The Wichita daily eagle. [volume] (Wichita, Kan.) 1890-1906, 1902-05-28
TELLS OF TIE EVENT
Novel SeiSmOScope Makes
Record of Earthquakes
DISASTER AT MARTINIQUE
Made Known at Washington
by Means of 1t.

of Martinique with a food Of fire. the
cataclysm was reported at Washington.
When La Soufriere burst forth upon
Bt. Vincent, the men in the weather bu-
reau in washington knew of the dis
turbance.
When an earthquake shakes the crust
of the earth, whether it be in Japan or
Italy. the earth brings the news to
Washington.
A delicate instrument, in a cellar Of
the weather bureau building, receives
the wireless message. It is written in
a cipher that is meaningless to the IN
trained mind but to the experts it is
as plain as the alphabet
The slip of paper upon which the wavy
lines are recorded tells them when and
where the earthquake occurred, how long
1t lasted and how severe it was.
No matter how slight the tremor, pro-
vided it is a distance away and not
superficial disturbance, the instrument
VIII record it.
Each day the scientist who has access
TO a seismoscope can survey the world
and know what is going on. 1t does not
matter whether mountains are shaking
or the earth's crust at the bottom of the
sea is rent asunder. The instrument
records both with equal accuracy.
It is far easier to keep track Of earth
quakes than of volcanic eruptions. In
less the volcanoes outbreak is accompa-
MED by an earthquake-which It usually
is. by the way, the seismoscope will have
no record Of it. Then scientific men must
depend upon the self-registering barom-
eter. And that does not give very ex-
act information.
The barometers within certain radius
all recorded the explosion at Mont Pc
lee, but not until the reports are all in
from the various meteorological stations
viii it be possible to learn just how
much is revealed by them.
When the explosion Of Krakatoa oc-
Cured in the straits of Sunda, between
Java and Sumatra in 1888. the seismic air
waves travelled seven times around the
earth. four times in one direction and
three times in the other, taking about
thirty-six hours to make the complete
circuit. a rate Of about 700 miles an hour.
But the seismoscope doesn't concern
Itself with air waves. Only the tremors
Of the earths crust affects it.
The wireless messages received by the
seismoscope do not follow the earth's
surface. They come right through the
earth This is proved by the fact that
there is only one impression ever record
ed by the instrument.
One Of the most remarkable things
about the seismoscope is the fact that it
takes just sixteen minutes for an earth
Il i, To-
anywhere else there is an instrument.
for that matter. The wave transmission
through the earth seems to be uniform.
This has been demonstrated time and
again.
Whenever there is an earthquake in
Japan-they have about three day on
an average there-it makes a vastly
greater disturbance on the other side of
the world than most people imagine.
II there is a good earthquake, the
ground in New York and Washington.
whether it supports a 2o-story sky scra-
per or the national capitol, rises and
falls about three inches.
That is the estimate made by John
Milne. and he knows more about seismic
disturbances generally than any other
man who has ever lived.
There isn't the slightest doubt about
the fact. he declares. Whenever there is
a big earthquake anywhere the solid
ground hereabouts rises and falls three
inches.
The earth's crust undulates like the
waves of the sea. But people are not
conscious OF the earth-waves. because
the waves are so long. One reason is
that it takes about fifteen secondA for
the earth-wave TO lift and as many to
descend Then. too, the earth-waves
are enormously long. probably as long
rs Manhattan Island from crest to crest
When It is understood that an earth
quake in Borneo or some other far-off
place can make such a row in New York
and Washington, the fact that instru-
ments can record the disturbances may
not seem SO remarkable
There are several kinds OF seismo-
scopes, but the principle OF all IS the
same pendulum whose supports rest
upon n slab Of cement or stone par
TALLY buried in the earth. The founda-
tion IS proof against superficial earth
sars.
The weather bureau seismoscope is a
pendulum with a needle at the top. II
one attaches a weight 10 a lead pencil
and then moves the weight around the
idea may be better understood
OF course the weight OF the seisno-
scope IS carefully balanced The needle
has platinum point and il fits IN
platinum-hned hole. The slightest ire
NOR Of the earth causes the balanced
weight 70 move, and Of course that az
fects the needle. II the point touches
the rim Of its enclosure an electric cir
cult is completed and record is made
on revolving drum Of paper.
Prof. Milne has an ordinary selsmo-
scope at his home on the Isle or WiSht
where he studies earthquakes 81 over
the world
Resting on q stone foundation is
sort OF iron mast, from which is sus-
pended boom. This covers little slit
that opens upon a sensitized film. The
rays OF a lamp are thrown upon the end
OF the boom by a mirror. The slightest
movement makes that boom vfhrate ana
Its movements are photographed auto
maticaIly And that boom will swing
whenever the earth's crust moves
The mast q the instrument rests ,,-on
solid column OF masonry that seems
as stable and immovable as anvthfur
can be in this world. Yet II the slightest
lateral pressure is exertod aEainsr the
coiumn-if one merely pushes 1t with
ones hand-the boom VIII swing 70 one
side
II one q these seiSmoscopes IS uiaced
IN elxx-crrr mar - ~-f1f -a-,-- , 49, d,