The great supply of salt brought by Ross and his men was welcome to Wareville, as the people had begun to suffer for it, but they would have enough now to last them a full year, and a year was a long time to look ahead. Great satisfaction was expressed on that score, but the news that a Shawnee war party was in Kentucky and had chased them far southward caused Mr. Ware and other heads of the village to look very grave and to hold various councils.

As a result of these talks the palisade was strengthened with another row of strong stakes, and they took careful stock of their supplies of ammunition. Lead they had in plenty, but powder was growing scarce. A fresh supply had been expected with a new band of settlers from Virginia but the band had failed to come, and the faces of the leaders grew yet graver, when they looked at the dwindling supply, and wondered how it could be replenished for the dire need that might arise. It was now that Mr. Pennypacker came forward with a suggestion and he showed how book learning could be made of great value, even in the wilderness.

"You will recall," he said to Mr. Ware and Mr. Upton, and other heads of the settlement, "that some of our hunters have reported the existence of great caves to the southwestward and that they have brought back from them wonderful stalactites and stalagmites and also dust from the cave floors. I find that this dust is strongly impregnated with niter; from niter we obtain saltpeter and from saltpeter we make gunpowder. We need not send to Virginia for our powder, we can make it here in Kentucky for ourselves."

"Do you truly think so, Mr. Pennypacker?" asked Mr. Ware, doubtfully.

"Think so, I know so," replied the schoolmaster in sanguine tones. "Why, what am I a teacher for if I don't know a little of such things? And even if you have doubts, think how well the experiment is worth trying. Situated as we are, in this wild land, powder is the most precious thing on earth."

"That is true! That is true!" said Mr. Ware with hasty emphasis. "Without it we shall lie helpless before the Indian attack, should it come. If, as you say, this cave dust contains the, saltpeter, the test will be easy."

"It contains saltpeter and the rest will be easy!"

"Then, you must go for it. Ross and Sol and a strong party must go with you, because we cannot run the risk of losing any of you through the Indians."

"I am sure," said Mr. Pennypacker, "that we shall incur no danger from Indians. The region of the great caves lies farther south than Wareville and the Southern Indians, who are less bold than the Northern tribes, are not likely to come again into Kentucky. The hunters say that Indians have not been in that particular region for years."

"Yes, I think you are right," said Mr. Ware, "but be careful anyhow."

Henry, when he heard of the new expedition, was wild to go, but his parents, remembering the great danger of the journey to the salt licks, were reluctant with their permission. Then Ross interceded effectively.

"The boy is just fitted for this sort of work," he said. "He isn't in love with farming, he's got other blood in him, but down there he will be just about the best man that Wareville has to send, an' there won't be any Indians."

There was no reply to such an argument, because in the border settlements the round peg must go in the round hole; the conditions of survival demanded no surplusage and no waste.

When Paul heard that Henry was to go he gave his parents no rest, and when Mr. Pennypacker, whose favorite he was, seconded his request, on the ground that he would need a scholar with him the permission had to be granted.

Rejoicing, the two boys set forth with the others, the dangers of the Shawnee battle and their terrors already gone from their minds. They would meet no Indians this time, and the whole powder-making expedition would be just one great picnic. The summer was now at hand, and the forests were an unbroken mass of brilliant green. In the little spaces of earth where the sunlight broke through, wild flowers, red, blue, pink and purple peeped up and nodded gaily, when the light winds blew. Game abounded, but they killed only enough for their needs, Ross saying it was against the will of God to shoot a splendid elk or buffalo and leave him to rot, merely for the pleasure of the killing.

After a while they forded a large river, passed out of the forests, and came into a great open region, to which they gave the name of Barrens, not because it was sterile, but because it was bare of trees. Henry, at first, thought it was the land of prairies, but Ross, after examining it minutely, said that if left to nature it would be forested. It was his theory that the Indians in former years had burned off the young tree growth repeatedly in order to make great grazing grounds for the big game. Whether his supposition was true or not, and Henry thought it likely to be true, the Barrens were covered with buffalo, elk and deer. In fact they saw buffalo in comparatively large numbers for the first time, and once they looked upon a herd of more than a hundred, grazing in the rich and open meadows. Panthers attracted by the quantity of game upon which they could prey screamed horribly at night, but the flaming camp fires of the travelers were sufficient to scare them away.

