CHAPTER I. WHICH IS INTRODUCTORY.
By looking at any comprehensive map it can be readily seen that upon the western end of the Island of Cuba there is a cape known as San Antonio.

Opposite it and upon the eastern extremity of mystic Yucatan is Cape Catoche. Between these two points of land lies that body of water which connects the Gulf of Mexico with the Caribbean Sea and known as the Yucatan Channel.

Mr. Wilbur Wade, the distinguished arch?ologist, geologist, naturalist and scientist in general, had startled his associates of the World’s Geographical Society by a positive and unheard-of statement.

“I have made very careful soundings in the Yucatan Channel,” he said; “also I have compared the strata of the two capes, and it is my firm belief that at a period not so very remote there existed no channel between the two points of land. In fact——”

“Then you claim the existence of an isthmus between Cuba and Yucatan at some time?” interrupted Professor Brown.

“Just so,” agreed Mr. Wade.

“What has become of it, I would like to ask?”

There was just a bit of cynicism in this query. But then these two men had never been the warmest of friends. Wade bit his lip.

“What do you suppose has become of it?” he retorted. “Surely you don’t think it has taken wings and flown away?”

“But you were going to prove the matter to us,” returned Professor Brown, with a bit of sarcasm.

“If it is not an impossibility,” said Mr. Wade, ironically, “my opinion is that the isthmus is at present at the bottom of the Yucatan Channel.”

A number of the scientists moved in their seats. Professor Brown smiled broadly.

“A very simple matter to look at,” he said, pointedly. “Of course, it will be easy to furnish absolute evidence?”

Mr. Wade turned a cold stare upon the man who could speak so insultingly. Then he said:

2“Before I allow the fact to go upon record I shall prove it.”

“Then we shall have an isthmus between Labrador and Greenland; another ‘twixt Japan and Corea; still another between Sicily and the Italian Peninsula, and again——”

“One moment,” said Wade, politely. “You must remember that there is nothing improbable in any hypothesis you have named. If I am not able to prove myself right, you are not able to prove that the sunken isthmus never existed. I leave it in all fairness to our fellow-members.”

There was a slight murmur of approval, but there was yet incredulity.

“How do you expect to prove that there was once an isthmus between Cape San Antonio and Cape Catoche, may I ask, Mr. Wade?” spoke the chairman.

Mr. Wade drew himself up.

“By the only possible method,” he replied. “I shall visit it.”

The scientists all looked surprised. Professor Brown actually laughed out loud and slyly tapped his forehead. Finally the chairman said:

“Really, Mr. Wade, you must allow that that is quite a remarkable assertion. In what manner can you expect to visit this—this imaginary sunken isthmus?”

Wade’s eyes flashed.

“Imaginary if you will,” he said; “I shall conduct my investigations with a submarine boat.”

There was a great stir in the assemblage. Even Professor Brown forgot to interject his sarcasm.

“In a submarine boat?” repeated the chairman. “Does such a craft exist?”

“It does!” replied Mr. Wade, suavely. “And a very dear friend of mine is the inventor and owner.”

“His name?”

“Frank Reade, Jr., of Readestown.”

A murmur went through the throng. At once the sentiment began to change. Professor Brown faded from view.

Not one in that distinguished company but had heard of Frank Reade, Jr. His name changed the tide.

“Indeed!” exclaimed the chairman, with interest. “Is not Mr. Reade the inventor of an airship?”

“Yes, sir.”

“And of other wonderful things?”

“Exactly.”

“So he has built a submarine boat?”

“He has, and it is a success. He has kindly consented to assist me in locating the sunken isthmus. This boat is capable of remaining weeks under the sea. The plan cannot fail.”

In a moment dozens of the men were thronging about Wade, congratulating him heartily. Skeptical they were no longer. Foes a moment back, now they were fawning friends. Truly, nothing creates friendship like one’s success.

He was at once the lion of the hour. Scores of requests were showered upon him. Would he procure such a specimen? Would he solve such a marine problem? Was there any room on board the Sea Diver for another savant?

Et cetera, et cetera.

One still incredulous man ventured to ask:

“Will not the sunken isthmus be like all the rest of the bed of the sea? How will you prove it was ever above the surface?”

“If an isthmus did exist in that locality,” said Wade, logically, “there must have been habitations upon it. Probably I shall find ruins of a village, town or city, or remains of forests or craters, or river beds. There will be plenty of evidence if there ever was an isthmus.”

Wade went to New York from Washington on the night train. As he was whirled away upon the fast express he felt that he had really gained a great victory.

“I silenced that old hard-skull, Brown,” he muttered, with keen satisfaction. “And he deserved it.”

I know the reader will agree with Wade in this. That night he consumed in getting back to his Manhattan home.

The next day he packed his effects and started for Readestown.

Deep down in the heart of lovely hills upon a river navigable to the sea was the beautiful little city of Readestown.

A number of generations of Reades had lived there, and all had been inventors. But Frank Reade, Jr., the handsome young scion of the race, had proved the most famous of all.

The fact was, everything he took hold of succeeded.

It was bound to “go,” and with a snap and vim characteristic of the young American.

In undertaking the construction of a submarine boat Frank had hit upon that which had been an enigma to thousands of inventors.

But his marvelous ingenuity won the day and he triumphed.

The Sea Diver was conceived, outlined, charted and built. Then she was tested and proved an unqualified success.

In her outline the Sea Diver was long, slender and cylindrical, 3in the shape of her hull. This rested upon a deep keel to insure steadiness, which was a highly important matter.

The hull of the submarine boat was constructed of plates of steel, closely riveted. Above the cigar-shaped hull there was an open deck, extending from stem to stern.

In the center of the deck rose the dome, with the skylight and great observation window. Under this was the luxuriously-appointed cabin.

Just forward of this dome was the pilot-house, a smaller dome with heavy plate-glass windows. Here the steersman could direct the course of the boat and operate the electric keyboard which directed the vessel’s engines, for the motive power of the Sea Diver was electricity, furnished by a wonderful storage system.

Aft there arose a square structure with bull’s-eye windows, with a railed quarterdeck above it. This was called the after-cabin, and here were the staterooms and living quarters of the submarine travelers.

On this quarter deck there was a powerful searchlight, capable of a reach of fully two miles.

The interior of the Sea Diver lacked nothing in the way of equipment and appointment.

There were supplies of all kinds aboard for a cruise of two years.

Amidships and under the big dome were the wonderful electric engines, by means of which power was furnished for all the mechanism of the boat.

In the pilot-house was the electric keyboard. Here were the various little buttons and brass levers by means of which the doors and windows could be hermetically sealed, the huge tank filled with water instantly for the sinking of the boat, or again for raising it by the expulsion of the water with pneumatic pressure.

Thus the boat could be made to sink or rise at any desired depth; to go forward or back at the pressure of a button.

As wonderful as anything was the system of circulation by means of chemically-made oxygen. Under the pilot-house there was placed a generator which was capable of manufacturing pure oxygen, and also of extracting and destroying the bad air or gases as fast as they were created.

Little pipes and open valves extended to every part of the boat through which the oxygen was continually disseminated, so that the submarine boat might remain an indefinite time under water and the voyagers could be sure of breathing pure air all the time.

In fact, not a detail was lacking to make the Sea Diver a safe vessel, a comfortable home and a symmetrical, beautiful craft.

It was true that Frank Reade, Jr., had done his best to perfect the new submarine boat.

That he had been successful it was easy enough to see. Nobody had more confidence in him than his friend, Mr. Wilbur Wade.

The scientist was ready to embark upon a voyage to any part of the submarine world without considering for a moment the possible perils of such a thing. He was a firm believer in the practicability of submarine navigation, and the seaworthiness of the new boat.
CHAPTER II. IN WHICH THE PROJECT IS UNDERTAKEN.
Mr. Wade reached Readestown in due time. He proceeded at once to a hotel and ate an early breakfast.

Then he called a carriage and rode down to the machine shops of Frank Reade, Jr. At that early hour he did not feel certain of meeting the young inventor.

But at the gate there was a sawed-off, comical little darky, who scraped and bowed and said:

“Yes, sah; I done reckon Marse Frank been lookin’ fo’ yo’ fo’ two days, sah. He am in his office, sah. Show yo’ in, or does yo’ know de way?”

“I know the way, Pomp,” said Wade, alighting from his carriage. “I’ll find him.”

Across the machine shop yard he went rapidly. He was about to enter a small brick building by a half-open door when a man came out.

He was a genuine type of Irishman, with comical mug, dancing blue eyes and a shock of red hair. He stopped at sight of Mr. Wade and exclaimed:

“Begorra, and I belave that is the gintlemin himsilf. Top av the day to ye, sor. Is yer name Misther Wade, sor?”

“It is,” replied the scientist. “And you are Barney?”

“Yis, sor; an’ I was jist on the way to the tillygraph office wid a message from Misther Frank for yez, sor. Shure, there’ll be no use av sindin’ it now.”

“Then he was about to wire me?”

“Yis sor?”

“Well, I must have kept him waiting,” declared Wade. “I will go right in and see him.”

“That’s roight, sor.”

Wade passed through a narrow hallway and entered a 4square, high-ceiled room, hung with curious looking charts and diagrams. A large table was also covered with the same.

At this sat a handsome young man, with a rare type of intellectual features, and the air which belongs to a brainy man.

“Wade!” he exclaimed, putting out his hand. “I was just going to wire you.”

“So I learn,” cried the scientist. “I am more than sorry if I have delayed you.”

“That is all right; you are quite ready for the start?”

“Yes.”

“Good! The Sea Diver is all equipped, and lies out there in the tank. All we have to do is to go aboard, run her down the canal to the river, and be off.”

“For the Sunken Isthmus?”

“Just so.”

“If it exists.”

“At any rate, we shall have a submarine voyage; but there is good reason to believe that it exists.”

“So I believe, though my fellow-members of the World’s Society are a bit incredulous. We had quite an argument at the last session.”

“Ah!”

“But when I informed them that I was going to visit the spot in a real submarine boat, they thought I was daft or gone mad until I mentioned your name. That was like magic.”

Frank laughed.

“Do they know me?” he asked.

“Indeed, yes, as the inventor of the airship. That settled a large measure of doubt in their minds right off. Then there were those who desired to share our fortunes.”

This amused Frank muchly.

“No doubt of it,” he laughed. “They began to see the elements of success in your project. You can afford to snub them well, whether the isthmus is discovered or not.”

“Well,” said Wade, with a thrill of pleasure in his voice, “I look forward with the keenest of pleasure to exploring the waters of the Yucatan Channel. I am in complete readiness to start.”

“Very good,” said Frank; “we will go on board to-night and start with the early morning light. The Sea Diver lies in the tank, all ready. Shall we take a look at her?”

“With pleasure,” replied Wade.

They left the office and crossed the yard to a gate. Passing through this, another and larger yard was seen. In the center of this was a large basin or tank of water.

And in it floated the new submarine boat.

5The tank was connected by a series of locks with a canal which led down to the river. It was thus an easy matter to sail direct from the factory yard for any part of the world.

Frank and Wade went on board the submarine boat. The latter picked out his stateroom and made other necessary arrangements. Then he said:

“I will go back to the hotel, Frank, and get my trunks. Then I will take up my quarters permanently aboard the Sea Diver.”

“Very good,” agreed Frank. “We will sail at an early hour in the morning.”

After Wade had gone, Frank called Barney and Pomp. He told these two servitors of his purpose, and added:

“You must be all in readiness; there must be no delay.”

“All roight,” cried Barney, as he ducked his head and threw a handspring; “it’s mesilf as will be there, sor.”

“Golly, dis chile neber miss de chance, Marse Frank,” cried Pomp, cutting a double-shuffle.

These two comical characters had been associated with all the thrilling experiences of Frank Reade, Jr., in his world-wide travels.

Barney and Pomp were his faithful companions, and he would hardly have been able to fill their places. Barney was an expert engineer and electrician, and Pomp was the prince of cooks and a generally handy man.

They were excellent company, and Frank never felt at a loss for entertainment while in their company. He could ill have spared Barney and Pomp.

Barney and Pomp were the best of friends in all things, but each was as full of fun as a nut is of meat. Consequently there was nothing they enjoyed more than a rough and tumble wrestle or the playing of a practical joke.

