad. There's not enough oxygen in it. I notice it, now that I've stopped working. The gage indicates it, too. The automatic air-changer must have stopped working. I'll fix it."

He hurried to the machine which was depended on to supply fresh air to the submarine.

"Why, the air tanks are empty!" the young inventor cried. "We haven't any more air except what is in the ship now!"

"And we're rapidly breathing that up," added Captain Weston solemnly.

"Can't you make more?" cried Mr. Damon. "I thought you said you could make oxygen aboard the ship."

"We can," answered Mr. Swift, "but I did not bring along a supply of the necessary chemicals. I did not think we would be submerged long enough for that. But there should have been enough in the reserve tank to last several days. How about it, Tom?"

"It's all leaked out, or else it wasn't filled," was the despairing answer. "All the air we have is what's in the ship, and we can't make more."

The treasure-seekers looked at each other. It was an awful situation.

"Then the only thing to do is to fix the machinery and rise to the surface," said Mr. Sharp simply. "We can have all the air we want, then."

"Yes, but the machinery doesn't seem possible of being fixed," spoke Tom in a low voice.

"We must do it!" cried his father.

They set to work again with fierce energy, laboring for their very lives. They all knew that they could not long remain in the ship without oxygen. Nor could they desert it to go to the surface, for the moment they left the protection of the thick steel sides the terrible pressure of the water would kill them. Nor were the diving suits available. They must stay in the craft and die a miserable death-unless the machinery could be repaired and the Advance sent to the surface. The emergency expanding lifting tank was not yet in working order.

More frantically they toiled, trying every device that was suggested to the mechanical minds of Tom, his father, Mr. Sharp or Mr. Jackson, to make the pumps work. But something was wrong. More and more foul grew the air. They were fairly gasping now. It was difficult to breathe, to say nothing of working, in that atmosphere. The thought of their terrible position was in the minds of all.

"Oh, for one breath of fresh air!" cried Mr. Damon, who seemed to suffer more than any of the others. Grim death was hovering around them, imprisoned as they were on the ocean's bed, over a mile from the surface.



Chapter Thirteen

Off for the Treasure

Suddenly Tom, after a moment's pause, seized a wrench and began loosening some nuts.

"What are you doing?" asked his father faintly, for he was being weakened by the vitiated atmosphere.

"I'm going to take this valve apart," replied his son. "We haven't looked there for the trouble. Maybe it's out of order."

He attacked the valve with energy, but his hands soon lagged. The lack of oxygen was telling on him. He could no longer work quickly.

"I'll help," murmured Mr. Sharp thickly. He took a wrench, but no sooner had he loosened one nut than he toppled over. "I'm all in," he murmured feebly.

"Is he dead?" cried Mr. Damon, himself gasping.

"No, only fainted. But he soon will be dead, and so will all of us, if we don't get fresh air," remarked Captain Weston. "Lie down on the floor, every one. There is a little fairly good air there. It's heavier than the air we've breathed, and we can exist on it for a little longer. Poor Sharp was so used to breathing the rarified air of high altitudes that he can't stand this heavy atmosphere."

Mr. Damon was gasping worse than ever, and so was Mr. Swift. The balloonist lay an inert heap on the floor, with Captain Weston trying to force a few drops of stimulant down his throat.

With a fierce determination in his heart, but with fingers that almost refused to do his bidding, Tom once more sought to open the big valve. He felt sure the trouble was located there, as they had tried to locate it in every other place without avail.

"I'll help," said Mr. Jackson in a whisper. He, too, was hardly able to move.

More and more devoid of oxygen grew the air. It gave Tom a sense as if his head was filled, and ready to burst with every breath he drew. Still he struggled to loosen the nuts. There were but four more now, and he took off three while Mr. Jackson removed one. The young inventor lifted off the valve cover, though it felt like a ton weight to him. He gave a glance inside.

"Here's the trouble!" he murmured. "The valve's clogged. No wonder it wouldn't work. The pumps couldn't force the water out."

It was the work of only a minute to adjust the valve. Then Tom and the engineer managed to get the cover back on.

How they inserted the bolts and screwed the nuts in place they never could remember clearly afterward, but they managed it somehow, with shaking, trembling hands and eyes that grew more and more dim.

"Now start the pumps!" cried Tom faintly. "The tanks will be emptied, and we can get to the surface."

Mr. Sharp was still unconscious, nor was Mr. Swift able to help. He lay with his eyes closed. Garret Jackson, however, managed to crawl to the engine-room, and soon the clank of machinery told Tom that the pumps were in motion. The lad staggered to the pilot house and threw the levers over. An instant later there was the hissing of water as it rushed from the ballast tanks. The submarine shivered, as though disliking to leave the bottom of the sea, and then slowly rose. As the pumps worked more rapidly, and the sea was sent from the tank in great volumes, the boat fairly shot to the surface. Tom was ready to open the conning tower and let in fresh air as soon as the top was above the surface.

With a bound the Advance reached the top. Tom frantically worked the worm gear that opened the tower. In rushed the fresh, life-giving air, and the treasure-hunters filled their lungs with it.

And it was only just in time, for Mr. Sharp was almost gone. He quickly revived, as did the others, when they could breathe as much as they wished of the glorious oxygen.

"That was a close call," commented Mr. Swift. "We'll not go below again until I have provided for all emergencies. I should have seen to the air tanks and the expanding one before going below. We'll sail home on the surface now."

The submarine was put about and headed for her dock. On the way she passed a small steamer, and the passengers looked down in wonder at the strange craft.

When the Advance reached the secluded creek where she had been launched, her passengers had fully recovered from their terrible experience, though the nerves of Mr. Swift and Mr. Damon were not at ease for some days thereafter.

"I should never have made a submerged test without making sure that we had a reserve supply of air," remarked the aged inventor. "I will not be caught that way again. But I can't understand how the pump valve got out of order."

"Maybe some one tampered with it," suggested Mr. Damon. "Could Andy Foger, any of the Happy Harry gang, or the rival gold-seekers have done it?"

"I hardly think so," answered Tom. "The place has been too carefully guarded since Berg and Andy once sneaked in. I think it was just an accident, but I have thought of a plan whereby such accidents can be avoided in the future. It needs a simple device."

"Better patent it," suggested Mr. Sharp with a smile.

"Maybe I will," replied the young inventor. "But not now. We haven't time, if we intend to get fitted out for our trip."

"No; I should say the sooner we started the better," remarked Captain Weston. "That is, if you don't mind me speaking about it," he added gently, and the others smiled, for his diffident comments were only a matter of habit.

The first act of the adventurers, after tying the submarine at the dock, was to proceed with the loading of the food and supplies. Tom and Mr. Damon looked to this, while Mr. Swift and Mr. Sharp made some necessary changes to the machinery. The next day the young inventor attached his device to the pump valve, and the loading of the craft was continued.

All was in readiness for the gold-seeking expedition a week later. Captain Weston had carefully charted the route they were to follow, and it was decided to move along on the surface for the first day, so as to get well out to sea before submerging the craft. Then it would sink below the surface, and run along under the water until the wreck was reached, rising at times, as needed, to renew the air supply.

