Evening star., 1926-04-22

For the past week, Mauna Loa. the
long mountain" in Hawaii, has been
heaving millions of tons of lava and
rock, with fame, high into the air
1t is reported quiet now, but scien'
lists do not believe the end of the
disturbance is yet reached. From half
a dozen openings the flames SCARED,
like giant conf1agrations. while
streams Of molten lava poured down
into the valley. threatening to wipe
out villages.
A volcanic eruption is a magnificent
though terrorizing spectacle, but vul-
canists and geologists assure us that
when considered in connection with
the whole world such eruptions are
very superficial disturbances, their
heat and lava coming from not more
than 10 or 20 miles below the surface
in rare cases 80 miles-while the
diameter of the earth through the
Equator Is 1926 miles and 1899 miles
through the poles. The height above
sea.level Of Mauna Loa is only about
I2h miles. In comparison with the
earth, it is like the smallest indenta.
ton of an orange skin, compared
with the orange. Out of that little
peak" comes a fame with smoke and
motion rock. History tells of the vol
canic burying of Pompeii with all its
people: Of the more recent eruption OF
Pelee, on Martinique, with its 10000
victims, and Of its lifting the whole
mountain top of Katmai, in Alaska,
| few years ago.
In Idaho, Oregon and the State OF
Washington, there Is an area Of 200.'
600 square miles buried in lava 2,00C
feet thick, which came from eruptions
| in tertiary times. In India there Is
| a plateau of lava 5000 feet deep
which fell millions of years earlier
' in. cretaceous times-but even that !:
I new" and shallow. compared with
the deposit around Lake Superior
from to S miles thick, which
dates back to the Keweenawan age
These deposits may have flowed out
gently from fissures or poured out
| frightfully from volcanic peaks which
have since disappeared.
In Mexico, close to Orizaba Volcano
there Is a sunken crater 1000 feet deer
and 5000 feet in diameter, which to
day is the most fertile soil on a great
hacienda, because in the millions o1
years since the mountain sank below
| the level Of the surrounding country
| winds have blown fertility into the
great cavity, covering its lava bottom
u \ n II
The world is a ball Of iron and
nickel, with other minerals mixed
but nearer the surface sthan the
nickel-iron core. AS descent is made
from the surface heat increases at the
rate Of / degree Fahrenheit for every
| 30 or 40 feet, so that before 20 miles
depth is reached 1t is many times
| hotter than the melting point Of any
! mineral or stone. All matter would
there be liquefied except that 1t il
under the tremendous pressure OF the
rock above. This pressure increases
with the increasing depth. so that, al
| though the heat increases, the pres
] sure still keeps the earth solid, fol
| there Is no room for heat expansion
/ Internal pressure creates mountain
| Gus volcanoes, for as the molten Laws
reaches the surface through f1ssure'
| II pours out and, solidifying in the
| outer air, 1t builds up a cone aroun6
| the fissure, in the center of which the
molten fluid continues to pour ou'
and solidify while it's cone grow.
higher and finally becomes a noun
tain.
Volcanoes may lie dormant fol
thousands Of years and then suddenl.
erupt or explode. According to &c
ology, by Thomas c. Chamberlin ant
Rollin D. Salisbury of the Universit.
of Chicago, there are from 300 to 35'
active volcanoes in the world.
Chamberlin and Salisbury lis
seven hypothesis which have beer
proposed by scientists to explain th'
phenomena of volcanic action:
Hypothesis No. lin early days o
geology-a century or two ago.
was supposed that the earth was .
4 molten mass surrounded by thil
.rust, and the volcanoes led down t.