The watchman and southron. [volume] (Sumter, S.C.) 1881-1930, 1910-08-17
BIRTH OF A VOLCANO,
Natures Process In Forming a
Mountain of Lava.
THE FORCE OF AN ERUPTION.
Uphssva' That Destroyed tho East
Indian Island Of Krakatoa In 1889
Propelled an Air Wave Three and Q
Half Times Round the Earth.

Though volcanoes are often spoken
OF as burning mountains, they do not
DurD at all. nor, I'm the proper sense of
the word. are they mountains at all.
A volcano is really faw In the crust
OF the earth through which the fierce
glowing heat lying below the crust has
managed to burst hole. Through this
hole great foods of melted rock spout
up. Some volcanoes work at inter.
walls; some are In eruption all the time.
As the melted rock Jets up into the
air and falls 1t naturally builds itself
Into mountain round the hole. The
next eruption has to burst its way
through the heart Of that mountain.
The chimney 1t 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 1t is burst into
bits. When 1t falls 1t is sometimes as
f1ne 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 porridge boils over the
edge Of pot. AS lava is LIQUID, the
slope OF lava volcano (or lava cone.
as 1t is usually called) is always very
gentle. Falling cinders. on the other
hand. pile themselves up quite steepIy.
A lava cone. then. is always less steep
than cinder cone.
And q 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 in the case of
the porridge. If the pressure Of steam
Is very great, then you have the lava
blown to bits and falling as cinders.
while the mighty clouds of steam rise
high above the mountain. 1t is this
steam that Is mistaken for smoke.
Sometimes cone sends out lava and
cinders alternately. SO that you have
gether by layers and walls of lava.
These walls of lava are due to the
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 in the sides of the
mountain. Etna has no fewer than
100 Of these cones on its slopes. One
OF them, Monte Rossi. is hill in
itself, being $50 feet high. Indeed. a
model of Etna looks as II 1t were COW
cred with pimples
When Etna Is really reused it Is far
more dangerous than Vesuvius. In
1869 1t nearly destroyed the city Of
Catania, killing $4,000 people. In 1869
1t found its pipe so incOnveniently
small that 1t had to crack one of its
sides. This crack was no less than
twelve miles long. At the bottom
white hot lava could dimly be seen
through the clouds of steam. In 17h5
millions Of gallons OF boiling water
were shot out Of the Val del Bove,
which Is a great circular pit OH the
slope OF the mountain. four or FIVE
miles In diameter. it's sides being cliffs
nearly mle high in places.
The greatest volcanic eruption ever
known took place In the East Indies
IN 1882. The story makes almost in
credible reading. The volcanic island
Of Krakatoa commenced proceedings
by blowing ha.f of itself into thin air.
IN
mile Of rock was shot out
A column of steam and lava dust
rose into the air to height six times
as great as thar Of Mount Everest. 1t
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 off.
Sea waves fifty feet high killed 35,-
GOO people and were felt as far Off as
California. Instead of an island half
mile high there was now hole a
quarter of 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 q strange
glow to the sunsets in England and
did not vanish completely for three
years
The exact cause Of the eruptions ia
not known for certain. A popular the
ory 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 1T Is certainly fact
that practically all volcanoes are close
70 the edge Of the sea.
Some lava flows slowly. some quick
1y. VesuTius in 1905 sent out a lava
stream that in four minutes had reach.
ed spot four miles off. The size Of
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
hundred feet.