The Osceola times., 1881-08-20
INSIDE THE EARTH.
a, Interior Department that is Supposed
to be Red Hot.
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That the interior of the earth is the
seat of intense heat is familiar truth.
Volcanic phenomena give US ocular
demonstration of it. Mining experiences,
moreover, have furnished MS with an
almost uniform rate at which the heat
increases, aud this is generally compu-
ted to be about one degree fahenheit
for every fifty five feet of descent. But
mining experiences are necessarily very
limited. The deepest mire in England,
that of the Rosebridge colliery, near
Wigan, takes us down only 2,445 feet
and to a temperature not exceeding 90
degrees Fahrenheit. 1t is hot enough 10
make the work exceedingly trying to
the miners, but that is all. This, how
ever, is (so to speak scarcely traversing
the earth's epidermis. But if we may
assume uniform increase Of heat in de-
scending, the temperature at deph Of
fifty miles may be expressed in figures
at 4 500 degrees Fahrenheit. In other
words, at less than an eighth Of the dis
tance which lies between the cir-
cumference of the earth and its center,
the heat would be about twenty-five
times the heat of boiling water at the
sea level. ProportIonate figures might,
OF course, express the heat at greater
depths still, but figures fail to convey
any idea to the mind Of that which
must necessarily transcend all imagina-
ton. Suffice it TO say that in descend
ing series we must eventually come to
heat so great that no substance with
which we are acquainted could, under
any conditions which we could imagine,
exist in it in either solid or fluid form.
And we conclude. therefore, that if the
earth's center be not itself in gaseous
condition land there is every reason to
think that it may not be so), there must
be a gaseous zone somewhere between
solid center and solid circumference.
Fdcilis d6Scepsus dterni is proyerbially
treated as truism. But If the classic
authors are to be our guides, and il in
the center OF our planet Acherotlan
shades and Elysian fields are to be To-
calized, there will be found practical diff
fculties TO success which might well
discourage even SO substantial a person
age as ghost. Nor can the
all powerful imagination accomplish
the descent with any approach to ease.
The distance We may suppose to be
nearly 3,400 miles; but along line Of
this length connecting the surface of the
earth with its centre, we may safely as
sumo that conditions would vary greats
", and (since heat and pressure have to
be balanced one against the other prob
ably by no means uniformly. We can
measure the power OF pressure uponth
surface, but IN the neither depths its
power is in part open to conjecture, nor
can we say how soon We may reach des
batable zone, at which the expansiveness
of heat may overcome the compressiye
force of gravitation. Nor, again, could
We venture to expect 10 find that zone
itself always at uniform depth. Here
and there it seems TO approach the SUR
face. The volcano is natures safety-
valve, and the cavernous rumble of the
earthquake warns us that there are i'm
prlsoned gases beneath our feet
which pressure but imperiectly pre-
vents from escaping. Upon other
grounds, also, it is quite evident that
our experience, limited as 1t is to the
surface Of the earth, may tend to mis-
lead us in regard to what lies beneath
the surface; for If pressure increased
uniformly with depth, the average den-
sity of the earth would be much greater
than what, upon astronomical data, We
know it to be. The earth, as a whole, is
about five and half times us heavy as
it would be if it were entirely composed
Of water; or, technially expressed, the
density OF water is one, and the mean
density Of the globe is FIVE and
half. But five and half is only about
double the density of rock matter upon
the surface; whereas, if nothing but
steadily increasing pressure be supposed,
it would vastly exceed this. There is,
therefore, only one possible explanation.
Heat, intense heat, somewhere or other,
overcomes pressure, and converts every
thing into gas; and if it were in our
power TO Try experiments, and to feed
the subterranean cruc.ble with The most
intraclable substances-asbesios, fire.
proof safes, or what we will-all would
there share the same fate-instant evan
escence.