TOM SWIFT AND HIS SUBMARINE BOAT

or

Under the Ocean for Sunken Treasure

by

VICTOR APPLETON

CONTENTS

 I News of a Treasure Wreck II Finishing the Submarine III Mr. Berg Is Astonished IV Tom Is Imprisoned V Mr. Berg Is Suspicious VI Turning the Tables VII Mr. Damon Will Go VIII Another Treasure Expedition IX Captain Weston's Advent X Trial of the Submarine XI On the Ocean Bed XII For a Breath of Air XIII Off for the Treasure XIV In the Diving Suits XV At the Tropical Island XVI "We'll Race You For It!" XVII The Race XVIII The Electric Gun XIX Captured XX Doomed to Death XXI The Escape XXII At the Wreck XXIII Attacked by Sharks XXIV Ramming the Wreck XXV Home with the Gold

TOM SWIFT AND HIS SUBMARINE BOAT

Chapter One

News of a Treasure Wreck

There was a rushing, whizzing, throbbing noise in the air. A greatbody, like that of some immense bird, sailed along, casting a grotesqueshadow on the ground below. An elderly man, who Was seated on theporch of a large house, started to his feet in alarm. 

"Gracious goodness! What was that, Mrs. Baggert?" he called to amotherly-looking woman who stood in the doorway. "What happened?"

"Nothing much, Mr. Swift, " was the calm reply "I think that was Tom andMr. Sharp in their airship, that's all. I didn't see it, but the noisesounded like that of the Red Cloud. "

"Of course! To be sure!" exclaimed Mr. Barton Swift, the well-knowninventor, as he started down the path in order to get a good view ofthe air, unobstructed by the trees. "Yes, there they are, " he added. "That's the airship, but I didn't expect them back so soon. They musthave made good time from Shopton. I wonder if anything can be thematter that they hurried so?"

He gazed aloft toward where a queerly-shaped machine was circling aboutnearly five hundred feet in the air, for the craft, after Swooping downclose to the house, had ascended and was now hovering just above theline of breakers that marked the New Jersey seacoast, where Mr. Swifthad taken up a temporary residence. 

"Don't begin worrying, Mr. Swift, " advised Mrs. Baggert, thehousekeeper. "You've got too much to do, if you get that new boat done, to worry. "

"That's so. I must not worry. But I wish Tom and Mr. Sharp would land, for I want to talk to them. "

As if the occupants of the airship had heard the words of the agedinventor, they headed their craft toward earth. The combined aeroplaneand dirigible balloon, a most wonderful traveler of the air, swungaround, and then, with the deflection rudders slanted downward, came onwith a rush. When near the landing place, just at the side of thehouse, the motor was stopped, and the gas, with a hissing noise, rushedinto the red aluminum container. This immediately made the ship morebuoyant and it landed almost as gently as a feather. 

No sooner had the wheels which formed the lower part of the crafttouched the ground than there leaped from the cabin of the Red Cloud ayoung man. 

"Well, dad!" he exclaimed. "Here we are again, safe and sound. Made arecord, too. Touched ninety miles an hour at times--didn't we, Mr. Sharp?"

"That's what, " agreed a tall, thin, dark-complexioned man, who followedTom Swift more leisurely in his exit from the cabin. Mr. Sharp, aveteran aeronaut, stopped to fasten guy ropes from the airship tostrong stakes driven into the ground. 

"And we'd have done better, only we struck a hard wind against us abouttwo miles up in the air, which delayed us, " went on Tom. "Did you hearus coming, dad?"

"Yes, and it startled him, " put in Mrs. Baggert. "I guess he wasn'texpecting you. "

"Oh, well, I shouldn't have been so alarmed, only I was thinking deeplyabout a certain change I am going to make in the submarine, Tom. I wasday-dreaming, I think, when your ship whizzed through the air. But tellme, did you find everything all right at Shopton? No signs of any ofthose scoundrels of the Happy Harry gang having been around?" and Mr. Swift looked anxiously at his son. 

"Not a sign, dad, " replied Tom quickly. "Everything was all right. Webrought the things you wanted. They're in the airship. Oh, but it was afine trip. I'd like to take another right out to sea. "

"Not now, Tom, " said his father. "I want you to help me. And I needMr. Sharp's help, too. Get the things out of the car, and we'll go tothe shop. "

"First I think we'd better put the airship away, " advised Mr. Sharp. "Idon't just like the looks of the weather, and, besides, if we leave theship exposed we'll be sure to have a crowd around sooner or later, andwe don't want that. "

"No, indeed, " remarked the aged inventor hastily. "I don't want peopleprying around the submarine shed. By all means put the airship away, and then come into the shop. "

In spite of its great size the aeroplane was easily wheeled along byTom and Mr. Sharp, for the gas in the container made it so buoyant thatit barely touched the earth. A little more of the powerful vapor andthe Red Cloud would have risen by itself. In a few minutes thewonderful craft, of which my readers have been told in detail in aprevious volume, was safely housed in a large tent, which was securelyfastened. 

Mr. Sharp and Tom, carrying some bundles which they had taken from thecar, or cabin, of the craft, went toward a large shed, which adjoinedthe house that Mr. Swift had hired for the season at the seashore. Theyfound the lad's father standing before a great shape, which loomed updimly in the semi-darkness of the building. It was like an immensecylinder, pointed at either end, and here and there were openings, covered with thick glass, like immense, bulging eyes. From the numberof tools and machinery all about the place, and from the appearance ofthe great cylinder itself, it was easy to see that it was only partlycompleted. 

"Well, how goes it, dad?" asked the youth, as he deposited his bundleon a bench. "Do you think you can make it work?"

"I think so, Tom. The positive and negative plates are giving meconsiderable trouble, though. But I guess we can solve the problem. Didyou bring me the galvanometer?"

"Yes, and all the other things, " and the young inventor proceeded totake the articles from the bundles he carried. 

Mr. Swift looked them over carefully, while Tom walked about examiningthe submarine, for such was the queer craft that was contained in theshed. He noted that some progress had been made on it since he hadleft the seacoast several days before to make a trip to Shopton, in NewYork State, where the Swift home was located, after some tools andapparatus that his father wanted to obtain from his workshop there. 

"You and Mr. Jackson have put on several new plates, " observed the ladafter a pause. 

"Yes, " admitted his father. "Garret and I weren't idle, were we, Garret?" and he nodded to the aged engineer, who had been in his employfor many years. 

"No; and I guess we'll soon have her in the water, Tom, now that youand Mr. Sharp are here to help us, " replied Garret Jackson. 

"We ought to have Mr. Damon here to bless the submarine and his liverand collar buttons a few times, " put in Mr. Sharp, who brought inanother bundle. He referred to an eccentric individual Who had recentlymade an airship voyage with himself and Tom, Mr. Damon's peculiaritybeing to use continually such expressions as: "Bless my soul! Bless myliver!"

"Well, I'll be glad when we can make a trial trip, " went on Tom. "I'vetraveled pretty fast on land with my motorcycle, and we certainly havehummed through the air. Now I want to see how it feels to scoot alongunder water. "

"Well, if everything goes well we'll be in position to make a trialtrip inside of a month, " remarked the aged inventor. "Look here, Mr. Sharp, I made a change in the steering gear, which I'd like you and Tomto consider. "

The three walked around to the rear of the odd-looking structure, if anobject shaped like a cigar can be said to have a front and rear, andthe inventor, his son, and the aeronaut were soon deep in a discussionof the technicalities connected with under-water navigation. 

A little later they went into the house, in response to a summons fromthe supper bell, vigorously rung by Mrs. Baggert. She was not fond ofwaiting with meals, and even the most serious problem of mechanics was, in her estimation, as nothing compared with having the soup get cold, or the possibility of not having the meat done to a turn. 

The meal was interspersed with remarks about the recent airship flightof Tom and Mr. Sharp, and discussions about the new submarine. Thistalk went on even after the table was cleared off and the three hadadjourned to the sitting-room. There Mr. Swift brought out pencil andpaper, and soon he and Mr. Sharp were engrossed in calculating thepressure per square inch of sea water at a depth of three miles. 

"Do you intend to go as deep as that?" asked Tom, looking up from apaper he was reading. 

"Possibly, " replied his father; and his son resumed his perusal of thesheet. 

"Now, " went on the inventor to the aeronaut, "I have another plan. Inaddition to the positive and negative plates which will form our motivepower, I am going to install forward and aft propellers, to use in caseof accident. "

"I say, dad! Did you see this?" suddenly exclaimed Tom, getting up fromhis chair, and holding his finger on a certain place in the page of thepaper. 

"Did I see what?" asked Mr. Swift. 

"Why, this account of the sinking of the treasure ship. "

"Treasure ship? No. Where?"

"Listen, " went on Tom. "I'll read it: 'Further advices from Montevideo, Uruguay, South America, state that all hope has been given up ofrecovering the steamship Boldero, which foundered and went down offthat coast in the recent gale. Not only has all hope been abandoned ofraising the vessel, but it is feared that no part of the three hundredthousand dollars in gold bullion which she carried will ever berecovered. Expert divers who were taken to the scene of the wreck statethat the depth of water, and the many currents existing there, due to asubmerged shoal, preclude any possibility of getting at the hull. Thebullion, it is believed, was to have been used to further the interestsof a certain revolutionary faction, but it seems likely that they willhave to look elsewhere for the sinews of war. Besides the bullion theship also carried several cases of rifles, it is stated, and othervaluable cargo. The crew and what few passengers the Boldero carriedwere, contrary to the first reports, all saved by taking to the boats. It appears that some of the ship's plates were sprung by the stress inwhich she labored in a storm, and she filled and sank gradually. 'There! what do you think of that, dad?" cried Tom as he finished. 

"What do I think of it? Why, I think it's too bad for therevolutionists, Tom, of course. "

"No; I mean about the treasure being still on board the ship. Whatabout that?"

"Well, it's likely to stay there, if the divers can't get at it. Now, Mr. Sharp, about the propellers--"

"Wait, dad!" cried Tom earnestly. 

"Why, Tom, what's the matter?" asked Mr. Swift in some surprise. 

"How soon before we can finish our submarine?" went on Tom, notanswering the question. 

"About a month. Why?"

"Why? Dad, why can't we have a try for that treasure? It ought to becomparatively easy to find that sunken ship off the coast of Uruguay. In our submarine we can get close up to it, and in the new diving suitsyou invented we can get at that gold bullion. Three hundred thousanddollars! Think of it, dad! Three hundred thousand dollars! We couldeasily claim all of it, since the owners have abandoned it, but wewould be satisfied with half. Let's hurry up, finish the submarine, andhave a try for it. "

"But, Tom, you forget that I am to enter my new ship in the trials forthe prize offered by the United States Government. "

"How much is the prize if you win it?" asked Tom. 

"Fifty thousand dollars. "

"Well, here's a chance to make three times that much at least, andmaybe more. Dad, let the Government prize go, and try for the treasure. Will you?"

Tom looked eagerly at his father, his eyes shining with anticipation. Mr. Swift was not a quick thinker, but the idea his son had proposedmade an impression on him. He reached out his hand for the paper inwhich the young inventor had seen the account of the sunken treasure. Slowly he read it through. Then he passed it to Mr. Sharp. 

"What do you think of it?" he asked of the aeronaut

"There's a possibility, " remarked the balloonist "We might try for it. We can easily go three miles down, and it doesn't lie as deeply asthat, if this account is true. Yes, we might try for it. But we'd haveto omit the Government contests. "

"Will you, dad?" asked Tom again. 

Mr. Swift considered a moment longer. 

"Yes, Tom, I will, " he finally decided. "Going after the treasure willbe likely to afford us a better test of the submarine than would anyGovernment tests. We'll try to locate the sunken Boldero. "

"Hurrah!" cried the lad, taking the paper from Mr. Sharp and waving itin the air. "That's the stuff! Now for a search for the submarinetreasure!"

Chapter Two

Finishing the Submarine

"What's the matter?" cried Mrs. Baggert, the housekeeper, hurrying infrom the kitchen, where she was washing the dishes. "Have you seen someof those scoundrels who robbed you, Mr. Swift? If you have, the policedown here ought to--"

"No, it's nothing like that, " explained Mr. Swift. "Tom has merelydiscovered in the paper an account of a sunken treasure ship, and hewants us to go after it, down under the ocean. "

"Oh, dear! Some more of Captain Kidd's hidden hoard, I suppose?"ventured the housekeeper. "Don't you bother with it, Mr. Swift. I had acousin once, and he got set in the notion that he knew where thatpirate's treasure was. He spent all the money he had and all he couldborrow digging for it, and he never found a penny. Don't waste yourtime on such foolishness. It's bad enough to be building airships andsubmarines without going after treasure. " Mrs. Baggert spoke with thefreedom of an old friend rather than a hired housekeeper, but she hadbeen in the family ever since Tom's mother died, when he was a baby, and she had many privileges. 

"Oh, this isn't any of Kidd's treasure, " Tom assured her. "If we getit, Mrs. Baggert, I'll buy you a diamond ring. "

"Humph!" she exclaimed, as Tom began to hug her in boyish fashion. "Iguess I'll have to buy all the diamond rings I want, if I have todepend on your treasure for them, " and she went back to the kitchen. 

"Well, " went on Mr. Swift after a pause, "if we are going into thetreasure-hunting business, Tom, we'll have to get right to work. In thefirst place, we must find out more about this ship, and just where itwas sunk. "

"I can do that part, " said Mr. Sharp. "I know some sea captains, andthey can put me on the track of locating the exact spot. In fact, itmight not be a bad idea to take an expert navigator with us. I canmanage in the air all right, but I confess that working out a locationunder water is beyond me. "

"Yes, an old sea captain wouldn't be a bad idea, by any means, "conceded Mr. Swift. "Well, if you'll attend to that detail, Mr. Sharp, Tom, Mr. Jackson and I will finish the submarine. Most of the work isdone, however, and it only remains to install the engine and motors. Now, in regard to the negative and positive electric plates, I'd likeyour opinion, Tom. "

For Tom Swift was an inventor, second in ability only to his father, and his advice was often sought by his parent on matters of electricalconstruction, for the lad had made a specialty of that branch ofscience. 

While father and son were deep in a discussion of the apparatus of thesubmarine, there will be an opportunity to make the reader a littlebetter acquainted with them. Those of you who have read the previousvolumes of this series do not need to be told who Tom Swift is. Others, however, may be glad to have a proper introduction to him. 

Tom Swift lived with his father, Barton Swift, in the village ofShopton, New York. The Swift home was on the outskirts of the town, andthe large house was surrounded by a number of machine shops, in whichfather and son, aided by Garret Jackson, the engineer, did theirexperimental and constructive work. Their house was not far from LakeCarlopa, a fairly large body of water, on which Tom often speeded hismotor-boat. 

In the first volume of this series, entitled "Tom Swift and HisMotor-Cycle, " it was told how he became acquainted with Mr. WakefieldDamon, who suffered an accident while riding one of the speedymachines. The accident disgusted Mr. Damon with motor-cycles, and Tomsecured it for a low price. He had many adventures on it, chief amongwhich was being knocked senseless and robbed of a valuable patent modelbelonging to his father, which he was taking to Albany. The attack wascommitted by a gang known as the Happy Harry gang, who were acting atthe instigation of a syndicate of rich men, who wanted to securecontrol of a certain patent turbine engine which Mr. Swift had invented. 

Tom set out in pursuit of the thieves, after recovering from theirattack, and had a strenuous time before he located them. 

In the second volume, entitled "Tom Swift and His Motor-Boat, " therewas related our hero's adventures in a fine craft which was recoveredfrom the thieves and sold at auction. There was a mystery connectedwith the boat, and for a long time Tom could not solve it. He wasaided, however, by his chum, Ned Newton, who worked in the ShoptonBank, and also by Mr. Damon and Eradicate Sampson, an aged coloredwhitewasher, who formed quite an attachment for Tom. 

In his motor-boat Tom had more than one race with Andy Foger, a richlad of Shopton, who was a sort of bully. He had red hair and squintyeyes, and was as mean in character as he was in looks. He and hiscronies, Sam Snedecker and Pete Bailey, made trouble for Tom, chieflybecause Tom managed to beat Andy twice in boat races. 

It was while in his motor-boat, Arrow, that Tom formed the acquaintanceof John Sharp, a veteran balloonist. While coming down Lake Carlopa onthe way to the Swift home, which had been entered by thieves, Tom, hisfather and Ned Newton, saw a balloon on fire over the lake. Hangingfrom a trapeze on it was Mr. Sharp, who had made an ascension from afair ground. By hard work on the part of Tom and his friends theaeronaut was saved, and took up his residence with the Swifts. 

His advent was most auspicious, for Tom and his father were thenengaged in perfecting an airship, and Mr. Sharp was able to lend themhis skill, so that the craft was soon constructed. 

In the third volume, called "Tom Swift and His Airship, " there was setdown the doings of the young inventor, Mr. Sharp and Mr. Damon on atrip above the clouds. They undertook it merely for pleasure, but theyencountered considerable danger, before they completed it, for theynearly fell into a blazing forest once, and were later fired at by acrowd of excited people. This last act was to effect their capture, forthey were taken for a gang of bank robbers, and this was due directlyto Andy Foger. 

The morning after Tom and his friends started on their trip in the air, the Shopton Bank was found to have been looted of seventy-five thousanddollars. Andy Foger at once told the police that Tom Swift had takenthe money, and when asked how he knew this, he said he had seen Tomhanging around the bank the night before the vault was burst open, andthat the young inventor had some burglar tools in his possession. Warrants were at once sworn out for Tom and Mr. Damon, who was alsoaccused of being one of the robbers, and a reward of five thousanddollars was offered. 

Tom, Mr. Damon and Mr. Sharp sailed on, all unaware of this, and unableto account for being fired upon, until they accidentally read in thepaper an account of their supposed misdeeds. They lost no time instarting back home, and on, the way got on the track of the real bankrobbers, who were members of the Happy Harry gang. 

How the robbers were captured in an exciting raid, how Tom recoveredmost of the stolen money, and how he gave Andy Foger a deservedthrashing for giving a false clue was told of, and there was an accountof a race in which the Red Cloud (as the airship was called) took part, as well as details of how Tom and his friends secured the reward, whichAndy Foger hoped to collect. 

Those of you who care to know how the Red Cloud was constructed, andhow she behaved in the air, even during accidents and when struck bylightning, may learn by reading the third volume, for the airship wasone of the most successful ever constructed. 

When the craft was finished, and the navigators were ready to start ontheir first long trip, Mr. Swift was asked to go with them. Hedeclined, but would not tell why, until Tom, pressing him for ananswer, learned that his father was planning a submarine boat, which hehoped to enter in some trials for Government prizes. Mr. Swift remainedat home to work on this submarine, while his son and Mr. Sharp weresailing above the clouds. 

On their return, however, and after the bank mystery had been clearedup, Tom and Mr. Sharp, aided Mr. Swift in completing the submarine, until, when the present story opens, it needed but little additionalwork to make the craft ready for the water. 

Of course it had to be built near the sea, as it would have beenimpossible to transport it overland from Shopton. So, before the keelwas laid, Mr. Swift rented a large cottage at a seaside place on theNew Jersey coast and there, after, erecting a large shed, the work onthe Advance, as the under-water ship was called, was begun. 

It was soon to be launched in a large creek that extended in from theocean and had plenty of water at high tide. Tom and Mr. Sharp madeseveral trips back and forth from Shopton in their airship, to see thatall was safe at home and occasionally to get needed tools and suppliesfrom the shops, for not all the apparatus could be moved from Shoptonto the coast. 

It was when returning from one of these trips that Tom brought with himthe paper containing an account of the wreck of the Boldero and thesinking of the treasure she carried. 

Until late that night the three fortune-hunters discussed variousmatters. 