With sufficient stores and provisions aboard to last several months, if necessary, though they did not expect to be gone more than sixty days at most, the adventurers arose early one morning and went down to the dock. Mr. Jackson was not to accompany them. He did not care about a submarine trip, he said, and Mr. Swift desired him to remain at the seaside cottage and guard the shops, which contained much valuable machinery. The airship was also left there.

"Well, are we all ready?" asked Mr. Swift of the little party of gold-seekers, as they were about to enter the conning tower hatchway of the submarine.

"All ready, dad," responded his son.

"Then let's get aboard," proposed Captain Weston. "But first let me take an observation."

He swept the horizon with his telescope, and Tom noticed that the sailor kept it fixed on one particular spot for some time.

"Did you see anything?" asked the lad.

"Well, there is a boat lying off there," was the answer. "And some one is observing us through a glass. But I don't believe it matters. Probably they're only trying to see what sort of an odd fish we are."

"All aboard, then," ordered Mr. Swift, and they went into the submarine. Tom and his father, with Captain Weston, remained in the conning tower. The signal was given, the electricity flowed into the forward and aft plates, and the Advance shot ahead on the surface.

The sailor raised his telescope once more and peered through a window in the tower. He uttered an exclamation.

"What's the matter?" asked Tom.

"That other ship—a small steamer—is weighing anchor and seems to be heading this way," was the reply.

"Maybe it's some one hired by Berg to follow us and trace our movements," suggested Tom.

"If it is we'll fool them," added his father. "Just keep an eye on them, captain, and I think we can show them a trick or two in a few minutes."

Faster shot the Advance through the water. She had started on her way to get the gold from the sunken wreck, but already enemies were on the trail of the adventurers, for the ship the sailor had noticed was steaming after them.



Chapter Fourteen

In the Diving Suits

There was no doubt that the steamer was coming after the submarine. Several observations Captain Weston made confirmed this, and he reported the fact to Mr. Swift.

"Well, we'll change our plans, then," said the inventor. "Instead of sailing on the surface we'll go below. But first let them get near so they may have the benefit of seeing what we do. Tom, go below, please, and tell Mr. Sharp to get every thing in readiness for a quick descent. We'll slow up a bit now, and let them get nearer to us."

The speed of the submarine was reduced, and in a short time the strange steamer had overhauled her, coming to within hailing distance.

Mr. Swift signaled for the machinery to stop and the submarine came to a halt on the surface, bobbing about like a half-submerged bottle. The inventor opened a bull's-eye in the tower, and called to a man on the bridge of the steamer:

"What are you following us for?"

"Following you?" repeated the man, for the strange vessel had also come to a stop. "We're not following you."

"It looks like it," replied Mr. Swift. "You'd better give it up."

"I guess the waters are free," was the quick retort. "We'll follow you if we like."

"Will you? Then come on!" cried the inventor as he quickly closed the heavy glass window and pulled a lever. An instant later the submarine began to sink, and Mr. Swift could not help laughing as, just before the tower went under water, he had a glimpse of the astonished face of the man on the bridge. The latter had evidently not expected such a move as that.

Lower and lower in the water went the craft, until it was about two hundred feet below the surface. Then Mr. Swift left the conning tower, descended to the main part of the ship, and asked Tom and Captain Weston to take charge of the pilot house.

"Send her ahead, Tom," his father said. "That fellow up above is rubbing his eyes yet, wondering where we are, I suppose."

Forward shot the Advance under water, the powerful electrical plates pulling and pushing her on the way to secure the sunken gold.

All that morning a fairly moderate rate of speed was maintained, as it was thought best not to run the new machinery too fast.

Dinner was eaten about a quarter of a mile below the surface, but no one inside the submarine would ever have known it. Electric lights made the place as brilliant as could be desired, and the food, which Tom and Mr. Damon prepared, was equal to any that could have been served on land. After the meal they opened the shutters over the windows in the sides of the craft, and looked at the myriads of fishes swimming past, as the creatures were disclosed in the glare of the searchlight.

That night they were several hundred miles on their journey, for the craft was speedy, and leaving Tom and Captain Weston to take the first watch, the others went to bed.

"Bless my soul, but it does seem odd, though, to go to bed under water, like a fish," remarked Mr. Damon. "If my wife knew this she would worry to death. She thinks I'm off automobiling. But this isn't half as dangerous as riding in a car that's always getting out of order. A submarine for mine, every time."

"Wait until we get to the end of this trip," advised Tom. "I guess you'll find almost as many things can happen in a submarine as can in an auto," and future events were to prove the young inventor to be right.

Everything worked well that night, and the ship made good progress. They rose to the surface the next morning to make sure of their position, and to get fresh air, though they did not really need the latter, as the reserve supply had not been drawn on, and was sufficient for several days, now that the oxygen machine had been put in running order.

On the second day the ship was sent to the bottom and halted there, as Mr. Swift wished to try the new diving suits. These were made of a new, light, but very strong metal to withstand the pressure of a great depth.

Tom, Mr. Sharp and Captain Weston donned the suits, the others agreeing to wait until they saw how the first trial resulted. Then, too, it was necessary for some one acquainted with the machinery to remain in the ship to operate the door and water chamber through which the divers had to pass to get out.

The usual plan, with some changes, was followed in letting the three out of the boat, and on to the bottom of the sea. They entered a chamber in the side of the submarine, water was gradually admitted until it equaled in pressure that outside, then an outer door was opened by means of levers, and they could step out.

It was a curious sensation to Tom and the others to feel that they were actually walking along the bed of the ocean. All around them was the water, and as they turned on the small electric lights in their helmets, which lights were fed by storage batteries fastened to the diving suits, they saw the fish, big and little, swarm up to them, doubtless astonished at the odd creatures which had entered their domain. On the sand of the bottom, and in and out among the shells and rocks, crawled great spider crabs, big eels and other odd creatures seldom seen on the surface of the water. The three divers found no difficulty in breathing, as there were air tanks fastened to their shoulders, and a constant supply of oxygen was fed through pipes into the helmets. The pressure of water did not bother them, and after the first sensation Tom began to enjoy the novelty of it. At first the inability to speak to his companions seemed odd, but he soon got so he could make signs and motions, and be understood.

They walked about for some time, and once the lad came upon a part of a wrecked vessel buried deep in the sand. There was no telling what ship it was, nor how long it had been there, and after silently viewing it, they continued on.

"It was great!" were the first words Tom uttered when he and the others were once more inside the submarine and had removed the suits. "If we can only walk around the wreck of the Boldero that way, we'll have all the gold out of her in no time. There are no life-lines nor air-hose to bother with in these diving suits."

"They certainly are a success," conceded Mr. Sharp.

"Bless my topknot!" cried Mr. Damon. "I'll try it next time. I've always wanted to be a diver, and now I have the chance."

The trip was resumed after the diving chamber had been closed, and on the third day Captain Weston announced, after a look at his chart, that they were nearing the Bahama Islands.

