St. Tammany farmer. [volume] (Covington, La.) 1874-current, 1885-05-16
contraction. On this view Of the earth's

contraction. On this view OF the earthi
condition, volcanic phenomena are ex-
planned as the result of the conversion
into heat of the mechanical force of
contraction; while earthquakes may
themselves be regarded as proceeding
from the crushing and bending OF the
| rocks BY the stress of contraction itself.
Again, there are those who regard tho
earth as globe mainly solid through
out, but with lakes of liquid matter in
| various parts near the surface, remnants
of its former heat, and believe that it is
| from these lakes, as the earth continues
to contract. that matter is forced into
| volcanic vents to feed their intermittent
fires; whilst, looking at the fact that
earthquakes so frequently precede an
eruption, these earth-tremors may from
this point be regarded as Intellectual
efforts by the pent-up subterranean
forces to establish volcanic outburst;
and since the observations ofMr. Mallet
in earthquake localities have demon
strated the fact that shocks emanate
from centers near the earth's surface,
being sometimes nearer. and sometimes
further, as the shocks are mainly hori-
| zontal or mainly vertical in character,
there would seem to be some proba-
bility in this latter view of the origin Of
the subterranean forces; but there are
many arguments which initiate against
its acceptance.
| There are those also who, while they
regard the matter of the earth as being
in a really solid condition, yet conce Give
that some portions of it may be in a
state of potential liquidity; that
is to say, ready to assume the
liquid form on a release of pressure:
and when it is remembered
that barometric fall of two inches-a
by no means remarkable circumstance
means the removal of millions of
pounds of air-pressure from off the sur
face of the earth, it seems as though
there might be some truth in this view
also; but it loses probability when we
reflect that for this release of pressure
to be effectual in producing liquidity. it
is necessary that the solid matter of the
earth should be just on that borderland
between the solid and liquid states,
which it is so difficult to imagine can
often be the case; and it must be finally
admitted that science has yet to frame
a perfectly satisfactory explanation OF
these interesting phenomena.
Human nature is too apt to dwell
upon the awful results of these
evident and striking manifestations
of nature, and to pass over her more
regular and noiseless. vet far more
potent, activity. 1t must not. therefore,
be forgotten that these subterranean
outbursts we have been considering are
but the more violent and pronounced
examples of slow and gradual process
of upheaval and depression which is
going on at all portions of the earth s
surface. And these movements of the
earth's crust, whether they be the slow
upheaval and depression to which ref
erence has Just been made, or the cata.
clysmal efforts of an earthquake or vol
canic outburst, are in the main most
beneficial to man, and have an i'm
portant influence on his progress and
well-being. 1t is the short-sighted
philosophy of imperfect knowledge
which regards only the evil which such
catastrophes produce. The heated re.
giOns of the earth's crust where the
volcanic forces are in energy are the
laboratories of nature, where her most
valued gems and minerals are produced;
whilst the earth-throes which de.
vastate q country. and seem to be
fraught only with evil to mankind, bring
the rock containing them to the surface;
and we may strangely reflect that, but
for these eruptive efforts, iron, and
many other minerals which have con.
tributed to the comfort and progress oi
man, might for ever have remained un.
known to him. One of 1.-THE fairy tales
of science and the long result of time
is the gradual change in the relative
positions of continent and sea which
these oscillations of the earth's crust
have brought about. Our own island
has now been submerged until the ses
washed its mountain tops, now elevated
until it ceased to be an island, and
Father Thames flowed across a great
stretch of land, which filed up the
North Sea, to join the great Rhine, the
two streams pouring their united water:
almost within the arctic circle. So
over all the earth; continents have
grown out of the sea, and great land:
have given place to vast oceans. 1.-THE
stony rocks are not primeval, but the
daughters of time" Everywhere, flu
and change-growth and decay; only
fixed and unalterable the immutable
and eternal laws which govern it,
Chambers journal.