"We'll hurry work on the ship, " said Mr. Swift it length. "Tom, Iwonder if your friend, Mr. Damon, would care to try how it seems underWater? He stood the air trip fairly well. "

"I'll write and ask him, " answered the lad. "I'm sure he'll go. "

Securing, a few days later, the assistance of two mechanics, whom heknew he could trust, for as yet the construction of the Advance was asecret, Mr. Swift prepared to rush work on the submarine, and for thenext three weeks there were busy times in the shed next to the seasidecottage. So busy, in fact, were Tom and Mr. Sharp, that they only foundopportunity for one trip in the airship, and that was to get somesupplies from the shops at home. 

"Well, " remarked Mr. Swift one night, at the close of a hard day'swork, "another week will see our craft completed. Then we will put itin the water and see how it floats, and whether it submerges as I hopeit does. But come on, Tom. I want to lock up. I'm very tired to-night. "

"All right, dad, " answered the young inventor coming from the darkenedrear of the shop. "I just want to--"

Ne paused suddenly, and appeared to be listening. Then he moved softlyback to where he had come from. 

"What's the matter?" asked his father in a whisper. "What's up, Tom?"

The lad did not answer Mr. Swift, with a worried look on his face, followed his son. Mr. Sharp stood in the door of the shop. 

"I thought I heard some one moving around back here, " went on Tomquietly. 

"Some one in this shop!" exclaimed the aged inventor excitedly. "Someone trying to steal my ideas again! Mr. Sharp, come here! Bring thatrifle! We'll teach these scoundrels a lesson!"

Tom quickly darted hack to the extreme rear of the building. There wasa scuffle, and the next minute Tom cried out:

"What are you doing here?"

"Ha! I beg your pardon, " replied a voice. "I am looking for Mr. BartonSwift. "

"My father, " remarked Tom. "But that's a queer place to look for him. He's up front. Father, here's a man who wishes to see you, " he called. 

"Yes, I strolled in, and seeing no one about I went to the rear of theplace, " the voice went on. "I hope I haven't transgressed. "

"We were busy on the other side of the shop, I guess, " replied Tom, andhe looked suspiciously at the man who emerged from the darkness intothe light from a window. "I beg your pardon for grabbing you the way Idid, " went on the lad, "but I thought you were one of a gang of menwe've been having trouble with. "

"Oh, that's all right, " continued the man easily. "I know Mr. Swift, and I think he will remember me. Ah, Mr. Swift, how do you do?" headded quickly, catching sight of Tom's father, who, with Mr. Sharp, wascoming to meet the lad. 

"Addison Berg!" exclaimed the aged inventor as he saw the man's facemore plainly. "What are you doing here?"

"I came to see you, " replied the man. "May I have a talk with youprivately?"

"I--I suppose so, " assented Mr. Swift nervously. "Come into the house. "

Mr. Berg left Tom's side and advanced to where Mr. Swift was standing. Together the two emerged from the now fast darkening shop and wenttoward the house. 

"Who is he?" asked Mr. Sharp of the young inventor in a whisper. 

"I don't know, " replied the lad; "but, whoever he is, dad seems afraidof him. I'm going to keep my eyes open. "

Chapter Three

Mr. Berg is Astonished

Following his father and the stranger whom the aged inventor hadaddressed as Mr. Berg, Tom and Mr. Sharp entered the house, the ladhaving first made sure that Garret Jackson was on guard in the shopthat contained the sub marine. 

"Now, " said Mr. Swift to the newcomer, "I am at your service. What isit you wish?"

"In the first place, let me apologize for having startled you and yourfriends, " began the man. "I had no idea of sneaking into your workshop, but I had just arrived here, and seeing the doors open I went in. Iheard no one about, and I wandered to the back of the place. There Ihappened to stumble over a board--"

"And I heard you, " interrupted Tom. 

"Is this one of your employees?" asked Mr. Berg in rather frigid tones. 

"That is my son, " replied Mr. Swift. 

"Oh, I beg your pardon. " The man's manner changed quickly. "Well, Iguess you did hear me, young man. I didn't intend to hark my shins theway I did, either. You must have taken me for a burglar or a sneakthief. "

"I have been very much bothered by a gang of unscrupulous men, " saidMr. Swift, "and I suppose Tom thought it was some of them sneakingaround again. "

"That's what I did, " added the lad. "I wasn't going to have any onesteal the secret of the submarine if I could help it. "

"Quite right! Quite right!" exclaimed Mr. Berg. "But my purpose was anopen one. As you know, Mr. Swift, I represent the firm of Bentley &Eagert, builders of submarine boats and torpedoes. They heard that youwere constructing a craft to take part in the competitive prize testsof the United States Government, and they asked me to come and see youto learn when your ship would be ready. Ours is completed, but werecognize that it will be for the best interests of all concerned ifthere are a number of contestants, and my firm did not want to send intheir entry until they knew that you were about finished with yourship. How about it? Are you ready to compete?"

"Yes, " said Mr. Swift slowly. "We are about ready. My craft needs a fewfinishing touches, and then it will be ready to launch. "

"Then we may expect a good contest on your part, " suggested Mr. Berg. 

"Well, " began the aged inventor, "I don't know about that. "

"What's that?" exclaimed Mr. Berg. 

"I said I wasn't quite sure that we would compete, " went on Mr. Swift. "You see, when I first got this idea for a submarine boat I had it inmind to try for the Government prize of fifty thousand dollars. "

"That's what we want, too, " interrupted Mr. Berg with a smile. 

"But, " went on Tom's father, "since then certain matters have come up, and I think, on the whole, that we'll not compete for the prize afterall. "

"Not compete for the prize?" almost shouted the agent for Bentley &Eagert. "Why, the idea! You ought to compete. It is good for the trade. We think we have a very fine craft, and probably we would beat you inthe tests, but--"

"I wouldn't be too sure of that, " put in Tom. "You have only seen theoutside of our boat. The inside is better yet. "

"Ah, I have no doubt of that, " spoke Mr. Berg, "but we have been at thebusiness longer than you have, and have had more experience. Still wewelcome competition. But I am very much surprised that you are notgoing to compete for the prize, Mr. Swift. Very much surprised, indeed!You see, I came down from Philadelphia to arrange so that we could bothenter our ships at the same time. I understand there is another firm ofsubmarine boat builders who are going to try for the prize, and I wantto arrange a date that will be satisfactory to all. I am greatlyastonished that you are not going to compete. "

"Well, we were going to, " said Mr. Swift, "only we have changed ourminds, that's all. My son and I have other plans. "

"May I ask what they are?" questioned Mr. Berg. 

"You may, " exclaimed Tom quickly; "but I don't believe we can tell you. They're a secret, " he added more cordially. 

"Oh, I see, " retorted Mr. Berg. "Well, of course I don't wish topenetrate any of your secrets, but I hoped we could contest togetherfor the Government prize. It is worth trying for I assure you--fiftythousand dollars. Besides, there is the possibility of selling a numberof submarines to the United States. It's a fine prize. "

"But the one we are after is a bigger one, " Cried Tom impetuously, andthe moment he had spoken the wished he could recall the words. 

"Eh? What's that?" exclaimed Mr. Berg. "You don't mean to say anothergovernment has offered a larger prize? If I had known that I would nothave let my firm enter into the competition for the bonus offered bythe United States. Please tell me. "

"I'm sorry, " went on Tom more soberly. "I shouldn't have spoken. Mr. Berg, the plans of my father and myself are such that we can't revealthem now. We are going to try for a prize, but not in competition withyou. It's an entirely different matter. "

"Well, I guess you'll find that the firm of Bentley & Eagert arecapable of trying for any prizes that are offered, " boasted the agent. "We may be competitors yet. "

"I don't believe so, " replied Mr. Swift

"We may, " repeated Mr. Berg. "And if we do, please remember that wewill show no mercy. Our boats are the best. "

"And may the best boat win, " interjected Mr. Sharp. "That's all weask. A fair field and no favors. "

"Of course, " spoke the agent coldly. "Is this another son of yours?" heasked. 

"No but a good friend, " replied the aged inventor. "No, Mr. Berg, wewon't compete this time. You may tell your firm so. "

"Very good, " was the other's stiff reply. "Then I will bid you goodnight. We shall carry off the Government prize, but permit me to addthat I am very much astonished, very much indeed, that you do not tryfor the prize. From what I have seen of your submarine you have a verygood one, almost as good, in some respects, as ours. I bid you goodnight, " and with a bow the man left the room and hurried away from thehouse. 

Chapter Four

Tom is Imprisoned

"Well, I must say he's a cool one, " remarked Tom, as the echoes of Mr. Berg's steps died away. "The idea of thinking his boat better thanours! I don't like that man, dad. I'm suspicious of him. Do you thinkhe came here to steal some of our ideas?"

"No, I hardly believe so, my son. But how did you discover him?"

"Just as you saw, dad. I heard a noise and went back there toinvestigate. I found him sneaking around, looking at the electricpropeller plates. I went to grab him just as he stumbled over a hoard. At first I thought it was one of the old gang. I'm almost sure he wastrying to discover something. "

"No, Tom. The firm he works for are good business men, and they wouldnot countenance anything like that. They are heartless competitors, however, and if they saw a legitimate chance to get ahead of me andtake advantage, they would do it. But they would not sneak in to stealmy ideas. I feel sure of that. Besides, they have a certain type ofsubmarine which they think is the best ever invented, and they wouldhardly change at this late day. They feel sure of winning theGovernment prize, and I'm just as glad we're not going to have acontest. "

"Do you think our boat is better than theirs?"

"Much better, in many respects. "

"I don't like that man Berg, though, " went on Tom. 

"Nor do I, " added his father. "There is something strange about him. He was very anxious that I should compete. Probably he thought hisfirm's boat would go so far ahead of ours that they would get an extrabonus. But I'm glad he didn't see our new method of propulsion. That isthe principal improvement in the Advance over other types ofsubmarines. Well, another week and we will be ready for the test. "

"Have you known Mr. Berg long, dad?"

"Not very. I met him in Washington when I was in the patent office. Hewas taking out papers on a submarine for his firm at the same time Igot mine for the Advance. It is rather curious that he should come allthe way here from Philadelphia, merely to see if I was going tocompete. There is something strange about it, something that I can'tunderstand. "

The time was to come when Mr. Swift and his son were to get at thebottom of Mr. Berg's reasons, and they learned to their sorrow that hehad penetrated some of their secrets. 

Before going to bed that night Tom and Mr. Sharp paid a visit to theshed where the submarine was resting on the ways, ready for launching. They found Mr. Jackson on guard and the engineer said that no one hadbeen around. Nor was anything found disturbed. 

"It certainly is a great machine, " remarked the lad as he looked up atthe cigar-shaped bulk towering over his head. "Dad has outdone himselfthis trip. "

"It looks all right, " commented Mr. Sharp. "Whether it will work isanother question. "

"Yes, we can't tell until it's in the water, " con ceded Tom. "But Ihope it does. Dad has spent much time and money on it. "

The Advance was, as her name indicated, much in advance of previoussubmarines. There was not so much difference in outward construction asthere was in the means of propulsion and in the manner in which theinterior and the machinery were arranged. 

The submarine planned by Mr. Swift and Tom jointly, and constructed bythem, with the aid of Mr. Sharp and Mr. Jackson, was shaped like aCigar, over one hundred feet long and twenty feet in diameter at thethickest part. It was divided into many compartments, all water-tight, so that if one or even three were flooded the ship would still beuseable. 

Buoyancy was provided for by having several tanks for the introductionof compressed air, and there was an emergency arrangement so that acollapsible aluminum container could be distended and filled with apowerful gas. This was to be used if, by any means, the ship wasdisabled on the bottom of the ocean. The container could be expandedand filled, and would send the Advance to the surface. 

Another peculiar feature was that the engine-room, dynamos and otherapparatus were all contained amidships. This gave stability to thecraft, and also enabled the same engine to operate both shafts andpropellers, as well as both the negative forward electrical plates, andthe positive rear ones. 

These plates were a new idea in submarine construction, and were theoutcome of an idea of Mr. Swift, with some suggestions from his son. 

The aged inventor did not want to depend on the usual screw propellersfor his craft, nor did he want to use a jet of compressed air, shootingout from a rear tube, nor yet a jet of water, by means of which thecreature called the squid shoots himself along. Mr. Swift planned tosend the Advance along under water by means of electricity. 

Certain peculiar plates were built at the forward and aft blunt nosesof the submarine. Into the forward plate a negative charge ofelectricity was sent, and into the one at the rear a positive charge, just as one end of a horseshoe magnet is positive and will repel thenorth end of a compass needle, while the other pole of a magnet isnegative and will attract it. In electricity like repels like, whilenegative and positive have a mutual attraction for each other. 

Mr. Swift figured out that if he could send a powerful current ofnegative electricity into the forward plate it would pull the boatalong, for water is a good conductor of electricity, while if apositive charge was sent into the rear plate it would serve to push thesubmarine along, and he would thus get a pulling and pushing motion, just as a forward and aft propeller works on some ferry boats. 

But the inventor did not depend on these plates alone. There wereauxiliary forward and aft propellers of the regular type, so that ifthe electrical plates did not work, or got out of order, the screwswould serve to send the Advance along. 

There was much machinery in the submarine There were gasolene motors, since space was too cramped to allow the carrying of coal for boilers. There were dynamos, motors and powerful pumps. Some of these were forair, and some for water. To sink the submarine below the surface largetanks were filled with water. To insure a more sudden descent, deflecting rudders were also used, similar to those on an airship. There were also special air pumps, and one for the powerful gas, whichwas manufactured on board. 

Forward from the engine-room was a cabin, where meals could be served, and where the travelers could remain in the daytime. There was also asmall cooking galley, or kitchen, there. Back of the engine-room werethe sleeping quarters and the storerooms. The submarine was steeredfrom the forward compartment, and here were also levers, wheels andvalves that controlled all the machinery, while a number of dialsshowed in which direction they were going, how deep they were, and atwhat speed they were moving, as well as what the ocean pressure was. 

On top, forward, was a small conning, or observation tower, withauxiliary and steering and controlling apparatus there. This was to beused when the ship was moving along on the surface of the ocean, ormerely with the deck awash. There was a small flat deck surroundingthe conning tower and this was available when the craft was on thesurface. 

There was provision made for leaving the ship when it was on the bed ofthe ocean. When it was desired to do this the occupants put on divingsuits, which were provided with portable oxygen tanks. Then theyentered a chamber into which water was admitted until it was equal inpressure to that outside. Then a steel door was opened, and they couldstep out. To re-enter the ship the operation was reversed. This wasnot a new feature. In fact, many submarines to-day use it. 

At certain places there were thick bull's-eye windows, by means ofwhich the under-water travelers could look out into the ocean throughwhich they were moving. As a defense against the attacks of submarinemonsters there was a steel, pointed ram, like a big harpoon. There werealso a bow and a stern electrical gun, of which more will be told later. 

In addition to ample sleeping accommodations, there were manyconveniences aboard the Advance. Plenty of fresh water could becarried, and there was an apparatus for distilling more from the seawater that surrounded the travelers. Compressed air was carried inlarge tanks, and oxygen could be made as needed. In short, nothing thatcould add to the comfort or safety of the travelers had been omitted. There was a powerful crane and windlass, which had been installed whenMr. Swift thought his boat might be bought by the Government. This wasto be used for raising wrecks or recovering objects from the bottom ofthe ocean. Ample stores and provisions were to be carried and, once thetravelers were shut up in the Advance, they could exist for a monthbelow the surface, providing no accident occurred. 

All these things Tom and Mr. Sharp thought of as they looked over theship before turning in for the night. The craft was made immenselystrong to withstand powerful pressure at the bottom of the ocean. Thesubmarine could penetrate to a depth of about three miles. Below thatit was dangerous to go, as the awful force would crush the plates, powerful as they were. 

"Well, we'll rush things to-morrow and the next day, " observed Tom ashe prepared to leave the building. "Then we'll soon see if it works. "

For the next week there were busy times in the shop near the ocean. Great secrecy was maintained, and though curiosity seekers did strollalong now and then, they received little satisfaction. At first Mr. Swift thought that the visit of Mr. Berg would have unpleasant results, for he feared that the agent would talk about the craft, of which hehad so unexpectedly gotten a sight. But nothing seemed to follow fromhis chance inspection, and it was forgotten. 

It was one evening, about a week later, that Tom was alone in the shop. The two mechanics that had been hired to help out in the rush had beenlet go, and the ship needed but a few adjustments to make it ready forthe sea. 

"I think I'll just take another look at the water tank valves, " saidTom to himself as he prepared to enter the big compartments whichreceived the water ballast. "I want to be sure they work properly andquickly. We've got to depend on them to make us sink when we want to, and, what's more important, to rise to the surface in a hurry. I've gottime enough to look them over before dad and Mr. Sharp get back. "

Tom entered the starboard tank by means of an emergency sliding doorbetween the big compartments and the main part of the ship. This wasclosed by a worm and screw gear, and once the ship was in the waterwould seldom be used. 

The young inventor proceeded with his task, carefully inspecting thevalves by the light of a lantern he carried. The apparatus seemed tobe all right, and Tom was about to leave when a peculiar noiseattracted his attention. It was the sound of metal scraping on metal, and the lad's quick and well-trained ear told him it was somewhereabout the ship. 

He turned to leave the tank, but as he wheeled around his light flashedon a solid wall of steel back of him. The emergency outlet had beenclosed! He was a prisoner in the water compartment, and he knew, frompast experience, that shout as he would, his voice could not be heardten feet away. His father and Mr. Sharp, as he was aware, had gone to anearby city for some tools, and Mr. Jackson, the engineer, wastemporarily away. Mrs. Baggert, in the house, could not hear his cries. 

"I'm locked in!" cried Tom aloud. "The worm gear must have shut ofitself. But I don't see how that could be. I've got to get out mightysoon, though, or I'll smother. This tank is airtight, and it won't takeme long to breath up all the oxygen there is here. I must get thatslide open. "

He sought to grasp the steel plate that closed the emergency opening. His fingers slipped over the smooth, polished surface. He washermetically sealed up--a captive! Blankly he set his lantern down andleaned hopelessly against the wall of the tank. 

"I've got to get out, " he murmured. 

As if in answer to him he heard a voice on the outside, crying:

"There, Tom Swift! I guess I've gotten even with you now! Maybe nexttime you won't take a reward away from me, and lick me into thebargain. I've got you shut up good and tight, and you'll stay thereuntil I get ready to let you out. "

"Andy Foger!" gasped Tom. "Andy Foger sneaked in here and turned thegear. But how did he get to this part of the coast? Andy Foger, you letme out!" shouted the young inventor; and as Andy's mocking laugh cameto him faintly through the steel sides of the submarine, the imprisonedlad beat desperately with his hands on the smooth sides of the tank, vainly wondering how his enemy had discovered him. 

Chapter Five

Mr. Berg is Suspicious

Not for long did the young inventor endeavor to break his way out ofthe water-ballast tank by striking the heavy sides of it. Tom realizedthat this was worse than useless. He listened intently, but could hearnothing. Even the retreating footsteps of Andy Foger were inaudible. 

"This certainly is a pickle!" exclaimed Tom aloud. "I can't understandhow he ever got here. He must have traced us after we went to Shoptonin the airship the last time. Then he sneaked in here. Probably he sawme enter, but how could he knew enough to work the worm gear and closethe door? Andy has had some experience with machinery, though, and oneof the vaults in the bank where his father is a director closed justlike this tank. That's very likely how he learned about it. But I'vegot to do something else besides thinking of that sneak, Andy. I've gotto get out of here. Let's see if I can work the gear from inside. "

Before he started, almost, Tom knew that it would be impossible. Thetank was made to close from the interior of the submarine, and theheavy door, built to withstand the pressure of tons of water, could notbe forced except by the proper means. 

"No use trying that, " concluded the lad, after a tiring attempt toforce back the sliding door with his hands. "I've got to call for help. "

He shouted until the vibrations in the confined space made his earsring, and the mere exertion of raising his voice to the highest pitchmade his heart beat quickly. Yet there came no response. He hardlyexpected that there would be any, for with his father and Mr. Sharpaway, the engineer absent on an errand, and Mrs. Baggert in the housesome distance off, there was no one to hear his calls for help, even ifthey had been capable of penetrating farther than the extent of theshed, where the under-water craft had been constructed. 