"We'll have to be careful not to run into any of the small keys," he said, that being the name for the many little points of land, hardly large enough to be dignified by the name of island. "We must keep a constant lookout."

Fortune favored them, though once, when Tom was steering, he narrowly avoided ramming a coral reef with the submarine. The searchlight showed it to him just in time, and he sheered off with a thumping in his heart.

The course was changed from south to east, so as to get ready to swing out of the way of the big shoulder of South America where Brazil takes up so much room, and as they went farther and farther toward the equator, they noticed that the waters teemed more and more with fish, some beautiful, some ugly and fear-inspiring, and some such monsters that it made one shudder to look at them, even through the thick glass of the bulls-eye windows.



Chapter Fifteen

At the Tropical Island

It was on the evening of the fourth day later that Captain Weston, who was steering the craft, suddenly called out:

"Land ho!"

"Where away?" inquired Tom quickly, for he had read that this was the proper response to make.

"Dead ahead," answered the sailor with a smile. "Shall we make for it, if I may be allowed the question?"

"What land is it likely to be?" Mr. Swift wanted to know.

"Oh, some small tropical island," replied the seafaring man. "It isn't down on the charts. Probably it's too small to note. I should say it was a coral island, but we may be able to find a Spring of fresh water there, and some fruit."

"Then we'll land there," decided the inventor. "We can use some fresh water, though our distilling and ice apparatus does very well."

They made the island just at dusk, and anchored in a little lagoon, where there was a good depth of water.

"Now for shore!" cried Tom, as the submarine swung around on the chain. "It looks like a fine place. I hope there are cocoanuts and oranges here. Shall I get out the electric launch, dad?"

"Yes, you may, and we'll all go ashore. It will do us good to stretch our legs a bit."

Carried in a sort of pocket on the deck of the submarine was a small electric boat, capable of holding six. It could be slid from the pocket, or depression, into the water without the use of davits, and, with Mr. Sharp to aid him, Tom soon had the little craft afloat. The batteries were already charged, and just as the sun was going down the gold-seekers entered the launch and were soon on shore.

They found a good spring of water close at hand, and Tom's wish regarding the cocoanuts was realized, though there were no oranges. The lad took several of the delicious nuts, and breaking them open poured the milk into a collapsible cup he carried, drinking it eagerly. The others followed his example, and pronounced it the best beverage they had tasted in a long time.

The island was a typical tropical one, not very large, and it did not appear to have been often visited by man. There were no animals to be seen, but myriads of birds flew here and there amid the trees, the trailing vines and streamers of moss.

"Let's spend a day here to-morrow and explore it," proposed Tom, and his father nodded an assent. They went back to the submarine as night was beginning to gather, and in the cabin, after supper, talked over the happenings of their trip so far.

"Do you think we'll have any trouble getting the gold out of the wrecked vessel?" asked Tom of Captain Weston, after a pause.

"Well, it's hard to say. I couldn't learn just how the wreck lays, whether it's on a sandy or a rocky bottom. If the latter, it won't be so hard, but if the sand has worked in and partly covered it, we'll have some difficulties, if I may be permitted to say so. However, don't borrow trouble. We're not there yet, though at the rate we're traveling it won't be long before we arrive."

No watch was set that night, as it was not considered necessary. Tom was the first to arise in the morning, and he went out on the deck for a breath of fresh air before breakfast.

He looked off at the beautiful little island, and as his eye took in all of the little lagoon where the submarine was anchored he uttered a startled cry.

And well he might, for, not a hundred yards away, and nearer to the island than was the Advance, floated another craft—another craft, almost similar in shape and size to the one built by the Swifts. Tom rubbed his eyes to make sure he was not seeing double. No, there could be no mistake about it. There was another submarine at the tropical island.

As he looked, some one emerged from the conning tower of the second craft. The figure seemed strangely familiar. Tom knew in a moment who it was—Addison Berg. The agent saw the lad, too, and taking off his cap and making a mocking bow, he called out:

"Good morning! Have you got the gold yet?"

Tom did not know what to answer. Seeing the other submarine, at an island where he had supposed they would not be disturbed, was disconcerting enough, but to be greeted by Berg was altogether too much, Tom thought. His fears that the rival boat builders would follow had not been without foundation.

"Rather surprised to see us, aren't you?" went on Mr. Berg, smiling.

"Rather," admitted Tom, choking over the word.

"Thought you'd be," continued Berg. "We didn't expect to meet you so soon, but we're glad we did. I don't altogether like hunting for sunken treasure, with such indefinite directions as I have."

"You—are going to—" stammered Tom, and then he concluded it would be best not to say anything. But his talk had been heard inside the submarine. His father came to the foot of the conning tower stairway.

"To whom are you speaking, Tom?" he asked.

"They're here, dad," was the youth's answer.

"Here? Who are here?"

"Berg and his employers. They've followed us, dad."



Chapter Sixteen

"We'll Race You For It"

Mr. Swift hurried up on deck. He was accompanied by Captain Weston. At the sight of Tom's father, Mr. Berg, who had been joined by' two other men, called out:

"You see we also concluded to give up the trial for the Government prize, Mr. Swift. We decided there was more money in something else. But we still will have a good chance to try the merits of our respective boats. We hurried and got ours fitted up almost as soon as you did yours, and I think we have the better craft."

"I don't care to enter into any competition with you," said Mr. Swift coldly.

"Ah, but I'm afraid you'll have to, whether you want to or not," was the insolent reply.

"What's that? Do you mean to force this matter upon me?"

"I'm afraid I'll have to—my employers and I, that is. You see, we managed to pick up your trail after you left the Jersey coast, having an idea where you were bound, and we don't intend to lose you now."

"Do you mean to follow us?" asked Captain Weston softly.

"Well, you can put it that way if you like," answered one of the two men with Mr. Berg.

"I forbid it!" cried Mr. Swift hotly. "You have no right to sneak after us."

"I guess the ocean is free," continued the rascally agent.

"Why do you persist in keeping after us?" inquired the aged inventor, thinking it well to ascertain, if possible, just how much the men knew.

"Because we're after that treasure as well as you," was the bold reply. "You have no exclusive right to it. The sunken ship is awaiting the first comer, and whoever gets there first can take the gold from the wreck. We intend to be there first, but we'll be fair with you."

"Fair? What do you mean?" demanded Tom.

"This: We'll race you for it. The first one to arrive will have the right to search the wreck for the gold bullion. Is that fair? Do you agree to it?"

"We agree to nothing with you," interrupted Captain Weston, his usual diffident manner all gone. "I happen to be in partial command of this craft, and I warn you that if I find you interfering with us it won't be healthy for you. I'm not fond of fighting, but when I begin I don't like to stop," and he smiled grimly. "You'd better not follow us."

"We'll do as we please," shouted the third member of the trio on the deck of the other boat, which, as Tom could see, was named the Wonder. "We intend to get that gold if we can."

