Bismarck daily tribune. [volume] (Bismarck, Dakota [N.D.]) 1881-1916, 1910-06-02
BIRTH Of A VOLCANO,
Natures Process In Forming a
Mountain of Lava.
THE FORCE OF AN ERUPTION.
Upheaval That DESTROYED the East
Indian Island Of krakatoa In 1888
Propelled an Air Wave Three and
Halt Times Round tho Earth.

! OF as burning mountains. they do not
burn al all. nor. in the proper sense Of
the word. are they mountains at all.
A Volcano Is really flaw ~ the crust
OF the earth through which tn" fierce
glowing heat lying below the crust has
managed to burst a hole. Through this
hole great foods of melted rock spout
up. Some volcanoes work at inter-
walls: some are in eruption aII the time.
AS the melted rock jets up into the
air and falls it 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 (anoth her name for
melted rock, spouts out it is burst into
bits. When it falS it is sometimes as
| fine as dust. sometimes the size of Gin
ders. Most volcanoes. indeed. are SIM
ply gigantic cindrr 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 boiIs over the
edge of pot As lava Is liquid. the
slope Of lava volcano Tor lava cone.
as it Is usually Called Is always very
! gentle. Falling cindprs. on the other
hand. pile themselves up quite steeply.
A lava cone. then. is always less steep
than cinder cone.
And volcano never burns. What
looks like fame 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 q cone sends out lava and
cinders alternately. so that you have
a great mountain of cinders bound to-
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
700 of these cones on its slopes One
Of them. Monte Rossi. is bill In
itself. being $50 feet high. Indeed.
model of Etna looks as if 1t were COW
cred with pimpIes.
When Etna is really reused 1t Is far
, more dangerous than Vesuvius. In
1169 it nearly destroyed the city Of
Catania, killing $1,000 people. In 1863
it found its pipe so inconveniently
small that it 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 1853
millions of gallons of boiling water
were shot out Of the Val del Bove,
which is great circular pit on the
slope Of the mountain. four or i've
miles In diameter. it's sides being cliffs
nearly mile high in places.
The greatest volcanic eruption ever
known took place in the East Indies
in 1883. 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 cubic
mile of rock was shot out
! A column of steam and lava dust
rose into the air to height six times
as great as that of Mount Everest. 1t
spread and spread till for hundreds OF
miles around the air was black as mid
night. bounds az Of distant cannonad-
ing were heard 1000 miles off.
/ Sea waves fifty feet high killed 3o'-
600 people and were felt as far of as
California. Instead of an island half
a mile high there was now hole
quarter of mile deep. The shock OF
the eruption sent air waves three ana
a half times around the earth. Inc
fine dust in the upper atmosphere add
ed for months afterward a strange
glow to the sunsets in England and
did not vanish completely for three
j years.
| The exact cause of the eruptions Is
not known for certain. A 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 it is certainly fact
that practically all volcanoes are close
to the edge of the sea.
Some lava flows slowly. some quick
". Vesuvius in 1905 sent out lava
stream that in four minutes had reach
ed a 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 q
hundred feet.
Lava cools very. very slowly. except
on the surface. which cools at once.
1t is an extremely bad conductor OF
heat. Twenty years after stream OF
/ lava was sent out from Jorullo. In Mex