"I've got to wait until some of them come out here, " thought Tom. "They'll be sure to release me and make a search. Then it will be easyenough to call to them and tell them where I am, once they are insidethe shed. But--" He paused, for a horrible fear came over him. "Supposethey should come--too late?" The tank was airtight. There was enoughair in it to last for some time, but, sooner or later, it would nolonger support life. Already, Tom thought, it seemed oppressive, thoughprobably that was his imagination. 

"I must get out!" he repeated frantically. "I'll die in here soon. "

Again he tried to shove back the steel door. Then he repeated his criesuntil he was weary. No one answered him. He fancied once he could hearfootsteps in the shed, and thought, perhaps, it was Andy, come back togloat over him. Then Tom knew the red-haired coward would not dareventure back. We must do Andy the justice to say that he never realizedthat he was endangering Tom's life. The bully had no idea the tank wasairtight when he closed it. He had seen Tom enter and a sudden whimcame to him to revenge himself. 

But that did not help the young inventor any. There was no doubt aboutit now--the air was becoming close. Tom had been imprisoned nearly twohours, and as he was a healthy, strong lad, he required plenty ofoxygen. There was certainly less than there had been in the tank. Hishead began to buzz, and there was a ringing in his ears. 

Once more he fell upon his knees, and his fingers sought the smallprojections of the gear on the inside of the door He could no morebudge the mechanism than a child could open a burglar-proof vault. 

"It's no use, " he moaned, and he sprawled at full length on the floorof the tank, for there the air was purer. As he did so his fingerstouched something. He started as they closed around the handle of a bigmonkey wrench. It was one he had brought into the place with him. Imbued with new hope be struck a match and lighted his lantern, whichhe had allowed to go out as it burned up too much of the oxygen. By thegleam of it he looked to see if there were any bolts or nuts he couldloosen with the wrench, in order to slide the door back. It needed buta glance to show him the futility of this. 

"It's no go, " he murmured, and he let the wrench fall to the floor. There was a ringing, clanging sound, and as it smote his ears Tomsprang up with an exclamation. 

"That's the thing!" he cried. "I wonder I didn't think of it before. Ican signal for help by pounding on the sides of the tank with thewrench. The blows will carry a good deal farther than my voice would. "Every one knows how far the noise of a boiler shop, with hammersfalling on steel plates, can be heard; much farther than can a humanvoice. 

Tom began a lusty tattoo on the metal sides of the tank. At first hemerely rattled out blow after blow, and then, as another thought cameto him, he adopted a certain plan. Some time previous, when he and Mr. Sharp had planned their trip in the air, the two had adopted a code ofsignals. As it was difficult in a high wind to shout from one end ofthe airship to the other, the young inventor would sometimes pound onthe pipe which ran from the pilot house of the Red Cloud to theengine-room. By a combination of numbers, simple messages could beconveyed. The code included a call for help. Forty-seven was thenumber, but there had never been any occasion to use it. 

Tom remembered this now. At once he ceased his indiscriminatehammering, and began to beat out regularly--one, two, three, four--thena pause, and seven blows would be given. Over and over again he rangout this number--forty seven--the call for help. 

"If Mr. Sharp only comes back he will hear that, even in the house, "thought poor Tom "Maybe Garret or Mrs. Baggert will hear it, too, butthey won't know what it means. They'll think I'm just working on thesubmarine. "

It seemed several hours to Tom that he pounded out that cry for aid, but, as he afterward learned, it was only a little over an hour. Signalafter signal he sent vibrating from the steel sides of the tank. Whenone arm tired he would use the other. He grew weary, his head wasaching, and there was a ringing in his ears; a ringing that seemed asif ten thousand bells were jangling out their peals, and he couldbarely distinguish his own pounding. 

Signal after signal he sounded. It was becoming like a dream to him, when suddenly, as he paused for a rest, he heard his name calledfaintly, as if far away. 

"Tom! Tom! Where are you?"

It was the voice of Mr. Sharp. Then followed the tones of the agedinventor. 

"My poor boy! Tom, are you still alive?"

"Yes, dad! In the starboard tank!" the lad gasped out, and then he losthis senses. When he revived he was lying on a pile of bagging in thesubmarine shop, and his father and the aeronaut were bending over him. 

"Are you all right, Tom?" asked Mr. Swift. 

"Yes--I--I guess so, " was the hesitating answer. "Yes, " the lad added, as the fresh air cleared his head. "I'll be all right pretty soon. Haveyou seen Andy Foger?"

"Did he shut you in there?" demanded Mr. Swift. 

Tom nodded. 

"I'll have him arrested!" declared Mr. Swift "I'll go to town as soonas you're in good shape again and notify the police. "

"No, don't, " pleaded Tom. "I'll take care of Andy myself. I don'treally believe he knew how serious it was. I'll settle with him later, though. "

"Well, it came mighty near being serious, " remarked Mr. Sharp grimly. "Your father and I came back a little sooner than we expected, and assoon as I got near the house I heard your signal. I knew what it was ina moment. There were Mrs. Baggert and Garret talking away, and when Iasked them why they didn't answer your call they said they thought youwere merely tinkering with the machinery. But I knew better. It's thefirst time we ever had a use for 'forty-seven, ' Tom. "

"And I hope it will be the last, " replied the young inventor with afaint smile. "But I'd like to know what Andy Foger is doing in thisneighborhood. "

Tom was soon himself again and able to go to the house, where he foundMrs. Baggert brewing a big basin of catnip tea, under the impressionthat it would in some way be good for his. She could not forgiveherself for not having answered his signal, and as for Mr. Jackson, hehad started for a doctor as soon as he learned that Tom was shut up inthe tank. The services of the medical man were canceled by telephone, as there was no need for him, and the engineer came back to the house. 

Tom was fully himself the next day, and aided his father and Mr. Sharpin putting the finishing touches to the Advance. It was found that somealteration was required in the auxiliary propellers, and this, much tothe regret of the young inventor, would necessitate postponing thetrial a few days. 

"But we'll have her in the water next Friday. " promised Mr. Swift. 

"Aren't you superstitious about Friday?" asked the balloonist. 

"Not a bit of it, " replied the aged inventor. "Tom, " he added, "I wishyou would go in the house and get me the roll of blueprints you'll findon my desk. "

As the lad neared the cottage he saw, standing in front of the place, asmall automobile. A man had just descended from it, and it needed but aglance to show that he was Mr. Addison Berg. 

"Ah, good morning, Mr. Swift, " greeted Mr. Berg. "I wish to see yourfather, but as I don't wish to lay myself open to suspicions byentering the shop, perhaps you will ask him to step here. "

"Certainly, " answered the lad, wondering why the agent had returned. Getting the blueprints, and asking Mr. Berg to sit down on the porch, Tom delivered the message. 

"You come back with me, Tom, " said his father. "I want you to be awitness to what he says. I'm not going to get into trouble with thesepeople. "

Mr. Berg came to the point at once. 

"Mr. Swift, " he said, "I wish you would reconsider your determinationnot to enter the Government trials. I'd like to see you compete. Sowould my firm. "

"There is no use going over that again, " replied the aged inventor. "Ihave another object in view now than trying for the Government prize. What it is I can't say, but it may develop in time--if we aresuccessful, " and he looked at his son, smiling the while. 

Mr. Berg tried to argue, but it was of no avail Then he changed hismanner, and said:

"Well, since you won't, you won't, I suppose. I'll go back and reportto my firm. Have you anything special to do this morning?" he went onto Tom. 

"Well, I can always find something to keep me busy, " replied the lad, "but as for anything special--"

"I thought perhaps you'd like to go for a trip in my auto, " interruptedMr. Berg. "I had asked a young man who is stopping at the same hotelwhere I am to accompany me, but he has unexpectedly left, and I don'tlike to go alone. His name was--let me see. I have a wretched memoryfor names, but it was something like Roger or Moger. "

"Foger!" cried Tom. "Was it Andy Foger?"

"Yes, that was it. Why, do you know him?" asked Mr. Berg in somesurprise. 

"I should say so, " replied Tom. "He was the cause of what might haveresulted in something serious for me, " and the lad explained aboutbeing imprisoned in the tank. 

"You don't tell me!" cried Mr. Berg. "I had no idea he was that kind ofa lad. You see, his father is one of the directors of the firm by whomI am employed. Andy came from home to spend a few weeks at the seaside, and stopped at the same hotel that I did. He went off yesterdayafternoon, and I haven't seen him since, though he promised to go for aride with me. He must have come over here and entered your shopunobserved. I remember now he asked me where the submarine was beingbuilt that was going to compete with our firm's, and I told him. Ididn't think he was that kind of a lad. Well, since he's probably goneback home, perhaps you will come for a ride with me, Tom. "

"I'm afraid I can't go, thank you, " answered the lad. "We are very busygetting our submarine in shape for a trial. But I can imagine why Andyleft so hurriedly. He probably learned that a doctor had been summonedfor me, though, as it happened, I didn't need one. But Andy probablygot frightened at what he had done, and left. I'll make him more sorry, when I meet him. "

"Don't blame you a bit, " commented Mr. Berg. "Well, I must be gettingback. "

He hastened out to his auto, while Tom and his father watched the agent. 

"Tom, never trust that man, " advised the aged inventor solemnly. 

"Just what I was about to remark, " said his son. "Well, let's get backto work. Queer that he should come here again, and it's queer aboutAndy Foger. "

Father and son returned to the machine shop, while Mr. Berg puffed awayin his auto. A little later, Tom having occasion to go to a buildingnear the boundary line of the cottage property which his father hadhired for the season, saw, through the hedge that bordered it, anautomobile standing in the road. A second glance showed him that it wasMr. Berg's machine. Something had gone wrong with it, and the agent hadalighted to make an adjustment. 

The young inventor was close to the man, though the latter was unawareof his presence. 

"Hang it all!" Tom heard Mr. Berg exclaim to himself. "I wonder whatthey can be up to? They won't enter the Government contests, and theywon't say why. I believe they're up to some game, and I've got to findout what it is. I wonder if I couldn't use this Foger chap?"

"He seems to have it in for this Tom Swift, " Mr. Berg went on, stilltalking to himself, though not so low but that Tom could hear him. "Ithink I'll try it. I'll get Andy Foger to sneak around and find outwhat the game is. He'll do it, I know. "

By this time the auto was in working order again, and the agent tookhis seat and started off. 

"So that's how matters lie, eh?" thought Tom. "Well, Mr. Berg, we'll bedoubly on the lookout for you after this. As for Andy Foger, I thinkI'll make him wish he'd never locked me in that tank. So you expect tofind out our 'game, ' eh, Mr. Berg? Well, when you do know it, I thinkit will astonish you. I only hope you don't learn what it is until weget at that sunken treasure, though. "

But alas for Tom's hopes. Mr. Berg did learn of the object of thetreasure-seekers, and sought to defeat them, as we shall learn as ourstory proceeds. 

Chapter Six

Turning the Tables

When the young inventor informed his father what he had overheard Mr. Berg saying, the aged inventor was not as much worried as his sonanticipated. 

"All we'll have to do, Tom, " he said, "is to keep quiet about where weare going. Once we have the Advance afloat, and try her out, we canstart on our voyage for the South American Coast and search for thesunken treasure. When we begin our voyage under water I defy any one totell where we are going, or what our plans are. No, I don't believe weneed worry about Mr. Berg, though he probably means mischief. "

"Well, I'm going to keep my eyes open for him and Andy Foger, " declaredTom. 

The days that followed were filled with work. Not only were there manyunexpected things to do about the submarine, but Mr. Sharp was keptbusy making inquiries about the sunken treasure ship. These inquirieshad to be made carefully, as the adventurers did not want their planstalked of, and nothing circulates more quickly than rumors of anexpedition after treasure of any kind. 

"What about the old sea captain you were going to get to go with us?"asked Mr. Swift of the balloonist one afternoon. "Have you succeededin finding one yet?"

"Yes; I am in communication with a man think will be just the personfor us. His name is Captain Alden Weston, and he has sailed all overthe world. He has also taken part in more than one revolution, and, infact, is a soldier of fortune. I do not know him personally, but afriend of mine knows him, and says he will serve us faithfully. I havewritten to him, and he will be here in a few days. "

"That's good. Now about the location of the wreck itself. Have youbeen able to learn any more details?"

"Well, not many. You see, the Boldero was abandoned in a storm, and thecaptain did not take very careful observations. As nearly as it can befigured out the treasure ship went to the bottom in latitude forty-fivedegrees south, and longitude twenty-seven east from Washington. That'sa pretty indefinite location, but I hope, once we get off the Uruguaycoast, we can better it. We can anchor or lay outside the harbor, andin the small boat we carry go ashore and possibly gain more details. For it was at Montevideo that the shipwrecked passengers and sailorslanded. "

"Does Captain Weston know our object?" inquired Tom. 

"No, and I don't propose to tell him until we are ready to start, "replied Mr. Sharp. "I don't know just how he'll consider a submarinetrip after treasure, but if I spring it on him suddenly he's lesslikely to back out. Oh, I think he'll go. "

Somewhat unexpectedly the next day it was discovered that certain toolsand appliances were needed for the submarine, and they had been left inthe house at Shopton, where Eradicate Sampson was in charge ascaretaker during the absence of Mr. Swift and his son and thehousekeeper. 

"Well, I suppose we'll have to go back after them, " remarked Tom. "We'll take the airship, dad, and make a two-days' trip of it. Is thereanything else you want?"

"Well, you might bring a bundle of papers you'll find in the lowerright hand drawer of my desk. They contain some memoranda I need. "

Tom and Mr. Sharp had become so used to traveling in the airship thatit seemed no novelty to them, though they attracted much attentionwherever they went. They soon had the Red Cloud in readiness for aflight, and rising in the air above the shop that contained thepowerful submarine, a craft utterly different in type from theaeroplane, the nose of the airship was pointed toward Shopton. 

They made a good flight and landed near the big shed where the bird ofthe air was kept. It was early evening when they got to the Swifthomestead, and Eradicate Sampson was glad to see them. 

Eradicate was a good cook, and soon had a meal ready for the travelers. Then, while Mr. Sharp selected the tools and other things needed, andput them in the airship ready for the start back the next morning, Tomconcluded he would take a stroll into Shopton, to see if he could seehis friend, Ned Newton. It was early evening, and the close of abeautiful day, a sharp shower in the morning having cooled the air. 

Tom was greeted by a number of acquaintances as he strolled along, for, since the episode of the bank robbery, when he had so unexpectedlyreturned with the thieves and the cash, the lad was better known thanever. 

"I guess Ned must be home, " thought our hero as he looked in vain forhis chum among the throng on the streets. "I've got time to take astroll down to his house. "

Tom was about to cross the street when he was startled by the sound ofan automobile horn loudly blown just at his side. Then a voice called:

"Hey, there! Git out of the way if you don't want to be run over!"

He looked up, and saw a car careening along. At the wheel was thered-haired bully, Andy Foger, and in the tonneau were Sam Snedecker andPete Bailey. 

"Git out of the way, " added Sam, and he grinned maliciously at Tom. 

The latter stepped back, well out of the path of the car, which was notmoving very fast. Just in front of Tom was a puddle of muddy water. There was no necessity for Andy steering into it, but he saw hisopportunity, and a moment later one of the big pneumatic tires hadplunged into the dirty fluid, spattering it all over Tom, some evengoing as high as his face. 

"Ha! ha!" laughed Andy. "Maybe you'll get out of my way next time, TomSwift. "

The young inventor was almost speechless from righteous anger. He wipedthe mud from his face, glanced down at his clothes, which were all butruined, and called out:

"Hold on there, Andy Foger! I want to see you!" for he thought of thetime when Andy had shut him in the tank. 

"Ta! ta!" shouted Pete Bailey. 

"See you later, " added Sam. 

"Better go home and take a bath, and then sail away in your submarine, "went on Andy. "I'll bet it will sink. "

Before Tom could reply the auto had turned a corner. Disgusted andangry, he tried to sop up some of the muddy water with hishandkerchief. While thus engaged he heard his name called, and lookedup to see Ned Newton. 

"What's the matter? Fall down?" asked his chum. 

"Andy Foger, " replied Tom. 

"That's enough, " retorted Ned. "I can guess the rest. We'll have totar and feather him some day, and ride him out of town on a rail. I'dkick him myself, only his father is a director in the bank where Iwork, and I'd be fired if I did. Can't afford any such pleasure. Butsome day I'll give Andy a good trouncing, and then resign before theycan discharge me. But I'll be looking for another job before I do that. Come on to my house, Tom, and I'll help you clean up. "

Tom was a little more presentable when he left his chum's residence, after spending the evening there, but he was still burning for revengeagainst Andy and his cronies. He had half a notion to go to Andy'shouse and tell Mr. Foger how nearly serious the bully's prank at thesub marine had been, but he concluded that Mr. Foger could only upholdhis son. "No, I'll settle with him myself, " decided Tom. 

Bidding Eradicate keep a watchful eye about the house, and leaving wordfor Mr. Damon to be sure to come to the coast if he again called at theShopton house, Tom and Mr. Sharp prepared to make their return tripearly the next morning. 

The gas tank was filled and the Red Cloud arose in the air. Then, withthe propellers moving at moderate speed, the nose of the craft waspointed toward the New Jersey coast. 

A few miles out from Shopton, finding there was a contrary wind in theupper regions where they were traveling, Mr. Sharp descended severalhundred feet. They were moving over a sparsely settled part of thecountry, and looking down, Tom saw, speeding along a highway, anautomobile. 

"I wonder who's in it?" he remarked, taking down a telescope andpeering over the window ledge of the cabin. The next moment he uttereda startled exclamation. 

"Andy Foger, Sam Snedecker and Pete Bailey!" he cried. "Oh, I wish Ihad a bucket of water to empty on them. "

"I know a better way to get even with them than that, " said Mr. Sharp. 

"How?" asked Tom eagerly. 

"I'll show you, " replied the balloonist. "It's a trick I once played ona fellow who did me an injury. Here, you steer for a minute until I getthe thing fixed, then I'll take charge. "

Mr. Sharp went to the storeroom and came back with a long, stout ropeand a small anchor of four prongs. It was carried to be used inemergencies, but so far had never been called into requisition. Fastening the grapple to the cable, the balloonist said:

"Now, Tom, they haven't seen you. You stand in the stern and pay outthe rope. I'll steer the airship, and what I want you to do is to catchthe anchor in the rear of their car. Then I'll show you some fun. "

Tom followed instructions. Slowly he lowered the rope with the danglinggrapple. The airship was also sent down, as the cable was not quitelong enough to reach the earth from the height at which they were. Theengine was run at slow speed, so that the noise would not attract theattention of the three cronies who were speeding along, all unconsciousof the craft in the air over their heads. The Red Cloud was moving inthe same direction as was the automobile. 

The anchor was now close to the rear of Andy's car. Suddenly it caughton the tonneau and Tom called that fact to Mr. Sharp. 

"Fasten the rope at the cleat, " directed the balloonist. 

Tom did so, and a moment later the aeronaut sent the airship up byturning more gas into the container. At the same time he reversed theengine and the Red Cloud began pulling the touring car backward, alsolifting the rear wheels clear from the earth. 

A startled cry from the occupants of the machine told Tom and hisfriend that Andy and his cronies were aware something was wrong. Amoment later Andy, looking up, saw the airship hovering in the airabove him. Then he saw the rope fast to his auto. The airship was notrising now, or the auto would have been turned over, but it was slowlypulling it backward, in spite of the fact that the motor of the car wasstill going. 

"Here! You let go of me!" cried Andy. "I'll have you arrested if youdamage my car. "

"Come up here and cut the rope. " called Tom leaning over and lookingdown. He could enjoy the bully's discomfiture. As for Sam and Pete, they were much frightened, and cowered down on the floor of the tonneau. 

