downward, but all was vacuity.

Here it was needful to pause. I had reached the brink of a cavity whose
depth it Avas impossible to ascertain. It might be a few inches beyond
my reach, or hundreds of feet. By leaping down I might incur no injury,
or might plunge into a lake or dash myself to pieces on the points of
rocks.

I now saw with new force the propriety of being furnished with a light.
The first suggestion was to return upon my footsteps, and resume my
undertaking on the morrow. Yet, having advanced thus far, I felt
reluctance to recede without accomplishing my purposes. I reflected
likewise that Clithero had boldly entered this recess, and had certainly
come forth at a different avenue from that at which he entered.

At length it occurred to me that, though I could not go forward, yet I
might proceed along the edge of this cavity. This edge would be as safe
a guidance, and would serve as well for a clue by which I might return,
as the wall which it was now necessary to forsake.

Intense dark is always the parent of fears. Impending injuries cannot in
this state be descried, nor shunned, nor repelled. I began to feel some
faltering of my courage, and seated myself, for a few minutes, on a
stony mass which arose before me. My situation was new. The caverns I
had hitherto met with in this desert were chiefly formed of low-browed
rocks. They were chambers, more or less spacious, into which twilight
was at least admitted; but here it seemed as if I were surrounded by
barriers that would forever cut off my return to air and to light.

Presently I resumed my courage and proceeded. My road appeared now to