Evening star. [volume] (Washington, D.C.) 1854-1972, 1903-06-13

airy. 1t replaced a more crude instrument
which for several years had been set TO
record merely the time of the beginning
of local earthquake shocks The new in
strument. imported from Strasburg, Ger
many, had been in place about fortnight,
when, on the morning of March 10, 1t re-
corded a zigzag, perfectly inscribed and
showing all of the recognized characters
tics of earthquake phenomena. The curve
shows that there were preliminary tremors
commencing at 9:29 am. and lasting five
minutes The main tremorS then succeed
ed for two minutes and thirty-six seconds
The terminal tremors lasted for twenty-sfx
minutes and tWenty-four seconds AFTER
ward. The total disturbance lasted thirty
four minutes. At its greatest height the
earth beneath the instruments moved
trifle over a hundredth of an inch from
side to side No wonder the public was
unaware OF the shock.
This earthquakes speed was timed by
Prof Marvin. Without announcing the
fact that his instrument had recorded the
phenomenon he put his record away and
correspondent with other stations. He
found that those of Baltimore, Toronto
and Victoria had recorded a shock at about
the same. time. BY careful estimate he
finds that it's first strong waves Travelled
from Victoria across the continent to To-
ronto in a fraction over eighteen minutes,
and from Toronto to Washington In one
and one-half minutes. The stronger waves
Travelled at the rate of nearly two miles
per second.
May Forecast Earthquakes.
To forecast earthquakes is ambition
not admitted by the weather bureau Yet
there is scientific foundation for the hope
that this may yet be accomplished The
Japanese observers believe that they have
had indications of earthquakes on the
records of their magnetic instruments pre-
- affn rtc oh o. n
graphs or earthquake recorders. They have
found what seem to them to be magnetic
warnings of earthquakes. They therefore
hope to be able some time to perfect sys-
tenn of earthquake prediction. If they do
cur weather bureau will doubtless profit by
it, and may then expect to see earth
quake warnings hung from mastheads
above our public buildings, or to read at the
top of the morning paper that there will
probably be an earthquake at such and
such an hour during the day. Pastors may
then gather in their f1ocks for public prayer,
and at the appointed moment the urban
population may have betaken themselves to
the open country. Then, II the earthquake
fails to appear the photographers will wax
facetious at the expense Of "Old Probs."
Earthquakes and magnetic storms are
found to be related 1t is partly for this
reason that the governments new magnetic
observatorfes are being equipped with seis
mographs like that installed at the weather
bureau. DR.. l.. A. Bauer. at the head of
the governments magnetic survey, observed
in the case of the Martinique disaster that
although there was no earthquake effect
perceptible at even the nearest station
where seismograph was in place, a mag
netic disturbance perceptible at stations
almost throughout the world was felt at
about the moment of the first eruption of
Mont Pelee. Throughout the period of erup-
tons there were magnetic perturbations.
and one conceded also with the second
eruption of Pelee In the same month eff
cote yafa 40
quake were experienced. Just month be-
fore the Mont Pelee eruption there was
percept1Dle magnetic storm, but whether
that could be interpreted natural warn
ing remains to be demonstrated
Luminous appearances are reported to ar
company earthquakes occurring at night
and 1t Is thought by some that these are
due to the friction of moving masses of
rock. The theory Of these observers is
that temporary electric currents are nv
such friction established in the line Of tho
earthquake. At or near the origin of great
EARTHQUAKES there is sometimes evidence of
podliy displacement of many cubic miles of
material. When this material is voIca mic
according to one authority. 1t is almost in
variably magnetic and it's readjustment
produces magnetic effects
Chain of Stations.
Practically the entire world will soon o.
operate in general earthquake survey and
tant part in this great work An organiza-
ton known THE International seismo
logical Association" under the leadership
of Prof. Gerland director of the Gernan
chronological observatory at Strasburg
has been formed for that purpose. The
united states has been asked to choose
representatives. and the coast and geodetic
survey has already designated one of its
officers for that function. An internationaI
la
De established and this will be a clearing
mousse ior the work of hundreds of sta
tons throughout the world.
Japan VIII fali In line with nearly 1000
s,auons italy with fifteen. England with
three Scotland two. India four. Canada
two. Australia three. Russia three Snain
two and South Africa. Egypt, Ceylon. lava
Maurltius' New Zealand. Syria Trinidad
Mexico. Peru, Argentina and Germany each
one. Thus Mother Earth will have left
scarcely single surface SPOT where she
can quake undetected. But inasmuch as
modern seismology has already established
that large earthquake originating IN anv
one part of the world can be recorded in al
most any other will practically keep tab
on every culver of our planet
The principal objects of this worldwide
survey Will be to determine the velocity
with which motion is propogated over the
surface and through the interior of the
earth; to locate positions of earthouake
Origins under the oceans, and generally,
W iititdSe hHOWleOge or the physical ma
ture OF the earth's crust and Interior
Average Speed of 'Quakes.
The average velocity Of earthquakes. as
thus far estimated, is about one and one
quarter miles per second for the first
tremors and about one mile per second for
the main shock. After few hundred miles
the velocity of the first tremors increases,
and over long distances has been esti-
mated to be greater than that of the waves
of compression through steel or glass The
fact that the vibrations of the first tremors
appear to travel faster than those of the
main shock indicates that the former pass
directly through the earth. while those of
the latter follow the longer course az ound
it's crust.
Surprising facts about the frequency OF