"Maybe you'll shut me in the tank again and splash mud on me!" shoutedTom. 

The rear wheels of the auto were lifted still higher from the ground, as Mr. Sharp turned on a little more gas. Andy was not proof againstthis. 

"Oh! oh!" he cried. "Please let me down, Tom. I'm awful sorry for whatI did! I'll never do it again! Please, please let me down! Don't You'lltip me over!"

He had shut off his motor now, and was frantically clinging to thesteering wheel. 

"Do you admit that you're a sneak and a coward?" asked Tom, "rubbing itin. "

"Yes, yes! Oh, please let me down!"

"Shall we?" asked Tom of Mr. Sharp. 

"Yes, " replied the balloonist. "We can afford to lose the rope andanchor for the sake of turning the tables. Cut the cable. "

Tom saw what was intended. Using a little hatchet, he severed the ropewith a single blow. With a crash that could be heard up in the airwhere the Red Cloud hovered, the rear wheels of the auto dropped to theground. Then came two loud reports. 

"Both tires busted!" commented Mr. Sharp dryly, and Tom, looking down, saw the trio of lads ruefully contemplating the collapsed rubber of therear wheels. The tables had been effectually turned on Andy Foger. Hisauto was disabled, and the airship, with a graceful sweep, mountedhigher and higher, continuing on its way to the coast. 

Chapter Seven

Mr. Damon Will Go

"Well, I guess they've had their lesson, " remarked Tom, as he took anobservation through the telescope and saw Andy and his cronies hard atwork trying to repair the ruptured tires. "That certainly was a corkinggood trick. "

"Yes, " admitted Mr. Sharp modestly. "I once did something similar, onlyit was a horse and wagon instead of an auto. But let's try for anotherspeed record. The conditions are just right. "

They arrived at the coast much sooner than they had dared to hope, theRed Cloud proving herself a veritable wonder. 

The remainder of that day, and part of the next, was spent in workingon the submarine. 

"We'll launch her day after to-morrow, " declared Mr. Swiftenthusiastically. "Then to see whether my calculations are right orwrong. "

"It won't be your fault if it doesn't work, " said his son. "Youcertainly have done your best. "

"And so have you and Mr. Sharp and the others, for that matter. Well, Ihave no doubt but that everything will be all right, Tom. "

"There!" exclaimed Mr. Sharp the next morning, as he was adjusting acertain gage. "I knew I'd forget something. That special brand oflubricating oil. I meant to bring it from Shopton, and I didn't. "

"Maybe I can get it in Atlantis, " suggested Tom, naming the coast citynearest to them. "I'll take a walk over. It isn't far. "

"Will you? I'll be glad to have you, " resumed the balloonist. "A gallonwill be all we'll need. "

Tom was soon on his way. He had to walk, as the roads were too poor topermit him to use the motor-cycle, and the airship attracted too muchattention to use on a short trip. He was strolling along, when fromthe other side of a row of sand dunes, that lined the uncertain road toAtlantis, he heard some one speaking. At first the tones were notdistinct, but as the lad drew nearer to the voice he heard anexclamation. 

"Bless my gold-headed cane! I believe I'm lost. He said it was out thisway somewhere, bet I don't see anything of it. If I had that EradicateSampson here now I'd--bless my shoelaces I don't know what I would doto him. "

"Mr. Damon! Mr. Damon!" cried Tom. "Is that you?"

"Me? Of course it's me! Who else would it be?" answered the voice. "Butwho are you. Why, bless my liver! If it isn't Tom Swift!" he cried. "Oh, but I'm glad to see you! I was afraid I was shipwrecked! Bless mygaiters, how are you, anyhow? How is your father? How is Mr. Sharp, andall the rest of them?"

"Pretty well. And you?"

"Me? Oh, I'm all right; only a trifle nervous. I called at your housein Shopton yesterday, and Eradicate told me, as well as he could, whereyou were located. I had nothing to do, so I thought I'd take a run downhere. But what's this I hear about you? Are you going on a voyage?"

"Yes. "

"In the air? May I go along again? I certainly enjoyed my other trip inthe Red Cloud. What is, all but the fire and being shot at. May I go?"

"We're going on a different sort of trip this time, " said the youth. 

"Where?"

"Under water. "

"Under water? Bless my sponge bath! You don't mean it!"

"Yes. Dad has completed the submarine he was working on when we wereoff in the airship, and it will be launched the day after to-morrow. "

"Oh, that's so. I'd forgotten about it. He's going to try for theGovernment prize, isn't he? But tell me more about it. Bless myscarf-pin, but I'm glad I met you! Going into town, I take it. Well, Ijust came from there, but I'll walk back with you. Do you think--isthere any possibility--that I could go with you? Of course, I don'twant to crowd you, but--"

"Oh, there'll be plenty of room, " replied the young inventor. "In fact, more room than we had in the airship. We were talking only the otherday about the possibility of you going with us, but we didn't thinkyou'd risk it. "

"Risk it? Bless my liver! Of course I'll risk' it! It can't be as badas sailing in the air. You can't fall, that's certain. "

"No; but maybe you can't rise, " remarked Tom grimly. 

"Oh, we won't think of that. Of course, I'd like to go. I fullyexpected to be killed in the Red Cloud, but as I wasn't I'm ready totake a chance in the water. On the whole, I think I prefer to be buriedat sea, anyhow. Now, then, will you take me?"

"I think I can safely promise, " answered Tom with a smile at hisfriend's enthusiasm. 

The two were approaching the city, having walked along as they talked. There were still some sand dunes near the road, and they kept on theside of these, nearest the beach, where they could watch the breakers. 

"But you haven't told me where you are going, " went on Mr. Damon, afterblessing a few dozen objects. "Where do the Government trials takeplace?"

"Well, " replied the lad, "to be frank with you, we have abandoned ourintention of trying for the Government prize. "

"Not going to try for it? Bless my slippers! Why not? Isn't fiftythousand dollars worth striving for? And, with the kind of a submarineyou say you have, you ought to be able to win. "

"Yes, probably we could win, " admitted the young inventor, "but we aregoing to try for a better prize. "

"A better one? I don't understand. "

"Sunken treasure, " explained Tom. "There's a ship sunk off the coast ofUruguay, with three hundred thousand dollars in gold bullion aboard. Dad and I are going to try to recover that in our submarine. We'regoing to start day after to-morrow, and, if you like, you may go along. "

"Go along! Of course I'll go along!" cried the eccentric man. "But Inever heard of such a thing. Sunken treasure! Three hundred thousanddollars in gold! My, what a lot of money! And to go after it in asubmarine! It's as good as a story!"

"Yes, we hope to recover all the treasure, " said the lad. "We ought tobe able to claim at least half of it. "

"Bless my pocketbook!" cried Mr. Damon, but Tom did not hear him. Atthat instant his attention was attracted by seeing two men emerge frombehind the sand dune near which he and Mr. Damon had haltedmomentarily, when the youth explained about the treasure. The manlooked sharply at Tom. A moment later the first man was joined byanother, and at the sight of him our hero could not repress anexclamation of alarm. For the second man was none other than AddisonBerg. 

The latter glanced quickly at Tom, and then, with a hasty word to hiscompanion, the two swung around and made off in the opposite directionto that in which they had been walking. 

"What's the matter?" asked Mr. Damon, seeing the young inventor wasstrangely affected. 

"That--that man, " stammered the lad. 

"You don't mean to tell me that was one the Happy Harry gang, do you?"

"No. But one, or both of those men, may prove to be worse. That secondman was Addison Berg, and he's agent for a firm of submarine boatbuilders who are rivals of dad's. Berg has been trying to find out whywe abandoned our intention of competing for the Government prize. "

"I hope you didn't tell him. "

"I didn't intend to, " replied Tom, smiling grimly, "but I'm afraid Ihave, however He certainly overheard what I said. I spoke too loud. Yes, he must have heard me. That's why he hurried off so. "

"Possibly no harm is done. You didn't give the location of the sunkenship. "

"No; but I guess from what I said it will be easy enough to find. Well, if we're going to have a fight for the possession of that sunken gold, I'm ready for it. The Advance is well equipped for a battle. I musttell dad of this. It's my fault. "

"And partly mine, for asking you such leading questions in a publicplace, " declared Mr. Damon. "Bless my coat-tails, but I'm sorry! Maybe, after all, those men were so interested in what they themselves weresaying that they didn't understand what you said. "

But if there had been any doubts on this score they would have beendissolved had Tom and his friend been able to see the actions of Mr. Berg and his companion a little later. The plans of thetreasure-hunters had been revealed to their ears. 

Chapter Eight

Another Treasure Expedition

While Tom and Mr. Damon continued on to Atlantis after the oil, theyoung inventor lamenting from time to time that his remarks about thereal destination of the Advance had been overheard by Mr. Berg, thelatter and his companion were hastening back along the path that ran onone side of the sand dunes. 

"What's your hurry?" asked Mr. Maxwell, who was with the submarineagent. "You turned around as if you were shot when you saw that man andthe lad. There didn't appear to be any cause for such a hurry. Fromwhat I could hear they were talking about a submarine. You're in thesame business. You might be friends. "

"Yes, we might, " admitted Mr. Berg with a peculiar smile; "but, unlessI'm very much mistaken, we're going to be rivals. "

"Rivals? What do you mean?"

"I can't tell you now. Perhaps I may later. But if you don't mind, walka little faster, please. I want to get to a long-distance telephone. "

"What for?"

"I have just overheard something that I wish to communicate to myemployers, Bentley & Eagert. "

"Overheard something? I don't see what it could be, unless that lad--"

"You'll learn in good time, " went on the submarine agent. "But I musttelephone at once. "

A little later the two men had reached a trolley line that ran intoAtlantis, and they arrived at the city before Mr. Damon and Tom gotthere, as the latter had to go by a circuitous route. Mr. Berg lost notime in calling up his firm by telephone. 

"I have had another talk with Mr. Swift, " he reported to Mr. Bentley, who came to the instrument in Philadelphia. 

"Well, what does he say?" was the impatient question. "I can'tunderstand his not wanting to try for the Government prize. It isastonishing. You said you were going to discover the reason, Mr Berg, but you haven't done so. "

"I have. "

"What is it?"

"Well, the reason Mr. Swift and his son don't care to try for the fiftythousand dollar prize is that they are after one of three hundredthousand dollars. "

"Three hundred thousand dollars!" cried Mr. Bentley. "What governmentis going to offer such a prize as that for submarines, when they aregetting almost as common as airships? We ought to have a try for thatourselves. What government is it?"

"No government at all. But I think we ought to have a try for it, Mr. Bentley. "

"Explain. "

"Well, I have just learned, most accidentally, that the Swifts aregoing after sunken treasure--three hundred thousand dollars in goldbullion. "

"Sunken treasure? Where?

"I don't know exactly, but off the coast of Uruguay, " and Mr. Bergrapidly related what he had overheard Tom tell Mr. Damon. Mr. Bentleywas much excited and impatient for more details, but his agent couldnot give them to him. 

"Well, " concluded the senior member of the firm of submarine boatbuilders, "if the Swifts are going after treasure, so can we. Come toPhiladelphia at once, Mr. Berg, and we'll talk this matter over. Thereis no time to lose. We can afford to forego the Government prize forthe chance of getting a much larger one. We have as much right tosearch for the sunken gold as the Swifts have. Come here at once, andwe will make our plans. "

"All right, " agreed the agent with a smile as he hung up the receiver. "I guess, " he murmured to himself, "that you won't be so high andmighty with me after this, Tom Swift. We'll see who has the best boat, after all. We'll have a contest and a competition, but not for agovernment prize. It will be for the sunken gold. "

It was easy to see that Mr. Berg was much pleased with himself. 

Meanwhile, Tom and Mr. Damon had reached Atlantis, and had purchasedthe oil. They started back, but Tom took a street leading toward thecenter of the place, instead of striking for the beach path, alongwhich they had come. 

"Where are you going?" asked Mr. Damon. 

"I want to see if that Andy Foger has come back here, " replied the lad, and he told of having been shut in the tank by the bully. 

"I've never properly punished him for that trick, " he went on, "thoughwe did manage to burst his auto tires. I'm curious to know how he knewenough to turn that gear and shut the tank door. He must have beenloitering near the shop, seen me go in the submarine alone, watched hischance and sneaked in after me. But I'd like to get a completeexplanation, and if I once got hold of Andy I could make him talk, " andTom clenched his fist in a manner that augured no good for thesquint-eyed lad. "He was stopping at the same hotel with Mr. Berg, andhe hurried away after the trick he played on me. I next saw him inShopton, but I thought perhaps he might have come back here. I'm goingto inquire at the hotel, " he added. 

Andy's name was not on the register since his hasty flight, however, and Tom, after inquiring from the clerk and learning that Mr. Berg wasstill a guest at the hostelry, rejoined Mr. Damon. 

"Bless my hat!" exclaimed that eccentric individual as they startedback to the lonely beach where the submarine was awaiting her adventinto the water. "The more I think of the trip I'm going to take, themore I like it. "

"I hope you will, " remarked Tom. "It will be a new experience for allof us. There's only one thing worrying me, and that is about Mr. Berghaving overheard what I said. "

"Oh, don't worry about that. Can't we slip away and leave no trace inthe water?"

"I hope so, but I must tell dad and Mr. Sharp about what happened. "

The aged inventor was not a little alarmed at what his son related, buthe agreed with Mr. Damon, whom he heartily welcomed, that little was tobe apprehended from Berg and his employers. 

"They know we're after a sunken wreck, but that's all they do know, "said Tom's father. "We are only waiting for the arrival of CaptainAlden Weston, and then we will go. Even if Bentley & Eagert make a tryfor the treasure we'll have the start of them, and this will be a caseof first come, first served. Don't worry, Tom. I'm glad you're going, Mr Damon. Come, I will show you our submarine. "

As father and son, with their guest, were going to the machine shop, Mr. Sharp met them. He had a letter in his hand. 

"Good news!" the balloonist cried. "Captain Weston will be with usto-morrow. He will arrive at the Beach Hotel in Atlantis, and wants oneof us to meet him there. He has considerable information about thewreck. "

"The Beach Hotel, " murmured Tom. "That is where Mr. Berg is stopping. Ihope he doesn't worm any of our secret from Captain Weston, " and it waswith a feeling of uneasiness that the young inventor continued afterhis father and Mr. Damon to where the submarine was. 

Chapter Nine

Captain Weston's Advent

"Bless my water ballast, but that certainly is a fine boat!" cried Mr. Damon, when he had been shown over the new craft. "I think I shallfeel even safer in that than in the Red Cloud. "

"Oh, don't go back on the airship!" exclaimed Mr Sharp. "I was countingon taking you on another trip. "

"Well, maybe after we get back from under the ocean, " agreed Mr. Damon. "I particularly like the cabin arrangements of the Advance. I think Ishall enjoy myself. "

He would be hard to please who could not take pleasure from a trip inthe submarine. The cabin was particularly fine, and the sleepingarrangements were good. 

More supplies could be carried than was possible on the airship, andthere was more room in which to cook and serve food. Mr. Damon was fondof good living, and the kitchen pleased him as much as anything else. 

Early the next morning Tom set out for Atlantis, to meet Captain Westonat the hotel. The young inventor inquired of the clerk whether theseafaring man had arrived, and was told that he had come the previousevening. 

"Is he in his room?" asked Tom. 

"No, " answered the clerk with a peculiar grin. "He's an odd character. Wouldn't go to bed last night until we had every window in his roomopen, though it was blowing quite hard, and likely to storm. Thecaptain said he was used to plenty of fresh air. Well, I guess he gotit, all right. "

"Where is he now?" asked the youth, wondering what sort of anindividual he was to meet. 

"Oh, he was up before sunrise, so some of the scrubwomen told me. Theymet him coming from his room, and he went right down to the beach witha big telescope he always carries with him. He hasn't come back yet. Probably he's down on the sand. "

"Hasn't he had breakfast?"

"No. He left word he didn't want to eat until about four bells, whatever time that is. "

"It's ten o'clock, " replied Tom, who had been studying up on sea termslately. "Eight bells is eight o'clock in the morning, or four in theafternoon or eight at night, according to the time of day. Then there'sone bell for every half hour, so four bells this morning would be teno'clock in this watch, I suppose. "

"Oh, that's the way it goes, eh?" asked the clerk. "I never could getit through my head. What is twelve o'clock noon?"

"That's eight bells, too; so is twelve o'clock midnight. Eight bellsis as high as they go on a ship. But I guess I'll go down and see if Ican meet the captain. It will soon be ten o'clock, or four bells, andhe must be hungry for breakfast. By the way, is that Mr. Berg stillhere?"

"No; he went away early this morning. He and Captain Weston seemed tostrike up quite an acquaintance, the night clerk told me. They sat andsmoked together until long after midnight, or eight bells, " and theclerk smiled as he glanced down at the big diamond ring on his littlefinger. 

"They did?" fairly exploded Tom, for he had visions of what the wilyMr. Berg might worm out of the simple captain. 

"Yes. Why, isn't the captain a proper man to make friends with?" andthe clerk looked at Tom curiously. 

"Oh, yes, of course, " was the hasty answer. "I guess I'll go and see ifI can find him--the captain, I mean. "

Tom hardly knew what to think. He wished his father, or Mr. Sharp, hadthought to warn Captain Weston against talking of the wreck. It mightbe too late now. 

The young inventor hurried to the beach, which was not far from thehotel. He saw a solitary figure pacing up and down, and from the factthat the man stopped, every now and then, and gazed seaward through alarge telescope, the lad concluded it was the captain for whom he wasin search. He approached, his footsteps making no sound on the sand. The man was still gazing through the glass. 

"Captain Weston?" spoke Tom. 

Without a show of haste, though the voice must have startled him, thecaptain turned. Slowly he lowered the telescope, and then he repliedsoftly:

"That's my name. Who are you, if I may ask?"

Tom was struck, more than by anything else, by the gentle voice of theseaman. He had prepared himself, from the description of Mr. Sharp, tomeet a gruff, bewhiskered individual, with a voice like a crosscut saw, and a rolling gait. Instead he saw a man of medium size, with a smoothface, merry blue eyes, and the softest voice and gentlest mannerimaginable. Tom was very much disappointed. He had looked for a regularsea-dog, and he met a landsman, as he said afterward. But it was notlong before our hero changed his mind regarding Captain Weston. 

"I'm Tom Swift, " the owner of that name said, "and I have been sent toshow you the way to where our ship is ready to launch. " The younginventor refrained from mentioning submarine, as it was the wish of MrSharp to disclose this feature of the voyage to the sailor himself. 

"Ha, I thought as much, " resumed the captain quietly. "It's a fineday, if I may be permitted to say so, " and he seemed to hesitate, as ifthere was some doubt whether or not he might make that observation. 

"It certainly is, " agreed the lad. Then, with a smile he added: "It isnearly eight bells. "

"Ha!" exclaimed the captain, also smiling, but even his manner ofsaying "Ha!" was less demonstrative than that of most persons. "Ibelieve I am getting hungry, if I may be allowed the remark, " and againhe seemed asking Tom's pardon for mentioning the fact. 

"Perhaps you will come back to the cabin and have a little breakfastwith me, " he went on. "I don't know what sort of a galley or cook theyhave aboard the Beach Hotel, but it can't be much worse than some I'vetackled. "

"No, thank you, " answered the youth. "I've had my breakfast. But I'llwait for you, and then I'd like to get back. Dad and Mr. Sharp areanxious to meet you. "

"And I am anxious to meet them, if you don't mind me mentioning it, "was the reply, as the captain once more put the spyglass to his eye andtook an observation. "Not many sails in sight this morning, " he added. "But the weather is fine, and we ought to get off in good shape to huntfor the treasure about which Mr. Sharp wrote me. I believe we are goingafter treasure, " he said; "that is, if you don't mind talking about it. "

"Not in the least, " replied Tom quickly, thinking this a goodopportunity for broaching a subject that was worrying him. "Did youmeet a Mr. Berg here last night, Captain Weston?" he went on. 

