Juniata sentinel and Republican. [volume] (Mifflintown, Juniata County, Pa.) 1873-1955, 1886-09-15

umn, but the people OF the island arr
convinced that q volcano has sprung
lup.
Earthquakes are not nearly so I'M.
common as Is generally supposed
Every year they occur somewhere in
sections of the United States. Ir
volcanic countries they are very nu
merous- Probably not day passes
in which there il not an earthquake
somewhere around our globe. Ge-
ology has taught us the causes Of
these daily tremors- They may be
easily understood by looking at the
bulb Of q thermometer. 1t is COM
posed of a solid glass shell and a IL
quid metallic interior. The liquid
expands and contracts with the
changes Of temperature very much
more than the solid. Hence the Ii
quid rises and falls in the thermom-
eter tubes. Our globe is composed
Of an outward solid shell less than
fifty miles thick, and the whole inte-
rior is highly heated liquid rock, the
heat is slowly radiatiny away into
empty space, and the liquid interior
is hourly contracting more than the
solid crust. Hence this outer crust
or shell becomes too large for the
interior. How shall it daily become
smaller SO as exactly to it on the I'll
quid interior and leave no vacant
space between the twoi Plainly
their must be mighty side pressure.
There must be a wrinkling. The
crust must be pressed up in some
places and down in others. The up
ward turns become the continents
and the downward turns become the
ocean beds. All continents and is
lands are composed Of strata which
have been deposited as sediment in
the bottoms of the oceans, and after
wards slowly raised up by the wrink
ling Of the earth's crust. This con-
tracing our earth's interior and the
bending Ct its solid outward shell
goes on so slowly as not generally
to be perceptable, but occasionly it
goes with sudden jerk, and this
sudden movement is an earthquake.
The severity of an earthquake, that
is, whether it be great or small, de-
pends upon the extent and the sud
denness of the adjustment necessary
to make the exterior crust agree with
interior fluid, which is constantly
growing smaller.
Instances are on record where the
land has been raised several feet in
single earthquake shock These
have recently happened on the west
coast of South America, where the
shore has boen elevated suddenly
from one to five feet Some ship
harbors have been totally ruined.
The Andes mountains, further inland
mus. have been raised still more, for
the streams running down to the
coast flow more rapidly than before
the earth quake shocks.
But mountains generally must be
raised up by the wrinkling of the
earth's crust with extreme siowness.
The Susquehanna above Harris
burg plainly and sharply cuts through
the ranges of the Allegheny noun
tains. 1t is deeply interesting to
see the vestiges of the mountain
in the bed of the river from the side
where it has been washed away by
the stream. Not here could the
river have come against the noun
tain side and dashed through the
solid appraised rocks. The river
was in its present bed before the
mountains were raised up. Then
when the mountains began to rise
with almost infinite slowness the
rivers had time to keep their chan
nels open through the mountains.
The wonder is that there are not
more numerous and severe earth.
guakes. The earth's crust is sew
eral miles in thickness and rigid.
Its bending can be only inconceiva-
bic strain. And yet with all its
thickness and rocky rigidity, it
slowly and gently rises up in some
regions and bends down in other
regions. The highest, the Himme-
layas, rise up five miles. The deep.
est ocean soundings are seven miles,
Added together these bendings
amount to twelve miles, and the in
stances of destructive violence in
are very rare. Philadelphia Bulletin.
There are very few visitors to
Charleston who stay oyer night.
The hotels are badly damaged and
most Of them are not in operation.
The Charleston has but q dozen
rooms out Of ITO that are habitable
and Of these many are so wrecked
as to be considered dangerous to