If half the things they said to each other could have been taken seriously, there would have been good ground for a duel at most any time. But they knew better.

So there were to be four people in the crew of the Sea Diver. Besides Barney and Pomp, there were Frank Reade, Jr., and Wilbur Wade.

All were on board the boat that night and all was in readiness for the early start. It is safe to say that none in the party slept much that night.

Barney and Pomp were first astir.

As they made things ship-shape and breakfast was announced by Pomp, Frank and Wade came tumbling out. Then, after a light meal, Frank went into the pilot-house.

There were men on hand to open the locks and the 6boat was locked down into the canal. Thence it glided on down into the river.

It was an easy matter for Frank to place his finger upon an electric button and direct the course of the boat where he chose.

When they emerged into the river they were surprised to see a great throng upon the river banks. Thousands of people were there gathered to get a look at the new submarine boat.

They cheered vociferously as the Sea Diver appeared. Down the river the submarine boat glided.

Soon Readestown was left behind. Other towns were passed, and in due course the river widened and the open sea was spread out to their view.

The great submarine cruise was really begun.

Out into the Atlantic the Sea Diver ran. Frank still kept her to the surface.

For he knew that she could travel faster and easier there. There would be enough deep-sea traveling later on.

The course of the Diver was set for the Gulf of Mexico.

Land faded quickly from view and soon only the boundless expanse of the sea was on every hand. The horizon was at times dotted with sails, and once one of the vessels in passing spoke the Sea Diver.

For two days the submarine boat kept her southward course. Then one morning as the voyagers tumbled out on deck Frank noted that the wind was in the east and was beginning to kick up a nasty sea.

The little boat rode the water like a cork. There was no question as to her seaworthiness.

But great, lowering clouds overhung the sky and pattering drops of rain fell. Distant vessels were seen scudding under bare poles.

“It’s my opinion,” said Wade who was something of a sailor, “that we are going to have a big blow.”

“I agree with you,” said Frank.

“However, I reckon the Diver is well able to cope with any such a storm?”

“Indeed, yes,” said Frank. “If it gets too rough on the surface we can take a trip below.”

“Sure enough; we would never feel the storm there.”

“It is hardly likely. Heigho! What is that? On my word, I believe those were signals of distress!”

Frank pointed to a distant vessel which had the appearance of a large schooner-yacht. There was no doubt but that the signal of distress was at her masthead.

“She’s in trouble, surely,” cried Wade. “Can she have struck a leak?”

7“Begorra, she’s carryin’ too much sail fer the loikes av this breeze,” cried Barney. “Shure, it’s crazy they are!”

This was true. The schooner carried every rag of canvas. This was plainly a reckless thing.

It looked as if the crew were panic-stricken, or else ignorant of the proper course of safety. Certainly the yacht was in a dangerous strait.

The submarine voyagers were in a bit of a quandary. What should they do?

Humanity dictated that they go to her assistance. Prudence, however, asserted the policy of keeping away from her.

There was no means of knowing how many were in her crew. They would doubtless have to leave the schooner and would all pile aboard the Sea Diver. This would be a perilous thing for the submarine voyagers. Moreover, what would be done with them?

Frank reflected some moments, then he said, with sudden resolution:

“Humanity demands it. I cannot conscientiously refuse to give them aid.”

“That’s right,” cried Wade. “We ought not to hesitate.”

Frank stepped into the pilot-house, but even as his fingers touched the keyboard a warning cry came from Wade.

“It is too late,” he cried.
CHAPTER III. AT THE BOTTOM OF THE SEA.
This startling announcement of Wade’s caused a chill to traverse Frank’s frame. He shot a hasty glance at the distant vessel.

Then he saw the startling scene which had induced Wade’s declaration.

The storm had swooped down upon the schooner like a foul fiend. One brief glimpse of her fate was had.

She was seen to keel over with the force of the blast. Then her sails were in ribbons and her foremast snapped like a pipestem.

The next moment she was on her beam-ends. Then the black cloud shut her from view.

The next moment the storm struck the Sea Diver. What followed was ever after like a dream.

The hurricane almost blew the staunch little boat out of 8the water. Enormous seas were hurrying and crashing over her deck.

Frank had ordered all into the cabin, and the doors and windows were closed hermetically. But the shock of the storm threatened to dash the little craft to pieces.

Frank saw the possibility of much damage being done, so he cried:

“Stand by the engines, Barney, I am going to send the boat down.”

Frank pressed an electric button. In a moment the Sea Diver sank below the surface.

Down she settled, and for a moment all was darkness aboard her. Then Frank pressed a small button.

In a moment every electric light aboard was in full blast. A wonderful scene was spread to view.

The depth of the sea at this point was not more than one hundred and fifty fathoms, so that the voyagers very quickly came in sight of the bottom.

Unlike the bed of the Pacific or the Indian Oceans, the Atlantic is mostly devoid of coral reefs or reaches of white sand.

There was a vast area of mud and slime, with some few marine plants spread to view. Huge serpent-like eels wriggled through this, and myriads of dark-hued fish scurried away rapidly.

The scene was a sombre and by no means attractive one. Wade was not much impressed.

“Pshaw,” he exclaimed, in sheer disappointment, “so this is the home of the mermaid and the charm of the deep sea, of which we read such alluring accounts? Ugh! What a disillusion!”

“Ah, but this is not a type of deep-sea regions,” replied Frank. “This is a dirty part of the Atlantic, but before we return I think you will see some beautiful sights. We shall find it different in the Caribbean.”

“I hope so,” replied the scientist, with disgust. “Certainly this is a horrible conception of deep-sea life, but I cannot help thinking of that vessel. Do you suppose she is weathering the storm?”

“It is a question,” replied Frank. “She was in very bad shape. However, let us hope that she will.”

“Amen to that. Is there nothing we can do to give her aid?”

“I fear not; at least until the storm abates.”

“She may be at the bottom by that time.”

“That is possible. If afloat, however, she will be crippled and sorely in need of aid.”

The Sea Diver did not rest upon the muddy bottom, but was held in suspension about twenty feet from it. Frank’s 9purpose was to return to the surface as quickly as possible after the abating of the storm.

After an hour had passed it was ventured to ascend. Frank took the wheel of the Diver and held her steady.

Up she went.

Soon she felt the motion of the sea’s surface. It was not rough, and Frank concluded that the hurricane had passed.

So he let the Diver leap up into daylight. The electric lights were shut off at the same moment.

Eagerly the voyagers swept the rolling expanse with their eyes. Not a sign of the schooner or any other vessel could be seen.

“She has gone to the bottom,” gasped Wade; “her fate is sealed!”

So it seemed. Frank procured his glass and scanned the vast expanse. He closed it, finally, saying:

“She has either gone down, or else the storm has blown her beyond our range of vision.”

“Do you believe the latter possible?” asked Wade.

“It is very likely.”

“I don’t know why it is,” said the scientist, “but I am mightily interested in that vessel. I would like to know her fate for a certainty.”

“Indeed!” exclaimed Frank, with some surprise. “Why more interested in her than any other craft we might meet?”

“I can hardly tell,” replied Wade, “but it is a certain fact that I am. I have some sort of a curious feeling that our career is in some manner intertwined with hers.”

Frank could not resist a laugh.

“Moonshine!” he said. “Your imagination is getting the best of you, Mr. Wade.”

The scientist shook his head.

“It may be all nonsense,” he said, “but we shall see.”

The sea was yet a trifle rough. The hurricane had swept away beyond the horizon and was quite out of sight.

The Sea Diver once more stood away on her course. In a little while matters had assumed the usual routine.

Barney was at work slushing the deck to get rid of the accumulation gained by the boat’s submersion. There were heaps of seaweed, great masses of jellyfish and other forms of marine life.

Pomp was in the galley preparing a smoking repast. He had opened a window to admit air, and Barney chanced to pass near it.

It was an ill moment for the Celt.

Pomp had mixed some dough for bread a short while before, and now had discovered that the yeast was unfit 10for use, and the bread as a result, was spoiled. This put the darky out of temper.

“I don’ see wha’ was de mattah wif dat ar yeast,” he grumbled. “Kain’t seem to do nuffin’ wif it. Dere am all dat dough sp’iled. It meks me berry mad. Well, dere’s one fing it can make food fo’, an’ dat am de fishes. So here goes!”

The coon picked up the huge mass of dough and hurled it through the open window. He expected that it would land far out in the water. But it didn’t.

As luck had it, Barney was just passing that way. He came in a line with the window just in time to get that soft, sticky mass full in the side of the head.

The soft dough split around his skull, with such force did it strike him, and stopped his ear, nostrils and eyes. The Celt went down as if struck by a cannonball.

For a second he was unable to realize what had happened. Pomp was for that brief instant aghast.

“Massy Lordy!” he muttered; “I done hit somebody!”

Then he ran to the window and looked out.

When he saw who it was and noted Barney’s comical plight he could not help but roar with laughter.

The Celt scrambled to his feet. His mop was at one end of the deck and his pail of suds at the other.

“Tare an’ ‘ounds!” he roared, as he put up his hands and felt the mass of soft dough, not knowing what it was, “it’s me brains they’ve knocked out av me! Howly murther! It’s kilt I am! It’s kilt I am!”

Then he chanced to uncover one eye and saw Pomp in a paroxysm at the galley window. He glanced down at his hand, which was full of dough.

Well, the transition was brief. A madder Irishman old Neptune never bore upon his heaving bosom.

With angry hands Barney tried to claw the dough from his mop of red hair. Of course, it only clung the worse.

He managed to get his eyes clear and his ear, then he made the air blue about him.

“Howly shmoke, but I’ll have the heart av yez fer that!” he roared, “yez black-skinned ape, yez! Have at yez! I’ll tache ye to insult a gintlemin!”

“Hi—hi—hi! Massy Lordy!” howled Pomp, “dat am de berry funniest fing!”

“Yez think it funny eh?” roared Barney. “Well, yez won’t think that way whin I git done wid yez!”

“Ho—ho—ho! hi—hi—hi!”

“Phwat do yez mane by threating me thot way?” roared Barney, trying to claw the dough out of his hair.

“How yo’ fink I know yo’ was gwine to get hit?” cried Pomp. “Wha’ yo’ git in de way, fo’?”

11“Do yez mane to say yez didn’t throw that on purpose?”

“Course I didn’. I was goin’ to frow it into de sea when yo’ head cum along an’ jes’ got in de way.”

“Arrah, an’ that’ll do very well fer yez to say,” cried the Celt, “but if yez think I belave it——”

“Shuah, it’s de troof,” protested Pomp.

“I’ll tache yez to hit me wid a doughball an’ thin lie about it aftherwards,” roared the Celt. And then he made a dive for the window.

But Pomp clashed it shut in his face. The Celt rushed around to the galley door.

But the darky shut the bolt in this, and for the time was master of the situation. But, though baffled, Barney was not defeated.

He retired, vowing the direst of vengeance. It took an hour’s hard work to get the clinging dough out of his hair.

Nor did he get any sympathy from any one. When Frank and Wade heard the story they laughed heartily. This made Barney only the madder.

“Be me sowl!” he muttered, “I’ll more than aven it up wid that black rascal. Shure, I’ll tache him manners!”

How Barney accomplished his purpose we shall see at a later day.

The Sea Diver kept on its course for the rest of that day.

Night finally shut down, dark and moonless. But with the searchlight it was easy for the Diver to travel, with no fear of a collision.

She was rapidly nearing Key West, and would the next day be in Gulf waters. The air was fresh and delightful, and the voyagers sat out on deck until a late hour.

While thus enjoying themselves, suddenly Barney sprung up.

“Shure, sor!” he cried, motioning to Frank, “there’s a lot of colored loights over there. Phwat do yez make av it?”

“A vessel in distress!” exclaimed Frank, as he scrutinized the distant signals. “Do you suppose it was our schooner?”
CHAPTER IV. A WONDERFUL NARRATIVE.
Perhaps the most startled member of the party was Wilbur Wade. He rushed to the rail, straining his gaze in the direction of the signal lights.

12“I knew it would come!” he cried, excitedly. “I was sure we had not seen the last of that schooner.”

Certainly some vessel, distant but a few miles, was flying signal lights of distress.

The submarine voyagers would have been inhuman, indeed, not to have responded. The Diver’s prow was turned toward the lights.

