The midland journal. (Rising Sun, Md.) 1885-1947, 1921-02-11
Earthquakes

pmIena the earthquake is prominent
and most appalling. The destruc-
We work of the volcano is confined
a comparatively small area; the tor
ado or hurricane devastates narrow
rip of territory; the bolt from a
under-cloud expends its energies
ION a single point, but the earthquake
Ia carry desolation into thousands Of
hare miles Of the z9arth's surface.
North America, and more particu-
|rly the United States, have seldom
cen subjected to such visitations,
lthough there are some portions of
She country that can yet show the
Wilderness of severe seismic disturb
hnce.
It may be well to explain here that
- science of earthquakes is called
mology, and that seismic means
taining to earthquakes.
n recent years the researches of
Geintists have added much to our
knowledge of earthquakes, though
there are yet many problems that
await solution.
Nearly every astronomical observa-
tory includes in it's equipment seis-
mometer, an instrument, as the name
signifies, that measures the direction,
duration and intensity Of the earth
quake.
In some parts of South America
Peru, for instance, where earthquakes
are as common as thunderstorms are
here stations have been established
solely for ne purpose of inyestigat-
ing the. Yrs of the earth.
II 4 earthquake areas of the
fe confined almost wholly to
n ,.shic regions.
Among the mightiest mountain chain
<of the southern hemisphere, the An
des. there are scores Of volcanoes. 1t
is significant fact that there are
more earthquakes in South America
than in any other portion of the globe
In Southern Europe. in the vast
stretches Of Australia, in Ireland, in
1.-The long chain of islands that consti-
butte the empire of Japan, and, in fact
fwherever active volcanoes exist the
stability of the earth's crust is threat
ened.
There are isolated instances, such
90 1%y Of
South Carolina, in 1887, where their
relation of earthquakes to volcanoes
cannot be established; but, as rule,
the former most frequntly occur where
the latter are found.
Very little is known of the origin
of earthquakes. Some suppose that
water finding its way through the
( crust of the earth comes in contact
with heated rocks and is converted
into. steam, which is clearly compe-
Tent to produce great effects.
Another theory that finds accept
ance, credits them to violent explo-
sions Of gaseous fluid in the interior
of the globe; bat of all the many
theories adduced, there has ever been
one whose correctness has been con-
clusively demonstrated. 1t is probable
that the exact nature of the causes
Of earthquakes will never be known,
owing to the impossibility of direct
observation.
Earthquakes are always most vio-
lent near the center, or what may be
termed the seat, of the disturbance,
lust as storms of rain or snow show
the greatest energy near the central
point, diminishing in severity. toward
the line that marks the limit of favor
able weather conditions.
In the progression of the earthquake
the ordinary movement is an undula-
tory one like the swell of the ocean,
though seldom on as large scale.
This motion Is much less dreaded than
the vertical shock, which, instead of
imparting s~waying movement to OBJ
iects on the surface of the earth,
losses them violently down, with ter
rifying results.
This was illustrated in the earth
quake of Lisbon, in Spain, in 1855,
when the wave-like motion was sue
ceeded by quick, vertical shocks,
which completed the work of destruc-
ton. More than fifty thousand people
were killed, and it was years before
the city recovered from the defects
of the upheaval.
Japan has been the scene of many
violent earthquakes, accompanied by
terrible loss of life and the destruc-
ton in a material way. Indeed. the
Japanese islands, from time imme-
mortal, have been noted for. their