"Yes. Mr. Berg and I had quite a talk. He is a well-informed man. "

"Did he mention the sunken treasure?" asked the lad, eager to find outif his suspicions were true. 

"Yes, he did, if you'll excuse me putting it so plainly, " answered theseaman, as if Tom might be offended at so direct a reply. But the younginventor was soon to learn that this was only an odd habit with theseaman. 

"Did he want to know where the wreck of the Boldero was located?"continued the lad. "That is, did he try to discover if you knewanything about it?"

"Yes, " said Mr. Weston, "he did. He pumped me, if you are acquaintedwith that term, and are not offended by it. You see, when I arrivedhere I made inquiries as to where your father's place was located. Mr. Berg overheard me, and introduced himself as agent for a shipbuildingconcern. He was very friendly, and when he said he knew you and yourparent, I thought he was all right. "

Tom's heart sank. His worst fears were to be realized, he thought. 

"Yes, he and I talked considerable, if I may be permitted to say so, "went on the captain. "He seemed to know about the wreck of the Boldero, and that she had three hundred thousand dollars in gold aboard. Theonly thing he didn't know was where the wreck was located. He knew itwas off Uruguay somewhere, but just where he couldn't say. So he askedme if I knew, since he must have concluded that I was going with you onthe gold-hunting expedition. "

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

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

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

"Yes, I'm afraid he did. "

"Did you give him the location?"

"Well, " remarked the captain, as he took another observation beforeclosing up the telescope, "you see, while we were talking, I happenedto 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 mayget to it ahead of us. It's too bad. "

"Yes, " continued the seaman calmly, "Mr. Berg picked up that map, andhe looked very closely at the latitude and longitude I had marked asthe 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 requestyou to repeat what you said. "

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

"Oh, but I think he will, if he depends on that map, " was theunexpected reply. "You see, " explained Mr. Weston, "I'm not so simpleas I look. I sensed what Mr. Berg was after, the minute he began totalk to me. So I fixed up a little game on him. The map which I droppedon purpose, not accidentally, where he would see it, did have thelocation of the wreck marked. Only it didn't happen to be the rightlocation. It was about five hundred miles out of the way, and I ratherguess if Mr. Berg and his friends go there for treasure they'll findconsiderable depth of water and quite a lonesome spot. Oh, no, I'm notas easy as I look, if you don't mind me mentioning that fact; and whena scoundrel sets out to get the best of me, I generally try to turn thetables on him. I've seen such men as Mr. Berg before. I'm afraid, I'mvery much afraid, the sight he had of the fake map I made won't do himmuch good. Well, I declare, it's past four bells. Let's go tobreakfast, if you don't mind me asking you, " and with that the captainstarted off up the beach, Tom following, his ideas all a whirl at theunlooked-for outcome of the interview. 

Chapter Ten

Trial of the Submarine

Tom felt such a relief at hearing of Captain Weston's ruse that hisappetite, sharpened by an early breakfast and the sea air, came to himwith 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 upfor a slick article as soon as I laid eyes on him. But he evidentlymisjudged me, if I may be permitted that term. Oh, well, we may meetagain, after we secure the treasure, and then I can show him the realmap 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 ofcoffee; his third, by the way. 

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

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

The young inventor blushed at his indiscretion. He felt that the newsof the search for the treasure had leaked out through him, though hewas the one to get on the trail of it by seeing the article in thepaper. Now he had nearly been guilty of another break. He realized thathe 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. Iwas the same myself when I was your age. But we'll soon be at yourplace, and then I'll tell you all I know. Sufficient now, to say that Ibelieve I have located the wreck within a few miles. I got on the trackof a sailor who had met one of the shipwrecked crew of the Boldero, andhe gave me valuable information. Now tell me about the craft we aregoing in. A good deal depends on that. "

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

"I mean, what type is your submarine? Does it go by compressed air, orwater 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 alot of information from him. He told me about the submarine his firmwas building, and, naturally, he mentioned yours. One thing led toanother until I got a pretty good idea of your craft. What do you callit?"

"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 tofrighten me, if you'll excuse the expression. I've always had ahankering 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, inwrecks, but I think I prefer your way. Now, if you're all done, anddon't mind me speaking of it, I think we'll start for your place. Wemust hustle, for Berg may yet get on our trail, even if he has got thewrong route, " and he laughed again. 

It was no small relief to Mr Swift and Mr. Sharp to learn that CaptainWeston had no objections to a submarine, as they feared he might have. The captain, in his diffident manner, made friends at once with thetreasure-hunters, and he and Mr. Damon struck up quite an acquaintance. Tom told of his meeting with the seaman, and the latter related, withmuch 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 isto be our home while we're beneath the water, " suggested Mr. Swift andthe sailor assenting, the aged inventor, with much pride, assisted byTom, pointed out on the Advance the features of interest. CaptainWeston gave hearty approval, making one or two minor suggestions, whichwere carried out. 

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

There were busy times around the machine shop next day. So much secrecyhad been maintained that none of the residents, or visitors to thecoast resort, were aware that in their midst was such a wonderful craftas the submarine. The last touches were put on the under-water ship;the ways, leading from the shop to the creek, were well greased, andall was in readiness for the launching. The tide would soon be atflood, and then the boat would slide down the timbers (at least, thatwas the hope of all), and would float in the element meant to receiveher. It was decided that no one should be aboard when the launchingtook place, as there was an element of risk attached, since it was notknown 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 Westonquietly, looking at his watch. Then he took an observation through thetelescope. "No hostile ships hanging in the offing, " he reported. "Allis favorable, if you don't mind me saying so, " and he seemed afraidlest his remark might give offense. 

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

"All clear, " reported the young inventor. 

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

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

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

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

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

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

For, true enough, the Advance was riding like a duck on the water. Shehad been proportioned just right, and her lines were perfect. She rodeas majestically as did any ship destined to sail on the surface, andnot intended to do double duty. 

"Come on, we must moor her to the pier, " directed Mr. Sharp. "The tidewill 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 asmall dock that had been built for the purpose. 

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

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

Little time was lost in entering the cabin and engine-room, GarretJackson accompanying the party to aid with the machinery. It did nottake long to start the motors, dynamos and the big gasolene engine thatwas the vital part of the craft. A little water was admitted to thetanks for ballast, since the food and other supplies were not yet onboard. The Advance now floated with the deck aft of the conning towershowing about two feet above the surface of the creek. Mr. Swift andTom entered the pilot house. 

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

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

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

"All ready, " came the answer. 

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

"She goes! She goes!" cried Tom

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

Faster and faster went the new craft. Mr. Swift headed her toward theopen sea, but stopped just before passing out of the creek, as he wasnot yet ready to venture into deep water. 

"I want to test the auxiliary propellers, " he said. After a littlelonger trial of the electric propulsion plates, which were found towork satisfactorily, sending the submarine up and down the creek at afast rate, the screws, such as are used on most submarines, were putinto gear. They did well, but were not equal to the plates, nor was somuch expected of them. 

"I am perfectly satisfied, " announced Mr. Swift as he once more headedthe 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 theconning tower door. Perhaps you will come in here with us, CaptainWeston, though it will be rather a tight fit. "

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

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

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

"Everything, " replied the lad nervously, for the anticipation of beingabout to sink below the surface was telling on them all, even on thecalm, 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 hissingsound, and the Advance began sinking. She was about to dive beneath thesurface of the ocean, and those aboard her were destined to go througha terrible experience before she rose again. 

Chapter Eleven

On the Ocean Bed

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

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

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

"Yes, and then we can see what sort of progress we will make, " addedMr. 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 Tomfelt a little disappointed that the sailor did not shout out some suchexpression 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 onnecessity, as Tom learned later. 

A few minutes more and the waters closed over the top of the conningtower. The Advance was completely submerged. Through the thick glasswindows of the pilot house the occupants looked out into the greenishwater that swirled about them; but it could not enter. Then, as theboat went lower, the light from above gradually died out, and thesemi-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 withlight. But as this had the effect of preventing the three from peeringout into the water, just as one in a lighted room cannot look out intothe night, Tom shut them off and switched on the great searchlight. This projected its powerful beams straight ahead and there, under theocean, was a pathway of illumination for the treasure-seekers. 

"Fine!" cried Captain Weston, with more enthusiasm than he had yetmanifested. "That's great, if you don't mind me mentioning it. How deepare 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 thesewaters around here, and that's about all the depth you've got. You'llbe on the bottom in a minute. "

"I intend to get on the bottom after a while, " said Mr. Swift, "but nothere. I want to try for a greater distance under water before I come torest 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 willprogress when fully submerged. "

The hissing stopped, and then, wishing to see how the motors and othermachinery would work, the aged inventor and his son, accompanied byCaptain Weston, descended from the conning tower, by means of an innerstairway, to the interior of the ship. The submarine could be steeredand managed from below or above. She was now floating about sixty-fivefeet below the surface of the bay. 

"Well, how do you like it?" asked Tom of Mr. Damon, as he saw hisfriend 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 beforehim. "To think that I'm away down under the surface, and yet as dry asa 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 sinceentering the craft, and opening it. "We may run afoul of something, ifyou don't mind me mentioning such a disagreeable subject. " Then, as hethought of the impossibility of using his glass under water, he closedit. 

"I shall have little use for this here, I'm afraid, " he remarked with asmile. "Well, there's some consolation. We're not likely to meet manyships in this part of the ocean. Other vessels are fond enough ofremaining on the surface. I fancy we shall have the depths toourselves, unless we meet a Government submarine, and they are hardlyable to go as deep as we can. No, I guess we won't run into anythingand 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 toworry over the unscrupulous agent. "No, I don't believe we'll meetthem, Tom. I guess Berg is trying to work out the longitude andlatitude I gave him. I wish I could see his face when he realizes thathe's been deceived by that fake map. "

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

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

"Is everything all right?" asked Mr Swift as he went into theengine-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 enoughwater. Start the engine. "

A moment later the powerful electric currents were flowing into theforward and aft plates, and the Advance began to gather way, forgingthrough 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, " commentedCaptain Weston with a smile. "Mind your helm, boy, for you don't wantto 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 awhile. "

"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 theshoals are. "

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

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

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

Captain Weston remained at Tom's side, giving him instructions, andwatching the compass in order to direct the steering so as to avoidcollisions. For an hour or more the craft was sent almost straightahead at medium speed. Then Mr. Swift, joining his son and thecaptain, 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 thetanks still more. 

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

"And use the deflecting rudder, also, " advised his father. "That willhasten 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. Itregistered a distance below the surface of the ocean of five thousandseven hundred feet--a little over a mile. The Advance had actually cometo rest on the bottom of the Atlantic. 

"Hurrah!" cried Tom. "Let's get on the diving suits, dad, and walkabout 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, andwe can't use them. There are still some things to do before we start onour treasure cruise. But I want to see how the plates are standingthis pressure. "

The Advance was made with a triple hull, the spaces between the layersof plates being filled with a secret material, capable of withstandingenormous pressure, as were also the plates themselves. Mr. Swift, aidedby Mr. Jackson and Captain Weston, made a thorough examination, andfound that not a drop of water had leaked in, nor was there the leastsign 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 thatcomparison, " remarked Captain Weston modestly. "I couldn't ask for adryer ship. "

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

There were several powerful searchlights on the Advance, so arrangedthat 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. Inthe gleams could be seen the sandy bed of the ocean, covered withshells of various kinds. Great crabs walked around on their long, jointed legs, and Tom saw some lobsters that would have brought joy tothe heart of a fisherman. 

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

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

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

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

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

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

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

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

Tom entered the lower pilot house, and turned the valve that opened thetanks. He also pulled the lever that started the pumps, so that thewater ballast would be more quickly emptied, as that would render thesubmarine buoyant, and she would quickly shoot to the surface. To thesurprise of the lad, however, there followed no outrushing of thewater. The Advance remained stationary on the ocean bed. Mr. Swiftlooked 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 hisson 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 hasgone wrong with the connections. Go look in the engine-room, and askMr. Sharp if everything is all right there. "

Tom made a quick trip, returning to report that the dynamos, motors andgas 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 gearto play tricks like that. "

Tom hurried up the circular stairway into the tower. He pulled thelevers and shifted the valves and wheels there. But there was noemptying of the water tanks. The weight and pressure of water in themstill held the submarine on the bottom of the sea, more than a milefrom the surface. The pumps in the engine-room were working at topspeed, 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 shapeagain. "

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

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

But it proved to be more difficult than he had imagined to re-establishthe connection between the pumps and the tanks. The valves, too, hadclogged 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 whenthe latter paused in his efforts. 

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

Just then Mr. Damon, who had been wandering about the ship, entered theengine-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 oddman 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 herepeated the words. 

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

"Why, there ought to be plenty of fresh air, " went on the inventor. "Itis 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 isbad. There's not enough oxygen in it. I notice it, now that I'vestopped working. The gage indicates it, too. The automatic air-changermust have stopped working. I'll fix it. "

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

"Why, the air tanks are empty!" the young inventor cried. "We haven'tany 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 couldmake oxygen aboard the ship. "

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

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

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 thesurface, " said Mr. Sharp simply. "We can have all the air we want, then. "

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

"We must do it!" cried his father. 

They set to work again with fierce energy, laboring for their verylives. They all knew that they could not long remain in the shipwithout oxygen. Nor could they desert it to go to the surface, for themoment they left the protection of the thick steel sides the terriblepressure of the water would kill them. Nor were the diving suitsavailable. They must stay in the craft and die a miserable death-unlessthe 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 tothe mechanical minds of Tom, his father, Mr. Sharp or Mr. Jackson, tomake the pumps work. But something was wrong. More and more foul grewthe air. They were fairly gasping now. It was difficult to breathe, tosay nothing of working, in that atmosphere. The thought of theirterrible position was in the minds of all. 

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

Chapter Thirteen

Off for the Treasure

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

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

"I'm going to take this valve apart, " replied his son. "We haven'tlooked there for the trouble. Maybe it's out of order. "

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

"I'll help, " murmured Mr. Sharp thickly. He took a wrench, but nosooner had he loosened one nut than he toppled over. "I'm all in, " hemurmured feebly. 

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

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

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

With a fierce determination in his heart, but with fingers that almostrefused 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 locateit in every other place without avail. 

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

More and more devoid of oxygen grew the air. It gave Tom a sense as ifhis 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 inventorlifted off the valve cover, though it felt like a ton weight to him. Hegave a glance inside. 

"Here's the trouble!" he murmured. "The valve's clogged. No wonder itwouldn'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 theengineer managed to get the cover back on. 

How they inserted the bolts and screwed the nuts in place they nevercould remember clearly afterward, but they managed it somehow, withshaking, 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 laywith his eyes closed. Garret Jackson, however, managed to crawl to theengine-room, and soon the clank of machinery told Tom that the pumpswere in motion. The lad staggered to the pilot house and threw thelevers over. An instant later there was the hissing of water as itrushed from the ballast tanks. The submarine shivered, as thoughdisliking to leave the bottom of the sea, and then slowly rose. As thepumps worked more rapidly, and the sea was sent from the tank in greatvolumes, the boat fairly shot to the surface. Tom was ready to open theconning tower and let in fresh air as soon as the top was above thesurface. 

With a bound the Advance reached the top. Tom frantically worked theworm 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 quicklyrevived, as did the others, when they could breathe as much as theywished of the glorious oxygen. 

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

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

When the Advance reached the secluded creek where she had beenlaunched, her passengers had fully recovered from their terribleexperience, though the nerves of Mr. Swift and Mr. Damon were not atease for some days thereafter. 

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

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

"I hardly think so, " answered Tom. "The place has been too carefullyguarded since Berg and Andy once sneaked in. I think it was just anaccident, but I have thought of a plan whereby such accidents can beavoided 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'ttime, if we intend to get fitted out for our trip. "

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

The first act of the adventurers, after tying the submarine at thedock, was to proceed with the loading of the food and supplies. Tom andMr. Damon looked to this, while Mr. Swift and Mr. Sharp made somenecessary changes to the machinery. The next day the young inventorattached his device to the pump valve, and the loading of the craft wascontinued. 

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

With sufficient stores and provisions aboard to last several months, ifnecessary, though they did not expect to be gone more than sixty daysat most, the adventurers arose early one morning and went down to thedock. Mr. Jackson was not to accompany them. He did not care about asubmarine trip, he said, and Mr. Swift desired him to remain at theseaside cottage and guard the shops, which contained much valuablemachinery. The airship was also left there. 

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

"All ready, dad, " responded his son. 

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

He swept the horizon with his telescope, and Tom noticed that thesailor 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 oneis 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 thesubmarine. Tom and his father, with Captain Weston, remained in theconning tower. The signal was given, the electricity flowed into theforward and aft plates, and the Advance shot ahead on the surface. 

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

"What's the matter?" asked Tom. 

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

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

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

Faster shot the Advance through the water. She had started on her wayto get the gold from the sunken wreck, but already enemies were on thetrail of the adventurers, for the ship the sailor had noticed wassteaming 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 hereported the fact to Mr. Swift. 

"Well, we'll change our plans, then, " said the inventor. "Instead ofsailing on the surface we'll go below. But first let them get near sothey 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 strangesteamer had overhauled her, coming to within hailing distance. 

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

"What are you following us for?"

"Following you?" repeated the man, for the strange vessel had also cometo 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 youif we like. "

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

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

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

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

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

Dinner was eaten about a quarter of a mile below the surface, but noone inside the submarine would ever have known it. Electric lights madethe place as brilliant as could be desired, and the food, which Tom andMr. Damon prepared, was equal to any that could have been served onland. After the meal they opened the shutters over the windows in thesides 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 thecraft was speedy, and leaving Tom and Captain Weston to take the firstwatch, 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 worryto death. She thinks I'm off automobiling. But this isn't half asdangerous as riding in a car that's always getting out of order. Asubmarine for mine, every time. "

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

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

On the second day the ship was sent to the bottom and halted there, asMr. 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 agreeingto wait until they saw how the first trial resulted. Then, too, it wasnecessary for some one acquainted with the machinery to remain in theship to operate the door and water chamber through which the divers hadto pass to get out. 

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

It was a curious sensation to Tom and the others to feel that they wereactually walking along the bed of the ocean. All around them was thewater, and as they turned on the small electric lights in theirhelmets, which lights were fed by storage batteries fastened to thediving suits, they saw the fish, big and little, swarm up to them, doubtless astonished at the odd creatures which had entered theirdomain. On the sand of the bottom, and in and out among the shells androcks, crawled great spider crabs, big eels and other odd creaturesseldom seen on the surface of the water. The three divers found nodifficulty in breathing, as there were air tanks fastened to theirshoulders, and a constant supply of oxygen was fed through pipes intothe helmets. The pressure of water did not bother them, and after thefirst sensation Tom began to enjoy the novelty of it. At first theinability to speak to his companions seemed odd, but he soon got so hecould make signs and motions, and be understood. 

They walked about for some time, and once the lad came upon a part of awrecked vessel buried deep in the sand. There was no telling what shipit 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 otherswere once more inside the submarine and had removed the suits. "If wecan only walk around the wreck of the Boldero that way, we'll have allthe gold out of her in no time. There are no life-lines nor air-hose tobother 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'vealways wanted to be a diver, and now I have the chance. "

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

"We'll have to be careful not to run into any of the small keys, " hesaid, that being the name for the many little points of land, hardlylarge enough to be dignified by the name of island. "We must keep aconstant lookout. "

Fortune favored them, though once, when Tom was steering, he narrowlyavoided ramming a coral reef with the submarine. The searchlightshowed it to him just in time, and he sheered off with a thumping inhis heart. 

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

Chapter Fifteen

At the Tropical Island

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

"Land ho!"

"Where away?" inquired Tom quickly, for he had read that this was theproper 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'tdown on the charts. Probably it's too small to note. I should say itwas a coral island, but we may be able to find a Spring of fresh waterthere, and some fruit. "

"Then we'll land there, " decided the inventor. "We can use some freshwater, 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 orangeshere. Shall I get out the electric launch, dad?"