Rapidly she drew nearer, and the searchlight was focused upon the vessel. Then there was a cry of recognition.

“I told you so!” cried Wade, eagerly; “it is the schooner!”

Nearer the Diver rapidly drew. When within fifty yards of the disabled schooner there came a loud hail:

“Steam yacht ahoy!”

“Ahoy the schooner!” replied Frank.

“What yacht is that?”

“This is not a yacht.”

“Oh, a torpedo cruiser, eh?”

“No,” replied Frank; “this is the submarine boat, the Sea Diver, Captain Frank Reade, Jr., of Readestown, U. S. A.”

There was a moment’s silence.

Then a surprised voice said:

“A submarine boat? Do you mean that literally?”

“I do,” replied Frank.

“Well, that beats me! Where are you bound?”

“Before I answer any more questions,” shouted Frank, “let me ask you a few.”

“All right.”

“What craft are you?”

“This is the schooner-yacht Meta, of the American Yacht Club, Captain Hardy Poole. We are bound for the Yucatan Channel, but this storm has taken away our foreyard, and we want to strike some vessel which carries a spare one.”

“Are you in distress in any other way?” asked Frank.

“No.”

“Well, then, we cannot help you. We wish you success and good-night.”

“Wait!” shouted the captain of the schooner; “don’t leave us yet. I am interested in your statement about your craft. I will send off a boat to bring you aboard. Perhaps I can tell you something of interest.”

Frank was surprised.

“What do you mean?” he asked.

“I will explain later. Look for our boat!”

Frank hesitated a moment. Then he turned to Wilbur Wade.

13“What can he desire to see us about?” he asked. “Is it worth while to wait and ascertain?”

“Oh, by all means!” cried Wade. “Don’t you remember what he said? He is also bound for the Yucatan Channel!”

“That is so,” exclaimed Frank, with sudden recollection.

“I tell you, this schooner is in some way bound to become involved in our project. Some strange presentiment has told me that!”

“It is quite a coincidence,” muttered Frank. “Yet I cannot see how his trip to the channel can in any way affect us.”

“We shall see. I would like to go aboard the schooner with you, Frank.”

“Certainly.”

Frank stepped into the pilot-house and gave Barney orders to lie by and wait for their return. Then he put on a light overcoat, as did Wade, and they were ready for the visit.

Very soon a dark object came bounding over the waves toward them. It was the yacht’s boat.

Presently it reached the gangway of the Diver.

“Ahoy!” came the hail; “this is the Meta’s boat waiting for Captain Reade.”

“All right,” cried Frank, as he slid down into the boat. He was followed by Wade.

A moment later four strong oarsmen were rowing them rapidly over to the yacht.

Once alongside it was an easy matter to mount the gangway and meet the captain of the Meta awaiting them at the rail.

He was a tall, powerfully framed man, and in the glare of the lanterns he was seen to be possessed of a dark, stern cast of features. Frank’s first glance was not exactly a favorable one.

He shook hands.

“This is Mr. Reade, I presume?” asked the captain of the yacht.

“It is,” replied Frank. “And this, I presume, is Captain Poole? I have brought my friend, Mr. Wilbur Wade, with me.”

Poole gave Wade a critical glance.

“You are both welcome,” he said. “Come into the cabin.”

Without further ceremony they followed the schooner’s captain. The cabin of the Meta was richly furnished.

But both Frank and Wade noted one curious fact.

Every man of the schooner’s crew, and even Poole himself 14carried arms. They wore belts and revolver pouches.

In these piping times of peace—and certainly in these seas—this could but be regarded as very strange. To the visitors it even had a sinister look.

On their way to the cabin Wade had an opportunity to whisper to Frank:

“Did you note those pistols?”

“Yes,” replied Frank.

“Are they cranks or pirates?”

Frank could hardly restrain a laugh.

“It is very mysterious!” he said. “Keep your eyes open. We will soon find out what it means.”

As they entered the cabin Poole motioned them to seats at a table. He sat opposite.

He was now plainly revealed in the glare of the cabin lamp. As his visitors thus got a good look at him, each experienced a peculiar sensation.

It seemed almost like a chill.

In all his life Frank thought he had never seen a man of such remarkable appearance.

His features were long and almost cadaverous. His eyes dark and piercing and burning with a strange light. He wore a sharp imperial and pointed mustache, with a saturnine smile which gave a truly Mephistophelian appearance.

In plain terms he was out and out the thorough type of the villain. Such both Frank and Wade adjudged him.

For a moment they sat there facing this strange being, who seemed like a portrait from a piratical past. Poole’s shifty gaze roamed over them, and then he spoke:

“I am honored by this visit, Mr. Reade. It is certainly fate which has thrown us together in this way, for I am very sure that we may be of mutual service to each other.”

“Indeed!” said Frank, with a little surprise; “I shall be pleased to know just how.”

“First I must tell you a story,” said Poole, with a crafty smile. “It concerns my mission and the character of my yacht and crew.”

“Really——”

“That is all right. I know that you have not failed to size up our peculiar appearance. Is it not true that we bear the appearance of latter-day pirates?”

“Why—I—I—had not thought much about that,” stammered Frank.

“Ah, yes, you have. It is not usual for people to go armed in these times. The days of Morgan, the rover, and Kidd, the buccaneer, are long past; yet we are seen emulating them.”

Frank and Wade were speechless. They could do nothing but stare at the speaker.

15He smiled in his saturnine way.

“Fear not,” he said, in his cool, almost impudent way. “I have not entrapped you, nor decoyed you on board this yacht for any nefarious purpose. Your statement that you were the possessor of a submarine boat has interested me, and I have a remarkable proposition to make. But first to my story:

“I am a native of Sicily, though an American by extraction, that is, I was born in that island, of Yankee parents. I was some years ago the possessor of a large fortune, but Monte Carlo and a fast life soon dissipated it.

“I had a half-brother, by name Alfonso, my father having married a Spanish lady. We were never good friends. We quarreled at every available opportunity.

“Despite this, Alfonso came to me when we were both penniless and begging for alms in Naples. He was a rogue, was Alfonso, but had no head for scheming. He assured me that he was on the track of a fortune.

“He produced a tin box, containing an ancient chart which had been an heirloom in his mother’s family. It was a map of an isle in the sea and described the location of a buried treasure upon that isle. Millions in Peruvian gold had been buried there by a buccaneering ancestor. But, alas! the latitude and longitude was so obscurely marked that it could not be deciphered.

“If there was any way to make that out, then the location of the treasure might be established and a fortune reaped. Alfonso had great faith in my sagacity, and deemed it possible that I might accomplish what others had failed to do. So he brought the charts to me.

“And he was right. I puzzled over the figures for a long time. Then I experimented with chemicals. I at length found a certain one which, by soaking the vellum, raised the obliterated figures and made them perceptible to the eye. By studying the map I learned that the gold was buried upon the Isle of Mona, in the Channel of Yucatan.

“We were half insane with our discovery. But for a time it seemed as if it would avail us naught.

“To reach the isle we must have a ship, and a crew of sworn and trusted men. For a long time we were in a quandary. But at length we found Signor Barboni, a merchant of Palermo, who lent us his assistance. A small ship was fitted out secretly and we sailed, nine men of us, Alfonso and Barboni.

“In due course we reached Mona. We landed at once and began to search for the treasure. And here was our grand mistake.

“We had traced our way into a rocky cavern. Digging in 16the sand we had, as we believed, almost reached the gold. A bit of earthen pottery was thrown out and a coin found, when a reverse came.

“Suddenly there descended upon us a hundred or more savage Caribs. A terrible battle ensued.

“We were not effectively armed, and the odds were tremendous. My brother Alfonso was brained by one of the savages. Signor Barboni was the next victim. We fought our way to the surf, and only three of us, covered with wounds, reached the ship.

“We spread sails to get away from the accursed place. A calm was on the sea, however, and there we lay until nightfall. Then a terrible thing happened.”
CHAPTER V. A BOLD ESCAPE.
Poole paused a moment, huskily. He arose and took down a decanter and glasses.

He filled and offered them to his visitors. They sipped the wine. He took a copious draught and then went on:

“Somewhat curiously, the Caribs did not come out to our boat to attack us. If they had we must have yielded easily.

“But we soon learned the reason why. They were treasure-mad. With our picks and shovels they had dug up the gold and were fighting over it like wolves.

“As darkness began to shut down the sea began to experience a strange motion. A dull, cannon-like roar came out of the west. Then we witnessed a terrible phenomenon.

“The waters rose like a mighty flood over the isle. At least that was the way it looked. But instead it was the isle which sank into the sea.”

Frank and Wade each drew a deep breath.

They had been intensely interested.

“Then,” continued Poole, “we had hard work to save the ship, but we made out to live through the vortex, and having fair weather worked the ship into the port of Havana.

“Here we sold her and returned to Paris. I separated from my companions. Monte Carlo drew me into its grip once more, and one night the devil aided me and I broke the bank.

“My first fate was to succumb to the treasure fever. I bought this yacht and fitted it out with a view to making 17a fighting vessel of it. This time I was bound to have means of defense in case of attack.

“My men are picked and trusty. They are all bound to me by the most powerful of oaths. I have every sort of diving apparatus aboard. In this manner I have hoped to recover the treasure. This is my story.”

Neither Frank nor Wade spoke. There was silence for a moment. Then Poole said, in a metallic voice:

“If you have a submarine boat it will be of more service to me than to you. How will you trade it for this yacht? Name your price!”

Frank met the other’s gaze steadily, and replied:

“I do not care to exchange.”

Poole’s face grew livid.

His hand instinctively went to his belt. He said:

“Oh, I can see your game. You will easily recover the treasure yourself of which I have told you. But I may as well tell you now that game will not work. You cannot leave this cabin alive unless you come to terms!”

It was a thrilling moment.

Wade’s face paled.

But Frank was as cool as an icicle.

“That is a strong statement,” he said. “Only a pirate would make it.”

“As you please,” said Poole, carelessly. “I claim the treasure, and it shall be mine!”

“For all of me, you can claim it and recover it,” said Frank. “We are not hunting for treasure.”

It was Poole’s turn now to look utter astonishment.

He sank back in his chair and looked cunningly at his visitors.

“Where are you bound?”

“To the Yucatan Channel,” replied Frank.

“On what errand?”

“A purely scientific one. My friend here, Mr. Wade, is a member of the American Scientific Society and claims that at one time an isthmus existed between the points of Cape San Antonio and Cape Catoche. To prove the matter we propose to explore the deep sea in that vicinity.”

Poole drew a deep breath.

His eyes glittered.

“Mona was upon that parallel,” he said. “You will be sure to locate the treasure that belongs to me; I claim it by right of prior discovery. Of this I warn you!”

“Claim it, and be hanged!” said Wade, with disgust. “Come, Frank, let us go back.”

Both men arose.

But Poole drew a brace of pistols and placed his back against the cabin door. He looked ugly.

18“You shall not leave here until you have given me your oath,” he said.

“You will obstruct us at your peril,” said Frank, very quietly.

“I seem to have the best of the situation just now,” said the villain, showing his white teeth.

“What sort of an oath do you require us to give?” asked Wade.

“You must swear that you will not touch the sunken treasure of Mona,” said the villain, intensely. “You look like men of honor. If you give me your word, you will be likely to keep it.”

“We will give our word,” replied the scientist. “Eh, Frank?”

“Certainly,” replied the young inventor.

Poole studied their faces a moment closely. Then the lines of his face relaxed.

“You will pardon the trouble I have put you to, gentlemen,” he said, “but I am gold-mad. I must have the treasure! I cannot be balked in my purpose!”

“Well,” said Wade, “we have agreed to your terms.”

The villain smiled.

“There are other things,” he said.

Frank’s eyes flashed. He drew his lithe form up.

Wade looked disappointed and not a little alarmed that his temporizing had not been a better success.

Poole fixed his keen gaze upon the two men and continued:

“You have the power to visit the depths of the sea. If Mona is sunk too deep our diving apparatus must fail. Since you will not trade or sell your boat, I must charter it for the purpose of bringing up the gold. I will pay you well for the service—yes, I will give you a fifth of the treasure. Come now, is not that fair?”

For a moment Frank Reade, Jr., was so overwhelmed with scorn that he could not speak. When he did recover his voice it was metallic and raspy.

