6 
FORMATION OF THE CAVE. 
deep, covering an area of from five acres to two thousand. The 
rim of sandstone surrounding these depressions is, generally, 
nearly level ; the outcropping rocks within are also nearly horizon- 
tal. Near the centre there is an opening of from three to fifteen 
feet in diameter ; into this opening tiie water which has fallen within 
the margin of the basin has been drained since the day when the 
rocks exposed within were raised above the drainage of the coun- 
try, and thus, by the slow process of washing and weathering, the 
rocks, which once filled these cavities, have been worn and carried 
down into the subterranean drainage of the country. All this has 
evidently come to pass in the most quiet and regular manner. 
The size of the central opening is too small to admit extraordinary 
fioods ; nor is it possible, with the level margin around, to suppose 
that these cavities were worn by eddies in a current that swept the 
whole cavernous member of the subcarboniferous limestone of 
western Kentucky ; but the opinion is probable that the upheaving 
force which raised these beds to their present level, at the same 
time ruptured and cracked the beds in certain lines ; that after- 
wards the rains were swallowed into openings on these fractures, 
producing, by denudation, the basins of the sinkhole country, and 
further enlarging the original fractures by flowing through them, 
and thus forming a vast system of caverns, wdiich surrounds the 
western coal field. The Mammoth Cave is, at present, the best 
known, and, therefore, the most remarkable.” 
So much has been written on the cave and its w'onders, that to 
give a description of its interior would be superfluous in this 
connection, even could we do so without unintentionally giving 
too exaggerated statements wdiich seems to be the natural result 
of a day underground, at least so far as this cave is concerned, 
for after reading any account of the cave, one is disappointed at 
finding the reality so unlike the picture. As the Association party 
was accompanied by one ^ who, while a most enthusiastic collector 
and explorer, was also a calm recorder of statements made by 
the geologists of the party, we cannot do better in conveying to 
our readers the general geological character and structure of the 
cave than to copy his account. 
“ As we expected to remain within the cave a long time, our 
trusty guide, Frank, had provided himself with a well-filled can 
of oil, to replenish our lamps, and with this strapped upon his 
back he led the way into the thick darkness. We shall attempt 
no description of the cave. Its darkness must be felt to be ap- 
preciated, and no form of expression, understood by mortals who 
have never descended to its cavernous depths, nor trod its gloomy 
*W. P. FISHBA.CK, Esq., of the Indianapolis Daily Journal. 
