erfall, into a great chamber under the rocks. Then the way goes
through a narrow passage, where the guide unlocks an iron gate to let
them in. The visitors now leave all thoughts of daylight behind, for the
breeze that put out their lights as they entered the cave is past, and
they stand in the Rotunda, a vast high-ceilinged chamber, silent and
impressive, with walls of creamy limestone, encrusted with gypsum, which
has been stained black by manganese. From the vestibule on, each passage
and each room has a name, based upon some historic event or some fancied
resemblance. The Giant's Coffin is a great kite-shaped rock lying in one
of the rooms of the cave. The Star Chamber has a wonderful
crystal-studded dome in which the guide produces the effect of a sunrise
by burning coloured lights. Bonfires built at suitable points produce
wonderful shadow effects, which are like nothing else in the world. The
old saltpetre vats which the visitors pass in taking the "Long Route"
through the cave, point them back to the days during the War of 1812,
when this valuable mineral was extracted from the earth in the floor of
the cave. The industry greatly enriched the thrifty owners of the cave,
but the works were abandoned after peace was declared.

It must be a wonderful experience to walk steadily for nine hours over
the Long Route, for so pure is the air and so wonderful is the scenery
that people rarely complain of fatigue when the experience is over.
There is no dust on the floors of these subterranean chambers, and they
are not damp except near places where water trickles, here and there, in
rivulets and cascades. Pools of water at the bottoms of pits so deep
that a lighted torch requires several seconds to reach the bottom, and
rivers and lakes of considerable size, show where some of the surface
water goes to. A strange underground suction creates whirlpools in some
of these streams. People go in boats holding twenty passengers for a row
on Echo River, and the guide dips up with a net the blind fish and
crayfish and cave lizards which inhabit these subterranean waters. The
echoes in various chambers of the Mammoth Cave are remarkable. In some
of them a song by a single voice comes back with full chords, as if
several voices carried the different parts. The single notes of flute
and cornet are returned with the same beautiful harmonies. A pistol shot
is given back a dozen times, the sound rebounding like a ball from rock
to rock o