Portage sentinel. [volume] (Ravenna, Ohio) 1845-1854, 1851-07-28
observations on the Mammoth Cave.

| The May number of Silliman's Journal
contains IN interesting nccount of the
| Mammoth Cave, i'll letter addressed to
| Prof. Guyot, by Prof. Benz. Sillmun, IT,,
| who has recently made an exploration OF
its mysteries; and also, in connection with
Mr.. r. N. Mantell, made collection of
the animals found there. One atmospheric
| phenomenon attracted the attention of these
gentlemen, and tasked their ingenuity for
satisfactory explanation, viz:-The blast
Of cool air blowing outward from the mouth
Of the cave, which renders it nearly impos.
sible to enter with lighted lamp Il the
external air has a temperature of 80 de-,
grees Fahrenheit, the blast amounts to
gale; but if the air without has tempera.
lure of59- 80 degrees, no current Of air
is observed, und the fame Of a lamp, held
in u favorable position, indicates none. .f
1t Immediately occurred to me (said Prof.
Silliman.) that there must be two currents,
one above of warmer air, passing inward,
and one below ofcolder air,passing outward,
and the reverse; but experiment soon salts
fled me that this was not the case. Only
one current could be discovered, and on
inquiry OF our intelligent guide, found that
this phenomenon had attracted his attention,
and that he was satisfied from many obser.
valions that only one current existed and
that this fared out when the external air
was above so degrees, and anward when
this was below so degrees. ..f.sx ss.. e,,.5s.
The phenomenon is accounted for by
Prof SlllimaE on scientific principles, as
follews:-The mouth of the cave IS the
only communication between the external
air and the vast labyrinth of galleries and
avenues which stretch away for many
miles in the solid limestone. The air in
these underground excavations is pure and
exhilerating, which mny, in part be ac-
counted for by the nitre beds of incredible
extent, as the nitrogen which is consumed
in the formation Of the nitrate of lime must
have its proportion Of free oxygen disen>
gagged, thus enriching this sublerranean
atmosphere with large portion of the ex.
hilerating principle. The temperature of
the cave is uniformity 50 degrees summer
and winter, and this probably very near to
the annual mean of the external air. The
expansion which accompanies ain elevation
of temperature in the outer air is immedi>
ately felt by the denser air Of the cave, and
it flows out in obedience to the law OF mo-
ton in fluids, and the outward current con-
tinues without interruption as long as the
outer air is possessed of ashigher5 5tempera-
ture than the caye.sla 51i y .aa6s 8 nH 7 .zB~l
The phenomena of life within the cave
are comparatively few, but interesting
There are several insects, the largest Of
which is sort Of cricket, with enormously
long antenna There nre several species
Of CaleoPtera, mostly burrowing in the nj
tire earth. There are some small species
Of water insects, supposed to crustaceous.
Of fish there are Two species, one Of which
as is well known, is entirely cyeless; the
other has external eyes, but is quite blind.
The only mammal, except the bats, is rat
which is very abundant. Prof. Sil,iman
is of opinion that the excavations Of the
Mammoth Cave have been formed by
water, and BY no other cause. " 4@@