“My friend,” he said, “you labor under a wrong impression. We are not fools; neither are we to be cajoled or bullied. If you had come to me in an honorable, open manner I would not have refused the favor, but as it stands, I would not grant it to you for any consideration. We are going back to our boat. Be so kind as to unbar that door.”

In spite of his pretended advantage the villain quailed before Frank’s eagle gaze and commanding manner.

He moved uneasily, then took up a whining tone:

“Now, come, my friend, don’t be unreasonable. I didn’t mean those threats. You shall not be sorry.”

19Frank took a step forward. The fellow raised one of his pistols. Quick as lightning Frank grabbed his wrist and then with a downright blow of his other hand, dashed the other pistol from his grip. At the same moment he drew back and hurled the villain from the door. It was done in the twinkling of an eye.

Poole himself was astounded at the ease with which Frank accomplished this. His murderous spirit at once flamed up.

“Curse you!” he hissed. “I’ll have your life for that!”

He wrenched his hand free and raised the pistol left him. But like a flash Wade brought his fist down upon the villain’s hand and dashed the weapon to the floor.

Then the scientist proved that he could fight as well as solve geographical problems. With a leap like a panther he had clutched Poole’s windpipe.

Frank came to his aid, and together they bore the villain to the cabin floor. He could make no outcry, and, furious though he was, could not act.

Could he have made an outcry, or a signal of alarm, in less time than it takes to tell it he would have had assistance which would have turned the tables.

But Frank and Wade were already determined upon their plan of action.

They knew well that if they allowed their prisoner to make an outcry their fate would be sealed. So while Wade held the helpless villain by the throat Frank forced a gag into his mouth.

Then he hastily tied his arms and legs with some cord which he found in the cabin. Thus placed hors-de-combat, the wretch was left.

Frank and Wade very coolly stepped out of the cabin and closed the door behind them. A moment later they were on deck.

Two armed men of the crew stood at the gangway, but neither Frank nor Wade affected to notice them, and descended to the boat.

“Row us back!” said Frank, authoritatively to the oarsmen.

“Ay, ay, sir!” was the reply, and they bent to their work. A few minutes later Frank and Wade were on board the Sea Diver.

They had barely gained the deck when an uproar was heard on board the schooner.

“They have found him!” exclaimed Wade. “What shall we do, Frank?”

“Put on all speed, Barney!” cried Frank. “Steer due west!”

“All roight, sor.”

20The submarine boat shot forward. But just at that moment a jet of flame shot from the side of the schooner, and a heavy boom smote upon the air.

A cannonball just grazed the stern of the Sea Diver.

“Egad!” cried Wade. “That won’t do, Frank! If that had struck us fair we would have gone to the bottom to stay!”

“Right!” cried Frank. “Douse the lights, Barney. Veer to the south.”

All was done in the twinkling of an eye. The Diver was in instant darkness and was running away like a flash on another course.

The piratical schooner kept up a random fire in an opposite direction. But the game had slipped them.

“Hurrah!” cried Wade, jubilantly, “didn’t we give them a good slip! Serves the rascals right!”

“Aye,” replied Frank; “he was more than a rogue, that fellow!”

“We may see him again.”

“If we do, we will not place ourselves in the lion’s mouth again.”

“You are right.”

It was true that their destination was the same—that is, the Yucatan Channel, but forewarned is forearmed, and the voyagers were not to be deceived in the character of Hardy Poole now.

“Begorra, it’s bad luck to the omadhouns,” cried Barney. “Av we only had a dynamite gun wid us now, we’d be able to settle their account foriver!”
CHAPTER VI. THE SUNKEN ISTHMUS.
The submarine boat ran on until the lights of the schooner were lost below the horizon. When daylight came there was naught but a clear sea between them.

“We are in the waters of the Gulf of Mexico,” said Frank, with some satisfaction. “Cuba is on our lee.”

This caused all a thrill of excitement.

It was not a long run to the extremity of the “ever-faithful isle,” and then the Channel of Yucatan would be reached.

Frank reckoned that they would make it easily by the next noon. The Meta would be certainly a day longer covering the same distance.

That the schooner would really visit the locality Frank 21had every reason to believe. But he anticipated no trouble in keeping out of her way.

Steadily onward the Sea Diver ran. At length land was sighted to the southwest.

“The Isle of Cuba!” cried Wade.

“No,” said Frank; “Cuba is farther to the east. Those are some little cays which lay off the coast. We must bear off a little to the west.”

At this moment Barney sighted a sail. It was a coast lugger and carried some trading natives from Honduras.

They signaled the Diver in a careless sort of way and then scurried off to the eastward.

“They are afraid of us,” cried Wade.

Frank laughed.

“Doubtless they think us a government boat or war vessel,” he said. “Their trade may be of an illicit kind.”

However this was, the lugger certainly got out of the way very rapidly. She was soon lost to view.

They were now well into the Yucatan Channel. Wilbur Wade was a very busy man.

He was hurriedly making his reckoning and drawing his lines for exploration. The Sea Diver sailed slowly westward the while.

At length she came to a stop. It was at this point that the quest was to begin.

If there was really such a thing in existence as the Sunken Isthmus this was certainly the locality to look for it.

“I have been thinking about that sunken Isle of Mona,” said Wade. “Why might it not have been a part of the isthmus?”

“Very likely,” agreed Frank. “We may be directly over it now.”

“Eh!” exclaimed Wade, with a start. “And if we should come across the treasure——”

The two men looked at each other.

“I don’t see why it would not be lawfully ours as well as Poole’s,” said Frank. “Yet, I have no hankering for it.”

“Still, we might rescue it from the sea. Certainly if Poole gets it he will make no good use of it. It would be a mercy to cheat him out of it. Yet we have given him our oath——”

“Pshaw!” said Frank. “That does not count. It is not binding after what followed.”

“That is true. However, I don’t believe there is a very great chance of our finding any treasure. Let it stay down there with the drowned Caribs. Doubtless it is accursed gold.”

22“I am agreeable.”

Down settled the boat.

The electric lights flashed forth, and now a remarkable scene was presented to the view of the voyagers.

In that one moment of strained gaze it was seen that the hypothesis of the Sunken Isthmus was a thrilling truth.

It was an exciting fact.

Below them the searchlight showed a deep defile between rocky hills. And upon the sides of those hills there were leafless trees, with arms and branches and trunks as natural as life.

The wonderful chemical action of the water in these seas had doubtless caused a species of petrifaction. Astounded, the voyagers gazed upon the wonderful spectacle.

Wade was right in his element.

His hobby, his pet theory, had found verification. It only needed more extensive research to establish the fact of the complete isthmus.

For there was, of course, always the chance that this might be a part of the sunken Island of Mona. But Wade would not credit this.

“It is the isthmus,” he declared; “of that I am very sure. Now, to locate its coasts and contour. This can only be done by following it.”

So the Diver sailed slowly on, it being an easy matter to trace the line of the sunken shore.

“Which way shall we go first?” asked Frank. “To Cape San Antonio or to Cape Catoche?”

“To the last,” replied Wade; “then we’ll come back and make a sure thing of the lines.”

Over the deep defiles and rocky heights the submarine boat sailed slowly on.

The searchlight was kept at work, flashing hither and thither, and every new object of interest was carefully studied.

Soon the topography of the Sunken Isthmus began to change. The rocky hills sloped gradually away into a plain.

Here the Diver descended very close to the bed of the sea and Wade outlined quite distinctly the original coast.

The sinking of the earth’s crust, which had resulted in this submersion of the isthmus, was not to be easily explained. Some internal revolution was very likely responsible for it.

“Now,” cried Wade, after some careful study, “let us change our course to the south; I would like to know the exact width of the isthmus.”

The Diver’s course was changed accordingly. For four hours it sailed over the deep-sea plain. Then indications 23were plainly seen which told that this was the southern extremity of the isthmus.

“Fifty miles,” announced Frank, as he consulted the gauge; “that is the breadth of the isthmus at this point.”

“It is probably the average breadth,” said Wade, “although it is not impossible that it may have been wider in some other localities.”

The course was now changed to the east. It was not a great distance to the Cuban coast.

Half a day’s steady deep-sea sailing showed the usual signs of the surface, and Frank brought the Diver to a stop just over a jagged reef of coral.

There were great reaches of sand before them which trended upwards. That they ultimately rose above the surface in the form of a beach there was no doubt.

“We have reached the end of the isthmus,” declared Frank, “or at least that end which once joined the Cuban isle.”

“To make sure of it,” said Wade, “suppose we rise to the surface.”

Frank touched the tank-lever and the boat sprung upward. The next moment it was above the surface.

But all was darkness upon the sea. The hour was 4 A. M. and the sun had not yet colored the east.

But Frank turned on the searchlight and showed the cliffs distant not quite a half mile. That it was the Cuban isle there could be little doubt.

However, to make sure, the Diver lay-to off the coast until daybreak. Then bearings were taken. A small pearl-fishing sloop passed near.

Wade hailed it and learned for a fact that the coast was that of Cuba. Then he said:

“Let us go back to the deep sea. I ask only to follow the isthmus to the peninsula of Yucatan. All doubt will then be settled. My friend, Professor Brown, will then be very willing to admit his error.”

“He will if he is not pig-headed,” said Frank.

He was about to touch the tank-lever when Barney from the deck, gave a sudden sharp cry:

“Whurroo, Misther Frank, shure, it’s a sail off to windward!”

“A sail?”

Frank and Wade gazed in that direction. Then both gave a violent start. A small schooner was seen bearing down upon the Diver.

Wade’s eyes dilated.

“It is the Meta!” he exclaimed; “they are making for us!”

24This was the truth. Hardy Poole’s piratical schooner it was, and they had sighted the submarine boat.

She was bearing down rapidly, with all sails set. Frank and his companions watched the schooner with some curiosity.

But Frank knew that it would never do for the schooner to come within cannon shot. One ball striking the submarine boat would be likely to ruin her.

So he ran up a signal flag of defiance. It was seen by Poole, and a cannon was fired in reply.

Then the voyagers skipped into the cabin and Frank sent the Diver to the bottom.

Westward now over the sunken isthmus her prow was turned. For hours she kept on.

Toward night the place where they had first descended was reached. Here a stop was made.

Thus far the trip was a glowing success. No serious mishap had marred the project.

But could the submarine voyagers have read the future they would have experienced not a little of fear and dread apprehension.

Thrilling events were in store.

So far there had been discovered no indication or logical evidence of the possible existence of inhabitants on the isthmus in former days. Wade was not a little disappointed.

But when he remembered that there was yet a goodly distance between them and the Yucatan coast he did not altogether lose faith.

He hoped for the best.

All were somewhat exhausted with the incidents of the past forty-eight hours, so they were glad enough to turn in, Barney being left on guard, to be relieved by Pomp later in the night.

This was the usual arrangement.

Barney was completely exhausted himself, and in spite of his efforts to the contrary fell asleep at his post.

He was far advanced into the mystic Land of Nod when a startling thing happened.

From the gloom of a defile near there appeared a monster black form. It glided once or twice around the Diver as if to size it up.

The creature’s powerful curiosity was aroused and it ventured into the glare of the searchlight.

It was a strange creature.

Had Barney been awake he would have seen a monster specimen of a fish which seemed a cross between a shark and a whale. But he failed to see it at that moment, though he speedily became aware of its proximity.
CHAPTER VII. A SERIOUS CATASTROPHE.
The curious fish passed several times around the Diver. Then it drew off with an apparent air of offended dignity and aroused jealousy.

What right had this unknown creature to venture into these waters? It looked as if this was the reasoning of the huge fish.

Whether it was or not, one thing was certain. The creature had made up its mind to attack the submarine boat.

Steadily it drew back, flopping its huge flukes, until finally it stopped and was motionless a moment.

Then it darted forward.

Barney was in the midst of a beautiful dream of home when suddenly he felt himself flying through space. Then it seemed as if he was coming in contact with a legion of hard objects and sharp corners.

In an instant he was wide awake. It required a moment for him to collect his scattered senses.

Then he realized that the boat was moving. It was flying upward like a rocket and suddenly popped up onto the surface of the sea.

The Celt, astounded beyond measure, rushed into the pilot-house. There he saw that things were thrown all about.

There was a dent in the wall of the structure large enough to force the electric keyboard from its post. The wires were all tangled up or disconnected and the tank-lever had been closed by the shock.

