The Bossier banner. [volume] (Bellevue, Bossier Parish, La.) 1859-1952, 1885-05-07

has been calculated portion of the
earth's surface equal TO four times the
area of Europe was included within its
range. From the West Indies and the
great inland lakes of Canada it extended
its range to our own country, to Sweden,
and to North Germany. The shock
then, too, was also felt at sea, producing
an effect similar to that which follows
when vessel strikes sunken rock or
runs aground.
But whilst earthquakes may thus
seem to happen without the slightest
warning, there can be but little doubt
that their apparent suddenness is due
either to want of observation or to
wilful disregard of the signs which indi-
cate the advent of subterranean out
bursts. Their approach is usually her
aided in many ways-underground
noises, gaseous emanations from the
soil, the drying up of wells, a change in
the temperature of thermal springs,
haziness in the air, being the more gem
eral forerunners of these phenomena.
At such periods, too, sense of diZzi
ness is often experienced by dwellers in
the threatened locality, whilst microcos-
mical instruments, if there be any in
the district, will register slight varia-
tions of subterranean activity. During
the continuance of the earthquake the
ground often heaves like the sea, pro-
ducing feelings akin to the familiar
pangs of sea-sickness; rivers seek fresh
channels; large assures open in the
earth, and permanent changes take
place in the geographical features of the
country. Thus the series of earth
quakes Which in 1926 and 1927 visited
New Zealand, caused SO distinct a
change that the former features of the
coast could be no longer recognized.
The earthquakes of the present century
in Chilli have produced a permanent
elevation of the coast there; and re-
cent subterranean outburts in Java
have considerably modified the geo.
graphy of that region. f
Concerning the origin of these phe-
nomena, SO far-reaching in their effects,
it must be admitted that the true theory
has never yet been framed. Early spec
ulations were much tinged with the su-
perstitions of the time; and even so
late as the beginning of the present
century we find a lingering remnant OF
this superstitious regard of physical
phenomena in the naming, by the in
habitants of Sindree, of mound
thrown up during the Indus earthquake,
-.'Ullah Bund, y or the Mound of God.
1t is obvious that the study of these
interesting phenomena is beset with
many difficulties. Observation can
often only be made at imminent per-
sonal risk. Yet, spite of this, begin
ming with the few observers and the al
most mythical records of the days oi
Pliny, the fascinating subject has con
tinued to attract an ever increasing
circle of students, who have ever more
earnestly endeavored to pierce the vel
of mystery which surrounds it. Each
fresh manifestation of subterranean en-,
ergy is now watched with increased in
terest. Whenever possible, the Sc
quence of events is noted with extreme
Esdetail, old theories become weakened
fresh ideas confirmed, and new avenue:
of thought open themselves to the earn
est investigator at every step. .
With the phenomena of earthquakes
those of volcanoes are closely linked
volcanic outbursts being frequently her
aided and accompanied by earthquake
shocks; and there can be little doub
that the two are most intimately bount
up, if, indeed, they are not two effect!
arising from a single cause. This being
so, the facts which surround the ont
class of phenomena may be drawn upoI
/ ~, oft 20 Srr
whence and how either originates
That some portions of the earth's inte
rior are In an immensely heated con
dition, the nature of the material
elected from volcanic vents renders ey-
dent, and observation has also clearl,
demonstrated the fact that the temper
ature increases from the surface of tht
earth downwards, the average inereas
being one degree Fahrenheit for ever,
fifty feet of descent. Now, from con
siderations connected with the figure o
the earth. and the other members. of tn
system to which it belongs, it has, witt
much probability. been inferred that th,
solar system has evolved from one 0
those glowing, gaseous aggregation
termed nebula.. that .st.this world wa
once a fluid haze of light;n and tha
lwhen it first existed as an independen
| bodyit was in a state of the most fer
vent heat, aresidue of which now give
rise to volcanic phenomena.
What happened, then, as our eartl
/ radiated its primitive heat into space
The question is vexed one. So man,
men. SO many minds. One class O
theorists, not giving sufficient weight t.
the fact that the increase of pressur,
towards the earth's center would tene
to keep matter solid there under the in
fluence of high temperatures, suppos
that the process of radiation by tn
earth into space has, throughout tn
/ lapse of ages, resulted in the formation
of solid external crust covering a still
| fluid nucleus sBatthis elassiof theorist
is, like the volcanoes of Britain, practi
! cally extinct, or is at least as subduet
and unpretending as the Suffolk earth
4 quake. Other geologists, giving NOR
weight to the fact of increase of press
ure towards thesearth's 9 center, conside
that its condition is that of a body witt
a solid naeleuss and a solid externa
crust, between which there still re
mains residue of liquid matter.