"All right. I've warned you," went on the sailor, and then, motioning to Tom and his father to follow, he went below.

"Well, what's to be done?" asked Mr. Swift when they were seated in the living-room, and had informed the others of the presence of the rival submarine.

"The only thing I see to do is to sneak away unobserved, go as deep as possible, and make all haste for the wreck," advised the captain. "They will depend on us, for they have evidently no chart of the wreck, though of course the general location of it may be known to them from reading the papers. I hoped I had thrown them off the track by the false chart I dropped, but it seems they were too smart for us."

"Have they a right to follow us?" asked Tom.

"Legally, but not morally. We can't prevent them, I'm afraid. The only thing to do is to get there ahead of them. It will be a race for the sunken treasure, and we must get there first."

"What do you propose doing, captain?" asked Mr. Damon. "Bless my shirt-studs, but can't we pull their ship up on the island and leave it there?"

"I'm afraid such high-handed proceedings would hardly answer," replied Mr. Swift. "No, as Captain Weston says, we must get there ahead of them. What do you think will be the best scheme, captain?"

"Well, there's no need for us to forego our plan to get fresh water. Suppose we go to the island, that is, some of us, leaving a guard on board here. We'll fill our tanks with fresh water, and at night we'll quietly sink below the surface and speed away."

They all voted that an excellent idea, and little time was lost putting it into operation.

All the remainder of that day not a sign of life was visible about the Wonder. She lay inert on the surface of the lagoon, not far away from the Advance; but, though no one showed himself on the deck, Tom and his friends had no doubt but that their enemies were closely watching them.

As dusk settled down over The tropical sea, and as the shadows of the trees on the little island lengthened, those on board the Advance closed the Conning tower. No lights were turned on, as they did not want their movements to be seen, but Tom, his father and Mr. Sharp took their positions near the various machines and apparatus, ready to open the tanks and let the submarine sink to the bottom, as soon as it was possible to do this unobserved.

"Luckily there's no moon," remarked Captain Weston, as he took his place beside Tom. "Once below the surface and we can defy them to find us. It is odd how they traced us, but I suppose that steamer gave them the clue."

It rapidly grew dark, as it always does in the tropics, and when a cautious observation from the conning tower did not disclose the outlines of the other boat, those aboard the Advance rightly concluded that their rivals were unable to see them.

"Send her down, Tom," called his father, and with a hiss the water entered the tanks. The submarine quickly sank below the surface, aided by the deflecting rudder.

But alas for the hopes of the gold-seekers. No sooner was she completely submerged, with the engine started so as to send her out of the lagoon and to the open sea, than the waters all about were made brilliant by the phosphorescent phenomenon. In southern waters this frequently occurs. Millions of tiny creatures, which, it is said, swarm in the warm currents, give an appearance of fire to the ocean, and any object moving through it can plainly be seen. It was so with the Advance. The motion she made in shooting forward, and the undulations caused by her submersion, seemed to start into activity the dormant phosphorus, and the submarine was afloat in a sea of fire.

"Quick!" cried Tom. "Speed her up! Maybe we can get out of this patch of water before they see us."

But it was too late. Above them they could hear the electric siren of the Wonder as it was blown to let them know that their escape had been noticed. A moment later the water, which acted as a sort of sounding-board, or telephone, brought to the ears of Tom Swift and his friends the noise of the engines of the other craft in operation. She was coming after them. The race for the possession of three hundred thousand dollars in gold was already under way. Fate seemed against those on board the Advance.



Chapter Seventeen

The Race

Directed by Captain Weston, who glanced at the compass and told him which way to steer to clear the outer coral reef, Tom sent the submarine ahead, signaling for full speed to the engine-room, where his father and Mr. Sharp were. The big dynamos purred like great cats, as they sent the electrical energy into the forward and aft plates, pulling and pushing the Advance forward. On and on she rushed under water, but ever as she shot ahead the disturbance in the phosphorescent water showed her position plainly. She would be easy to follow.

"Can't you get any more speed out of her?" asked the captain of the lad.

"Yes," was the quick reply; "by using the auxiliary screws I think we can. I'll try it."

He signaled for the propellers, forward and aft, to be put in operation, and the motor moving the twin screws was turned on. At once there was a perceptible increase to the speed of the Advance.

"Are we leaving them behind?" asked Tom anxiously, as he glanced at the speed gage, and noted that the submarine was now about five hundred feet below the surface.

"Hard to tell," replied the Captain. "You'd have to take an observation to make sure."

"I'll do it," cried the youth. "You steer, please, and I'll go in the conning tower. I can look forward and aft there, as well as straight up. Maybe I can see the Wonder."

Springing up the circular ladder leading into the tower, Tom glanced through the windows all about the small pilot house. He saw a curious sight. It was as if the submarine was in a sea of yellowish liquid fire. She was immersed in water which glowed with the flames that contained no heat. So light was it, in fact, that there was no need of the incandescents in the tower. The young inventor could have seen to read a paper by the illumination of the phosphorus. But he had something else to do than observe this phenomenon. He wanted to see if he could catch sight of the rival submarine.

At first he could make out nothing save the swirl and boiling of the sea, caused by the progress of the Advance through it. But suddenly, as he looked up, he was aware of some great, black body a little to the rear and about ten feet above his craft.

"A shark!" he exclaimed aloud. "An immense one, too."

But the closer he looked the less it seemed like a shark. The position of the black object changed. It appeared to settle down, to be approaching the top of the conning tower. Then, with a suddenness that unnerved him for the time being, Tom recognized what it was; it was the underside of a ship. He could see the plates riveted together, and then, as he noted the rounded, cylindrical shape, he knew that it was a submarine. It was the Wonder. She was close at hand and was creeping up on the Advance. But, what was more dangerous, she seemed to be slowly settling in the water. Another moment and her great screws might crash into the Conning tower of the Swifts' boat and shave it off. Then the water would rush in, drowning the treasure-seekers like rats in a trap.

With a quick motion Tom yanked over the lever that allowed more water to flow into the ballast tanks. The effect was at once apparent. The Advance shot down toward the bottom of the sea. At the same time the young inventor signaled to Captain Weston to notify those in the engine-room to put on a little more speed. The Advance fairly leaped ahead, and the lad, looking up through the bull's-eye in the roof of the conning tower, had the satisfaction of seeing the rival submarine left behind.

The youth hurried down into the interior of the ship to tell what he had seen, and explain the reason for opening the ballast tanks. He found his father and Mr. Sharp somewhat excited over the unexpected maneuver of the craft.

"So they're still following us," murmured Mr. Swift. "I don't see why we can't shake them off."

"It's on account of this luminous water," explained Captain Weston. "Once we are clear of that it will be easy, I think, to give them the slip. That is, if we can get out of their sight long enough. Of course, if they keep close after us, they can pick us up with their searchlight, for I suppose they carry one."

"Yes," admitted the aged inventor, "they have as strong a one as we have. In fact, their ship is second only to this one in speed and power. I know, for Bentley & Eagert showed me some of the plans before they started it, and asked my opinion. This was before I had the notion of building a submarine. Yes, I am afraid we'll have trouble getting away from them."