All these things, the former salt-makers, and powder-makers that hoped to be, saw only in passing. They knew the value of time and they hastened on to the region of great caves, guided this time by one of their hunters, Jim Hart, although Ross as usual was in supreme command. But Hart had spent some months hunting in the great cave region and his report was full of wonders.

"I think there are caves all over, or rather, under this country that the Indians call Kaintuckee," he said, "but down in this part of it they're the biggest."

"You are right about Kentucky being a cave region," said the schoolmaster, "I think most of it is underlaid with rock, anywhere from five thousand to ten thousand feet thick, and in the course of ages, through geological decay or some kindred cause, it has become crisscrossed with holes like a great honeycomb."

"I'm pretty sure about the caves," said Ross, "but what I want to know is about this peter dirt."

"We'll find it and plenty of it," replied the master confidently. "That sample was full of niter, and when we leach it in our tubs we shall have the genuine saltpeter, explosive dust, if you choose to call it, that is the solution of gunpowder."

"Which we can't do without," said Henry.

They passed out of the Barrens, and entered a region of high, rough hills, and narrow little valleys. Hills and valleys alike were densely clothed with forest.

Hart pointed to several, large holes in the sides of the hills, always at or near the base and said they were the mouths of caves.

"But the big one, in which I got the peter dirt is farther on," he said.

They came to the place he had in mind, just as the twilight was falling, a hole, a full man's height at the bottom of a narrow valley, but leading directly into the side of the circling hill that inclosed the bowl-like depression. Henry and Paul looked curiously at the black mouth and they felt some tremors at the knowledge that they were to go in there, and to remain inside the earth for a long time, shut from the light of day. It was the dark and not the fear of anything visible, that frightened them. But they made no attempt to enter that evening, although night would be the same as day in the cave. Instead they provided for a camp, as the horses and a sufficient guard would have to remain outside. The valley itself was an admirable place, since it contained pasturage for the horses, while at the far end was a little stream of water, flowing out of the hill and trickling away through a cleft into another and slightly lower valley.

After tethering the horses, they built a fire near the cave mouth and sat down to cook, eat, rest and talk.

"Ain't there danger from bad air in there?" asked Ross. "I've heard tell that sometimes in the ground air will blow all up, when fire is touched to it, just like a bar'l o' gunpowder."

"The air felt just as fresh an' nice as daylight when I went in," said Hart, "an' if it comes to that it will be better than it is out here because it's allus even and cool."

"It is so," said the master meditatively. " All the caves discovered so far in Kentucky have fresh pure air. I do not undertake to account for it."

That night they cut long torches of resinous wood, and early the next morning all except two, who were left to guard the horses, entered the cave, led by Hart, who was a fearless man with an inquiring mind. Everyone carried a torch, burning with little smoke, and after they had passed the cave mouth, which was slightly damp, they came to a perfectly dry passage, all the time breathing a delightfully cool and fresh air, full of vigor and stimulus.

Paul and Henry looked back. They had come so far now that the light of day from the cave mouth could no reach them, and behind them was only thick impervious blackness. Before them, where the light of the torches died was the same black wall, and they themselves were only a little island of light. But they could see that the cave ran on before them, as if it were a subterranean, vaulted gallery, hewed out of the stone by hands of many Titans! Henry held up his torch, and from the roof twenty feet above his head the stone flashed back multicolored and glittering lights. Paul's eyes followed Henry's and the gleaming roof appealed to his sensitive mind.

"Why, it's all a great underground palace!" he exclaimed, "and we are the princes who are living in it."

Hart heard Paul's enthusiastic words and he smiled.

"Come here, Paul," he said, "I want to show you something."

Paul came at once and Hart swung the light of his torch into a dark cryptlike opening from the gallery.

"I see some dim shapes lying on the floor in there, but I can't tell exactly what they are," said Paul.

" Come into this place itself."

Paul stepped into the crypt, and Hart with the tip of his moccasined toe gently moved one of the recumbent forms. Paul could not repress a little cry as he jumped back. He was looking at the dark, withered face of an Indian, that seemed to him a thousand years old.

