closed altogether, except at
the very bottom, where a low cavern-like fissure dimly appeared. A
hasty consultation passed between them, resulting in a determination to
go forward and explore the fissure.

Fortunately for their purpose they had, at an early stage of their
difficulties, provided themselves with a couple of stoutish pine
branches--wrenched from their parent stems and hurled into the ravine
perchance by some winter storm--to aid them in surmounting the
difficulties of the way, and these they now determined to utilise if
possible as torches.

With some little difficulty the smaller ends of these brands were
induced to kindle; but, once fairly ignited, they blazed up bravely, and
thus provided with the necessary lights the adventurers boldly pushed
forward and plunged into the recesses of the fissure.

CHAPTER THIRTEEN.

AT THE NORTH POLE.

The opening was so low and so narrow, that for the first fifty or sixty
feet the explorers were I obliged to creep forward on their hands and
knees; then it widened and became gradually higher, so that by the time
they had penetrated a couple of hundred feet they were able to resume a
perpendicular attitude. The cavern, if such it could be called, still
however remained so narrow that it was only here and there possible for
them to walk side by side. It was also very tortuous; and the heights
varied momentarily, at one time compelling them to stoop almost double
in order to pass beneath some immense projection, and anon increasing so
greatly that the light of their torches failed to reach and reveal the
roof. They observed several rifts or crevices to the right and left of
them as they pressed forward, but, with one or two exceptions, these
were quite impassable, and those which were not so were still so cramped
that they offered no inducement to deviate from the main passage.

Groping thus in semi-darkness over painfully rough and broken ground, a
full hour was spent, and the colonel was just expressing his conviction
that they must have traversed a distance of fully two miles when a faint
glimmer of daylight revealed itself on one of the rocky walls of the
passage; and, turning sharply round an angle, the pair suddenly found
themselves once more within a few yards of the open air.

Emerging into broad daylight a most wonderful spectacle greeted the two
adventurous explorers. They found themselves standing on a narrow strip
of coarse sandy beach at the b