The youth felt a strong undercurrent, and, finding that he could not reach the island, he tried to get back to the sh.o.r.e he had left.

By this time the pony was struggling helplessly in the mysterious power sucking it downward.

Then, before Jack could clear his feet from the stirrups, so as to look out for himself, he was drawn under the seething waters with his horse!

Chapter XVI

At the Boiling Lake

As Jack felt the swirling waters closing over him, he made greater effort to keep on the surface.

His gallant pony was struggling furiously for the same purpose, but the power pulling them down was irresistible.

A continual roaring filled his ears, and it seemed as if he was being drawn into some infernal region.

In spite of all he could do he was carried downward, until suddenly he felt a terrible shock, as if he had been hurled against some stony surface, and the next he knew he was floating on the water near the north end of the lake, which was then quite tranquil. He had no difficulty in swimming to the nearest point of land.

Scrambling up the precipitous bank he was glad to sink upon the ground for rest.

He was wondering if his pony had perished, when he was gladdened by the sight of the animal on the opposite side of the lake.

Before going to the horse Jack resolved to try to swim out to the island, and as the water had now a.s.sumed the calmness which had prevailed at the time he had first seen it, he did not think of further trouble. He had received some bruises from his recent experience, but beyond them he felt little the worse for his adventure.

Removing his outer garments, so as to give greater freedom to his movements, he stepped down to the edge of the dark flood, which was filled with the fine particles of earth it had swallowed.

As calm as the water was then, he had barely touched it with one foot before a shriek, which rang in his ears for a long time afterwards, rang high and far, cut short in its midst by a fearful rush of the aroused flood, and a column was suddenly thrown into the air to the height of a hundred feet!

It was such a terrific, appalling outburst that he hastily clambered back upon the bank, to watch the strange sight. For fully two minutes the waterspout quivered and vibrated in the air, when it collapsed as abruptly as it had appeared.

The water of the lake continued to boil for five minutes, when it began to subside, though bearing traces of agitation for five minutes longer, during which Jack watched it with intense interest.

Still undaunted by this marvelous display, Jack resolved to try a third time to reach the island, selecting a more favorable place for his descent into the water this time.

As no outbreak had immediately followed his entrance into the lake this time, he was beginning to think that the strange phenomenon was over. But he was soon to be undeceived.

All at once, without warning, a dozen columns of water sprang upward, threatening for a moment to drain the lake dry, and among these rushing, writhing pillars Jack was borne into the air.

When the powers subsided he fell back with such a force as to render him almost senseless. The lake was still churned and convulsed by the mighty agency controlling it, and he had a hard fight to reach the sh.o.r.e, where he lay completely exhausted.

Slowly recovering his strength he finally sat up and began to wring the water out of his clothes, deciding to leave the place as soon as he felt able. The water was calm then; though a short time before it had been tossed and whipped into fury by the mysterious element controlling it.

"Were the whole Incas treasure buried on that island it would be safe from the hand of the despoiler," he said, speaking aloud his thoughts. "But I do not understand it. I am willing to wager that this is the same valley I saw when I was this way before, though it was as dry as a palm leaf then.

How calm it is now, but I suppose if I should dare to enter its sacred precinct it would begin again its fearful convulsions."

As he finished speaking, Jack picked up a small stone and tossed it into the lake. No sooner had it disappeared beneath its dark surface than another column of water shot upward with a sort of hissing that was terrific, and in a moment the whole body was once more undergoing a series of spasms frightful to behold.

Watching it until the outbreak was over, Jack lost no further time in seeking the pony. Then he began to climb the hillside leading from the place.

Upon the crest he paused for a last look, saying:

"It is calm enough now. Sometime I will come again, for I will know its secret if I die for it. There is and must be a natural explanation for all this."

Finding Plum Plucky waiting anxiously for him at the expected place of meeting, Jack led the way toward civilization, having come to the conclusion to close the trade on one of the nitrate beds he had seen and begin operations as soon as possible.

He said nothing to his companion of his experience in the valley of mystery, partly because the stirring scenes immediately following caused him to put it in the background of his memory for a while.

He was the more anxious to get his first cargo of nitrate off as the war cloud was deepening fast, and not only was Peru and Chili at a state of bitter antagonism, but Bolivia was threatening to mix in the trouble. A three-cornered war, with Southern Peru for its battleground, was anything but what he desired to see.

The next day he bought his first nitrate bed, paying for it forty pistoles, which was considerably more than he had expected, but it was large, and if his plans only worked he believed there was a small fortune in it.

He then hired oxen enough to make two six-ox teams, with suitable wagons to draw the nitrate on, and he engaged the services of half a dozen Peruvians to help in the work of getting out the first loads.

As the bed lay remote from the few beaten paths of the thinly populated country, it would involve considerable hard work and time to get pa.s.sable roads cut through, so as to be able to draw loads of any size.

"By gosh!" drawled Plum Plucky, as they set out on their work, "I'm going to stand by yeou; but yeou may hang my hat on a scare-crow if I don't think yeou'll blow yerself dry."

"By that I suppose you mean that I shall lose all I am putting into my venture," said Jack, good-naturedly.

"That's just what I mean. I'll bet yeou have got about every dollar yeou have into it now."

"I have figured up that I shall have about twenty pounds left when I have paid off my help."

"Say, Jack! I'd like to be there when you get in with yer first load of dirt and see 'em laugh. Don't s'pose yeou have any dirt in the teown yeou come from."

"Not dirt that is pure nitrate of soda, and possessing the highest qualities for fertilization of any known compound. h.e.l.lo! what is up now?"

Chapter XVII

In the Nitrate Fields

The last exclamation was called from Jack by the fact that the teams had suddenly stopped, and the native drivers were shouting excitedly over something which had happened.

They were at the time trying to make a roadway to the nitrate bed through a trackless wilderness, and had thus far progressed with greater ease than the young speculator had calculated.

But upon reaching the spot where the teamsters and workmen were holding an excited controversy, Jack found that the cause of the excitement was the fact that the way had been stopped by a sharp, rocky ridge, which extended for miles in both directions.

"We can't go any further, senor," declared the head driver. "No team can find its way through these rocks and up and down the hill."

Jack had seen this place when making his survey and had calculated upon the difficulty in pa.s.sing it, having the route most feasible at this point.