"I can't understand this phosphorescent glow keeping up so long," remarked Captain Weston. "I've seen it in this locality several times, but it never covered such an extent of the ocean in my time. There must be changed conditions here now."

For an hour or more the race was kept up, and the two submarines forged ahead through the glowing sea. The Wonder remained slightly above and to the rear of the other, the better to keep sight of her, and though the Advance was run to her limit of speed, her rival could not be shaken off. Clearly the Wonder was a speedy craft.

"It's too bad that we've got to fight them, as well as run the risk of lots of other troubles which are always present when sailing under water," observed Mr Damon, who wandered about the submarine like the nervous person he was. "Bless my shirt-studs! Can't we blow them up, or cripple them in some way? They have no right to go after our treasure."

"Well, I guess they've got as much right as we have," declared Tom. "It goes to whoever reaches the wreck first. But what I don't like is their mean, sneaking way of doing it. If they went off on their own hook and looked for it I wouldn't say a word. But they expect us to lead them to the wreck, and then they'll rob us if they can. That's not fair."

"Indeed, it isn't," agreed Captain Weston, "if I may be allowed the expression. We ought to find some way of stopping them. But, if I'm not mistaken," he added quickly, looking from one of the port bull's-eyes, "the phosphorescent glow is lessening. I believe we are running beyond that part of the ocean."

There was no doubt of it, the glow was growing less and less, and ten minutes later the Advance was speeding along through a sea as black as night. Then, to avoid running into some wreck, it was necessary to turn on the searchlight.

"Are they still after us?" asked Mr. Swift of his son, as he emerged from the engine-room, where he had gone to make some adjustments to the machinery, with the hope of increasing the speed.

"I'll go look," volunteered the lad. He climbed up into the conning tower again, and for a moment, as he gazed back into the black waters swirling all about, he hoped that they had lost the Wonder. But a moment later his heart sank as he caught sight, through the liquid element, of the flickering gleams of another searchlight, the rays undulating through the sea.

"Still following," murmured the young inventor. "They're not going to give up. But we must make 'em—that's all."

He went down to report what he had seen, and a consultation was held. Captain Weston carefully studied the charts of that part of the ocean, and finding that there was a great depth of water at hand, proposed a series of evolutions.

"We can go up and down, shoot first to one side and then to the other," he explained. "We can even drop down to the bottom and rest there for a while. Perhaps, in that way, we can shake them off."

They tried it. The Advance was sent up until her conning tower was out of the water, and then she was suddenly forced down until she was but a few feet from the bottom. She darted to the left, to the right, and even doubled and went back over the course she had taken. But all to no purpose. The Wonder proved fully as speedy, and those in her seemed to know just how to handle the submarine, so that every evolution of the Advance was duplicated. Her rival could not be shaken off.

All night this was kept up, and when morning came, though only the clocks told it, for eternal night was below the surface, the rival gold-seekers were still on the trail.

"They won't give up," declared Mr. Swift hopelessly.

"No, we've got to race them for it, just as Berg proposed," admitted Tom. "But if they want a straightaway race we'll give it to 'em Let's run her to the limit, dad."

"That's what we've been doing, Tom."

"No, not exactly, for we've been submerged a little too much to get the best speed out of our craft. Let's go a little nearer the surface, and give them the best race they'll ever have."

Then the race began; and such a contest of speed as it was! With her propellers working to the limit, and every volt of electricity that was available forced into the forward and aft plates, the Advance surged through the water, about ten feet below the surface. But the Wonder kept after her, giving her knot for knot. The course of the leading submarine was easy to trace now, in the morning light which penetrated ten feet down.

"No use," remarked Tom again, when, after two hours, the Wonder was still close behind them. "Our only chance is that they may have a breakdown."

"Or run out of air, or something like that," added Captain Weston. "They are crowding us pretty close. I had no idea they could keep up this speed. If they don't look out," he went on as he looked from one of the aft observation windows, "they'll foul us, and—"

His remarks were interrupted by a jar to the Advance. She seemed to shiver and careened to one side. Then came another bump.

"Slow down!" cried the captain, rushing toward the pilot house.

"What's the matter?" asked Tom, as he threw the engines and electrical machines out of gear. "Have we hit anything?"

"No. Something has hit us," cried the captain. "Their submarine has rammed us."

"Rammed us!" repeated Mr. Swift. "Tom, run out the electric cannon! They're trying to sink us! We'll have to fight them. Run out the stern electric gun and we'll make them wish they'd not followed us."



Chapter Eighteen

The Electric Gun

There was much excitement aboard the Advance. The submarine came to a stop in the water, while the treasure-seekers waited anxiously for what was to follow. Would they be rammed again? This time, stationary as they were, and with the other boat coming swiftly on, a hole might be stove through the Advance, in spite of her powerful sides.

They had not long to wait. Again there came a jar, and once more the Swifts' boat careened. But the blow was a glancing one and, fortunately, did little damage.

"They certainly must be trying to sink us," agreed Captain Weston. "Come, Tom, we'll take a look from the stern and see what they're up to."

"And get the stern electric gun ready to fire," repeated Mr. Swift. "We must protect ourselves. Mr. Sharp and I will go to the bow. There is no telling what they may do. They're desperate, and may ram us from in front."

Tom and the captain hurried aft. Through the thick plate-glass windows they could see the blunt nose of the Wonder not far away, the rival submarine having come to a halt. There she lay, black and silent, like some monster fish waiting to devour its victim.

"There doesn't appear to be much damage done back here," observed Tom. "No leaks. Guess they didn't puncture us."

"Perhaps it was due to an accident that they rammed us," suggested the captain.

"Well, they wouldn't have done it if they hadn't followed us so close," was the opinion of the young inventor. "They're taking too many chances. We've got to stop 'em."

"What is this electric gun your father speaks of?"

"Why, it's a regular electric cannon. It fires a solid ball, weighing about twenty-five pounds, but instead of powder, which would hardly do under water, and instead of compressed air, which is used in the torpedo tubes of the Government submarines, we use a current of electricity. It forces the cannon ball out with great energy."

"I wonder what they will do next?" observed the captain, peering through a bull'seye.

"We can soon tell," replied the youth. "We'll go ahead, and if they try to follow I'm going to fire on them."

"Suppose you sink them?"

"I won't fire to do that; only to disable them. They brought it on themselves. We can't risk having them damage us. Help me with the cannon, will you please, captain?"

The electric cannon was a long, steel tube in the after part of the submarine. It projected a slight distance from the sides of the ship, and by an ingenious arrangement could be swung around in a ball and socket joint, thus enabling it to shoot in almost any direction.

It was the work of but a few minutes to get it ready and, with the muzzle pointing toward the Wonder, Tom adjusted the electric wires and inserted the solid shot.

"Now we're prepared for them!" he cried. "I think a good plan will be to start ahead, and if they try to follow to fire on them. They've brought it on themselves."

"Correct," spoke Captain Weston.

