The St. Mary banner. (Franklin, Parish of St. Mary, La.) 1889-1931, 1902-11-08
THE CAUSES CT VOLCANOES
THEORIES 6r rHE GREAT SclEN.
lists AS TO PHENOMENA.

lists As TO fHsNoMENA.
Sir Robert Balls Nebuia hypothesis
disturbances That Take Place
Under Very Extraordinary Pres
sure.
The cause Of voicaooes and Garth
quakes; line most scientific questions,
is, for the 1f1ost Fart, only theofetieai'
ly explained, that thecfy gaining cur
rency which will solve Tvs largest
number Of problems. "The Eaf'h 3
Beginning" is the title of book by
Sir Robert Ball. the chief astronomer
of England, published by d. Appleton
& Co. In this book Sir Robert Ball
says that the nebula theory, outlined
by Kant and Latlace, will account for
all the phenomena 6f earth ana
heaven. This theory md;tsains that
the earth, sun and solar system G'sl-
mated from a vast contracting nebula.
THE internal heat of the earth, de-
rived frpm the primeyal nebula, is IN
no way iflofe striktngly illustrat-
ed than by the pseuemena OF
Volcanoes says Sir Robert. THE
evidence has proved that Under
the extraordinary pressure which
prevails in the earth the ma
terials in the central portions of our
globe behave with the characteristics
Of solids rather than of liquids. Many,
if not all. solids may be made to flow
like liquid If only adequate pressure
be applied The fact is that the terms
solid and liquid appear to have no
physical meaning with regard to
bodies subjected to these tremendous
pressures. But when the cIrcum-
stances are such that the pressure IS
relaxed, then the heat is permitted to
exercise its property Of transforming
the solids into liquids. Masses of
matter near the earth's crust are thus
in certain circumstances transformed
into the fluid form and issue from a
volcano in sluggish currents Of lava
There has been much difference in
opinion as to the immediate cause Of
volcanic action, but there can be little
doubt that the energy which is mani
tested in a volcanic eruption has been
originally derived in come way from
the contraction of the primeval
nebula."
Lord Kelvin. says robert Ball. has
demonstrated that, whatever its ma
ture. the earth possesses an intense
rigidity, and this Is proved from the
study of earthquake phenomena. "As
to the immediate cause of earth
quakes." he adds, there is consider
able difference of opinion. But think
that an earthquake is one Of the con-
sequences of the gradual loss of in.
ternal heat from the earth. AS this
terrestrial heat is gradually declining,
1t follows that the bulk of the earth
must be shrinking, and, accordingly,
the crust of the earth has from time
to time to be accommodated to the
fact that the whole globe Is lessening.
1t follows from these considerations
that the rocks which form the earth's
crust must have lessening acreage
from year to year. These rocks must,
therefore, submit to compression, and
the necessary yielding of the rocks
will, in general, take place in those
regions where the materials Of the
earth's crust happen to have compara-
lively small powers of resistance. The
acts of compression will often and.
perhaps generally, not proceed with
uniformity, but rather with small sue
cessive shifts, and even though the
displacements of the rocks in these
slips be actually very small, yet the
pressures to which the rocks are sub
shift may correspond to a very great
terrestrial disturbance. The effect Of
such a shock would be propagated in
the form of waves through TIE globe,
and when the effect Of this adjustment
reaches the earth's surface it will
sometimes be great enough to be per-
ceptible in the shaking it gives that
surface. The shaking may be so vio-
lent that buildings may not be able
to withstand it. Such is the phenome-
non of an earthquake"
Albert Perry Brigham. professor Of
geology in Colgate University, says in
his textbook Geology (aiso published
by D. Appleton and Company: THE
great number of earthquakes ara
probably due to the shrinking of the
earth's crust in cooling. A compare
lively stiff crust over a cooling and
interior must shrink. 1t be-
comes cracked in some places and
folded in others. Stupendous strains
are thus set up and rock masses are
liable to move suddenly upon each
other. All points to which the Inn
pulse is transmitted experience an
Writing on the causes Of volcanic
action he says: mo conclusive word
has been spoken on the subject.
final conclusion may lie beyond the
bounds of human investigation. Vol
canic heat has been thought to be
of the original heat OF the
globe. But on this theory it would
seem that vulcanism should gradually
have declined through the ages of geo
logical history This has not been
proved and some facts look in the op-
posite direction. The sudden conver-
sion of water into steam is thought to
have much to do with explosive erup-
tions, and the more as most volcanoes