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

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

They found a good spring of water close at hand, and Tom's wishregarding the cocoanuts was realized, though there were no oranges. Thelad took several of the delicious nuts, and breaking them open pouredthe milk into a collapsible cup he carried, drinking it eagerly. Theothers followed his example, and pronounced it the best beverage theyhad tasted in a long time. 

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

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

"Do you think we'll have any trouble getting the gold out of thewrecked 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 beso hard, but if the sand has worked in and partly covered it, we'llhave some difficulties, if I may be permitted to say so. However, don'tborrow trouble. We're not there yet, though at the rate we'retraveling it won't be long before we arrive. "

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

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

And well he might, for, not a hundred yards away, and nearer to theisland than was the Advance, floated another craft--another craft, almost similar in shape and size to the one built by the Swifts. Tomrubbed his eyes to make sure he was not seeing double. No, there couldbe no mistake about it. There was another submarine at the tropicalisland. 

As he looked, some one emerged from the conning tower of the secondcraft. The figure seemed strangely familiar. Tom knew in a moment whoit was--Addison Berg. The agent saw the lad, too, and taking off hiscap 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 anisland where he had supposed they would not be disturbed, wasdisconcerting enough, but to be greeted by Berg was altogether toomuch, Tom thought. His fears that the rival boat builders would followhad 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 sosoon, but we're glad we did. I don't altogether like hunting for sunkentreasure, with such indefinite directions as I have. "

"You--are going to--" stammered Tom, and then he concluded it would bebest not to say anything. But his talk had been heard inside thesubmarine. 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. Atthe sight of Tom's father, Mr. Berg, who had been joined by' two othermen, called out:

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

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

"Ah, but I'm afraid you'll have to, whether you want to or not, " wasthe 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, wemanaged to pick up your trail after you left the Jersey coast, havingan 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 twomen with Mr. Berg. 

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

"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 thefirst comer, and whoever gets there first can take the gold from thewreck. 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 theright to search the wreck for the gold bullion. Is that fair? Do youagree to it?"

"We agree to nothing with you, " interrupted Captain Weston, his usualdiffident manner all gone. "I happen to be in partial command of thiscraft, and I warn you that if I find you interfering with us it won'tbe healthy for you. I'm not fond of fighting, but when I begin I don'tlike 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 thedeck 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, motioningto Tom and his father to follow, he went below. 

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

"The only thing I see to do is to sneak away unobserved, go as deep aspossible, and make all haste for the wreck, " advised the captain. "Theywill 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 fromreading the papers. I hoped I had thrown them off the track by thefalse 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 onlything to do is to get there ahead of them. It will be a race for thesunken treasure, and we must get there first. "

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

"I'm afraid such high-handed proceedings would hardly answer, " repliedMr. Swift. "No, as Captain Weston says, we must get there ahead ofthem. 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 onboard here. We'll fill our tanks with fresh water, and at night we'llquietly sink below the surface and speed away. "

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

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

As dusk settled down over The tropical sea, and as the shadows of thetrees on the little island lengthened, those on board the Advanceclosed the Conning tower. No lights were turned on, as they did notwant their movements to be seen, but Tom, his father and Mr. Sharp tooktheir positions near the various machines and apparatus, ready to openthe tanks and let the submarine sink to the bottom, as soon as it waspossible to do this unobserved. 

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

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

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

But alas for the hopes of the gold-seekers. No sooner was shecompletely submerged, with the engine started so as to send her out ofthe lagoon and to the open sea, than the waters all about were madebrilliant by the phosphorescent phenomenon. In southern waters thisfrequently 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 withthe Advance. The motion she made in shooting forward, and theundulations caused by her submersion, seemed to start into activity thedormant phosphorus, and the submarine was afloat in a sea of fire. 

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

But it was too late. Above them they could hear the electric siren ofthe Wonder as it was blown to let them know that their escape had beennoticed. A moment later the water, which acted as a sort ofsounding-board, or telephone, brought to the ears of Tom Swift and hisfriends the noise of the engines of the other craft in operation. Shewas coming after them. The race for the possession of three hundredthousand dollars in gold was already under way. Fate seemed againstthose on board the Advance. 

Chapter Seventeen

The Race

Directed by Captain Weston, who glanced at the compass and told himwhich way to steer to clear the outer coral reef, Tom sent thesubmarine ahead, signaling for full speed to the engine-room, where hisfather and Mr. Sharp were. The big dynamos purred like great cats, asthey sent the electrical energy into the forward and aft plates, pulling and pushing the Advance forward. On and on she rushed underwater, but ever as she shot ahead the disturbance in the phosphorescentwater 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 wecan. I'll try it. "

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

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

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

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

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

At first he could make out nothing save the swirl and boiling of thesea, caused by the progress of the Advance through it. But suddenly, ashe looked up, he was aware of some great, black body a little to therear 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 positionof the black object changed. It appeared to settle down, to beapproaching the top of the conning tower. Then, with a suddenness thatunnerved him for the time being, Tom recognized what it was; it was theunderside of a ship. He could see the plates riveted together, andthen, as he noted the rounded, cylindrical shape, he knew that it was asubmarine. It was the Wonder. She was close at hand and was creeping upon the Advance. But, what was more dangerous, she seemed to be slowlysettling in the water. Another moment and her great screws might crashinto the Conning tower of the Swifts' boat and shave it off. Then thewater would rush in, drowning the treasure-seekers like rats in a trap. 

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

The youth hurried down into the interior of the ship to tell what hehad seen, and explain the reason for opening the ballast tanks. Hefound his father and Mr. Sharp somewhat excited over the unexpectedmaneuver of the craft. 

"So they're still following us, " murmured Mr. Swift. "I don't see whywe 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 theslip. 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 theirsearchlight, for I suppose they carry one. "

"Yes, " admitted the aged inventor, "they have as strong a one as wehave. In fact, their ship is second only to this one in speed andpower. I know, for Bentley & Eagert showed me some of the plans beforethey started it, and asked my opinion. This was before I had the notionof building a submarine. Yes, I am afraid we'll have trouble gettingaway 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. Theremust be changed conditions here now. "

For an hour or more the race was kept up, and the two submarines forgedahead through the glowing sea. The Wonder remained slightly above andto the rear of the other, the better to keep sight of her, and thoughthe Advance was run to her limit of speed, her rival could not beshaken 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 oflots of other troubles which are always present when sailing underwater, " observed Mr Damon, who wandered about the submarine like thenervous person he was. "Bless my shirt-studs! Can't we blow them up, orcripple 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. "Itgoes to whoever reaches the wreck first. But what I don't like istheir mean, sneaking way of doing it. If they went off on their ownhook and looked for it I wouldn't say a word. But they expect us tolead them to the wreck, and then they'll rob us if they can. That's notfair. "

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

There was no doubt of it, the glow was growing less and less, and tenminutes later the Advance was speeding along through a sea as black asnight. Then, to avoid running into some wreck, it was necessary to turnon the searchlight. 

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

"I'll go look, " volunteered the lad. He climbed up into the conningtower again, and for a moment, as he gazed back into the black watersswirling all about, he hoped that they had lost the Wonder. But amoment later his heart sank as he caught sight, through the liquidelement, of the flickering gleams of another searchlight, the raysundulating through the sea. 

"Still following, " murmured the young inventor. "They're not going togive 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 aseries 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 awhile. Perhaps, in that way, we can shake them off. "

They tried it. The Advance was sent up until her conning tower was outof the water, and then she was suddenly forced down until she was but afew feet from the bottom. She darted to the left, to the right, andeven doubled and went back over the course she had taken. But all to nopurpose. The Wonder proved fully as speedy, and those in her seemed toknow just how to handle the submarine, so that every evolution of theAdvance was duplicated. Her rival could not be shaken off. 

All night this was kept up, and when morning came, though only theclocks told it, for eternal night was below the surface, the rivalgold-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, " admittedTom. "But if they want a straightaway race we'll give it to 'em Let'srun 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 thebest speed out of our craft. Let's go a little nearer the surface, andgive them the best race they'll ever have. "

Then the race began; and such a contest of speed as it was! With herpropellers working to the limit, and every volt of electricity that wasavailable forced into the forward and aft plates, the Advance surgedthrough the water, about ten feet below the surface. But the Wonderkept after her, giving her knot for knot. The course of the leadingsubmarine was easy to trace now, in the morning light which penetratedten feet down. 

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

"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 upthis speed. If they don't look out, " he went on as he looked from oneof the aft observation windows, "they'll foul us, and--"

His remarks were interrupted by a jar to the Advance. She seemed toshiver 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 electricalmachines out of gear. "Have we hit anything?"

"No. Something has hit us, " cried the captain. "Their submarine hasrammed 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 sternelectric 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 astop in the water, while the treasure-seekers waited anxiously for whatwas to follow. Would they be rammed again? This time, stationary asthey were, and with the other boat coming swiftly on, a hole might bestove through the Advance, in spite of her powerful sides. 

They had not long to wait. Again there came a jar, and once more theSwifts' 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 upto. "

"And get the stern electric gun ready to fire, " repeated Mr. Swift. "Wemust protect ourselves. Mr. Sharp and I will go to the bow. There is notelling what they may do. They're desperate, and may ram us from infront. "

Tom and the captain hurried aft. Through the thick plate-glass windowsthey could see the blunt nose of the Wonder not far away, the rivalsubmarine having come to a halt. There she lay, black and silent, likesome 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 thecaptain. 

"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 manychances. 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, weighingabout twenty-five pounds, but instead of powder, which would hardly dounder water, and instead of compressed air, which is used in thetorpedo tubes of the Government submarines, we use a current ofelectricity. It forces the cannon ball out with great energy. "

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

"We can soon tell, " replied the youth. "We'll go ahead, and if they tryto 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 onthemselves. We can't risk having them damage us. Help me with thecannon, will you please, captain?"

The electric cannon was a long, steel tube in the after part of thesubmarine. It projected a slight distance from the sides of the ship, and by an ingenious arrangement could be swung around in a ball andsocket 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 themuzzle pointing toward the Wonder, Tom adjusted the electric wires andinserted the solid shot. 

"Now we're prepared for them!" he cried. "I think a good plan will beto start ahead, and if they try to follow to fire on them. They'vebrought 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 ifthose scoundrels will follow. "

The young inventor returned on the run to the electric cannon. Therewas a whir of machinery, and the Advance moved forward. She increasedher speed, and the two watchers in the stern looked anxiously out ofthe 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 whichthey depended to pilot them to the sunken treasure was slipping away, word was given to follow. The ship of Berg and his employers shot afterthe 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 rapidlyincreasing. Suddenly she bumped the Advance, and then, as if it was anunavoidable accident, the rear submarine sheered off to one side. 

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

He shoved over the lever, making the proper connection. There was nocorresponding report, for the cannon was noiseless, but there was aslight jar as the projectile left the muzzle. The Wonder could be seento 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 thinkyou've put her out of business. Yes, they're rising to the surface. "

The lad rapidly inserted another ball, and recharged the cannon. Thenhe 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 thesurface. Clearly something had happened. 

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

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 slipaway, " 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 theconning tower, which was out of water, on to the little flat deck ashort distance away lay the Wonder, and on her deck was Berg and anumber 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, notanswering the question. "You'll suffer for this! I'll have youarrested. "

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

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

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

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

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

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

Five minutes later the Advance sank from sight, the last glimpse Tomhad of Berg and his men being a sight of them standing on the deck oftheir floating boat, gazing in the direction of their successful rival. The Wonder was left behind, while Tom and his friends were soon oncemore 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 thenforward. We'll take no more chances with these fellows. "

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

"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 reachingthe wreck will not amount to anything. "

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

"They're not very likely to do that, " was the captain's opinion. "Itwas 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 practicallyimpossible for them to catch up to us. No, I think we have nothing tofear from them. "

But though danger from Berg and his crowd was somewhat remote, perilsof another sort were hovering around the treasure-seekers, and theywere 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 notlook down and observe, far below them, cities and villages. Nor couldthey breathe the bracing atmosphere of the upper regions. 

But if there was lack of the rarefied air of the clouds, there was nolack of fresh atmosphere. The big tanks carried a large supply, andwhenever more was needed the oxygen machine would supply it. 

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

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

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

"Well, at the calculation we made yesterday, we are within about athousand 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'squite a depth, and of course impossible for ordinary divers to reach. But it will be possible in this submarine and in the strong divingsuits your father has invented for us to get to it. Yes, I don'tanticipate much trouble in getting out the gold, once we reach thewreck of course--"

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

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

"Take the wheel!" cried the lad to the captain. "I must go to myfather. " 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 heprepared to pull his parent from the whirring machine. Then hehesitated, for he feared he, too, would be glued fast by the terriblecurrent, and so be unable to help Mr. Swift. 

"I'm held fast here, too, " replied the balloonist. "I started to cutout 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 mainswitchboard forward. "

Tom realized that this was the only thing to do. He ran forward andwith 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 asif 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 sprangto 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 himto the fresh air at once. Start the tank pumps. We'll rise to thesurface. "

The youth needed no second bidding. Once more turning on the electriccurrent, he set the powerful pumps in motion and the submarine began torise. Then, aided by Captain Weston and Mr. Damon, the young inventorcarried his father to a couch in the main cabin. Mr. Sharp took chargeof the machinery. 

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

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

Up shot the Advance, while Mr. Sharp stood ready to open the conningtower as soon as it should be out of water. Mr. Swift seemed to berapidly reviving. With a bound the submarine, forced upward from thegreat depth, fairly shot out of the water. There was a clanking soundas the aeronaut opened the airtight door of the tower, and a breath offresh 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 soonbe all right when I get out on deck. My foot slipped as I was adjustinga wire that had gotten out of order, and I fell so that I received alarge part of the current. I'm glad I was not burned. Was Mr. Sharphurt? 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 youout to the fresh air. You'll feel much better then. "

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

There, not one hundred yards away, was a great warship, flying a flagwhich, in a moment. Tom recognized as that of Brazil. The cruiser waslying off a small island, and all about were small boats, filled withnatives, who seemed to be bringing supplies from land to the ship. Atthe unexpected sight of the submarine, bobbing up from the bottom ofthe ocean, the natives uttered cries of fright. The attention of thoseon the warship was attracted, and the bridge and rails were lined withcurious 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 feelbetter, dad?" he asked, his wonder over the sight of the big vesseltemporarily eclipsed in his anxiety for his parent. 

"Oh, yes, much better. I'm all right now. But I wish we hadn'tdisclosed ourselves to these people. They may demand to know where weare going, and Brazil is too near Uruguay to make it safe to tell ourerrand. They may guess it, however, from having read of the wreck, andour departure. "

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

"There's a boat, with some officers in it, to judge by the amount ofgold 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. Ithink 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 hisunfamiliarity 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? Weare an American ship, sailing under American colors. Is this Brazilianterritory?"

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

With a flourish, the officer who had done the questioning drew hissword. 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 ofone of our friends, and grasping an arm. 

"What does this mean?" cried Captain Weston indignantly. "If this is ajoke, you're carrying it too far. If you're in earnest, let me warn youagainst 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 atighter grip. The captain turned suddenly, and seizing the man aboutthe waist, with an exercise of tremendous strength hurled him over hishead 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-manneredindividual into an angry, modern giant. There was a gasp ofastonishment at his feat, as the ducked sailor crawled back into thesmall 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 heand his fellows, including the crew, crowded so closely around Tom andhis friends that they could do nothing. Even Captain Weston found itimpossible to offer any resistance, for three men grabbed hold of himbut his spirit was still a fighting one, and he struggled desperatelybut 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 wordthat you intend to damage our shipping, and may try to torpedo ourwarships. I believe you tried to disable us a little while ago, butfailed. We consider that an act of war and you will be treatedaccordingly. Take them on board the San Paulo, " the officer Went on, turning to his aides. "We'll try them by court-marital here. Some ofyou remain and guard this submarine. We will teach these filibusteringAmericans a lesson. "

Chapter Twenty

Doomed to Death

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

At another command from the officer, who was addressed as AdmiralFanchetti, several of the sailors began to lead Tom and his friendstoward the small boat. 

"Do you feel all right, father?" inquired the lad anxiously, as helooked 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, butI don't like to be handled in this fashion. "

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

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

"It is most unpleasant, if I may be allowed the expression, " commentedCaptain Weston mildly. He seemed to have lost his sudden anger, butthere was a steely glint in his eyes, and a grim, set look around hismonth 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 ifhe should once get loose, and it was noticed that they were on theirguard. 

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

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

"Lieutenant Drascalo, eh?" murmured Mr. Damon. "I think they made amistake 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 notappear to mind. 

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

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

"If they do, we'll complain to the United States consul and demanddamages, " 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 willthese scoundrels--"

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

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

"What I mean, " went on the captain, "is that these people may carry theproceedings off with a high hand. You heard the admiral speak of acourt-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 admiralis newly in command; his uniform shows that He wants to make a name forhimself, and he seizes on our submarine as an excuse. He can send wordto his government that he destroyed a torpedo craft that sought towreck his ship. Thus he will acquire a reputation. "

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

"Oh, he would not claim to have acted against the United States as apower. He would say that it was a private submarine, and, as a matterof fact, it is. While we are under the protection of the stars andstripes, our vessel is not a Government one, " and Captain Weston spokethe 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, "andconfiscate our craft Then they will send us back home, I expect forthey 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 companionladder that hung over the side. In a short time they were on deck, amida crowd of sailors, and they could see the boat going back to bring offthe admiral, who signaled from the submarine. Tom and his friends weretaken below to a room that looked like a prison, and there, a littlelater, they were visited by Admiral Fanchetti and several officers. 

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

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

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

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

"Silenceo!" cried Lieutenant Drascalo, the admonition to silenceseeming 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 betried at once. "

It was in vain for the prisoners to protest. Matters were carried witha high hand. They were allowed a spokesman, and Captain Weston, whounderstood Spanish, was selected, that language being used. But thedefense was a farce, for he was scarcely listened to. Several officerstestified before the admiral, who was judge, that they had seen thesubmarine rise out of the water, almost under the prow of the SanPaulo. 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 toldof the reason for their rapid ascent from the ocean depths--that Mr. Swift had been shocked, and needed fresh air. Their story was notbelieved. 

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

"Shot!" cried Captain Weston, staggering back at this unexpectedsentence. His companions turned white, and Mr. Swift leaned against hisson 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 ofthe honorable court?" he asked, looking at his fellow officers. Theyall nodded gravely. 

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

"I consider you no better than pirates, " interrupted the admiral. "Youhave an armed submarine--a submarine with torpedo tubes. You invade ourharbor with it, and come up almost under my ship. You have forfeitedyour right to the protection of your country, and I have no fear onthat score. You will be shot within three days. That is all. Removethe prisoners. "

Protests were in vain, and it was equally useless to struggle. Theprisoners were taken out on deck, for which they were thankful, for theinterior of the ship was close and hot, the weather being intenselydisagreeable. They were told to keep within a certain space on deck, and a guard of sailors, all armed, was placed near them. From wherethey were they could see their submarine floating on the surface of thelittle bay, with several Brazilians on the small deck. The Advance hadbeen 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, " hereplied, "made to scare us so we will consent to giving up thesubmarine, which they have no right to confiscate. But these fellowslook ugly enough for anything, " he went on. 

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

"Bless my gizzard, of course!" exclaimed Mr. Damon. "But what? That'sthe question. To be shot! Why, that's a terrible threat! The villains--"

"Silenceo!" shouted Lieutenant Drascalo, coming up at that moment. 

Chapter Twenty-One

The Escape

Events had happened so quickly that day that the gold-hunters couldscarcely comprehend them. It seemed only a short time since Mr. Swifthad been discovered lying disabled on the dynamo, and what hadtranspired since seemed to have taken place in a few minutes, though itwas, in reality, several hours. This was made manifest by the feelingof hunger on the part of Tom and his friends. 