Tom hurried forward to tell his father of this plan.

"We'll do it!" cried Mr. Swift. "Go ahead, Mr. Sharp, and we'll see if those scoundrels will follow."

The young inventor returned on the run to the electric cannon. There was a whir of machinery, and the Advance moved forward. She increased her speed, and the two watchers in the stern looked anxiously out of the windows to see what their rivals would do.

For a moment no movement was noticeable on the part of the Wonder. Then, as those aboard her appeared to realize that the craft on which they depended to pilot them to the sunken treasure was slipping away, word was given to follow. The ship of Berg and his employers shot after the Advance.

"Here they come!" cried Captain Weston. "They're going to ram us again!"

"Then I'm going to fire on them!" declared Tom savagely.

On came the Wonder, nearer and nearer. Her speed was rapidly increasing. Suddenly she bumped the Advance, and then, as if it was an unavoidable accident, the rear submarine sheered off to one side.

"They're certainly at it again!" cried Tom, and peering from the bull's-eye he saw the Wonder shoot past the mouth of the electric cannon. "Here it goes!" he added.

He shoved over the lever, making the proper connection. There was no corresponding report, for the cannon was noiseless, but there was a slight jar as the projectile left the muzzle. The Wonder could be seen to heel over.

"You hit her! You hit her!" cried Captain Weston. "A good shot!"

"I was afraid she was past me when I pulled the lever," explained Tom. "She went like a flash."

"No, you caught her on the rudder," declared the captain. "I think you've put her out of business. Yes, they're rising to the surface."

The lad rapidly inserted another ball, and recharged the cannon. Then he peered out into the water, illuminated by the light of day overhead, as they were not far down. He could see the Wonder rising to the surface. Clearly something had happened.

"Maybe they're going to drop down on us from above, and try to sink us," suggested the youth, while he stood ready to fire again. "If they do—"

His words were interrupted by a slight jar throughout the submarine.

"What was that?" cried the captain.

"Dad fired the bow gun at them, but I don't believe he hit them," answered the young inventor.

"I wonder what damage I did? Guess we'll go to the surface to find out."

Clearly the Wonder had given up the fight for the time being. In fact, she had no weapon with which to respond to a fusillade from her rival. Tom hastened forward and informed his father of what had happened.

"If her steering gear is out of order, we may have a chance to slip away," said Mr. Swift "We'll go up and see what we can learn."

A few minutes later Tom, his father and Captain Weston stepped from the conning tower, which was out of water, on to the little flat deck a short distance away lay the Wonder, and on her deck was Berg and a number of men, evidently members of the crew.

"Why did you fire on us?" shouted the agent angrily.

"Why did you follow us?" retorted Torn.

"Well, you've broken our rudder and disabled us," went on Berg, not answering the question. "You'll suffer for this! I'll have you arrested."

"You only got what you deserved," added Mr. Swift. "You were acting illegally, following us, and you tried to sink us by ramming my craft before we retaliated by firing on you."

"It was an accident, ramming you," said Berg. "We couldn't help it. I now demand that you help us make repairs."

"Well, you've got nerve!" cried Captain Weston, his eyes flashing. "I'd like to have a personal interview with you for about ten minutes. Maybe something besides your ship would need repairs then."

Berg turned away, scowling, but did not reply. He began directing the crew what to do about the broken rudder.

"Come on," proposed Tom in a low voice, for sounds carry very easily over water. "Let's go below and skip out while we have a chance. They can't follow now, and we can get to the sunken treasure ahead of them."

"Good advice," commented his father. "Come, Captain Weston, we'll go below and close the conning tower."

Five minutes later the Advance sank from sight, the last glimpse Tom had of Berg and his men being a sight of them standing on the deck of their floating boat, gazing in the direction of their successful rival. The Wonder was left behind, while Tom and his friends were soon once more speeding toward the treasure wreck.



Chapter Nineteen

Captured

"Down deep," advised Captain Weston, as he stood beside Tom and Mr. Swift in the pilot house. "As far as you can manage her, and then forward. We'll take no more chances with these fellows."

"The only trouble is," replied the young inventor, "that the deeper we go the slower we have to travel. The water is so dense that it holds us back."

"Well, there is no special need of hurrying now," went on the sailor. "No one is following you, and two or three days difference in reaching the wreck will not amount to anything."

"Unless they repair their rudder, and take after us again," suggested Mr. Swift.

"They're not very likely to do that," was the captain's opinion. "It was more by luck than good management that they picked us up before. Now, having to delay, as they will, to repair their steering gear, while we can go as deep as we please and speed ahead, it is practically impossible for them to catch up to us. No, I think we have nothing to fear from them."

But though danger from Berg and his crowd was somewhat remote, perils of another sort were hovering around the treasure-seekers, and they were soon to experience them.

It was much different from sailing along in the airship, Tom thought, for there was no blue sky and fleecy clouds to see, and they could not look down and observe, far below them, cities and villages. Nor could they breathe the bracing atmosphere of the upper regions.

But if there was lack of the rarefied air of the clouds, there was no lack of fresh atmosphere. The big tanks carried a large supply, and whenever more was needed the oxygen machine would supply it.

As there was no need, however, of remaining under water for any great stretch of time, it was their practice to rise every day and renew the air supply, also to float along on the surface for a while, or speed along, with only the conning tower out, in order to afford a view, and to enable Captain Weston to take observations. But care was always exercised to make sure no ships were in sight when emerging on the surface, for the gold-seekers did not want to be hailed and questioned by inquisitive persons.

It was about four days after the disabling of the rival submarine, and the Advance was speeding along about a mile and a half under water. Tom was in the pilot house with Captain Weston, Mr. Damon was at his favorite pastime of looking out of the glass side windows into the ocean and its wonders, and Mr. Swift and the balloonists were, as usual, in the engine-room.

"How near do you calculate we are to the sunken wreck?" asked Tom of his companion.

"Well, at the calculation we made yesterday, we are within about a thousand miles of it now. We ought to reach it in about four more days, if we don't have any accidents."

"And how deep do you think it is?" went on the lad.

"Well, I'm afraid it's pretty close to two miles, if not more. It's quite a depth, and of course impossible for ordinary divers to reach. But it will be possible in this submarine and in the strong diving suits your father has invented for us to get to it. Yes, I don't anticipate much trouble in getting out the gold, once we reach the wreck of course—"

The captain's remark was not finished. From the engine-room there came a startled shout:

"Tom! Tom! Your father is hurt! Come here, quick!"

"Take the wheel!" cried the lad to the captain. "I must go to my father." It was Mr. Sharp's voice he had heard.

Racing to the engine-room, Tom saw his parent doubled up over a dynamo, while to one side, his hand on a copper switch, stood Mr. Sharp.

"What's the matter?" shouted the lad.

"He's held there by a current of electricity," replied the balloonist. "The wires are crossed."

"Why don't you shut off the current?" demanded the youth, as he prepared to pull his parent from the whirring machine. Then he hesitated, for he feared he, too, would be glued fast by the terrible current, and so be unable to help Mr. Swift.

