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.