“Mither presarve us!” muttered the Celt. “Phwat the divil happened?”

At that moment Frank and Pomp and Wade came rushing in.

“For mercy’s sake, what struck us, Barney?” cried the young inventor. “What’s the matter?”

“Shure, sor—I—that is—it must have been an airthquake, sor!”

“More likely an avalanche,” declared Wade. “Heigho! how came we on the surface?”

“Golly, look at dat keyb’d!” ejaculated Pomp.

Frank gazed at Barney.

“What was the cause of this, sir?” he asked, sternly. “Why don’t you speak?”

Poor Barney!

Cold sweat stood out upon his brow. He knew that he 26had been guilty of a serious misdemeanor. A culpable act of negligence.

“Shure, sor—I—I—don’t know,” he stammered.

“You don’t know?” exclaimed Frank, severely. “Were you not on guard?”

“Yis, sor.”

“And you don’t know what caused all this wreckage?”

“Well, sor, somethin’ must av sthruck the boat, sor—an’—I didn’t see phwat it was, sor.”

Frank looked keenly at the Celt.

“Tell me truly,” he said; “were you asleep?”

It was against Barney’s principle to lie.

“Yis, sor,” he replied.

Frank turned away.

“That is enough!” he said, reproachfully. “I thought I could trust you.”

With his nerves tingling with shame, Barney slunk away. But Frank uttered no further words of censure, for he knew that the poor fellow was wellnigh warranted in his negligence, for he was extremely exhausted.

Still, he should have kept awake.

The Diver rocked in the rolling waves of the sea. The night was as dark as a pocket.

Frank would have sent the boat to the bottom again, but he soon found that he was unable to do this. The lever was out of order.

In order to locate the break he would be obliged to put hours of hard work into the task. He decided to wait for daylight.

So he put Pomp on watch and then all retired again to their slumbers. The coon was not in danger of sleeping after what had happened to Barney.

He paced the deck of the Diver and kept a close watch of the sea. It was in that interval of darkness just before the dawn that he saw a light off the port bow.

It seemed to come from the masthead of a distant vessel and was a colored light. The coon watched it.

When he saw it was drawing nearer he started to call Frank, but he changed his mind a moment later.

The unknown craft passed to windward and the light suddenly vanished and was not seen again.

Morning came and brought a surprise. The first thing Pomp’s eager eyes rested on was a dark hull off to the southward.

It was a small vessel bearing down toward the Diver.

Pomp gave a sharp look at it and then muttered:

“Fo’ de lan’s sake, I done beliebe dat am dat piratical schooner. Reckon Frank bettah see ‘bout dat.”

But Frank was already coming on deck.

27He met the excited darky, and seeing his trepidation, asked:

“What’s the matter now, Pomp?”

“A heap de mattah, sah. I reckon dat ole schooner am comin’ fo’ us again.”

Frank gave a violent start.

“Is that so?” he ejaculated. “Why, we seem fated to be followed by her. It will hardly be safe to fall in with her in our present condition, either.”

“Yo’ am right, sah.”

Wade was just behind Frank.

“Eh, what’s that?” he asked. “You don’t mean to say that that accursed schooner has overtaken us again?”

“Dat am so, sah,” replied Pomp.

“That is very bad.”

Frank and Wade went to the rail with their glasses. It did not require much of a scrutiny to determine that Pomp was right.

It was the Meta, and she had evidently sighted the Diver. She was coming on with all sails spread.

“By Jove!” exclaimed Frank, “she will be down onto us in a jiffy. We must get out of here right away.”

“For a fact!” agreed Wade. “What shall we do, Frank? We cannot sink the boat, can we?”

“No,” replied the young inventor. “Our only hope is to run away from her until we can get our tank machinery repaired.”

“But is not the other machinery out of order, too? Have you tried the motor-lever yet?”

Frank’s face paled.

“No,” he admitted, “but I think it will be all right. We will soon know the truth now!”

It must be confessed that with some feeling of trepidation and doubt Frank now entered the pilot-house. He tried to adjust the shattered keyboard.

And now he saw that a great peril threatened! The motor-lever would not work. The electric lights even could not be shut off.

There was no way to start the machinery of the boat without restoring the keyboard connection. This would require some hours of hard work.

In the meantime the Meta was rapidly coming down upon them. Frank shivered as he thought of this.

He regretted now that he had not at once set about repairing the machinery the night before. But it was of no use to cry over spilled milk.

Something must be done, and that at once.

Wade came into the pilot-house white as chalk.

“They mean to sink us!” he gasped; “they have just 28fired a shot across our stern. When they get our range they will certainly hit us!”

“Run up a signal,” replied Frank, hastily. “You must temporize with them. Partly accede to their terms. Anything to gain time.”

And Frank began work at once upon the keyboard. Wade took the tip and rushed out on deck.

The Meta was now within easy cannon shot. She was training her gun again when Wade ran up a signal flag.

It implied a parley, and at once the Meta answered it.

“Begorra, I only wish we had our electric gun wid us!” cried Barney. “Shure, we’d jist play wid thim, yez kin be sure!”

But Wade knew well that their only hope was a shrewd game of policy. He went back to the pilot-house.

“How much time do you want, Frank?” he asked.

“At least two hours,” replied the young inventor. “Send Barney here to me.”

Barney came, and together they worked at repairing the keyboard. Wade went back to the deck.

The Meta had signaled again. Wade answered the signal.

Then the schooner drew within hailing distance. Wade had resolved upon a daring and diplomatic move.

“Ahoy, the Diver!” came across the water in Poole’s voice.

“Ahoy, the Meta!” replied Wade.

“You signaled us for a parley?”

“Yes.”

“Well, what is it?”

“We have considered your terms,” replied Wade. “Send a boat over and I’ll come and talk with you.”

There was a thrill of exultation in Poole’s voice as he replied:

“I thought you would reach a sensible decision. I will send a boat.”

A few moments later a boat put off from the schooner. Wade went into the cabin.

His purpose was wholly to gain time. It required fifteen minutes for the boat to cross the intervening distance.

Then Wade kept them waiting at the gangway fifteen minutes. When he appeared he managed to squander some time getting into the boat.

Then it required fully twenty minutes to pull back to the schooner against the strong wind. Nearly an hour was thus consumed.

Mounting to the deck Wade met Poole politely, but he did not fail to see the cunning and treacherous light in the villain’s eye.

29“Where is Mr. Reade?” asked the treasure-hunter, in surprise.

“He is indisposed, and has authorized me to act in his place,” said Wade, wincing a little at this white lie. It seemed to satisfy Poole, however.

“Come into the cabin,” he said.

Wade leisurely followed him. He affected a desire to smoke and proffered Poole a cigar. Some time was thus consumed, and fully a quarter of an hour was passed before Poole was able to say:

“Well, have you decided to come to my terms?”

“We have talked the matter all over,” said Wade, shrewdly; “and we have decided to accept your story as the truth, though you will pardon me if I say that this was not the case when we first heard you tell it.”

The villain looked astonished.
CHAPTER VIII. THE VILLAIN OUTWITTED.
“Oh!” he ejaculated. “Then you didn’t believe me?”

“Of course, you will understand,” said Wade, diplomatically, “that such a story from the lips of a stranger looked a bit large. We must be excused for a bit of incredulity.”

The villain’s face lit up.

“But you believe it now?” he asked.

“It looks more plausible,” admitted Wade. “We are prepared to accept it as true.”

“I am glad you have come to your senses,” growled the villain. “I haven’t any hard feelings against you, though it was pretty hard usage you gave me on board my own vessel.”

“We acted, as we believed, in self-defense.”

“Well, I reckon so. However, we’ll let by-gones be by-gones. In regard to this offer of mine—do you accept it? One-fifth of the gold shall be yours for the recovery of it.”

“Do you reckon that a fair share?” asked Wade, diplomatically.

The villain swore horribly.

“Why is it not?” he cried. “I am sure that you could get no better terms from any one. It will make you all rich enough.”

Wade feigned avarice.

“I think we ought to have half,” he said.

30Poole uttered a frightful oath.

“Well, you will never get half!” he cried, “nor nobody else.” Then, after a moment’s thought: “Well, I’ll do a little better. I’ll give you one-fourth.”

Wade took a notebook from his pocket and wrote down all in serious fashion.

“Now,” he said, “for other terms. You are to show us the place, and we are to dive for the gold.”

Poole rubbed his hands.

“Yes, yes!” he said, briskly, “but there is a stipulation.”

“Oh!”

“You must allow me and two of my men to go down with you while the gold is being taken up!”

Wade jotted this down.

“What else?” he asked.

“That’s all. What are you doing?”

“I am making a report to present to Mr. Reade. I will give him these terms and return with an answer as quickly as possible. Have no apprehension. He will be quite likely to accept the terms.”

Poole looked annoyed.

“I thought you came prepared to accept them?” he said.

“No, sir!” replied Wade, decisively. “Mr. Reade is the master of the submarine boat.”

“And you are his envoy?”

“Yes.”

“Tell him to come himself next time. I don’t feel like being trifled with. Be quick as you can about the answer.”

“I will report at once!” replied Wade, with a manner which belied his words. “Have another cigar.”

“No; confound your cigars!”

“Sir!”

“Excuse me, but I am nervous over this situation. Bring me an answer as quick as you can.”

Wade pretended to hurry to the gangway. Then he got into the boat. He had been forty minutes aboard the schooner.

The men bent to their oars and rowed to the gangway of the Diver. Wade turned to them and said:

“You are to wait here for me; do not get impatient.”

Then he went into the pilot-house. Frank and Barney were puffing like beavers, amid a heap of debris.

“How is it?” asked Wade.

“You are a brick!” cried Frank. “There is only one more nut to adjust. What did you do?”

Wade told his story.

31Frank was delighted.

“We will send him an answer,” he said. “I will write it.”

He sprung into his private cabin and wrote a hasty note as follows:

“Dear Captain Poole: My friend Wade has brought me your terms. They are hardly liberal enough. However, if I decide to accept them, will let you know at an early day. Very respectfully,
Frank Reade, Jr.”

Wade could not help a chuckle.

“How he will swear!” he said. “He will be as mad as a hornet.”

“But he will not be able to injure us,” said Frank, “for, thanks to your skillful diplomacy, the Diver is all right once more.”

Frank went into the gangway and handed the letter to the coxswain.

“This is for your captain,” he said; “deliver it to him immediately.”

“All right, sir.”

The boat shot away. When it was twenty yards distant Frank cried:

“Into the cabin, everybody! We’re going down!”

The order was obeyed. The doors and Windows were closed instantly.

Then Frank touched the tank-valve. There was a sudden quivering of the boat, and down she went like a flash.

Poole, standing on his schooner’s deck, was astounded.

When a few moments later he read the message sent him he was more than furious.

“Curse the luck!” he cried. “What stupidity in me! I ought to have held that fellow as a hostage. They will go and recover the gold themselves now. Up sails, men! Bear away at the tiller there! We must be the first to reach the spot. If the water is not too deep our diving suits will be as good as their boat.”

The Diver went down quickly to the bottom of the sea. No sooner, however, had the sandy bottom come into view than another peril presented itself.

A huge monster shot out of a dark defile.

It was the same giant fish which had attacked the boat once before. Frank saw him coming.

He at once suspected that this was the fellow who had dented the shell of the pilot-house. He saw the risk of another collision.

“Look out!” he shouted. “We may hit that fellow.”

In the stem of the submarine boat was a long steel ram. 32This was provided with electric communication with the dynamos.

Frank had foreseen just such an exigency.

He knew that if he could only strike the fish with this heavily-charged ram the trouble would be quickly over. The monster would be sure to succumb.

So he turned the boat about as quickly as possible to meet the fish. He partly succeeded.

The cetacean struck the boat just abaft her bow. For a moment the partial shock it received dazed it.

The boat was flung almost upon its side, but as it righted Frank instantly brought it about and drove it forward.

The ram struck the cetacean in the gills. It literally tore these away and the monster turned over dead. It was a signal victory.

“Whew!” exclaimed Wade. “I would not care to meet many of that fellow’s stripe. He is quite a match for the Diver.”

“There are many heavier monsters in the deep sea,” declared Frank. “We may run across a worse tussle yet.”

“I hope not.”

