idge, my guide flung one of his Bengal
lights far upward, in the midst of the slow-falling drops that had
already carved out this tremendous well and were still making it larger.
The light turned them for an instant into a shower of diamonds; then
down it fell, down, down! As in its descent it passed the bridge on
which we stood, the shadows of our two figures rushed up the opposite
wall, like a pair of demons scared out of their abode by the hissing
flame; and Nick, the guide, as he leaned over, looking downward after
it,--every one of the innumerable wrinkles in his black face made more
distinct, with his white beard and mustache, and the whites of his eyes
seeming to glow in the blue elfish light,--was a caricature, half
grotesque, almost terrible, of Satan himself.

Minerva's Dome and Side-Saddle Pit, both being one place and formed by
the same dripping water, correspond to Gorin's Dome and the pit beneath
it; that part which has been hollowed out above the roof of the cave
being called the dome, and the part below the floor of the cave the pit.
The only difference between the two is that in the case of Gorin's Dome
the dripping waters have bored their huge shaft on one side of the track
of the cave, only just piercing the wall of it in one spot, to make the
window through which it is viewed; while in the case of the Side-Saddle
Pit the vertical shaft cuts directly across the track of the cave, or,
to speak more correctly, across the tunnel which was once the bed of a
subterranean river, but which is now a broad, smooth, dry path.

The topography of this underground realm may be divided into three
departments, as follows:--

First,--as being greatest in extent,--the "avenues," or tunnels, which
present conclusive evidence of having once been the channels of a
subterranean stream, whose waters, having some peculiar solvent
property, wore their bed lower and lower in the rock, until they cut
through into some lower opening, through which they were drawn off,
leaving the old channels dry. Imagine one of the narrow, crooked streets
in the old part of Boston, spanned by a continuous stone archway from
the summits of the buildings on either hand; then close with solid
masonry every window and loop-hole by which a ray of light could
struggle in, and you have for proportions and sinuosity not a bad
semblance of these tunnels, which constitute four fifths of the extent
of the Mammoth Cave.

The second and next largest de