of the lanthorn and looked at the
light anxiously, but they had not burned an inch.

"We could easily get another light," said Vince; "and we must go on now.
Here, shall I go down first?"

"No; I'll keep to it," cried Mike. "I'm not going to have you jeering
at me afterwards and telling me I was afraid. But look here, Cinder:
you can't walk down--it really is too steep."

"Let's try the rope: I'll fasten it, and then you can hold on."

"Nothing to fasten it to."

"Soon get over that," said Vince; and, taking out the iron bar and the
hammer, he found a crack in the rock directly, into which he drove the
narrow edge till it was perfectly firm, the roof just overhead echoing
the blows of the hammer so rapidly that in a short time it sounded as if
a dozen smiths were at work.

"Stop a moment," cried Mike, as he held the light, and Vince began to
tie the end of the rope to the strong iron peg he had formed.

"What for?"

"Suppose when we get down we want the rope for another place, what
should we do if we leave it here?"

Vince took the lanthorn and held it out before him, so that he could
examine the trough-like slope.

"I shouldn't like to trust myself to slide down here," he said; "but
there's nothing to prevent our climbing up. Let's double the rope and
hook the middle over the bar; then, when we're down, we can pull one end
and get it free."

This was done, and, tying the lanthorn to his neck by means of his
kerchief, Mike secured the doubled rope and let himself down, his
companion soon after seeing him standing some thirty feet lower.

A minute later Vince was by his side, and they looked about them, but
there was nothing fresh to see. The roof was only a foot above their
heads. The width of the place averaged six or seven feet, and there was
this to encourage them--no branches occurred to form puzzling
labyrinths. If they had been overtaken by darkness there was nothing to
prevent their feeling their way back into the sunshine. So, growing
accustomed to the place, familiarity, if it did not breed contempt, made
them cooler and more ready to go on descending over similar obstacles to
those they had previously encountered, till all at once Mike stopped
short, and held up the lanthorn beneath which he peered.

"What is it?" said Vince anxiously.

"Hark! What's that?" said Mike, in a whisper full of awe.

A dull rushing sound smote upon their ears, but in a muffled, strange
way, that puzzled th