The morning news. [volume] (Savannah, Ga.) 1887-1900, 1892-07-31


makes an outleT IL none previously
existed, and carries with il cloud of vRpor
and smoke, q stream Of molten rock, a
shower of stone, cinders and ashes. The
molten mass flows down the sides or the
mountain, and with the ashes and cinders
carries desolation and death to the country
below. Some of the matter thrown out
lodges around the mouth of the crater,
raising it still higher; or the struggling
mass unable to lift the accumulated ma
terial from the chimney, or 60 force hole
through the floor of the crater, may tear Off
a part OF the rim Of the crater or reno a
assure from top to bottom.
Volcanoes are pretty widely distributed
over the face Of the earth, but in general it
may be said that they lie along mountain
| ranges bordering on the ocean and in the
the water. They are located in lines or
groups and are always at weak points Ia the
| earth's surface.
Volcanoes have been in existence during
every principal geologic age, at least as far
| back at the lower silurian, the rocks OF
which age are very nearly the oldest In OK
istence. New volcanoes in later years have
7 appeared above the surface of the sea.
There are three classes of volcanoes, the
active, dormant and extinct, but these
classes are likely to overlap. With one or
| two possible but somewhat doubtful ex-
ceptions, the eruption OF volcanoes
occur at no regular periods
Prior to the memorable outbreak of Vesu-
vius in the year 70 even tradition had not
| handed down an account of an eruption
Since the above date Vesuvius has been
Internationally active, but from the year
| 1900 to 1851 the crater was so Guieb that it
became choked with woody growth. In
| 1871 an eruption occurred, exceeding in
violence only by that of the year 1879.
First and last in a volcanoes life history
gases and vepors are prominent OF the
vast clouds which sometimes hang over
| active volcanoes, it is calculated that
999-1, 000ths is steam. The amount of vapor
emitted by Etna during period of 100 deys
has been estimated as, If condensed, equal
to some $50, 900, 900 gallons of water. Some
idea Of this amount OF water can be con-
veyed by stating that the amount OF water
from one days vapor would equal the
water supply for family Of ten for II 900
days, or thirty years, allowing fifty gallons
| per day to each person.
These vapors condense and give rise TO
| large volumes Of water, part OF which falls
| as rain in the vicinity and part OF which
runs down the sides of the volcano. This
water from vapor is increased, in some
| cases, by melting snow from high points on
| the volcanoes and from vast reservoirs of
water in the bowels Of the earth, or from
lakes in the Orators of such volcanoes as for
some time have been at rest. In the latter
case hundreds upon hundreds of dead fish
are sometimes swept down the mountain
side, and wherever the water joins with the
| volcanic dust it forms q mud, more or less
thick, which rushes downward, emitting
steam and gases as it goes. This mud finally
| becomes solid and Is known as uu4, or tuffa
of which there are many kinds, all formed
| from volcanic matter which has in some
| way been broken up and afterwards solid
| lied.
The red-hot molten rock which is dis
| charged from volcanoes is known as lava.
This varies in character, when cool, from
masses OF crystals. whole and broken and
| women together, TO veritable honeyoombs,
the latter being caused by cavities in the
hot lava filled with steam. some lava has
| been so completely burned as to become
CLASSY and is known as volcanic glass or
| obsidian.
Ashes and sand, fragments from the
size of a pea to that Of q walnut, known as
lapilli, and coarser materials ranging to
huge blocks Of many tons weight are hurled
from these immense chimneys Of the earth.
Most volcanoes have periods of rest. A
very few are continually active, as Strom-
boil III the Mediterranean, which, from the
earliest historic times, has been emitting
steam, lava and hot stones without stop
ping, or as Sioa among the Molucca islands,
] or 1OIuh among buo tFl6nulY lSlhuUS, or
Sangsy, a volcano OF the Andes.
The demonstrations accompanying q vol
canic eruption depend upon the character
of the material within the crater and the
passage leading downward. IL the crater
has a thin floor, and the passage below is
partially open, or filed with molten lava,
the volanic gases can escape upward and
outward with comparative quiet. But if
the passage is badly INSTRUCTED violent
| fak al hu
rumblings and even by earthquakes, far
reaching in effect.
In Hawaii the lavas are very liquid, and
often are discharged quietly, but in 1868 a
great eruption was accompanied by earth
quakes.
When tho sides of the volcano gave way
| before the door of the crater or before the
hardened materials for the passage yield to
the upward pressure, assures occur in the
mountain, generally diverging from the
cone toward the base and showing the red
hot mass within, if indeed, as most likely,
lava is not discharged from these vents.
Finally, the lava in the assures cools and
binds the mountain together more firmly
than before.
At times lava may appear at the mouth
| OF the volcano without overlooking, or it
may break out in spots causing minor
cones.
The force Of volcanic explosions cannot
be comprehended, nor can the depths from
which material is thrown be stated. We
only know that thousands and thousands OF
tons of ashes and both liquid and solid
rock are thrown from the points far from
the crater of the volcano, and that the force
which is sufficient for such exsrtions is
mighty. It Is reported that the volcano
Antuco, in Chile, has thrown stones thirty
six miles, and that Cotopaxi threw block
weighing 200 tons for a distance OF nine
miles
Ashes thrown from volcanoes travel many
miles awav and carry darkness with them.
In the year 1885 a volcano in Nicaragua
called Coseguina caused darkness in ell
directions for Assistance of thirty-hve miles,
and deposited ashes, it is said, TO depth OF
ten feet over twenty miles away, while
soma Of the minute volcanic dust was
carried up 20 a high current of air and fell
four days later 100 miles away at Kingston,
Jamaica.
The ashes and other fine materials thrown
from volcanoes are said TO he caused by the
action OF steam, which penetrates and d.
vides into minute particles the white-hot
lava, and when the explosion which throws
! out the LIQUID steam-laden lava occurs the
once solid matter is scattered in dust.
The immense volumes OF mud, ashes and
rock which are throw from volcanoes
change entirely the surface Of the surround
ing country, building up the well-known
volcanic cones and sometimes changing