Evening star. [volume] (Washington, D.C.) 1854-1972, 1930-07-25
G. j. MACHINES
TRACE ITALY QUAKE
Record in U. S. Was "Writ-
ten" on Seismograph
Within 40 Minutes.

Within 40 minutes after the first
great earthquake rocked Southern italy,
taking its toll of thousands of lives,
five seismograph machines at George
town University were writing with I'M
canny precision the permanent records
of the tremors hours before the rest of
the world was aware of the disaster.
Rev J. S. O'Conor, S. j., acting
director of the chronological observatory
at the university, today explained a
record sheet of the earthquake taken
from one of the smaller instruments
that registers the vertical movements
of the earth. With other machines
that recorded the horizontal movements
of the quake, the observatory has a
complete and carefully checked scientific
record of the earthquake which proved
one of the most disastrous Of modern
times.
Forty Minutes From Italy.
Travelling a distance of 4,575 miles,
the first two waves of tremorS recorded
here passed through the earth. They
were recorded on the seismograph at
7:20 pm. Tuesday evening, Eastern
Standard time. That would be at /
O'Clock Wednesday morning in Italy
and the fact that the quake caught
Maple SOulu dSleCp' Hooitei -
said, probably explains the great loss
Of life.
ut took 40 minutes for the surface
waves to travel the distance. from
Naples and Southern Italy" he ex-
planned. THE main wave, which SHOWS
the quake at it's severest, came at 1:3l
O'Clock. 81 minutes later. The& were
other waves of lesser tremors, lasting
until 9 o'clock"
II is a comparatively simple matter
for a trained seismogolist to estimate
the distance of a quake and It's ncatlon
by the chart sheet. The intervals pc
tween the different waves gives tne dls-
lance. AS the machine records the
movements of the earth, the wave ire
mors are separated at intervals .of one
minute. The waves travel considerably
over 100 miles a minute Although the
seismograph pen is commonly 1eferreo
tn as "writing," it is actually Sfe sheet
that does the writing. The pen! Is Sta :
tionary, except when it Is thrown from
it's base sometimes during violent move
nents. The sheet is blackened. thus
leaving the record traced In white Jag
ged marks.
Magnifies Ground Notion
Father O'Conor explained that the
machine mdRIllIlcS blie elNuL.N ,Oe--.
approximately 1000 times. The lsrgest
ground motions, as indicated by tne
chart. are shown in the Jagged alnes al
the top of the sheet. -.
Father O'Conor believes therf Is Ut
tie likelihood of volcanic .frnptioi
from Mount Versuvius and dfscreolt'
press reports indicating that the ltaiiar
quake was of volcanic nature. Sucn
ouakes have never been known 10 OF
as deep seated rs this one, ne salo.
The acting director OF the selsmo'
graph observatory at Georgetown came
TO take over those duties this summer
He is from New York and started M
earthquake studies at Fordham UNI
versity in 1924. For the last four year:
| he has been continuing seisniologica
| work at st. Louis University undel
! Father Macelwave, one of the foremos
| authorities in the United States. Father
| O'Concr is a Georgetown graduate o.
| about 1915.
The director of the Georgetown OBJ
! seryatory Is Father Sohon, who Is at
| tending Summer school at Fordham
| in New York. He succeeded Rev
Francis A. Tondorf, who died last year