However, the coast was clear once more. The Diver ascended the ragged, rocky hills and passed over what was really a mountain range.

For what Frank reckoned as a distance of twenty miles, the submarine boat kept on thus.

Then the sunken isthmus began to undergo a change.

Rolling land spread out beneath them, and suddenly Wade clutched Frank’s arm.

“Look!” he gasped; “just what I expected.”

“A submarine city!”

“Just so!”

The spectacle presented to the view of the voyagers was a remarkable one. There in the heart of the rolling country was unmistakably the walls and housetops, streets and squares of a city.

But the streets were silent, the windows and doors deserted and kelp and debris clung to all. It was a marvelous spectacle.

What curious reflections might be drawn from this spectacle!

Here was once a thickly-populated center. In these dismal streets a people thronged, here trade flourished and society held sway.

What manner of people the lost inhabitants were could only be imagined. But that they were wellnigh the mark of civilization was certain.

In one fell hour their great mass of human souls had been swept into eternity!

33The waters had rushed remorselessly over all, and in the mad vortex life had counted for naught. What tragedies were there enacted upon this spot! What moments of horror preceded the dread event!

Instinctively these thoughts came to all as they gazed upon the sunken city. Perhaps Wade was the most deeply impressed.

The Diver sailed slowly down over the sunken city.

Frank selected a broad square near one of the open gates and allowed the submarine boat to rest upon the bottom.

Then he focused the searchlight upon the entire length of a broad street before them.

“Here we are, Wade,” he said. “Now is your chance for arch?ological research.”

“Just so,” agreed the scientist. “I judge these people a branch of the old race which built Palenque and other Yucatan cities. I fear we shall find but slight clews to guide us.”

“Then you reckon that time and the action of the salt water has removed everything of value?” asked Frank.

“Everything but the bare walls of the buildings,” replied Wade. “However, we can make a little exploring tour, if you are willing.”

“I shall be glad,” replied Frank. “Barney, bring up the diving-suits.”

“All roight, sor.”

The Celt disappeared in the after-cabin. Very soon he came back with the suits.

There were two of them, and they were of an unusual pattern.

The usual diving-suit, as we all know, is operated by means of an air-pump and life-line, but these suits were the special invention of Frank Reade, Jr.

They consisted simply of a very heavy helmet, with connections with a square box-like case, which was strapped on the back.

This was the chemical generator, which furnished plenty of pure air for the diver for an indefinite period of time.
CHAPTER IX. THE SUNKEN CITY.
The diving-suits were a very clever invention. They were superior to the old style for the fact that the diver had free use of his limbs and was hampered by no life-line or tube.

34Frank gave instruction to Barney and Pomp to remain aboard the Diver and keep a good watch of the two divers all the while. Then he helped Wade to don his suit and put on his own.

They were now ready to leave the boat.

This was accomplished in an ingenious manner. Of course, it would be impossible to merely open a door and step out.

Water would rush in and flood the cabin.

But Frank had provided a vestibule with two doors, one opening into the cabin and the other out on deck.

He had merely to enter the vestibule and close the cabin door. Then, by turning a valve, the vestibule would fill with water. It was easy then to open the outer door and walk out.

The return was accomplished much the same, though the pressure of a lever set the force-pump at work and cleared the water from the vestibule in quick time.

Frank and Wade entered the vestibule, and a few moments later were out on the vessel’s deck.

They clambered down the side and stood upon the pavement of the sunken city.

It was a strange sensation.

Probably no other men living could boast of the same experience. Down the street of the sunken city they walked.

It required Wade some little time to get used to the pressure, he being inexperienced.

But soon he had overcome the unpleasant sensation and was quite himself again. Together they strolled along the thoroughfare.

There was no conversation, for one could not have heard the other speak at that depth. Moreover, the helmets deadened the sound.

But conversation could be carried on by placing the two helmets close together and shouting. This was only resorted to in case of necessity.

The buildings of the sunken city were of two stories only and not at all pretentious—like the ruins of Palenque.

But there was one higher-arched structure, just back from the street, which claimed their attention.

There was a quantity of curious carving and scroll-work in its front. Frank concluded that it must be either a palace or a temple.

He was determined to ascertain.

Motioning to Wade he entered the place. The scientist was not slow to follow him.

Each wore upon his helmet a small electric globe. This made objects plain in the place.

35As they passed through the great portico it was easy to see at once what sort of a place it was. For a moment they were spellbound.

It was unquestionably a temple.

In front of them was a broad dais of stone. Upon this there rested a gigantic and grotesque image. It was plainly an idol.

The ancient inhabitants of the sunken city were then idolators. This fact was settled.

The idol was fully fifteen feet in height, and in shape was a cross between a sphynx and satyr. Its eyes were of some brilliant stone.

Around the temple were other idols of various sizes. Each had its dais, and there were the worn hollows in the stone made by the knees of kneeling thousands.

Frank placed his helmet close to Wade’s and shouted:

“Is this discovery of value to you?”

“Much!” replied the scientist; “it establishes the fact of idolatry, and also that these people were much like the Aztecs and worshiped the same gods. There are the idols Quetzal and Quetzalcoatl. They are Aztec gods.”

“That is certainly a great point,” replied Frank. “Yonder I can see some hieroglyphics on a stone. Is it possible to read them?”

“I am not familiar enough with Aztec cryptography,” said Wade. “I shall not attempt it.”

But another discovery was made.

Before the large idol was a broad and richly carved altar. Below it was a pit for the reception of the blood of the victims.

The two explorers gazed upon this gruesome object with a thrill.

“Many a poor wretch has gone to his doom on that stony surface,” declared Frank. “What barbarity!”

“True,” agreed Wade; “the ancient ideas of sacrifice were something simply savage.”

No small object of any kind of metal could be found. Every vestige of any material but stone had been absorbed by time and the water.

So Wade could find no other specimen to take with him but a small idol, which he placed in his pocket.

“I shall keep this for a talisman,” he declared. “Perhaps it will bring me good luck!”

“I believe I will do the same,” said Frank; “so here goes.”

He also took one of the idols. Then they left the temple.

Once out upon the street again they began to look for another object of interest.

36This soon turned up.

Passing through a sort of peristyle they came out into a large court, in the center of which was a large basin. Here no doubt a fountain had once played.

This court had no doubt once been the scene of magnificence. There was every indication of it.

Statues of the nude adorned its circle. These were hardly to be compared with Grecian sculpture, but they represented a very good knowledge of the art.

Instinctively both men pictured the place as it might once have been.

Flowering trees and shrubs, noble palms and trailing vines had once made the spot beautiful.

The sunlight had once glinted in upon these alabaster walls, with their setting of beautiful green. It had given light to a gay assemblage of dark-skinned people, and fell upon the state throne of the king.

For this stood at one end of the court just as it must have stood in those old days. It was a great chair of carven stone, with a canopy over it, or at least the frame where the canopy had once been.

But nothing was left of all this magnificence but the bare walls. These alone were imperishable.

Only their marble sides and columns remained. All else was dust.

Time and the action of the water had worn them away.

“This is probably the king’s palace,” said Frank; “don’t you think so?”

“Yes,” agreed Wade. “I tell you these were no ordinary people.”

“I believe you.”

But they did not conduct their research much further.

There were chambers beyond the whole interior of the sunken palace, but the two explorers had seen enough.

Frank began to wonder if all was well aboard the Diver, and as for Wade, his head ached to bursting.

So Frank said:

“Have you gone far enough, Wade?”

The scientist nodded his head.

“Yes,” he said, “I am satisfied. Let us go back.”

Frank was glad to lead the way out again into the street. They then turned their footsteps toward the submarine boat.

Barney and Pomp were waiting for them. Straight to the gangway they came.

In a few moments they were safe in the cabin once more. The trip had been a success.

But Wade was still looking ahead, and was anxious to continue on his way along the isthmus.

37So the Diver arose and headed for awhile over the sunken city. Then it left it behind.

The presence of the sunken city settled a number of facts. It was true beyond peradventure that there had once been an isthmus between Capes San Antonio and Catoche.

It was also certain that there had once dwelt upon it a race of people of great intelligence. That the sea had wiped all out of existence was certain.

Wade studied the matter thoroughly and most scientifically. So he said to Frank:

“I have seen enough; let us go along.”

“All right,” agreed Frank. “A due west course is sure to bring us to Yucatan.”

“Very true,” agreed Wade, “but above all things go well armed and prepared for trouble. I feel sure that we have not seen the last of that schooner!”

The young inventor could not help a laugh at Wade’s earnestness.

“That is your bugbear,” he said. “How are they going to injure us at this depth of the sea? They have only the very crudest of diving-suits.”

“I don’t know,” replied Wade, “but I cannot help a feeling of that sort. I believe we have not seen the last of Poole.”

“It is a little curious that we have not as yet come to the sunken isle,” said Frank. “That I must regard as only a small part of the isthmus which did not sink in the first earthquake.”

“Beyond a doubt,” agreed Wade. “In that case we shall certainly come across it.”

“We will keep a lookout. It should be in about this latitude.”

The course they were pursuing was along the northern shore of the isthmus. It was easy to follow its conformation.

As Frank had declared, they could not be far from the sunken Isle of Mona. And, indeed, a few hours later they came upon precipitous bluffs and forests of decaying trees.

The island was beneath them. There was no doubt of this. The voyagers were alive with the keenest of interest.

Ordinarily there would have been but a scant desire to search for the buried treasure. But their experience with Poole had aroused their interest.

Frank had a strong inclination to visit the scene of the treasure hunt. So he held the Diver closely along the island and shore.

It was remembered that Poole had described the gold cave as upon the northern shore. When attacked by the 38Caribs he and his companions had escaped in their boat, so it could not have been far from the surf to the cave.

It should, therefore, be easy to find. Barney and Pomp were especially on the lookout.
CHAPTER X. AT THE TREASURE CAVE.
Slowly and steadily the Diver crept along the shore of the sunken island. The voyagers were on the qui vive.

“Perhaps Poole is there before us,” said Wade. “He has had plenty of time.”

But Frank was incredulous.

“I don’t believe it,” he said. “It would take him a long while to locate the exact spot. Hello! what is that?”

A dark object loomed up before the gaze of the voyagers. It required but a moment’s scrutiny to make it out as the hull of a sunken vessel.

It lay upon the shore of the sunken isle, and might have foundered at the time of the earthquake. She was a small schooner of the coast trading class.

The submarine boat sailed near to her and the searchlight was focused upon her. But there seemed no good reason for paying her a visit, so presently she was left behind.

But now developments came in swift order. Rounding a headland the Diver came upon a collection of partly demolished huts and other evidences of habitation. This was doubtless the village of the savage Caribs who had descended upon the gold hunters.

Wade was now much excited.

“We ought to be getting near the spot where the treasure is located,” he said. “I surely hope so!”

A few moments later a long cliff-wall was reached. Then a huge, dark-mouthed cavern yawned to view.

“Down with the boat!” cried Frank. “Let her rest here, Barney. This is the spot beyond doubt.”

The order was obeyed. The submarine boat rested upon the sands and hastily preparations were made for leaving the cabin.

As usual Barney and Pomp were left aboard. Frank and Wade quickly donned their diving-suits.

Then they left the cabin and soon were striding along the beach. They had not gone a dozen yards before Wade paused.

There, imbedded in the sand, was a skeleton. The fishes had long since eaten away all but the bones. Whether it 39was the skeleton of one of the gold hunters or a Carib it was not easy to guess.

Other skeletons were also found in the vicinity. Then they reached the mouth of the cave.

Here were found the rusted digging tools of the gold diggers. Also a huge cavity in the cavern floor was revealed.

And partly upon its verge there was a huge chest, with one end knocked out. In the chest was a heap of round objects. They were coins.

Much corroded they were, and as Frank and Wade picked up several of them it was hard to tell whether they were gold or merely silver.

There were others strewn in the sands of the cavern. The cavity in the sands did not seem to contain any other chest.

If this was the total amount of the treasure it certainly was small, and did not greatly pay for the effort to recover it. However, Frank and Wade had begun to make preparations to remove it when a startling thing happened.

Suddenly into the cavern there flashed a light. Astonished the two divers turned. Two forms were at the entrance.

It required but a glance to see that they were divers. Moreover, they wore the common diving-suit, hampered with life-lines and cords. In an instant the truth burst upon Frank and Wade.

