"Light nothing!" declared Sandy.

"But I did see a light!" insisted the other.

"Perhaps you did," replied Sandy, "but if there's any light there it's merely a reflection from our electrics. There may be a metallic surface down there which throws back the light rays."

"Have it your own way!" grunted Tommy. "You know yourself that the caretaker said there were lights in the mine which no one could account for, and he especially mentioned the light in Tunnel Six."

"All right!" Sandy grinned. "We'll sneak down so quietly that any person who happens to be at the bottom of the shaft with the light will never suspect that we are within a hundred miles of the place. We may be able to geezle the fellow that's making the ghost walk around here nights."

The boys took to the ladders and moved down as silently as possible. Now and then a rung creaked softly under their feet, but they got to the bottom without any special mishap.

Tommy drew a long breath when at last they landed at the bottom of the shaft. He threw his light upward, then, and declared that in his opinion they were at least ten thousand feet nearer the center of the earth than they were when they started down.

"I remember now," Sandy said with a grin, "that the Labyrinth mine is only about five hundred feet deep. If I remember correctly, there are three levels; one at three hundred feet; one at four, and one at five."

"And which level is this?" asked Tommy.

"Why, we're on the bottom, ain't we?"

"Of course," laughed Tommy. "I ought to have known that!"

"Well come along if you want to see the mine!" urged Sandy. "All we have to do is to push our searchlights ahead and walk down the gangway. We'll come to something worth seeing after a while."

As the boys advanced they found the gangway considerably cluttered with "gob," or refuse, and the air was none of the best.

"I wish we could set the air shaft working," suggested Sandy.

"Well, we can't!" Tommy answered with a scornful shrug of his shoulders.

"We can't set the whole works going in order to give us a midnight view of the Labyrinth mine. What gets me is, how are we going to find our way back? There seem to be a good many pa.s.sages here."

"I've got that fixed all right!" Sandy exclaimed.

As the lad spoke he took a ball of strong string from his pocket and tied one end to the cage which lay at the bottom of the shaft.

"Now we can go anywhere we please," he chuckled "and when we want to return, all we've got to do is to follow the string."

"Quite an idea!" laughed Tommy.

The boys proceeded along the gangway, walking between the rails of the tramway by means of which the coal was delivered at the bottom of the shaft. The experience was a novel one to them. The dark walls of the pa.s.sage, the echoes which came from the counter gangways, the monotonous dripping of water as it seeped through seams and crevices in the rock, all gave a weird and uncanny expression to the place.

After walking for some distance the boys came to a level which showed several inches of water.

"We can't wade through that!" Tommy declared.

"Well," Sandy suggested, "if we go back a little ways, we can follow a cross heading and get into the mine by another way."

The boys followed this plan, and, after winding about several half-loaded cars which had been left on the tramway, found themselves in a large chamber from which numerous benches were cut.

"Where does all this gas come from?" asked Tommy stopping short and putting a hand to his nose.

"There must be a blower somewhere," Sandy explained.

"What's a blower?" demanded Tommy. "What does it look like, and does it always smell like this?"

"It doesn't look like anything!" replied Sandy. "It's composed of natural gas, and they call it a blower because it blows up out of crevices in the coal and in the rocks."

"If I should light a match, would it set it on fire?" asked Tommy.

"I wouldn't like to have you try it!"

The boys continued on their way for some moments, and then Tommy stopped and extinguished his light, whispering to Sandy to do the same.

"What's that for?" demanded the latter.

"Didn't you hear that noise behind the cribbing?" asked Tommy.

"Rats, probably!"

"Rats nothing!" replied Tommy. "Rats don't make sounds like people whispering, do they? Keep still a minute, and we'll find out what it is!"

"You'll be seeing a light next!" Sandy suggested.

"I see it now!" answered Tommy.

Sandy saw it, too, in a moment. It seemed at first to be floating in the air at the very top of the gangway. It moved from side to side, and finally dropped down nearer to the floor. There seemed to be no one near it or under it. Its small circle of illumination showed only the empty air.

"What do you make of it?" asked Tommy.

"Is this Tunnel Six?" asked his chum.

"I don't know! If it is, we've seen the light the caretaker referred to.

We'll have a great story to tell in the morning!"

The boys stood in the darkness of the gangway watching the light for what seemed to them to be a long time. Now the light advanced toward them, now it receded. Now it lifted to the roof of the gangway, now it dropped almost to the floor.

At intervals, the noises behind the cribbing to which Tommy had referred were repeated, and the boys at last moved over so as to stand with their ears almost against the wooden walls.

"There is some one behind the cribbing, all right!" Tommy declared. "I hear some one breathing."

"Aw, keep still!" whispered Sandy. "If there is anyone there, you'll frighten them away! I thought I heard some one myself!"

"I'll tell you what I think," Tommy suggested in a moment, "and that is that either Will and George, or both of them, beat us to this gangway.

They are hiding behind there on purpose to give us a scare."

"That's a dream!" replied Sandy. "We left them both asleep."

"Dream, is it?" repeated Tommy scornfully. "You just listen to the sound that comes from behind this cribbing, and tell me what you make of it!"