Chapter XXIII: More Mystery

The two boys remained quiet for several minutes listening to the bell's deep toned tolling. At last Walter remarked, "It don't sound as though it was very far away from us, not over two miles, I should say."

"Good," exclaimed Charley with satisfaction, "I was about to ask you what you thought the distance was. Two miles is about what I had estimated. We can't say very exactly, for sound is likely to travel far in this still air. But let us make a liberal allowance for the stillness. I think we are safe in saying that the sound comes from a point not more than four miles distant from this island. Now, the next question is, from what direction does it come?"

"It's hard to tell exactly, the sound seems to fill the air so, but I should say that it came from the westward," said Walter after another moment of careful listening.

"We agree again," declared Charley, "it is not likely that we are both mistaken. Now that we have settled the distance and the direction from which the sound comes, what do you say to starting out in the morning and trying to solve the mystery?"

"The captain will not let us go," Walter objected.

"For this once, I do not intend to consult him," Charley said. "We will get off before he is awake. We can leave a note saying that we will be back before dark."

"Good," exclaimed his chum, "even if we accomplish nothing else, we may find an island that can be defended better than this one."

So it was settled and the boys crept back to bed eager for the coming of the morrow.

The eastern sky was just beginning to lighten a little when the boys got up and dressed, collected what cold food they could find, and, leaving a note where the captain could not fail to find it, stole down to the canoe and quietly embarked.

Charley's shoulder was still too sore to permit of his using the paddle so he made himself comfortable in the bow while Walter in the stern wielded the blade.

The canoe was headed around to the westward, as near as they could determine, for the point from whence had come the tolling of the bell. "I noticed what looked like a large island, from our camp, about two miles off and in the direction we are headed," observed Walter as they glided swiftly away.

"I noticed it too," Charley answered, "and I do not think we can do better than start our search there, if it proves to be an island. We will be there in an hour at this rate. I wish I could spell you, Walt, but it don't seem right for you to be doing all the work."

"Nonsense, I am enjoying it," his chum protested, "everything about this swamp is so novel and strange. See those cute little turtles on every log, and those curious looking smoke-birds, and did you ever see anything more beautiful than those trees with their hanging moss and with every bough full of orchids of every color of the rainbow?" Walter ceased his paddling for several minutes and the canoe drifted slowly on while the two boys gazed with delight at the novel beauty that surrounded them. The dark, stagnant water through which they drifted was nearly hidden from view by great white and gold water-lilies and the butterfly flowers of water hyacinths, the trees on either side stood like beautiful gray ghosts under their festoons of Spanish moss through which flashed the blazing hues of flowering orchids. Brilliant-hued paroquets and other birds flitted amongst the tree-tops, while to finish the delicious languor of the scene the air hung heavy with the subtle, drowsy scent of wild jasmine.

"It is the great swamp in its happiest mood," observed Charley, "but even here under all this beauty are hidden countless serpents and crawling things, while everywhere under this fair appearance lurks fever and disease."

Walter resumed his paddle with a sigh of regret and sent the canoe flying around a point and away from the scene of beauty. Here the stream widened out to about half a mile in width and increased in breadth as they advanced. Half a mile ahead lay the island they were seeking, its banks rising high above the great lagoon in which it lay. It was about four hundred acres in extent and its shores were covered with a dense tropical growth. Between it and the canoe was another tiny island about two hundred yards distant from its big sister. Between the boys and the smaller island floated a score of dark masses like the roots of trees.

"Alligators," declared Walter as they drew nearer to the floating objects.

"I am not so sure about that," said Charley, who was watching the objects with closest attention. "Sheer off, Walt, and give them as wide a berth as possible."

He watched with anxiety as two or three of the strange creatures, as though impelled by curiosity, swam lazily out towards the canoe. "Give way, Walt," he cried, "paddle as fast as you can."

Under Walter's vigorous strokes the canoe shot past the lazily swimming creatures whose curiosity did not appear to be great enough to induce them to increase their exertions.

When they were left behind Charley heaved a sigh of relief. "They are crocodiles," he explained, seeing his chum's look of surprise. "Alligators are harmless, generally speaking, but if one of those fellows should upset you, you'd be chewed up into mince meat in a jiffy. But here's island number one. I guess we do not care about landing there now, do we? The bigger one looks far more promising, let's try it first."

Walter gave ready assent, and they passed by the little island with only a casual glance.