They were beyond doubt members of the crew of the Meta. Indeed, Poole himself doubtless was one of them.

Frank and Wade placed their helmets together tightly.

“By Jove!” cried the young inventor, “we’re in a scrape now!”

“You’re right, Frank. I believe one of them is Poole himself.”

“There is little doubt of it.”

“What shall we do?”

“There is no way but to face them.”

“Will it be safe? Will they not attack us?”

“It is likely; but I can see no way to evade them.”

“Then we must defend ourselves!”

“Just so; our chances are as good as theirs, and we have an advantage in having no life-lines to bother us. Come along, we might as well meet them half way!”

Poole and his men, for there were now four of the divers in the cavern, had caught sight of Frank and Wade.

It could be easily seen from their actions that they were frantic and would present a hostile front. But Frank and Wade gripped the handles of their axes and marched steadily on.

40In a few moments they were near the other divers. One of them was recognized as Poole.

The villain was the personification of fury. He swung his ax aloft and made a rush at Frank.

His companions did the same. It was fortunate for our friends that they did not come to close quarters. They evaded the attack, for they could move more easily.

Frank’s purpose was to get out of the cavern. He knew that if they were hemmed in there, their fate would be sealed.

So he motioned Wade to follow him, and, parrying Poole’s attack, hurled one of his foes back and with a swift rush gained the object. Wade came close behind him.

Once outside the cavern the danger was over. The rascals could follow them but a limited ways.

Back to the submarine boat Frank and Wade rushed. They clambered aboard and soon were in the cabin.

Barney and Pomp were astonished.

“Fo’ de lan’s sake,” cried the coon, “wha’ am de mattah? Wha’ hab happened?”

“Well, Pomp,” replied Wade, “we fell in with Poole again, as I feared we would. We gave him the slip, though.”

“Begorra, yez don’t say!” exclaimed Barney, in amazement. “Shure, howiver did the omadhouns git down here?”

Wade told the story, to the edification of Barney and Pomp. Meanwhile, Frank had been examining specimens of the coins which he had found.

Wade went over to him.

“Well,” he asked, “what do you make of them, Frank?”

“Nothing but silver,” he said. “A heap of pistareens—that is all.”

The scientist was astonished.

“Mercy!” he exclaimed; “what a disappointment that will be to Poole! He declared that millions in gold were buried in that cavern.”

“So his avarice is repaid,” said Frank, with a laugh. “Poor wretch! Let him have his treasure and all the good it may do him.”

“Then you will not interfere?”

“Certainly not.”

“Good,” cried Wade. “Let us then go on to Yucatan and finish our exploration of the sunken isthmus. We will leave Mr. Poole to the exclusive enjoyment of his much-vaunted treasure.”

“Just so,” said Frank. “Start the engines, Barney; let us get under way.”

41Barney hastened to obey. As the Diver sailed away to the westward the searchlight was focused upon the cavern mouth.

There a curious scene was revealed.

Poole and his men were digging in the sands for the coins scattered by the Caribs. They seemed to act like madmen, so strong was the treasure fever upon them.

The submarine voyagers were glad to leave the sunken Isle of Mona behind them. The Diver glided on through the deep sea.

They made rapid course now toward Yucatan. The course was very easy to follow, the sunken isthmus being an established fact.

Many beautiful sights were daily witnessed in the sea depths. Many strange specimens were secured.

But no incident of a thrilling sort occurred until one day they had arrived within a few miles of Cape Catoche, as Frank estimated by his measurement of distance.

“It should be in sight,” he declared, “if we were on the surface.”

“Why not rise and take a sight at it to make sure?” asked Wade.

“We can,” agreed Frank.

So he stepped into the pilot-house and touched the lever. The next moment the submarine boat was flying upward.

Up out of the briny deep she shot, but the moment she emerged a disappointment was in store.

They had expected to sight the rugged headland of Cape Catoche directly in front of them, but they were in the midst of an impenetrable fog.

No object could be seen ten yards away. It was a discouraging predicament.

“Well!” ejaculated Wade, “here is a pretty how-do-ye-do! What is to be done?”

“I reckon we bettah wait fo’ de fog to lift, sah!” suggested Pomp.

“Bejabers, it may be a good while at that,” averred Barney.

“Oh, I think not,” said Wade. “What shall it be, Frank?”

“We will lay-to for a short while,” said the young inventor. “There can be no harm in that.”

So the Diver continued to rock upon the swelling surface of the sea, while the voyagers at times tried to pierce the fog with their eyes.

Perhaps an hour had passed thus when a curious thing happened. Out of the fog there came plainly to the hearing of all, voices raised in laughter and jest.

They seemed but a few yards away, and startled, the submarine 42voyagers instinctively looked, with the expectation of seeing a vessel bear down upon them out of the fog.

But none appeared.

One moment the voices appeared to sound in one quarter, and then they would change to another, even sounding directly overhead.

“Begorra, that’s quare,” cried Barney; “shure, they’re niver in the same place at all, at all. They must be thraveling around us, an’ divil a bit do I loike it! Shure, it’s a sorry place for banshees, but on me loife it may be that same!”

“Nonsense,” said Frank, sharply, “it is a common enough phenomenon, and due to the fog.”

“Right,” cried Wade. “Somewhere near us a ship is anchored and her crew are doubtless whiling away the time in games and pleasure. A peculiar condition of the atmosphere brings their voices to us.”

“Dat am berry funny,” said Pomp, in mystified tones.

“Begorra, yez are roight,” averred Barney.

But the voices presently died away, becoming fainter and fainter. Then the fog was seen to be in motion.

Gradually it lifted and the sea was seen north, south and east of them, but to the west there was a long line of coast.

A bold headland rose to view, and with a thrill of joy Wade cried:

“That is Cape Catoche. We have thoroughly explored the sunken isthmus. Our expedition has been a success. We have rendered science a mighty service, and have good reason to feel proud of it.”
CHAPTER XI. POOLE PLAYS A NEW CARD.
Down in the ocean depths, Poole and his men had been at work digging out the supposed mighty treasure of the Isle of Mona.

Every skeleton was unearthed and the sand around it closely sifted. Thus the coins were recovered.

Also further excavations were made in the cavern, but without success.

However, believing the coins to be gold, the villain was fairly well satisfied. He piled them into the chest and had it hoisted aboard the schooner.

“Ha,” he muttered, “I was just in time to foil those dogs. They were sure of beating me, but Hardy Poole has staked too much upon this game to lose. Curse them, 43I will some day have a chance to settle the score with them.”

With this venomous decision he removed his diving-suit and had begun to examine his treasure when an incident occurred.

One of the men who had been in the shrouds cried:

“Sail ho!”

“What?” cried Poole, with a sudden start. “Bearing our way?”

“Yes.”

“What does she look like?”

“She looks like a fast craft, sir. Most likely a coast guard vessel,” was the reply.

“Change course. Bear nor’-nor’-west!” ordered the villain. “We don’t want to fall in with any Cuban cruiser just now.”

The schooner lay about on the new course. She was a fairly fast sailer and cut the water rapidly.

But in a few moments the man aloft again shouted:

“Ahoy, the chase!”

“Eh?” roared Poole. “Is she giving us a chase?”

“That she is, sir, and she is gaining on us. She has steam up and can sail two knots to our one.”

“A steam vessel!” gasped Poole. “Then she is certainly a Cuban cruiser. She takes us for a filibuster. If she overtakes us nothing will convince her that we are not and our jig is up! Ho, there, all aloft and crowd on sail! We must make a run for it! If she overhauls us——”

“Well?” asked one of the men.

Poole’s grim face hardened.

“We will fight for it!” he said, “for they will never take the treasure from us while we live.”

The crew cheered at this bold declaration and then scampered aloft. Meanwhile Poole watched the distant steamer with varied sensations.

“Just our luck,” he muttered. “By the gods, I believe I am cursed by fate! Let them overhaul us, curse them! We will give them all the fight they want.”

Then he went back to the cabin and began to gloat over the treasure. He picked up one of the coins and scraped away the rust and mold. Then he snapped his eyes.

How was this?

It was white metal instead of yellow—silver instead of gold!

If all that bulk of coin was silver, its value was but small; if of gold, it would be immense. Quite a difference. He dropped the coin with a grunt.

He picked up another and scratched its surface. It was also silver.

44Another and another. Then a sickening sensation came over him, and he smiled in a ghastly way.

“Silver!” he hissed. “Can all of them be such? Is there no gold?”

He kept at his work. It soon became apparent to him that this was a terrible fact. He sank in a chair, with distorted features and bursting veins.

For a moment he was apoplectic. Then great curses rolled from his lips. He struck the table with his clenched hand.

“They have beaten me!” he hissed; “they have taken the gold and left me the silver! Curse them! they have beaten me, but the end is not yet!”

He was too unreasonable to consider the situation logically. He could accept but one conclusion, and this was that the submarine voyagers had taken the gold and outwitted him.

“Why did I allow them to escape me?” he gritted. “I should have killed them all! They were in my power! Fool! Fool!”

He raved like a maniac in his impotent wrath, frothed at the mouth, and might have really yielded to apoplexy or some other fit had not an interruption come.

The distant boom of a gun was heard. Poole turned a ghastly pallor.

He knew what that meant.

“They are overhauling us!” he gritted. “We are to lose even this pittance of silver! But I will have the gold if I have to follow Frank Reade, Jr., to the end of the earth!”

He hastened upon deck.

The cruiser had come up within gunshot and had sent a summons to heave-to. There was no alternative but to obey or fight or go to the bottom.

For a moment Poole considered seriously the question of a fight. He would gladly have accepted it had the conditions been anywhere near equal.

But the cruiser had heavier guns and more men. There was no other course but to heave-to.

So the schooner came up to the wind, her mainsail slacked, and the two vessels drifted within speaking distance.

“Ahoy, the schooner!” came the hail in Spanish. The Cuban flag was seen to be flying at the yard of the cruiser.

“Ahoy!” replied Poole.

“What craft is that?”

“The Meta; pleasure yacht, under the United States flag,” replied Poole.

For a time there seemed to be a consultation held aboard the cruiser. Then another hail came:

45“Captain of the Meta, we are going to send our lieutenant aboard you!”

“What is that?” shouted Poole. “We are under the protection of the United States flag. I warn you not to trouble us!”

A jeering laugh came back.

“Lower your gangway,” was the reply.

Then a boat slid down from the Santa Maria’s davits and six men entered it. One in the uniform of a lieutenant entered and stood in the bow.

Another boat followed this, with a dozen armed marines. Matters began to look serious.

The wrath and alarm felt by Poole was of the most intense description. He was utterly powerless, though.

How he would have liked to turn his gun upon the oncoming boats and sink them! But he did not dare to do this.

He stood savagely by the gangway, therefore, as they came on. The first boat touched the Meta’s side, and the natty Spanish lieutenant sprung upon deck.

“Buenas, Senor Capitan,” he said, touching his gold-laced cap, with much politeness. “I am Carriero, lieutenant of His Majesty’s navy. I salute you in the name of the king of Spain.”

Poole could talk Spanish fairly well, so he said:

“Well, what can I do for you, sir?”

His manner was so brusque that the dapper little Spaniard straightened up. With an affectation of dignity, he said:

“We must search your vessel, senor!”

Then he motioned to the marines. In a moment they were over the rail and ranged upon the deck.

The Meta was in the power of the Spanish. Poole turned black in the face.

“What!” he roared, “you dare to board a vessel flying the United States flag? This is an outrage and you will pay dearly for it, I promise you.”

Carriero smiled suavely in reply.

“What do you think we are?” cried Poole in desperation. “We are not filibusters.”

Again the lieutenant smiled and bowed. Then he spoke sharp orders to his men.

A midshipman, with two marines, invaded the forecastle. Two more went into the forward cabin. Then the lieutenant himself, with two guards, entered the main cabin.

Poole followed, expostulating, but it was of no use.

The vessel was thoroughly searched. Of course, the silver coins were discovered, and also the fact made clear that the vessel carried arms.

46By Carriero’s orders every gun was seized and brought out on deck. Then the chest of treasure was also taken.

A boat was sent back to the Santa Maria, and the captain, Don Azata, was brought off. He was a fiery, bewhiskered little fellow.

Without waste of time a court of inquiry was inaugurated on the Meta’s deck. The decision, based upon the evidence, was quickly rendered.

