n towards where it
was again solid.

"Don't seem much of a place," said Mike, rising upright, but having to
keep himself in that position by resting a foot on either side of the
rift. "Goes in, though."

"Yes," said Vince, "and I was right, for the pigeons must have flown
through."

"No," said Mike, looking about: "nests somewhere on one of the ledges."

"Are no ledges here," said Vince: "the top goes up to a point. Shall we
go on?"

"Of course," said Mike; and, taking up the lanthorn, Vince began to
shuffle himself along the narrow, awkward place, till, at the end of a
dozen yards, in darkness which grew thicker as he went, the great crack
turned suddenly right off to the right, and again directly after to the
left.

"Why, it looks just the same shape as a flash of lightning," cried Mike.
"Does it get any bigger?"

"Doesn't seem to," was the reply; "but there's plenty of room to walk
along."

"Walk? I don't call this walking? I'm going along like a lame duck
striddling a gutter. I say, think there's ever been water along here?"

"Sure there hasn't," said Vince, holding the light low down. "Why, you
can see. The rock isn't worn a bit, but looks as sharp as if it had
only lately been split."

"But what could split it? The lightning?"

"No: father says these rocks crack from the water washing the stuff away
from beneath them, and then the tremendous weight does the rest. But I
don't know. I say, though, I shouldn't wonder if this goes on into
another cave. Look here."

Mike pressed forward, and found, as his companion held up the light,
that the fault in the rock shot off sharply now to the left, and sloped
up at an angle of some forty-five degrees.

"Looks awkward," said Mike. "Are we going up there?"

"Of course. Why not? We can climb it."

"Oh yes, I can get up there; but it isn't very good for the boots."

Good or bad, Vince did not hesitate, but, lanthorn in hand, commenced
the ascent by climbing right in the narrow part of the rift, where each
foot became wedged between the sides of the opening, and had to be
dragged out again as the next foot was brought over and placed in front.

"Awkward travelling," said Vince; "but you can't slip."

"Begin to feel as if I can," replied Mike--"right out of my shoes. I
say, it is awkward."

The distance they had to traverse here, however, was but short, and the
next angle showed that the fault was at a much easier slope, while the
opening