In a few minutes more they had left it behind and had drawn close to its bigger sister. Choosing a place at which the timber seemed thinnest they ran the canoe up on shore and fastened it securely.

With guns in hand they scrambled up the high bank and stood for a moment surveying the surroundings. From that elevation, they could see quite clearly for a couple of miles in each direction. Save for the little island they had passed they could see no other solid land within the range of their vision.

Charley noted the fact with satisfaction. "The solution of our mystery must lie on one of these two islands," he declared, "and the chances are in favor of this one, so here goes to discover it," and he plunged into the timber with Walter close at his heels. He had taken no more than twenty steps when he stopped with an exclamation of surprise and astonishment, his way was barred by a great wall of stone that towered several feet above his head. It had once been a fortification of considerable strength, but growing trees had made breaches in it here and there, their thrusting, up-growing trunks tumbling its blocks to the ground, where they lay hidden by covering vines.

"Whew," whistled Walter as he readied his chumps side, "who could have built this? It could hardly have been done by the Seminoles."

"No," said Charley, who was examining the strange wall carefully, "this stone is all limestone, which is found only along the coast or at a great depth. It has been brought here from a considerable distance. Indians may have done the work, but they never did it willingly. If they did it at all, it was as slaves. But we have no time for idle speculation. Let's walk along it and see how far it extends."

But after forcing their way along the wall for almost a quarter of a mile, at the expense of a good deal of exertion, they gave up the task.

"I believe it extends clear around the island," Walter declared, "we can't spare any more time to follow it up; it's noon already. Let's see what is inside."

Charley offered no objection, and the two boys climbed through a gap in the wall and reached the great enclosure.

At first glance, they could see but little difference between the dense growth amongst which they stood and that outside the wall, but a closer examination showed that, while the timber was very thick, it was of smaller size than that which they had left behind.

"This was a clearing at one time, years and years ago," Charley said, "see, there is an ironwood stump there that still shows the signs of an axe. It takes generations and generations for one of those stumps to rot."

"Look, Charley," cried his chum who had pushed a little ahead, "just see this."

A couple of strides brought Charley to his side, "A road," he cried in amazement.

Straight as an arrow, it extended before them into the depth of the forest. So well and carefully had its smooth surface been laid that even the assaults of time and the forest had been unable to dislodge the great blocks of stone of which it was composed. Vines and creepers had grown over its surface and the forest trees had met in solid mass above it, but still it lay intact, a triumph of road building, as solid and strong as when built.

With a feeling of awe, the boys moved forward over its hard surface. They had to stoop continually to avoid branches and the tangled vines and briers had often to be cut away, but their progress was easier and far more rapid than it would have been through the forest itself.

They had proceeded perhaps a quarter of a mile when the road ended suddenly at the base of another wall. A break in the wall told of an ancient gateway but the gate itself was gone, probably rotted into dust by the passage of time.

The boys pushed through the gap and stopped short with a cry of wonder. Before them lay an inclosure of perhaps two acres, and in its center stood a half dozen buildings of stone, all in a fair state of preservation. Near the building closest to the boys, a sparkling little spring gushed forth and flowed away down a gentle incline towards a corner of the wall.

"Someone must be living here," Walter cried, "see, there are no trees or vines growing here."

But Charley stooped and scratched away the dead leaves blown in from the trees of the forest. "As I suspected," he said, after a moment's inspection, "this enclosure is paved like the road. My, what workmen those fellows that did this job must have been for their work to continue so perfect down to this day! I tell you this thing makes me feel creepy, Walt."

"And me too," agreed his chum. "Instead of solving a mystery, we have discovered a greater one."

But the young hunters were not the kind of boys to remain long under a superstitious dread, and they were soon approaching the buildings before them.

The first building was the largest of the group. It was constructed entirely of stone and had been little hurt by the passage of time. Its doors and windows had, of course, rotted away, but otherwise it appeared uninjured. Passing through the arched doorway the boys found themselves in a large apartment divided into two by a stone partition. Small holes here and there in the walls left little doubt as to the character of the building.

"It was their strong house or fort," Charley declared, as he gazed around. "Here was where they used to gather when danger threatened. The other buildings are no doubt dwelling-houses where they lived in time of peace. You take one side and I will take the other and we will search this one over carefully."

But although the boys searched closely they could discover nothing to tell them who had been the builders of this little city in the swamp.

By the time they had completed their search of the larger building, it was nearly noon and they sat down in the shade in the great arched doorway and ate the lunch they had brought with them.