A GUIDE M-NUAL

                    OF THE

MAMMOTH CAVE OF KENTUCKY.

                       O

         ENTRANCE TO THE CAVE.
     HE ENTRANCE to the Cave is one hundred and
     ninety-four feet above Green River, and is
     about twenty-five feet in height, by about thir-
tv in width, oN-e-. which may b3 seen, at all seasons,
a mist or feg, which, wher'. the -xtel nal air is warmer
than that of the Cave, is produced bv the condensa-
tion of the moisture of the fbrewer shy the reduced
temperature of the Matter. COl the contrary, when
the temperature of the external atmosphere is less
than that of the Cave, the n!oistu1b of the air of the
latter is condensed in a similar manner. When the
temperature of the outer air is the same as that of
the Cave, no fog or cloud is observable at its mouth.
  The entrance to the Mammoth Cave, at an early
period of its history, was situated about half a mile
from its present location, constituting what is now
called the mouth of Dickson's Cave. This cave ter-
minates within a few feet of the mouth of the Mam-
moth Cave, but there is at present no direct commu-
nication between the two. The voice of a person at