News and citizen. [volume] (Morrisville, Vt. ;) 1881-current, 1886-09-30

of heat, all which is lost to the earth
through radiation. The secular cool
ing which results from the above causes
must necessarily diminish the magni-
tude of the earth, and as it shrinks the
solid exterior crust must in some man
er yield so as to conform to the lesser
magnitude thus produced. The stresses
produced in the crust of the earth ~
the shrinking of the interior are modi-
fed by another class of agencies. The
land surface of the arth is washed By
rains and rivers, and in the aggregate
la ge bodies of material are carried
away and deposited in lake bottoms,
which a gradually filed up, and espe
cially deposited along the shore of the
seas. The unloading of land areas and
the oyerloa ing o certain water areas
to large extent lOcalize it. Again,
tn fui or plastic material of the in
terror changes its position beneath the
crust of the earth, and portions of it
flow out as lavas, thus an additional set
of stresses is established Thus stresses
are established through the agency of a
contracting interior through loading
ana unloading at the surface and
through the flow of the interior IN tier
to the lava beds, where such matter is
poured out upon the surface. The
stresses p oduced by the various agen-
cies thus described gradually become so
great that at last the crust of the earth
must yield, and earthquakes are pro-
duced.
The occurrence of earthquakes in the
eastern portion of the United States
seems to be related in a very interesting
way to certain geological facts observed
in the region. At least a considerable
share of the Atlantic slope earthquakes
are supposed to have sequential con-
necuion with line of displacem Mt
p ssing through the Carolinas, Virginia,
Maryland, Delaware and New Jersey.
This Ii of displacement has fol some !
time past been a subject of investiga-
ton by the Geological Survey. In
Georgia and the Carolinas it is repre-
sented by general seward fitting of
e. the surface, unquestionably connected
with subterrane N movements, and in
Virginia this widespread fitting begins
to concentrate in definite line of dis
placement which in the latitude at
Fredericksburg is a gentle monoclinal -
:. g, the rock strata are there locally
bent Onward, and here, as elsewhere
along the di placement, the land towards
the sea is depressed, and that towards
the mountains is elevated. In the lati-
tude of Washington the displacement
becomes either close flexure or frac-
ture, and lies in the eastern branch. Its
amount here is eighty feet. At the
head of Chesapeake Bay the displace-
ment is 100 feet, and it appears to
increase northward, reaching two hun
dred or three hundred feet in the lower
Hudson Valley
The whole of this movement has prob
ably occurred in post-quaternary times
and is still in progress-indeed, it may
be questioned whether any general orc
graphic movement on any part of the
earth's surface during any period of
geologic time has been much more en-
ergetic and rapid than that now taking
place along the Atlantic slope, and our
comparative immunity from serious
earthquakes here is to be attributed not
so much to absence of these great earth
movements resulting in the formation
of mountain chains and even the up
heaval of continents, as to the probably
less profound depth of this great dis
placement than those of mountain re-
gions, and especially to the fact that
no volcanic vents have been estab-
lished.
RELATION OF EARTHQUAKE TO THE
WEATHER.
Prof. Stevens of Packer Institute
says:
By comparison of records covering
long periods of time earthquakes have
been found to be very slightly more fire.
quent In winter than in summer. and at
times when the relative positions of the
sun and moon is such as to produce the
highest tides. But no intimate rela-
ton between earthquakes and the minor
fluctuations of the weather has been es-
tablished on any basis of careful obser-
walton. At certain points the earth's
crust may be in a condition of strain,
almost at the critical point of rupture.
y prolonged depression of temperature
tends to increase the contraction, and
an earthquake may possibly be thus de-
ermlned. The moons attraction may
likewise increase the strain very slight.
ly. But beyond this, the weather pro-
phet of earthquakes is left to nothing
OSS1CA IMAM
In volcanic regions the escape of
soluble gases through minute cracks in
the ground may serve as an indication
of subterranean disturbance by altering
the taste of mineral springs. This has
sometimes excited lucky conjectures of
approaching earthquakes as the fore
runner of volcanic eruption. Rumb-
ling in the ground is not infrequeutIv a
very brief fOreruEner. But such signs
are very unreliable, and no method of
predicting an earthquake has yet been
discovered. Immediately after a shock
there are always claimants for the honor
of having guessed its approach; but in
0ariably they are unable to give any
definite ground upon which the relation
between cause and effect can be traced
Stories about peculiar conditions of the
ar, or of the human system, or about
the terror displayed by animals, as pre-
onl;Ions of earthquakes are exclusive
ly the products of superstition.
AN EARTHQUAKE LINE.
The London Telegraph exhibits map
Of the terrible Lisbon earthquake, in
tended to portray the fact that the
tountry shaken on Tuesday night was a
Part of the area of the American Con-
i'nent over which that great historic
snock was felt, while the larger effects
OF the movement were experienced in
Europe The waves of forces were
lropagated across the Atlantic and felt
along the whole eastern seaboard of the
States and Canada, from South Carolina
10 Labrador. 1t is not, perhaps, to be
argued that there is any permanent
connection between the two areas under
e bed of the Atlantic, but at the
particular moment when Lisbon was
destroyed the entire arch of the globe,
outlined in our map, was objected
10 a tremendous subterranean strain
y hich it was unable to resist" 1t re-
fcrs to Sir William DawsOn's address
before the British Association. in which