"I'm held fast here, too," replied the balloonist. "I started to cut out the current at this switch, but there's a short circuit somewhere, and I can't let go, either. Quick, shut off all power at the main switchboard forward."

Tom realized that this was the only thing to do. He ran forward and with a yank cut out all the electric wires. With a sigh of relief Mr. Sharp pulled his hands from the copper where he had been held fast as if by some powerful magnet, his muscles cramped by the current. Fortunately the electricity was of low voltage, and he was not burned. The body of Mr. Swift toppled backward from the dynamo, as Tom sprang to reach his father.

"He's dead!" he cried, as he saw the pale face and the closed eyes.

"No, only badly shocked, I hope," spoke Mr. Sharp. "But we must get him to the fresh air at once. Start the tank pumps. We'll rise to the surface."

The youth needed no second bidding. Once more turning on the electric current, he set the powerful pumps in motion and the submarine began to rise. Then, aided by Captain Weston and Mr. Damon, the young inventor carried his father to a couch in the main cabin. Mr. Sharp took charge of the machinery.

Restoratives were applied, and there was a flutter of the eyelids of the aged inventor.

"I think he'll come around all right," said the sailor kindly, as he saw Tom's grief. "Fresh air will be the thing for him. We'll be on the surface in a minute."

Up shot the Advance, while Mr. Sharp stood ready to open the conning tower as soon as it should be out of water. Mr. Swift seemed to be rapidly reviving. With a bound the submarine, forced upward from the great depth, fairly shot out of the water. There was a clanking sound as the aeronaut opened the airtight door of the tower, and a breath of fresh air came in.

"Can you walk, dad, or shall we carry you?" asked Tom solicitously.

"Oh, I—I'm feeling better now," was the inventor's reply. "I'll soon be all right when I get out on deck. My foot slipped as I was adjusting a wire that had gotten out of order, and I fell so that I received a large part of the current. I'm glad I was not burned. Was Mr. Sharp hurt? I saw him run to the switch, just before I lost consciousness."

"No, I'm all right," answered the balloonist. "But allow us to get you out to the fresh air. You'll feel much better then."

Mr. Swift managed to walk slowly to the ladder leading to the conning tower, and thence to the deck. The others followed him. As all emerged from the submarine they uttered a cry of astonishment.

There, not one hundred yards away, was a great warship, flying a flag which, in a moment. Tom recognized as that of Brazil. The cruiser was lying off a small island, and all about were small boats, filled with natives, who seemed to be bringing supplies from land to the ship. At the unexpected sight of the submarine, bobbing up from the bottom of the ocean, the natives uttered cries of fright. The attention of those on the warship was attracted, and the bridge and rails were lined with curious officers and men.

"It's a good thing we didn't come up under that ship," observed Tom. "They would have thought we were trying to torpedo her. Do you feel better, dad?" he asked, his wonder over the sight of the big vessel temporarily eclipsed in his anxiety for his parent.

"Oh, yes, much better. I'm all right now. But I wish we hadn't disclosed ourselves to these people. They may demand to know where we are going, and Brazil is too near Uruguay to make it safe to tell our errand. They may guess it, however, from having read of the wreck, and our departure."

"Oh, I guess it will be all right," replied Captain Weston. "We can tell them we are on a pleasure trip. That's true enough. It would give us great pleasure to find that gold."

"There's a boat, with some officers in it, to judge by the amount of gold lace on them, putting off from the ship," remarked Mr. Sharp.

"Ha! Yes! Evidently they intend to pay us a formal visit," observed Mr. Damon. "Bless my gaiters, though. I'm not dressed to receive company. I think I'll put on my dress suit."

"It's too late," advised Tom. "They'll be here in a minute."

Urged on by the lusty arms of the Brazilian sailors, the boat, containing several officers, neared the floating submarine rapidly.

"Ahoy there!" called an officer in the bow, his accent betraying his unfamiliarity with the English language. "What craft are you?"

"Submarine, Advance, from New Jersey," replied Tom. "Who are you?"

"Brazilian cruiser San Paulo," was the reply. "Where are you bound?" went on the officer.

"On pleasure," answered Captain Weston quickly. "But why do you ask? We are an American ship, sailing under American colors. Is this Brazilian territory?"

"This island is—yes," came back the answer, and by this time the small boat was at the side of the submarine. Before the adventurers could have protested, had they a desire to do so, there were a number of officers and the crew of the San Paulo on the small deck.

With a flourish, the officer who had done the questioning drew his sword. Waving it in the air with a dramatic gesture, he exclaimed:

"You're our prisoners! Resist and my men shall cut you down like dogs! Seize them, men!"

The sailors sprang forward, each one stationing himself at the side of one of our friends, and grasping an arm.

"What does this mean?" cried Captain Weston indignantly. "If this is a joke, you're carrying it too far. If you're in earnest, let me warn you against interfering with Americans!"

"We know what we are doing," was the answer from the officer.

The sailor who had hold of Captain Weston endeavored to secure a tighter grip. The captain turned suddenly, and seizing the man about the waist, with an exercise of tremendous strength hurled him over his head and into the sea, the man making a great splash.

"That's the way I'll treat any one else who dares lay a hand on me!" shouted the captain, who was transformed from a mild-mannered individual into an angry, modern giant. There was a gasp of astonishment at his feat, as the ducked sailor crawled back into the small boat. And he did not again venture on the deck of the submarine.

"Seize them, men!" cried the gold-laced officer again, and this time he and his fellows, including the crew, crowded so closely around Tom and his friends that they could do nothing. Even Captain Weston found it impossible to offer any resistance, for three men grabbed hold of him but his spirit was still a fighting one, and he struggled desperately but uselessly.

"How dare you do this?" he cried.

"Yes," added Tom, "what right have you to interfere with us?"

"Every right," declared the gold-laced officer.

"You are in Brazilian territory, and I arrest you."

"What for?" demanded Mr. Sharp.

"Because your ship is an American submarine, and we have received word that you intend to damage our shipping, and may try to torpedo our warships. I believe you tried to disable us a little while ago, but failed. We consider that an act of war and you will be treated accordingly. Take them on board the San Paulo," the officer Went on, turning to his aides. "We'll try them by court-marital here. Some of you remain and guard this submarine. We will teach these filibustering Americans a lesson."



Chapter Twenty

Doomed to Death

There was no room on the small deck of the submarine to make a stand against the officers and crew of the Brazilian warship. In fact, the capture of the gold-seekers had been effected so suddenly that their astonishment almost deprived them of the power to think clearly.

At another command from the officer, who was addressed as Admiral Fanchetti, several of the sailors began to lead Tom and his friends toward the small boat.

"Do you feel all right, father?" inquired the lad anxiously, as he looked at his parent. "These scoundrels have no right to treat us so."

"Yes, Tom, I'm all right as far as the electric shock is concerned, but I don't like to be handled in this fashion."

"We ought not to submit!" burst out Mr. Damon. "Bless the stars and stripes! We ought to fight."