"An' the others are Indians, too," said Hart. "An' they needn't trouble us. God knows how long they've been a-layin' here where their friends brought 'em for burial. See the bows an' arrows beside 'em. They ain't like any that the Indians use now."

"And the dry cave air has preserved them, for maybe two or three hundred years," said the schoolmaster. "No, their dress and equipment do not look like those of any Indians whom I have seen."

"Let's leave them just as they are," said Paul.

"Of course," said Ross, "it would be bad luck to move 'em."

They went on farther into the cave, and found that it increased in grandeur and beauty. The walls glittered with the light of the torches, the ceiling rose higher, and became a great vaulted dome. From the roof hung fantastic stalactites and from the floor stalagmites equally fantastic shot up to meet them. Slow water fell drop by drop from the point of the stalactite upon the point of the stalagmite.

"That has been going on for ages," said the schoolmaster, "and the same drop of water that leaves some of its substance to form the stalactite, hanging from the roof, goes to form the stalagmite jutting up from the floor. Come, Paul, here's a seat for you. You must rest a bit."

They beheld a rock formation almost like a chair, and, Paul sitting down in it, found it quite comfortable. But they paused only a moment, and then passed on, devoting their attention now to the cave dust, which was growing thicker under their feet. The master scooped up handfuls of it and regarded it attentively by the close light of his torch.

"It's the genuine Peter dust!" he exclaimed exultantly. "Why, we can make powder here as long as we care to do so."

"You are sure of it, master?" asked Ross anxiously.

"Sure of it!" replied Mr. Pennypacker. "Why, I know it. If we stayed here long enough we could make a thousand barrels of gunpowder, good enough to kill any elk or buffalo or Indian that ever lived."

Ross breathed a deep sigh of relief. He had had his doubts to the last, and none knew better than he how much depended on the correctness of the schoolmaster's assertion.

"There seems to be acres of the dust about here," said Ross, "an' I guess we'd better begin the makin' of our powder at once."

They went no farther for the present, but carried the dust in, sack after sack, to the mouth of the cave. Then they leached it, pouring water on it in improvised tubs, and dissolving the niter. This solution they boiled down and the residuum was saltpeter or gunpowder, without which no settlement in Kentucky could exist. The little valley now became a scene of great activity. The fires were always burning and sack after sack of gunpowder was laid safely away in a dry place. Henry and Paul worked hard with the others, but they never passed the crypt containing the mummies, without a little shudder. In some of the intervals of rest they explored portions of the cave, although they were very cautious. It was well that they were so as one day Henry stopped abruptly with a little gasp of terror. Not five feet before him appeared the mouth of a great perpendicular well. It was perfectly round, about ten feet across, and when Henry and Paul held their torches over the edge, they could see no bottom. Henry shouted, throwing his voice as far forward as possible,, but only a dull, distant echo came back.

"We'll call that the Bottomless Pit," he said.

"Bottomless or not, it's a good thing to keep out of," said Paul. "It gives me the shudders, Henry, and I don't think I'll do much more exploring in this cave."

In fact, the gunpowder-making did not give them much more chance, and they were content with what they had already seen. The cave had many wonders, but the sunshine outside was glorious and the vast mass of green forest was very restful to the eye. There was hunting to be done, too, and in this Henry bore a good part, he and Ross supplying the fresh meat for their table.

A fine river flowed not two miles away and Paul installed himself as chief fisherman, bringing them any number of splendid large fish, very savory to the taste. Ross and Sol roamed far among the woods, but they reported absolutely no Indian sign.

"I don't believe any of the warriors from either north or south have been in these parts for years," said Ross.

"Luckily for us," added Mr. Pennypacker, "I don't want another such retreat as that we had from the salt springs."

Ross's words came true. The powder-making was finished in peace, and the journey home was made under the same conditions. At Wareville there was a shout of joy and exultation at their arrival. They felt that they could hold their village now against any attack, and Mr. Pennypacker was a great man, justly honored among his people. He had shown them how to make powder, which was almost as necessary to them as the air they breathed, and moreover they knew where they could always get materials needed for making more of it.

Truly learning was a great thing to have, and they respected it.