"The next day Mike smiled to himself when the men laughed at his suspicions. They were so far from any settlement and the mountains were so great and silent, that it gave them confidence in the peace and good will with all men.
"The second night the men were again playing cards near the camp-fire. Mike sat on the ledge in front of the cave with the hound stretched out on a slab of rock at his feet. The giant wooden flume could be faintly discerned, through the smoke of the fire and from the pipes of the men, not twenty feet away from the engines that worked it.
"Suddenly the hound lifted his head and pointed his ears. Mike leaned forward with face turned towards the flume, listening. Then he laid his pipe down on the rock and crawled away upon his hands and knees, followed closely by the hound.
"Do you remember the giant flume we planned to carry off the water of the river that flowed underground; the one into which Nolla and you dropped the torch the day you found the cave?"
Polly silently signified that she remembered, and Tom continued: "Well, we used that flume during the work of mining and washing trash from the ore, but at night, when there was no need for the water to pour through it, we turned the current down the other way on the opposite side of the mountain.
"Mike crept silently across the ledge and peered far down into the black chasm below, to ascertain if the suspicious sounds came from that pit. But the dog crawled noiselessly across the ledge to the flume and there he stood with tense nerves. His ears were erect and his tail was standing out straight behind him, as he stood and glared at the wooden flume.
"As the dog was so well-trained, Mike did not doubt his instinct, but crept over to his side and there waited and listened.
"Had he not been absolutely quiet, the faint sound of something moving inside that flume would have been lost on the outside. But Mike was as keen a hunter as his dog, and they both sensed that something very foreign to water was passing through that flume.
"Accompanying the strange muffled sound inside the flume every few moments, there came a different sound, as if something sharp was being driven into the wood for a hold. Mike figured out that the inside of the flume had been worn so slippery with the flood of waters and sand or pebbles passing through it in torrents, that it was necessary to use steel-pointed staffs and creepers to help anyone in the dangerous ascent.