"There's no chance," said Mr. Sharp. "We are right under the guns of the ship. They could sink us with one shot. I guess we'll have to give in for the time being."

"It is most unpleasant, if I may be allowed the expression," commented Captain Weston mildly. He seemed to have lost his sudden anger, but there was a steely glint in his eyes, and a grim, set look around his month that showed his temper was kept under control only by an effort. It boded no good to the sailors who had hold of the doughty captain if he should once get loose, and it was noticed that they were on their guard.

As for Tom, he submitted quietly to the two Brazilians who had hold of either arm, and Mr. Swift was held by only one, for it was seen that he was feeble.

"Into the boat with them!" cried Admiral Fanchetti. "And guard them well, Lieutenant Drascalo, for I heard them plotting to escape," and the admiral signaled to a younger officer, who was in charge of the men guarding the prisoners.

"Lieutenant Drascalo, eh?" murmured Mr. Damon. "I think they made a mistake naming him. It ought to be Rascalo. He looks like a rascal."

"Silenceo!" exclaimed the lieutenant, scowling at the odd character'.

"Bless my spark plug! He's a regular fire-eater!" went on Mr. Damon, who appeared to have fully recovered his spirits.

"Silenceo!" cried the lieutenant, scowling again, but Mr. Damon did not appear to mind.

Admiral Fanchetti and several others of the gold-laced officers remained aboard the submarine, while Tom and his friends were hustled into the small boat and rowed toward the warship.

"I hope they don't damage our craft," murmured the young inventor, as he saw the admiral enter the conning tower.

"If they do, we'll complain to the United States consul and demand damages," said Mr. Swift.

"I'm afraid we won't have a chance to communicate with the consul," remarked Captain Weston.

"What do you mean?" asked Mr. Damon. "Bless my shoelaces, but will these scoundrels—"

"Silenceo!" cried Lieutenant Drascalo quickly. "Dogs of Americans, do you wish to insult us?"

"Impossible; you wouldn't appreciate a good, genuine United States insult," murmured Tom under his breath.

"What I mean," went on the captain, "is that these people may carry the proceedings off with a high hand. You heard the admiral speak of a court-martial."

"Would they dare do that?" inquired Mr. Sharp.

"They would dare anything in this part of the world, I'm afraid," resumed Captain Weston. "I think I see their plan, though. This admiral is newly in command; his uniform shows that He wants to make a name for himself, and he seizes on our submarine as an excuse. He can send word to his government that he destroyed a torpedo craft that sought to wreck his ship. Thus he will acquire a reputation."

"But would his government support him in such a hostile act against the United States, a friendly nation?" asked Tom.

"Oh, he would not claim to have acted against the United States as a power. He would say that it was a private submarine, and, as a matter of fact, it is. While we are under the protection of the stars and stripes, our vessel is not a Government one," and Captain Weston spoke the last in a low voice, so the scowling lieutenant could not hear.

"What will they do with us?" inquired Mr. Swift.

"Have some sort of a court-martial, perhaps," went on the captain, "and confiscate our craft Then they will send us back home, I expect for they would not dare harm us."

"But take our submarine!" cried Tom. "The villains—"

"Silenceo!" shouted Lieutenant Drascalo and he drew his sword.

By this time the small boat was under the big guns of the San Paulo, and the prisoners were ordered, in broken English, to mount a companion ladder that hung over the side. In a short time they were on deck, amid a crowd of sailors, and they could see the boat going back to bring off the admiral, who signaled from the submarine. Tom and his friends were taken below to a room that looked like a prison, and there, a little later, they were visited by Admiral Fanchetti and several officers.

"You will be tried at once," said the admiral. "I have examined your submarine and I find she carries two torpedo tubes. It is a wonder you did not sink me at once."

"Those are not torpedo tubes!" cried Tom, unable to keep silent, though Captain Weston motioned him to do so.

"I know torpedo tubes when I see them," declared the admiral. "I consider I had a very narrow escape. Your country is fortunate that mine does not declare war against it for this act. But I take it you are acting privately, for you fly no flag, though you claim to be from the United States."

"There's no place for a flag on the submarine," went on Tom. "What good would it be under water?"

"Silenceo!" cried Lieutenant Drascalo, the admonition to silence seeming to be the only command of which he was capable.

"I shall confiscate your craft for my government," went on the admiral, "and shall punish you as the court-martial may direct. You will be tried at once."

It was in vain for the prisoners to protest. Matters were carried with a high hand. They were allowed a spokesman, and Captain Weston, who understood Spanish, was selected, that language being used. But the defense was a farce, for he was scarcely listened to. Several officers testified before the admiral, who was judge, that they had seen the submarine rise out of the water, almost under the prow of the San Paulo. It was assumed that the Advance had tried to wreck the warship, but had failed. It was in vain that Captain Weston and the others told of the reason for their rapid ascent from the ocean depths—that Mr. Swift had been shocked, and needed fresh air. Their story was not believed.

"We have heard enough!" suddenly exclaimed the admiral. "The evidence against you is over-whelming—er—what you Americans call conclusive," and he was speaking then in broken English. "I find you guilty, and the sentence of this court-martial is that you be shot at sunrise, three days hence!"

"Shot!" cried Captain Weston, staggering back at this unexpected sentence. His companions turned white, and Mr. Swift leaned against his son for support.

"Bless my stars! Of all the scoundrelly!" began Mr. Damon.

"Silenceo!" shouted the lieutenant, waving his sword.

"You will be shot," proceeded the admiral. "Is not that the verdict of the honorable court?" he asked, looking at his fellow officers. They all nodded gravely.

"But look here!" objected Captain Weston. "You don't dare do that! We are citizens of the United States, and—"

"I consider you no better than pirates," interrupted the admiral. "You have an armed submarine—a submarine with torpedo tubes. You invade our harbor with it, and come up almost under my ship. You have forfeited your right to the protection of your country, and I have no fear on that score. You will be shot within three days. That is all. Remove the prisoners."

Protests were in vain, and it was equally useless to struggle. The prisoners were taken out on deck, for which they were thankful, for the interior of the ship was close and hot, the weather being intensely disagreeable. They were told to keep within a certain space on deck, and a guard of sailors, all armed, was placed near them. From where they were they could see their submarine floating on the surface of the little bay, with several Brazilians on the small deck. The Advance had been anchored, and was surrounded by a flotilla of the native boats, the brown-skinned paddlers gazing curiously at the odd craft.

"Well, this is tough luck!" murmured Tom. "How do you feel, dad?"

"As well as can be expected under the circumstances," was the reply. "What do you think about this, Captain Weston?"

"Not very much, if I may be allowed the expression," was the answer.

"Do you think they will dare carry out that threat?" asked Mr. Sharp.

The captain shrugged his shoulders. "I hope it is only a bluff," he replied, "made to scare us so we will consent to giving up the submarine, which they have no right to confiscate. But these fellows look ugly enough for anything," he went on.

"Then if there's any chance of them attempting to carry it out," spoke Tom, "we've got to do something."