The Colfax chronicle. [volume] (Colfax, Grant Parish, La.) 1877-1981, 1885-06-20

an effect similar to that which follows
when a 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 a
wilful disregard of the signs which indi-
cate the advent of subterranean out
bursts. Their approach is usually her
aided in many acknowledgement
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 gen.
eral forerunners of these phenomena.
At such periods, too. a sense OF dizzi-
ness is often experienced by jewellers in
the threatened locality, whilst microcos-
mical instruments, if there be any in
the district. will register slight varia-
tons of subterrauean 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 Chill have produced permanent
elevation of the coast there; and re-
cent subterranean outburts in Java
have considerably modified the geo.
graphy of that region.
Concerning the origin of these phe-
nomena, so far-reaching in their effects,
it must be admitted that the true theory
has never vet been framed. Early spec
ulations were much tinged with the SUI
perstitions of the time; and even so
late as the beginning of the present
century'we find 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," 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 of
Pliny, the fascinating subject has con-
tinued to attract an ever increasing
circle of students, who have ever more
earnestly endeavored to pierce the veil
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
detail, old theories become weakened.
fresh ideas confirmed, and new avenues
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 doubt
that the. two are most intimately bound
up, if, indeed, they are not two effects
arising from single cause. This being
so, the facts which surround the one
class of phenomena may be drawn upon
in attempting to frame an explanation
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 materials
elected from volcanic vents renders ey =
dent, and observation has also clearly
demonstrated the fact that the temper
AZURE increases from the surface of the
earth downwards, the average increase
being one degree Fahrenheit for every
fifty feet of descent Now, from con-
siderations connected with the figure of
the earth and the other members of the
system to which it belongs, it has. with
much probability, been inferred that the
solar system has evolved from one of
those glowing gaseous aggregations
termed nebul8, that ''this world was
once fluid haze of light" and that
when it first existed as AN Independent
body it was in state of the most fer
vent heat. residue of which now gives
rise to volcanic phenomena.
What happened, then, as our earth
radiated its primitive heat into space?
The question is a vexed one. So many
men. so many minds. One class of
theorists, not giving sufficient weight to
the fact that the increase of pressure
towards the earth's center would tend
to keep matter solid there under the in
fluence of high temperatures, suppose
that the process of radiation by the
earth into space has, throughout the
lapse of ages, resulted in the formation
of a solid external crust covering a still
fluid nucleus. But this class of theorists
is, like the volcanoes of Britain, practi-
cally extinct, or is at least as subdued
and unpretending as the Suffolk earth
quake. Other BIOLOGISTS, giving more
weight to the fact of increase of press
ure towards the earth's center, consider
that its condition is that of body with
a solid nucleus and solid external
crust, between which there still re-
mains residue of liquid matter.
In objection to both these views it has
been shown that for the earth to maintain
its rigidity under the moons attraction,
such crust must be of enormous thick