"I wonder if they're going to starve us, the scoundrels?" asked Mr. Sharp, when the irate lieutenant was beyond hearing. "It's not fair tomake us go hungry and shoot us in the bargain. "

"That's so, they ought to feed us, " put in Tom. As yet neither he northe others fully realized the meaning of the sentence passed on them. 

From where they were on deck they could look off to the little island. From it boats manned by natives were constantly putting off, bringingsupplies to the ship. The place appeared to be a sort of callingstation for Brazilian warships, where they could get fresh water andfruit and other food. 

From the island the gaze of the adventurers wandered to the submarine, which lay not far away. They were chagrined to see several of thebolder natives clambering over the deck. 

"I hope they keep out of the interior, " commented Tom. "If they get topulling or hauling on the levers and wheels they may open the tanks andsink her, with the Conning tower open. "

"Better that, perhaps, than to have her fall into the hands of aforeign power, " commented Captain Weston. "Besides, I don't see thatit's going to matter much to us what becomes of her after we're--"

He did not finish, but every one knew what he meant, and a grim silencefell upon the little group. 

There came a welcome diversion, however, in the shape of three sailors, bearing trays of food, which were placed on the deck in front of theprisoners, who were sitting or lying in the shade of an awning, for thesun was very hot. 

"Ha! Bless my napkin-ring!" cried Mr. Damon with something of hisformer gaiety. "Here's a meal, at all events. They don't intend tostarve us. Eat hearty, every one. "

"Yes, we need to keep up our strength, " observed Captain Weston. 

"Why?" inquired Mr. Sharp. 

"Because we're going to try to escape!" exclaimed Tom in a low voice, when the sailors who had brought the food had gone. "Isn't that whatyou mean, captain?"

"Exactly. We'll try to give these villains the slip, and we'll need allour strength and wits to do it. We'll wait until night, and see what wecan do. "

"But where will we escape to?" asked Mr. Swift. "The island will affordno shelter, and--"

"No, but our submarine will, " went on the sailor. 

"It's in the possession of the Brazilians, " objected Tom. 

"Once I get aboard the Advance twenty of those brown-skinned villainswon't keep me prisoner, " declared Captain Weston fiercely. "If we canonly slip away from here, get into the small boat, or even swim to thesubmarine, I'll make those chaps on board her think a hurricane hasbroken loose. "

"Yes, and I'll help, " said Mr. Damon. 

"And I, " added Tom and the balloonist. 

"That's the way to talk, " commented the captain. "Now let's eat, for Isee that rascally lieutenant coming this way, and we mustn't appear tobe plotting, or he'll be suspicious. "

The day passed slowly, and though the prisoners seemed to be allowedconsiderable liberty, they soon found that it was only apparent. OnceTom walked some distance from that portion of the deck where he and theothers had been told to remain. A sailor with a gun at once ordered himback. Nor could they approach the rails without being directed, harshlyenough at times, to move back amidships. 

As night approached the gold-seekers were on the alert for any chancethat might offer to slip away, or even attack their guard, but thenumber of Brazilians around them was doubled in the evening, and aftersupper, which was served to them on deck by the light of swinginglanterns, they were taken below and locked in a stuffy cabin. Theylooked helplessly at each other. 

"Don't give up, " advised Captain Weston. "It's a long night. We may beable to get out of here. "

But this hope was in vain. Several times he and Tom, thinking theguards outside the cabin were asleep, tried to force the lock of thedoor with their pocket-knives, which had not been taken from them. Butone of the sailors was aroused each time by the noise, and looked inthrough a barred window, so they had to give it up. Slowly the nightpassed, and morning found the prisoners pale, tired and discouraged. They were brought up on deck again, for which they were thankful, as inthat tropical climate it was stifling below. 

During the day they saw Admiral Fanchetti and several of his officerspay a visit to the submarine. They went below through the openedconning tower, and were gone some time. 

"I hope they don't disturb any of the machinery, " remarked Mr. Swift. "That could easily do great damage. "

Admiral Fanchetti seemed much pleased with himself when he returnedfrom his visit to the submarine. 

"You have a fine craft, " he said to the prisoners. "Or, rather, you hadone. My government now owns it. It seems a pity to shoot such good boatbuilders, but you are too dangerous to be allowed to go. "

If there had been any doubt in the minds of Tom and his friends thatthe sentence of the court-martial was only for effect, it was dispelledthat day. A firing squad was told off in plain view of them, and themen were put through their evolutions by Lieutenant Drascalo, who hadthem load, aim and fire blank cartridges at an imaginary line ofprisoners. Tom could not repress a shudder as he noted the leveledrifles, and saw the fire and smoke spurt from the muzzles. 

"Thus we shall do to you at sunrise to-morrow, " said the lieutenant, grinning, as he once more had his men practice their grim work. 

It seemed hotter than ever that day. The sun was fairly broiling, andthere was a curious haziness and stillness to the air. It was noticedthat the sailors on the San Paulo were busy making fast all loosearticles on deck with extra lashings, and hatch coverings were doublysecured. 

"What do you suppose they are up to?" asked Tom of Captain Weston. 

"I think it is coming on to blow, " he replied, "and they don't want tobe caught napping. They have fearful storms down in this region at thisseason of the year, and I think one is about due. "

"I hope it doesn't wreck the submarine, " spoke Mr. Swift. "They oughtto close the hatch of the conning tower, for it won't take much of asea to make her ship considerable water. "

Admiral Fanchetti had thought of this, however, and as the afternoonwore away and the storm signs multiplied, he sent word to close thesubmarine. He left a few sailors aboard inside on guard. 

"It's too hot to eat, " observed Tom, when their supper had been broughtto them, and the others felt the same way about it. They managed todrink some cocoanut milk, prepared in a palatable fashion by thenatives of the island, and then, much to their disgust, they were takenbelow again and locked in the cabin. 

"Whew! But it certainly is hot!" exclaimed Mr. Damon as he sat down ona couch and fanned himself. "This is awful!"

"Yes, something is going to happen pretty soon, " observed CaptainWeston. "The storm will break shortly, I think. "

They sat languidly about the cabin. It was so oppressive that even thethought of the doom that awaited them in the morning could hardly seemworse than the terrible heat. They could hear movements going on aboutthe ship, movements which indicated that preparations were being madefor something unusual. There was a rattling of a chain through a hawsehole, and Captain Weston remarked:

"They're putting down another anchor. Admiral Fanchetti had better getaway from the island, though, unless he wants to be wrecked. He'll beblown ashore in less than no time. No cable or chain will hold in suchstorms as they have here. "

There came a period of silence, which was suddenly broken by a howl asof some wild beast. 

"What's that?" cried Tom, springing up from where he was stretched outon the cabin floor. 

"Only the wind, " replied the captain. "The storm has arrived. "

The howling kept up, and soon the ship began to rock. The windincreased, and a little later there could be heard, through an openedport in the prisoners' cabin, the dash of rain. 

"It's a regular hurricane!" exclaimed the captain. "I wonder if thecables will hold?"

"What about the submarine?" asked Mr. Swift anxiously. 

"I haven't much fear for her. She lies so low in the water that thewind can't get much hold on her. I don't believe she'll drag heranchor. "

Once more came a fierce burst of wind, and a dash of rain, and then, suddenly above the outburst of the elements, there sounded a crash ondeck. It was followed by excited cries. 

"Something's happened!" yelled Tom. The prisoners gathered in afrightened group in the middle of the cabin. The cries were repeated, and then came a rush of feet just outside the cabin door. 

"Our guards! They're leaving!" shouted Tom. 

"Right!" exclaimed Captain Weston. "Now's our chance! Come on! If we'regoing to escape we must do it while the storm is at its height, and allis in confusion. Come on!"

Tom tried the door. It was locked. 

"One side!" shouted the captain, and this time he did not pause to say"by your leave. " He came at the portal on the run, and his shoulderstruck it squarely. There was a splintering and crashing of wood, andthe door was burst open. 

"Follow me!" cried the valiant sailor, and Tom and the others rushedafter him. They could hear the wind howling more loudly than ever, andas they reached the deck the rain dashed into their faces with suchviolence that they could hardly see. But they were aware that somethinghad occurred. By the light of several lanterns swaying in the terrificblast they saw that one of the auxiliary masts had broken off near thedeck. 

It had fallen against the chart house, smashing it, and a number ofsailors were laboring to clear away the wreckage. 

"Fortune favors us!" cried Captain Weston. "Come on! Make for the smallboat. It's near the side ladder. We'll lower the boat and pull to thesubmarine. "

There came a flash of lightning, and in its glare Tom saw somethingthat caused him to cry out. 

"Look!" he shouted. "The submarine. She's dragged her anchors!"

The Advance was much closer to the warship than she had been thatafternoon. Captain Weston looked over the side. 

"It's the San Paulo that's dragging her anchors, not the submarine!" heshouted. "We're bearing down on her! We must act quickly. Come on, we'll lower the boat!"

In the rush of wind and the dash of rain the prisoners crowded to theaccommodation companion ladder, which was still over the side of thebig ship. No one seemed to be noticing them, for Admiral Fanchetti wason the bridge, yelling orders for the clearing away of the wreckage. But Lieutenant Drascalo, coming up from below at that moment, caughtsight of the fleeing ones. Drawing his sword, he rushed at them, shouting:

"The prisoners! The prisoners! They are escaping!"

Captain Weston leaped toward the lieutenant

"Look out for his sword!" cried Tom. But the doughty sailor did notfear the weapon. Catching up a coil of rope, he cast it at thelieutenant. It struck him in the chest, and he staggered back, loweringhis sword. 

Captain Weston leaped forward, and with a terrific blow sent LieutenantDrascalo to the deck. 

"There!" cried the sailor. "I guess you won't yell 'Silenceo!' for awhile now. "

There was a rush of Brazilians toward the group of prisoners. Tomcaught one with a blow on the chin, and felled him, while CaptainWeston disposed of two more, and Mr. Sharp and Mr. Damon one each. Thesavage fighting of the Americans was too much for the foreigners, andthey drew back. 

"Come on!" cried Captain Weston again. "The storm is getting worse. Thewarship will crash into the submarine in a few minutes. Her anchorsaren't holding. I didn't think they would. "

He made a dash for the ladder, and a glance showed him that the smallboat was in the water at the foot of it. The craft had not been hoistedon the davits. 

"Luck's with us at last!" cried Tom, Seeing it also. "Shall I helpyou, dad?"

"No; I think I'm all right. Go ahead. "

There came such a gust of wind that the San Paulo was heeled over, andthe wreck of the mast, rolling about, crashed into the side of a deckhouse, splintering it. A crowd of sailors, led by Admiral Fanchetti, who were again rushing on the escaping prisoners, had to leap back outof the way of the rolling mast. 

"Catch them! Don't let them get away!" begged the commander, but thesailors evidently had no desire to close in with the Americans. 

Through the rush of wind and rain Tom and his friends staggered downthe ladder. It was hard work to maintain one's footing, but theymanaged it. On account of the high side of the ship the water wascomparatively calm under her lee, and, though the small boat wasbobbing about, they got aboard. The oars were in place, and in anothermoment they had shoved off from the landing stage which formed the footof the accommodation ladder. 

"Now for the Advance!" murmured Captain Weston. 

"Come back! Come back, dogs of Americans!" cried a voice at the railover their heads, and looking up, Tom saw Lieutenant Drascalo. He hadsnatched a carbine from a marine, and was pointing it at the recentprisoners. He fired, the flash of the gun and a dazzling chain oflightning coming together. The thunder swallowed up the report of thecarbine, but the bullet whistled uncomfortable close to Tom's head. Theblackness that followed the lightning shut out the view of everythingfor a few seconds, and when the next flash came the adventurers sawthat they were close to their submarine. 

A fusillade of shots sounded from the deck of the warship, but as themarines were poor marksmen at best, and as the swaying of the shipdisconcerted them, our friends were in little danger. 

There was quite a sea once they were beyond the protection of the sideof the warship, but Captain Weston, who was rowing, knew how to managea boat skillfully, and he soon had the craft alongside the bobbingsubmarine. 

"Get aboard, now, quick!" he cried. 

They leaped to the small deck, casting the rowboat adrift. It was thework of but a moment to open the conning tower. As they started todescend they were met by several Brazilians coming up. 

"Overboard with 'em!" yelled the captain. "Let them swim ashore or totheir ship!"

With almost superhuman strength he tossed one big sailor from the smalldeck. Another showed fight, but he went to join his companion in theswirling water. A man rushed at Tom, seeking the while to draw hissword, but the young inventor, with a neat left-hander, sent him tojoin the other two, and the remainder did not wait to try conclusions. They leaped for their lives, and soon all could be seen, in thefrequent lightning flashes, swimming toward the warship which was nowcloser than ever to the submarine. 

"Get inside and we'll sink below the surface!" called Tom. "Then wedon't care what happens. "

They closed the steel door of the conning tower. As they did so theyheard the patter of bullets from carbines fired from the San Paulo. Then came a violent tossing of the Advance; the waves were becominghigher as they caught the full force of the hurricane. It took but aninstant to sever, from within, the cable attached to the anchor, whichwas one belonging to the warship. The Advance began drifting. 

"Open the tanks, Mr. Sharp!" cried Tom. "Captain Weston and I willsteer. Once below we'll start the engines. "

Amid a crash of thunder and dazzling flashes of lightning, thesubmarine began to sink. Tom, in the conning tower had a sight of theSan Paulo as it drifted nearer and nearer under the influence of themighty wind. As one bright flash came he saw Admiral Fanchetti andLieutenant Drascalo leaning over the rail and gazing at the Advance. 

A moment later the view faded from sight as the submarine sank belowthe surface of the troubled sea. She was tossed about for some timeuntil deep enough to escape the surface motion. Waiting until she wasfar enough down so that her lights would not offer a mark for the gunsof the warship, the electrics were switched on. 

"We're safe now!" cried Tom, helping his father to his cabin. "They'vegot too much to attend to themselves to follow us now, even if theycould. Shall we go ahead, Captain Weston?"

"I think so, yes, if I may be allowed to express my opinion, " was themild reply, in strange contrast to the strenuous work in which thecaptain had just been engaged. 

Tom signaled to Mr. Sharp in the engine-room, and in a few seconds theAdvance was speeding away from the island and the hostile vessel. Nor, deep as she was now, was there any sign of the hurricane. In thepeaceful depths she was once more speeding toward the sunken treasure. 

Chapter Twenty-Two

At the Wreck

"Well, " remarked Mr. Damon, as the submarine hurled herself forwardthrough the ocean, "I guess that firing party will have something elseto do to-morrow morning besides aiming those rifles at us. "

"Yes, indeed, " agreed Tom. "They'll be lucky if they save their ship. My, how that wind did blow!"

"You're right, " put in Captain Weston. "When they get a hurricane downin this region it's no cat's paw. But they were a mighty careless lotof sailors. The idea of leaving the ladder over the side, and the boatin the water. "

"It was a good thing for us, though, " was Tom's opinion. 

"Indeed it was, " came from the captain. "But as long as we are safe nowI think we'd better take a look about the craft to see if those chapsdid any damage. They can't have done much, though, or she wouldn't berunning so smoothly. Suppose you go take a look, Tom, and ask yourfather and Mr. Sharp what they think. I'll steer for a while, until weget well away from the island. "

The young inventor found his father and the balloonist busy in theengine-room. Mr. Swift had already begun an inspection of themachinery, and so far found that it had not been injured. A furtherinspection showed that no damage had been done by the foreign guardthat had been in temporary possession of the Advance, though thesailors had made free in the cabins, and had broken into the foodlockers, helping themselves plentifully. But there was still enough forthe gold-seekers. 

"You'd never know there was a storm raging up above, " observed Tom ashe rejoined Captain Weston in the lower pilot house, where he wasmanaging the craft. "It's as still and peaceful here as one could wish. "

"Yes, the extreme depths are seldom disturbed by a surface storm. Butwe are over a mile deep now. I sent her down a little while you weregone, as I think she rides a little more steadily. "

All that night they speeded forward, and the next day, rising to thesurface to take an observation, they found no traces of the storm, which had blown itself out. They were several hundred miles away fromthe hostile warship, and there was not a vessel in sight on the broadexpanse of blue ocean. 

The air tanks were refilled, and after sailing along on the surface foran hour or two, the submarine was again sent below, as Captain Westonsighted through his telescope the smoke of a distant steamer. 

"As long as it isn't the Wonder, we're all right, " said Tom. "Still, wedon't want to answer a lot of questions about ourselves and our object. "

"No. I fancy the Wonder will give up the search, " remarked the captain, as the Advance was sinking to the depths. 

"We must be getting pretty near to the end of our search ourselves, "ventured the young inventor. 

"We are within five hundred miles of the intersection of theforty-fifth parallel and the twenty-seventh meridian, east fromWashington, " said the captain. "That's as near as I could locate thewreck. Once we reach that point we will have to search about underwater, for I don't fancy the other divers left any buoys to mark thespot. "

It was two days later, after uneventful sailing, partly on the surface, and partly submerged, that Captain Weston, taking a noon observation, announced:

"Well, we're here!"

"Do you mean at the wreck?" asked Mr. Swift eagerly. 

"We're at the place where she is supposed to lie, in about two miles ofwater, " replied the captain. "We are quite a distance off the coast ofUruguay, about opposite the harbor of Rio de La Plata. From now on weshall have to nose about under water, and trust to luck. "

With her air tanks filled to their capacity, and Tom having seen thatthe oxygen machine and other apparatus was in perfect working order, the submarine was sent below on her search. Though they were in theneighborhood of the wreck, the adventurers might still have to doconsiderable searching before locating it. Lower and lower they sankinto the depths of the sea, down and down, until they were deeper thanthey had ever gone before. The pressure was tremendous, but the steelsides of the Advance withstood it. 

Then began a search that lasted nearly a week. Back and forth theycruised, around in great circles, with the powerful searchlight focusedto disclose the sunken treasure ship. Once Tom, who was observing thepath of light in the depths from the conning tower, thought he had seenthe remains of the Boldero, for a misty shape loomed up in front of thesubmarine, and he signaled for a quick stop. It was a wreck, but it hadbeen on the ocean bed for a score of years, and only a few timbersremained of what had been a great ship. Much disappointed, Tom rang forfull speed ahead again, and the current was sent into the greatelectric plates that pulled and pushed the submarine forward. 

For two days more nothing happened. They searched around under thegreen waters, on the alert for the first sign, but they saw nothing. Great fish swam about them, sometimes racing with the Advance. Theadventurers beheld great ocean caverns, and skirted immense rocks, where dwelt monsters of the deep. Once a great octopus tried to dobattle with the submarine and crush it in its snaky arms, but Tom sawthe great white body, with saucer-shaped eyes, in the path of light andrammed him with the steel point. The creature died after a struggle. 

They were beginning to despair when a full week had passed and theywere seemingly as far from the wreck as ever. They went to the surfaceto enable Captain Weston to take another observation. It only confirmedthe other, and showed that they were in the right vicinity. But it waslike looking for a needle in a haystack, almost, to and the sunken shipin that depth of water. 

"Well, we'll try again, " said Mr. Swift, as they sank once more beneaththe surface. 

It was toward evening, on the second day after this, that Tom, who wason duty in the conning tower, saw a black shape looming up in front ofthe submarine, the searchlight revealing it to him far enough away sothat he could steer to avoid it. He thought at first that it was agreat rock, for they were moving along near the bottom, but thepeculiar shape of it soon convinced him that this could not be. It camemore plainly into view as the submarine approached it more slowly, thensuddenly, out of the depths in the illumination from the searchlight, the young inventor saw the steel sides of a steamer. His heart gave agreat thump, but he would not call out yet, fearing that it might besome other vessel than the one containing the treasure. 

He steered the Advance so as to circle it. As he swept past the bows hesaw in big letters near the sharp prow the word, Boldero. 

"The wreck! The wreck!" he cried, his voice ringing through the craftfrom end to end. "We've found the wreck at last!"

"Are you sure?" cried his father, hurrying to his son, Captain Westonfollowing. 

