Clarke courier. [volume] (Berryville, Va.) 1869-1997, 1910-06-01
vIRTH OF A VOLCANO.
Natures Process In Forming a
Mountain of Lava.
THE FORCE OF AN ERUPTION.
uphsavai That Destroyed the East
Indian Island Of krakstos In 1888
Propelled an Air Wave Three ard
Half Times Round the Earth.


Half Times Round the Earth.
Though volcanoes are often 'spokcn
OF as burning mountains. they do no,
burn at all. nor, ia the proper sense OF
the word, are they mountains mt all.
a volcano is really flaw In the crust
OF the earth through whleh the fierce
glowing heat lying below the crust has
managed to burst a hole. Through this
hole great floods OF melted rock spout
up. Some volcanoes work at inter.
walls; some are I'm eruption all the time.
As the melted rock Jets up into the
air and falls II naturally builds itself
into a mountain round the hole. The
next eruption has TO burst its way
through the heart of that mountain.
The chimney IL spouts through Is usu-
ally called "the pipe
Sometimes an eruption Is so fierce
that when the lava (another name for
melted rock spouts out Il Is burst into
bits When II falls IL is sometimes as
fine as dust, sometimes the size OF Gin
ders. Most volcanoes. indeed. are sim
ply gigantic cinder heaps.
When the force is not so great the
lava In the pipe simply bubbles over
and flows down the sides OF the noun
tain, exactly as porridSe boils over the
edge OF a pot. AS lava Is liquid, the
slope OF lava volcano Tor lava cone.
as II is usually calledl is always very
gentle. Failing cinders. ON the other
hand. pile themselves up quite steeply.
A lava cone. then. is always less steep
than a cinder cone
And volcano never burns What
looks like flame Is only the glow OF
the white hot lava on the clouds of
steam. The more steam there is fore
ing its way up the pipe the more the
lava bubbles. just as i'm the case of
the porridgc. IL the pressure OF steam
is very great. then You have the lava
blown to bits and falling as ciuders,
while the mighty clouds OF steam rise
high above the mountain. II Is this
steam that is mistaken for smoke.
Sometimes cone sends out lava and
cindcrs alternately. SD that you have
n great mountain OF cinders bound to-
gcther By layers and walls of lava.
h(ct N1A4c vi AstN Qut W TUE
fact that sometimes more lava wants
TO come up the pipe than the pipe will
hold. so the lava bursts its way out
through weak spots i'm the sides OF the
mountain. Etna has no fewer than
200 of these cones on its slopes. One
OF them. Monte RossL is hill in
itself. being $50 feet high. Indeed. n
model Of Etna looks as IL IL were COW
cred with pimples.
When Etna is really reused II is far
more dangerous than Vesuvius. In
1169 IL nearly destroyed the city OF
Catania. killing $4,000 people. In 1869
IL found its pipe SO inconveniently
small that IL had 10 crack one Of its
sides. This crack was no less than
twelve miles long. At the bottom
white hot lava could dlmly be seen
through the clouds OF steam. In 1855
millions Of gallons Of boiling water
were shot out OF the Val del Bove.
which is n great circular pit on the
slope OF the mountain. four or five
miles in diameter. its sides being cliffs
nearly a mile high in places.
The greatest volcanic eruption ever
known took place in the East Indies
In 1888. The story makes almost in
credible reading. The volcanic island
Of Krakatoa commenced proceedings
by blowing half OF itself into thin air.
From the opening no less than n cubic
mile of rock was shot out.
a column Of steam and lava dust
rose into the air TO a height six times
as great as that OF Mount Everest. II
spread and spread till for hundreds of
miles around the air was black as mid
night. Sounds as OF distant cannonad-
ing were heard 1000 miles OF
Sea waves fifty feet high killed 3d.
oOo people and were felt as far of as
California. Instead Of an island half
mile high there was now hole a
quarter of 4 mile deep. The shock OF
the eruption sent air waves three and
a half times around the earth. The
fine dust IN the upper atmosphere add
ed for months afterward strange
glow to the sunsets i'm England and
did not vanish completely for three
years.
The exact cause of the eruptions is
not known for certain. \ popular the
DRY is that they are caused by water
getting in to the white hot mass which
is supposed to lie under the outer crust
OF the earth. And IL is certainly n fact
that practically all volcanoes are close
TO the edge OF the sea.
Some lava flows slowly. some quick
ly. Vesuvius in 1905 sent out lava
stream that in four minutes had reach
ed a spot four miles off. The size OF q
lava stream is sometimes gigantic. In
1888 Skaptar Jokull in Iceland emitted
two streams at one time. One was
forty miles long by seven miles broad
the other fifty miles by fifteen. The
average depth of both was about q
hundred feet.
Lava cools very, very slowly. except
on the surface. which cools at once
II is an extremely bad conductor OF
heat. Twenty years after stream OF
lava was sent out from Jorullo. In Mex
Eco, tourists could light their cigar,
through chinks in the surface. and the
surface had been cold for twenty years
In 1928 a layer OF snow many fee
thick was found under a layer OF Vesu
Wan lava. II was still unmeited and
Is probably there stu. = Pearson,
Weekly.
MH Tvs