The Meta had been captured in Cuban waters carrying an armament. Certainly this was suspicious and warranted her in being condemned as a filibustering craft.

In vain Poole protested.

The Spanish officers only smiled and discredited his statements. He kept getting madder and madder.

Finally he yelled:

“Get off the deck of my schooner, the whole parcel of you! If you don’t I’ll kill you!”

Grabbing an iron bar he knocked the nearest marine senseless. Don Azata shouted fiery orders and Poole was quickly overpowered.

The little Spanish captain’s face blazed. A rope was brought. It was decided to hang the captain of the Meta at his own yard-arm.

But at this critical moment the captain’s eyes fell upon the chest of coins. At once he became interested. He fell to examining them.

Then he catechised Poole. The latter answered ungraciously at first.

To his surprise the Spanish captain ordered his bonds cut, and, thrusting his eager face forward into his, said:

“It is buried treasure; you have dug it out of the ground; tell me, senor capitan, where you found it, and I will spare your life.”

“What good will that do you?” asked Poole. “There is no more to be found there.”

“Do you think so, senor? There must be gold where this was found. This is but silver.”

A sudden swift thought flashed across Poole’s brain. He had abandoned all hopes of the treasure, but he thirsted for revenge.

And here seemed a chance offered him. He accepted it.

A few moments later he was closeted in the cabin with Don Azata. He told him the whole story of the Isle of Mona.

The Spanish captain listened.

“Perdita!” he exclaimed, “that is wonderful! But the treasure was found upon Spanish soil, and I claim it in the name of the King of Spain. This Captain Reade, you say, has the gold?”

47“Yes,” cried Poole, “and curse him, he robbed me of it! Follow him and wrest it from him. I will ask of you no greater favor.”

“But where shall we look for him?” asked the little captain; “in what direction shall we sail?”

“He will be found in the neighborhood of Cape Catoche.”

“You believe that?”

“Yes,” replied Poole, “but you will never catch them if you are not shrewd.”

“Ah, senor?”

“You see, his boat is a submarine craft, and he can sink out of sight and reach in a moment.”

“Perdita! Senor shall tell me what to do?”

“Use a subterfuge; trick him!” cried Poole, fiendishly. “When you sight him lure him toward you! Fly a signal of distress; when he gets within range give him a shot that will cripple him, or he will get away.”

Don Azata’s eyes glittered.

“That would be an assault upon the American flag,” he began.

“Hang the American flag! Who will ever know the story? Sink the accursed submarine boat with every man on board! The secret will be well kept. All we want is the gold.”

The two rascals looked at each other for fully a minute. Then Don Azata said, softly:

“Senor, you are wise; I shall do as you say. It is true that we must have the gold. May le diable aid us!”
CHAPTER XII. A TURNING OF TABLES—THE END.
The sunken isthmus had been discovered and explored. The mission of the Diver and its voyagers was thus accomplished.

The only thing now left to be done, as it seemed, was to start for home. All were in favor of this.

“Bejabers, I’m more than ready to be off,” cried Barney. “Shure, it’s an outlandish counthry about here, onyway.”

“Huh,” sniffed Pomp, “I don’t see no country, nuffin’ but de ocean all about us!”

“Arrah, an’ don’t yez be so funny,” retorted Barney. “Shure, ain’t the counthry underneath us, an’ phwativer more kin yez ask fer than that?”

This put Pomp to thinking, and no more was said just then. But Frank and Wade discussed the question.

And the result was, it was finally decided to return home 48after first paying a visit to Belize and having the boat’s engines overhauled.

The Diver, meanwhile, had been drifting all the time nearer to Cape Catoche. The shore presented an alluring aspect, and Wade exclaimed:

“I say, Frank, we ought really to run ashore here for a little while. It will give us a chance to stretch our legs, and I may find a few specimens.”

“Or fall into the grip of the Caribs,” laughed Frank.

“I’ll risk that.”

So the Diver was steered in close to the shore. A small boat was brought out and Frank and Wade rowed ashore.

They went well armed. But they were accorded a genuine surprise.

In place of possible cannibalistic Caribs or pirates they discovered the extensive fruit plantation of an enterprising Yankee, named Walton.

This gentleman invited them up to his dwelling in a lovely grove of palms, and treated them to pulque and other fine things.

He even insisted upon their remaining over night. As Frank knew that all was well on board the Diver he did not refuse.

Thus it happened that Barney and Pomp spent the night alone on board the Diver. And they had a high old time.

Barney managed to square accounts with the darky for the dough episode of some days past. After a lively scrap they finally made up and were good friends again.

They wondered somewhat at the non-return of Frank and Wade. But at nightfall Frank signaled them from the cliffs and they were reassured.

With the first gray streak of dawn across the Caribbean Sea the two jokers were given a little thrill of surprise.

A vessel had suddenly swung around a headland and was bearing down toward them. It was a small steamer, and as Barney studied it with his glass he made an astonishing discovery.

“For Hivin’s sakes,” he cried, “it’s wan av thim prowlin’ Cuban cruisers. Phwat the divil are they up to? It’s mischief, I believe.”

“Golly, wha’ am we gwine to do? Reckon Marse Frank ought to be here!”

“Bejabers, I’ll put up the Yankee flag an’ they’ll never dare touch us then,” cried Barney.

And he ran up the Stars and Stripes. But the Cuban vessel continued to advance. She ran up a signal flag.

It read that she desired to speak the submarine boat. This was a reasonable request and Barney answered it.

49On the quarterdeck stood Azata and Poole. The latter’s first proposition had been to creep up on the Diver and fire a ball through its hull.

But Azata had conceived a more cunning plan. The Meta was anchored in a cove some miles up the coast.

His game was to speak the Diver and make inquiry concerning the Meta. This would disarm the submarine voyagers and he would send a boat off to interview the captain.

Once his men were on the deck of the Diver quick work would be made. The submarine voyagers were to be overpowered and the boat seized.

Then it would be ransacked, the gold recovered, the voyagers shot and the craft confiscated. The two wretches had not decided further than this, but there were hints that the Diver would be a good craft to go seeking sunken treasure with in other parts of the world.

This was a very fine scheme. Barney and Pomp were all unsuspecting. Yet they cast anxious glances toward the shore for Frank and Wade.

They did not appear, however, so Barney had to make the best of it. The Santa Maria bore down within hailing distance and the summons came:

“Ahoy, Senor Americano!”

“Ahoy, yersilf!” replied Barney.

The hail had come in American and the voice sounded strangely familiar. But Barney never dreamed that it was really Poole who was shouting.

“What craft is that?”

“The Diver, submarine boat,” replied Barney. “Phwat do yez want?”

“This is the Cuban cruiser, Santa Maria. We are looking for an armed schooner, the Meta. Have you spoken her?”

“Tare an’ ‘ounds!” exclaimed Barney; “they’re afther the Meta, an’ may they catch her. Shure, they’ll hang that Poole as shure as preachin’.”

Then he replied:

“Aye, aye, sor! Not more than two or three days ago.”

“Lower your gangway,” was the Spanish hail, “we want to come aboard and ask you about her.”

Barney was for a moment nonplussed. He was averse to being boarded by any craft. But this must be all right, he reflected. Spain and the United States were at peace. These Cubans officers could not have any harmful intention.

So he and Pomp lowered the gangway. A boatload of marines and an officer put off. The officer was Azata.

50A few moments later the boat was alongside. Not until then did Barney see his mistake.

Over the rail like wolves came the Spaniards. Barney and Pomp fled toward the pilot-house to close the doors and sink the boat. But they were too late.

The Spaniards were upon them. A sharp struggle followed and they were quickly overpowered. Then from the bottom of the cruiser’s boat Poole sprung up and cleared the rail with a yell of triumph.

“Throw them overboard!” he yelled. “Dead men tell no tales! The submarine boat is ours!”

But Azata was cooler, and said:

“Not yet, senor. There is time enough for that. We may need them to tell us where the gold is. Search the craft!”

Poole led the marines exultantly into the Diver’s cabin. The submarine boat was thoroughly ransacked, but of course no gold was found.

Poole was furious and Azata was crestfallen. The Spanish captain began to have suspicions that he was the victim of a hoax.

“Where is the gold, senors?” he asked of Barney and Pomp, in crude English.

“There is none on board, sor,” replied Barney, and then the Celt told the whole story of the quest for the treasure.

Even Poole began to see his error. After all, his supposition that the gold was on board the Diver appeared to be founded upon the most chimerical of evidence. Indeed, there was not the slightest thing to warrant the assumption.

Don Azata’s face hardened. He turned upon Poole savagely.

“You have deceived me,” he said, with true Spanish temper. “You are a lying dog!”

“I am no worse than you!” retorted Poole. “You have committed a piratical act in boarding this vessel.”

Don Azata folded his arms.

“My purpose was to demand the gold in the name of the King of Spain,” he said. “I act in his name. I will have no more to do with you. Unbind the prisoners!”

Barney and Pomp were set free.

They were not a little astonished at this act of the Spaniard. But Don Azata had his reason, and a good one, for the act.

Steadily bearing in toward the coast he saw a huge white-hulled steamer. It required but a glance to recognize one of Uncle Sam’s White Squadron. The tables were turned.

Meanwhile a small boat had left the shore and was 51coming rapidly up. In a few moments more it was alongside and Frank and Wade sprung aboard.

The owner of the Diver took in the situation with a sweeping glance. His eye flashed angrily.

“What is this, sir?” he demanded angrily of Don Azata. “What right have you to board this boat in my absence?”

The Spanish captain bowed to the deck.

“Is this Captain Reade?” he asked.

“It is,” replied Frank.

“I am honored, most noble senor. You will accept my explanation and apology. This lying dog”—indicating the cowering Poole—“told me that you were of a piratical character and had seized upon a buried treasure, which, found in the domain of the good King of Spain, by every right belongs to him. He induced me to commit this outrage, for which my government tenders abject apology.”

Frank turned his gaze upon Poole.

“You scoundrel!” he exclaimed. “We took none of that buried treasure. You recovered all of it. So you have sought to make trouble for us, sir? Well, your effort has proved a boomerang. Do you see yonder vessel? That is one of our cruisers, and I shall signal her and turn you over to her officers to be dealt with according to your just deserts.”

Poole was ghastly pale and trembled like an aspen.

“Have mercy!” he whined.

The Spanish officer bowed to the deck again, and made a move to the gangway.

“Adios, senor capitan,” he said. “I know in the largeness of your heart you have pardoned me.”

Frank smiled grimly and made no reply. He allowed the Spaniards to depart. A few moments later the Santa Maria was scampering for the Isle of Cuba with all speed.

But Poole had no thought of surrendering himself to the mercies of a naval tribunal.

He gave a sudden mad yell and ran along the deck.

“Stop him!” cried Frank.

But it was too late.

With one wild plunge he went over the rail. He was a strong swimmer and went for the shore. Barney would have pursued him in the boat.

But Frank said:

“No, let him go. He will never trouble us again, and we are well rid of him.”

Whether the villain ever reached the shore or not was never known. Nor was the fate of the Meta ever learned.

The white cruiser was not signaled. Instead, the Diver raised her anchor and set out for Belize.

The voyage home was a stormy one. When at length 52the Diver entered the river leading to Readestown she was pretty badly racked and strained.

“I’m afraid she’ll not go another cruise, Frank,” said Wade.

“I’ll not ask her to,” declared the young inventor. “She has done enough. She has well repaid me.”

Their arrival in Readestown was the signal for a grand ovation. The whole city turned out to do them honor.

Wilbur Wade was very happy.

He had brought home complete maps and charts of the sunken isthmus, and many valuable specimens.

He was the only member of the American Society that visited the deep sea and witnessed its wonders.

He had the satisfaction of attending the next meeting of the American Society and proving his claims in regard to the Sunken Isthmus, to the utter rout and discomfiture of the fractious Professor Brown. And this was a happy triumph.

Frank Reade, Jr., Barney and Pomp are yet in Readestown. Of course, the young inventor is not idle.

53But what his next invention will be we are not as yet prepared to say. Only time will tell.

But one thing is sure. None of our adventurers in this tale of the Sunken Isthmus will quite forget the incidents connected therewith.

With which statement we have reached the end of our story and with the reader’s kind permission will write adieu.

The End