"Positive, " answered the lad. The submarine was slowing up now, and Tomsent her around on the other side. They had a good view of the sunkenship. It seemed to be intact, no gaping holes in her sides, for onlyher plates had started, allowing her to sink gradually. 

"At last, " murmured Mr. Swift. "Can it be possible we are about to getthe treasure?"

"That's the Boldero, all right, " affirmed Captain Weston. "I recognizeher, even if the name wasn't on her bow. Go right down on the bottom, Tom, and we'll get out the diving suits and make an examination. "

The submarine settled to the ocean bed. Tom glanced at the depth gage. It showed over two miles and a half. Would they be able to venture outinto water of such enormous pressure in the comparatively frail divingsuits, and wrest the gold from the wreck? It was a serious question. 

The Advance came to a stop. In front of her loomed the great bulk ofthe Boldero, vague and shadowy in the flickering gleam of thesearchlight As the gold-seekers looked at her through the bull's-eyesof the conning tower, several great forms emerged from beneath thewreck's bows. 

"Deep-water sharks!" exclaimed Captain Weston, "and monsters, too. Butthey can't bother us. Now to get out the gold!"

Chapter Twenty-Three

Attacked by Sharks

For a few minutes after reaching the wreck, which had so occupied theirthoughts for the past weeks, the adventurers did nothing but gaze at itfrom the ports of the submarine. The appearance of the deep-watersharks gave them no concern, for they did not imagine the uglycreatures would attack them. The treasure-seekers were more engrossedwith the problem of getting out the gold. 

"How are we going to get at it?" asked Tom, as he looked at the highsides of the sunken ship, which towered well above the comparativelysmall Advance. 

"Why, just go in and get it, " suggested Mr. Damon. "Where is gold in acargo usually kept, Captain Weston? You ought to know, I should think. Bless my pocketbook!"

"Well, I should say that in this case the bullion would be kept in asafe in the captain's cabin, " replied the sailor. "Or, if not there, in some after part of the vessel, away from where the crew isquartered. But it is going to be quite a problem to get at it. We can'tclimb the sides of the wreck, and it will be impossible to lower herladder over the side. However, I think we had better get into thediving suits and take a closer look. We can walk around her. "

"That's my idea, " put in Mr. Sharp. "But who will go, and who will staywith the ship?"

"I think Tom and Captain Weston had better go, " suggested Mr. Swift. "Then, in case anything happens, Mr. Sharp, you and I will be on boardto manage matters. "

"You don't think anything will happen, do you, dad?" asked his son witha laugh, but it was not an easy one, for the lad was thinking of theshadowy forms of the ugly sharks. 

"Oh, no, but it's best to be prepared, " answered his father. 

The captain and the young inventor lost no time in donning the divingsuits. They each took a heavy metal bar, pointed at one end, to use inassisting them to walk on the bed of the ocean, and as a protection incase the sharks might attack them. Entering the diving chamber, theywere shut in, and then water was admitted until the pressure was seen, by gauges, to be the same as that outside the submarine. Then thesliding steel door was opened. At first Tom and the captain couldbarely move, so great was the pressure of water on their bodies. Theywould have been crushed but for the protection afforded by the strongdiving suits. 

In a few minutes they became used to it, and stepped out on the floorof the ocean. They could not, of course, speak to each other, but Tomlooked through the glass eyes of his helmet at the captain, and thelatter motioned for the lad to follow. The two divers could breatheperfectly, and by means of small, but powerful lights on the helmets, the way was lighted for them as they advanced. 

Slowly they approached the wreck, and began a circuit of her. Theycould see several places where the pressure of the water, and thestrain of the storm in which she had foundered, had 'opened the platesof the ship, but in no case were the openings large enough to admit aperson. Captain Weston put his steel bar in one crack, and tried topry it farther open, but his strength was not equal to the task. Hemade some peculiar motions, but Tom could not understand them. 

They looked for some means by which they could mount to the decks ofthe Boldero, but none was visible. It was like trying to scale afifty-foot smooth steel wall. There was no place for a foothold. Againthe sailor made some peculiar motions, and the lad puzzled over them. They had gone nearly around the wreck now, and as yet had seen no wayin which to get at the gold. As they passed around the bow, which wasin a deep shadow from a great rock, they caught sight of the submarinelying a short distance away. Light streamed from many hull's-eyes, andTom felt a sense of security as he looked at her, for it was lonesomeenough in that great depth of water, unable to speak to his companion, who was a few feet in advance. 

Suddenly there was a swirling of the water, and Tom was nearly thrownoff his feet by the rush of some great body. A long, black shadowpassed over his head, and an instant later he saw the form of a greatshark launched at Captain Weston. The lad involuntarily cried in alarm, but the result was surprising. He was nearly deafened by his own voice, confined as the sound was in the helmet he wore. But the sailor, too, had felt the movement of the water, and turned just in time. He thrustupward with his pointed bar. But he missed the stroke, and Tom, amoment later, saw the great fish turn over so that its mouth, which isfar underneath its snout, could take in the queer shape which the sharkevidently thought was a choice morsel. The big fish did actually getthe helmet of Captain Weston inside its jaws, but probably it wouldhave found it impossible to crush the strong steel. Still it might havesprung the joints, and water would have entered, which would have beenas fatal as though the sailor had been swallowed by the shark. Tomrealized this and, moving as fast as he could through the water, hecame up behind the monster and drove his steel bar deep into it. 

The sea was crimsoned with blood, and the savage creature, opening itsmouth, let go of the captain. It turned on Tom, who again harpooned it. Then the fish darted off and began a wild flurry, for it was dying. Therush of water nearly threw Tom off his feet, but he managed to make hisway over to his friend, and assist him to rise. A confident look fromthe sailor showed the lad that Captain Weston was uninjured, though hemust have been frightened. As the two turned to make their way back tothe submarine, the waters about them seemed alive with the horriblemonsters. 

It needed but a glance to show what they were, Sharks! Scores of them, long, black ones, with their ugly, undershot mouths. They had beenattracted by the blood of the one Tom had killed, but there was not ameal for all of them off the dying creature, and the great fish mightturn on the young inventor and his companion. 

The two shrank closer toward the wreck. They might get under the prowof that and be safe. But even as they started to move, several of thesea wolves darted quickly at them. Tom glanced at the captain. Whatcould they do? Strong as were the diving suits, a combined attack bythe sharks, with their powerful jaws, would do untold damage. 

At that moment there seemed some movement on board the submarine. Tomcould see his father looking from the conning tower, and the agedinventor seemed to be making some motions. Then Tom understood. Mr. Swift was directing his son and Captain Weston to crouch down. The laddid so, pulling the sailor after him. Then Tom saw the bow electric gunrun out, and aimed at the mass of sharks, most of whom were congregatedabout the dead one. Into the midst of the monsters was fired a numberof small projectiles, which could be used in the electric cannon inplace of the solid shot. Once more the waters were red with blood, andthose sharks which were not killed swirled off. Tom and Captain Westonwere saved. They were soon inside the submarine again, telling theirthrilling story. 

"It's lucky you saw us, dad, " remarked the lad, blushing at the praiseMr. Damon bestowed on him for killing the monster which had attackedthe captain. 

"Oh, I was on the lookout, " said the inventor. "But what about gettinginto the wreck?"

"I think the only way we can do it will be to ram a hole in her side, "said Captain Weston. "That was what I tried to tell Tom by motions, buthe didn't seem to understand me. "

"No, " replied the lad, who was still a little nervous from his recentexperience. "I thought you meant for us to turn it over, bottom sideup, " and he laughed. 

"Bless my gizzard! Just like a shark, " commented Mr. Damon. 

"Please don't mention them, " begged Tom. "I hope we don't see any moreof them. "

"Oh, I fancy they have been driven far enough away from thisneighborhood now, " commented the captain. "But now about the wreck. Wemay be able to approach it from above. Suppose we try to lower thesubmarine on it? That will save ripping it open. "

This was tried a little later, but would not work. There were strongcurrents sweeping over the top of the Boldero, caused by a submergedreef near which she had settled. It was a delicate task to sink thesubmarine on her decks, and with the deep waters swirling about wasfound to be impossible, even with the use of the electric plates andthe auxiliary screws. Once more the Advance settled to the ocean bed, near the wreck. 

"Well, what's to be done?" asked Tom, as he looked at the high steelsides. 

"Ram her, tear a hole, and then use dynamite, " decided Captain Westonpromptly. "You have some explosive, haven't you, Mr. Swift?"

"Oh, yes. I came prepared for emergencies. "

"Then we'll blow up the wreck and get at the gold. "

Chapter Twenty-Four

Ramming the Wreck

Fitted with a long, sharp steel ram in front, the Advance waspeculiarly adapted for this sort of work. In designing the ship thisram was calculated to be used against hostile vessels in war time, forthe submarine was at first, as we know, destined for a Government boat. Now the ram was to serve a good turn. 

To make sure that the attempt would be a success, the machinery of thecraft was carefully gone over. It was found to be in perfect order, save for a few adjustments which were needed. Then, as it was night, though there was no difference in the appearance of things below thesurface, it was decided to turn in, and begin work in the morning. Nordid the gold-seekers go to the surface, for they feared they mightencounter a storm. 

"We had trouble enough locating the wreck, " said Captain Weston, "andif we go up we may be blown off our course. We have air enough to staybelow, haven't we, Tom?"

"Plenty, " answered the lad, looking at the gages. 

After a hearty breakfast the next morning, the submarine crew got readyfor their hard task. The craft was backed away as far as was practical, and then, running at full speed, she rammed the wreck. The shock wasterrific, and at first it was feared some damage had been done to theAdvance, but she stood the strain. 

"Did we open up much of a hole?" anxiously asked Mr. Swift. 

"Pretty good, " replied Tom, observing it through the conning towerbull's-eyes, when the submarine had backed off again. "Let's give heranother. "

Once more the great steel ram hit into the side of the Boldero, andagain the submarine shivered from the shock. But there was a biggerhole in the wreck now, and after Captain Weston had viewed it hedecided it was large enough to allow a person to enter and place acharge of dynamite so that the treasure ship would be broken up. 

Tom and the captain placed the explosive. Then the Advance waswithdrawn to a safe distance. There was a dull rumble, a great swirlingof the water, which was made murky; but when it cleared, and thesubmarine went back, it was seen that the wreck was effectively brokenup. It was in two parts, each one easy of access. 

"That's the stuff!" cried Tom. "Now to get at the gold!"

"Yes, get out the diving suits, " added Mr. Damon. "Bless mywatch-charm, I think I'll chance it in one myself! Do you think thesharks are all gone, Captain Weston?"

"I think so. "

In a short time Tom, the captain, Mr. Sharp and Mr. Damon were attiredin the diving suits, Mr. Swift not caring to venture into such a greatdepth of water. Besides, it was necessary for at least one person toremain in the submarine to operate the diving chamber. 

Walking slowly along the bottom of the sea the four gold-seekersapproached the wreck. They looked on all sides for a sight of thesharks, but the monster fish seemed to have deserted that part of theocean. Tom was the first to reach the now disrupted steamer. He foundhe could easily climb up, for boxes and barrels from the cargo holdswere scattered all about by the explosion. Captain Weston soon joinedthe lad. The sailor motioned Tom to follow him, and being more familiarwith ocean craft the captain was permitted to take the lead. He headedaft, seeking to locate the captain's cabin. Nor was he long in findingit. He motioned for the others to enter, that the combined illuminationof the lamps in their helmets would make the place bright enough so asearch could be made for the gold. Tom suddenly seized the arm of thecaptain, and pointed to one corner of the cabin. There stood a smallsafe, and at the sight of it Captain Weston moved toward it. The doorwas not locked, probably having been left open when the ship wasdeserted. Swinging it back the interior was revealed. 

It was empty. There was no gold bullion in it. 

There was no mistaking the dejected air of Captain Weston. The othersshared his feelings, but though they all felt like voicing theirdisappointment, not a word could be spoken. Mr. Sharp, by vigorousmotions, indicated to his companions to seek further. 

They did so, spending all the rest of the day in the wreck, save for ashort interval for dinner. But no gold rewarded their search. 

Tom, late that afternoon, wandered away from the others, and foundhimself in the captain's cabin again, with the empty safe showing dimlyin the water that was all about. 

"Hang it all!" thought the lad, "we've had all our trouble for nothing!They must have taken the gold with them. "

Idly he raised his steel bar, and struck it against the partition backof the safe. To his astonishment the partition seemed to fall inward, revealing a secret compartment. The lad leaned forward to bring thelight for his helmet to play on the recess. He saw a number of boxes, piled one upon the other. He had accidentally touched a hidden springand opened a secret receptacle. But what did it contain?

Tom reached in and tried to lift one of the boxes. He found it beyondhis strength. Trembling from excitement, he went in search of theothers. He found them delving in the after part of the wreck, but bymotions our hero caused them to follow him. Captain Weston showed theexcitement he felt as soon as he caught sight of the boxes. He and Mr. Sharp lifted one out, and placed it on the cabin floor. They pried offthe top with their bars. 

There, packed in layers, were small yellow bars; dull, gleaming, yellowbars! It needed but a glance to show that they were gold bullion. Tomhad found the treasure. The lad tried to dance around there in thecabin of the wreck, nearly three miles below the surface of the ocean, but the pressure of water was too much for him. Their trip had beensuccessful. 

Chapter Twenty-Five

Home With the Gold

There was no time to be lost. They were in a treacherous part of theocean, and strong currents might at any time further break up thewreck, so that they could not come at the gold. It was decided, bymeans of motions, to at once transfer the treasure to the submarine. Asthe boxes were too heavy to carry easily, especially as two men, whowere required to lift one, could not walk together in the uncertainfooting afforded by the wreck, another plan was adopted. The boxes wereopened and the bars, a few at a time, were dropped on a firm, sandyplace at the side of the wreck. Tom and Captain Weston did this work, while Mr. Sharp and Mr. Damon carried the bullion to the diving chamberof the Advance. They put the yellow bars inside, and when quite anumber had been thus shifted, Mr. Swift, closing the chamber, pumpedthe water out and removed the gold. Then he opened the chamber to thedivers again, and the process was repeated, until all the bullion hadbeen secured. 

Tom would have been glad to make a further examination of the wreck, for he thought he could get some of the rifles the ship carried, butCaptain Weston signed to him not to attempt this. 

The lad went to the pilot house, while his father and Mr. Sharp tooktheir places in the engine-room. The gold had been safely stowed in Mr. Swift's cabin. 

Tom took a last look at the wreck before he gave the starting signal. As he gazed at the bent and twisted mass of steel that had once been agreat ship, he saw something long, black and shadowy moving around fromthe other side, coming across the bows. 

"There's another big shark, " he observed to Captain Weston. "They'recoming back after us. "

The captain did not speak. He was staring at the dark form. Suddenly, from what seemed the pointed nose of it, there gleamed a light, as fromsome great eye. 

"Look at that!" cried Tom. "That's no shark!"

"If you want my opinion, " remarked the sailor, "I should say it was theother submarine--that of Berg and his friends--the Wonder. They'vemanaged to fix up their craft and are after the gold. "

"But they're too late!" cried Tom excitedly. "Let's tell them so. "

"No, " advised the captain. "We don't want any trouble with them. "

Mr. Swift came forward to see why his son had not given the signal tostart. He was shown the other submarine, for now that the Wonder hadturned on several searchlights, there was no doubt as to the identityof the craft. 

"Let's get away unobserved if we can, " he suggested. "We have hadtrouble enough. "

It was easy to do this, as the Advance was hidden behind the wreck, andher lights were glowing but dimly. Then, too, those in the othersubmarine were so excited over the finding of what they supposed wasthe wreck containing the treasure, that they paid little attention toanything else. 

"I wonder how they'll feel when they find the gold gone?" asked Tom ashe pulled the lever starting the pumps. 

"Well, we may have a chance to learn, when we get back tocivilization, " remarked the captain. 

The surface was soon reached, and then, under fair skies, and on a calmsea, the voyage home was begun. Part of the time the Advance sailed onthe top, and part of the time submerged. 

They met with but a single accident, and that was when the forwardelectrical plate broke. But with the aft one still in commission, andthe auxiliary screws, they made good time. Just before reaching homethey settled down to the bottom and donned the diving suits again, evenMr. Swift taking his turn. Mr. Damon caught some large lobsters, ofwhich he was very fond, or, rather, to be more correct, the lobsterscaught him. When he entered the diving chamber there were four fineones clinging to different parts of his diving suit. Some of them wereserved for dinner. 

The adventurers safely reached the New Jersey coast, and the submarinewas docked. Mr. Swift at once communicated with the proper authoritiesconcerning the recovery of the gold. He offered to divide with theactual owners, after he and his friends had been paid for theirservices, but as the revolutionary party to whom the bullion wasintended had gone out of existence, there was no one to officiallyclaim the treasure, so it all went to Tom and his friends, who made anequitable distribution of it. The young inventor did not forget to buyMrs. Baggert a fine diamond ring, as he had promised. 

As for Berg and his employers, they were, it was learned later, greatlychagrined at finding the wreck valueless. They tried to make troublefor Tom and his father, but were not successful. 

A few days after arriving at the seacoast cottage, Tom, his father andMr. Damon went to Shopton in the airship. Captain Weston, GarretJackson and Mr Sharp remained behind in charge of the submarine. It wasdecided that the Swifts would keep the craft and not sell it to theGovernment, as Tom said they might want to go after more treasure someday. 

"I must first deposit this gold, " said Mr. Swift as the airship landedin front of the shed at his home. "It won't do to keep it in the houseover night, even if the Happy Harry gang is in jail. "

Tom helped him take it to the bank. As they were making perhaps thelargest single deposit ever put in the institution, Ned Newton came out. 

"Well, Tom, " he cried to his chum, "it seems that you are never goingto stop doing things. You've conquered the air, the earth and thewater. "

"What have you been doing while I've been under water, Ned?" asked theyoung inventor. 

"Oh, the same old thing. Running errands and doing all sorts of work inthe bank. "

Tom had a sudden idea. He whispered to his father and Mr. Swift nodded. A little later he was closeted with Mr. Prendergast, the bankpresident. It was not long before Ned and Tom were called in. 

"I have some good news for you, Ned, " said Mr. Prendergast, while Tomsmiled. "Mr. Swift er--ahem--one of our largest depositors, has spokento me about you, Ned. I find that you have been very faithful. You arehereby appointed assistant cashier, and of course you will get a muchlarger salary. "

Ned could hardly believe it, but he knew then what Tom had whispered toMr. Swift. The wishes of a depositor who brings much gold bullion to abank can hardly be ignored. 

"Come on out and have some soda, " invited Tom, and when Ned lookedinquiringly at the president, the latter nodded an assent. 

As the two lads were crossing the street to a drug store, somethingwhizzed past them, nearly running them down. 

"What sort of an auto was that?" cried Tom. 

"That? Oh, that was Andy Foger's new car, " answered Ned. "He's beenbreaking the speed laws every day lately, but no one seems to botherhim. It's because his father is rich, I suppose. Andy says he has thefastest car ever built. "

"He has, eh?" remarked Tom, while a curious look came into his eyes. "Well, maybe I can build one that will beat his. "

And whether the young inventor did or not you can learn by reading thefifth volume of this series, to be called "Tom Swift and His ElectricRunabout; Or, The Speediest Car on the Road. "

"Well, Tom, I certainly appreciate what you did for me in getting me abetter position, " remarked Ned as they left the drug store. "I wasbeginning to think I'd never get promoted. Say, have you anything to dothis evening? If you haven't, I wish you'd come over to my house. I'vegot a lot of pictures I took while you were away. "

"Sorry, but I can't, " replied Tom. 

"Why, are you going to build another airship or submarine?"

"No, but I'm going to see-- Oh, what do you want to know for, anyhow?"demanded the young inventor with a blush. "Can't a fellow go see agirl without being cross-questioned?"

"Oh, of course, " replied Ned with a laugh. "Give Miss Nestor myregards, " and at this Tom blushed still more. But, as he said, that washis own affair.