The sun. [volume] (New York [N.Y.]) 1833-1916, 1906-04-19
SHOOK THE ENTIRE COUNTRY.
GROUND MOVED FOUR-TENTHS OF
INCH IN WASHINGTON
Migratory Wave Took -Four Minutes
Twenty Seconds to Travel Across the
Contlnent-Recording Pen Of BeaSmoA
graph Out OF Business for q Time.

WASHINGTON; April 1s.-Although Wash
ington did not feel the shock OF the Pacific
Coast earthquake, the delicate instruments
Of the United States Weather Bureau used
that the vibrations had spread clear across
the country, II, as reported from San
Francis co. the first shock was experienced
there at 5:l5 A. NJ. (s16 A. NJ. Washington
time) it tool the vibrant wave four minutes
and twenty seconds to travel the 1900 miles
from the Pacific to the Atlantic coast.
According to the records of the Weather
Bureau s~eismograph, the first vibration
reached Washington at 10 minutes and
20 seconds past s O'Clock this mo rning.
The observer of the United States Coast
and Geodetic Survey at C~heltenham, Md.
reported that his instrument showed that
the disturbance there was begun at s o clock.
Eastern time. and that it was very great
On the Weather Bureaus seismog graph a
strong wave motion began to show about
six minutes after the first record appeared.
For three minutes beginning at 1882.
or approximately thirteen minutes after
the initial vibration, the violence of the
motion was 80 great as to completely throw
the recording pen off the record sheet.
1t was not until 1925 P. NJ. or four hours
and sixteen minutes after the first record,
that the vibrations ceased. For more
than half an hour before they ceased the
quavers recorded were almost impercepti-
BILE. A little later the vibrations we're
renewed, but not violently and continued
for a short time.
The following official bulletin OF The in
formation noted through the seismograph
was issued by the Weather Bureau:
The great San Francisco earthquake of
April Is, 1906, was registered upon the
Bosch-0mori seismograph beginning at
8 hours 10 minute 20 seconds A. NJ, seventy
fifth meridian time. The record shows
a disturbance Of considerable magnitude
at Washington, although not severe enough
to De felt by individuals.
THE stronger wave motion began al
1925 A. NJ, that is, about five minutes after
the first imperceptible tremors. The re-
cording pen was carried entirely oil the
record sheet by the violence OF the motion
from s;92 to S:3J A. NJ. After the latter
time the motion gradually diminished over
a long period Of time, but did not entirely
cease until about 12:35 p. Nj.
The vibratory motion of the ground at
Washington was really a comparatively
slow INT deliberate motion, each back
and forth movement taking fifteen to twenty
seconds OF time. The largest movement
of the ground registered before the pen
went of the sheet amounted to about four
tenths Of an inch
WATCHING THE s~EISMoGRAPH.
The Weather Bureau here was thronged
the better part Of the day by scientific
men and others who were anxious to hear
the results recorded on the seismograph.
Only a chosen few we're admitted at inter-
walls to the room in which the instrument
is installed. 1t was explained that jars,
no matter how slight, would effect the
sensitive machine and mar TO a consider
able extent the accuracy of the results
recorded on the sheet upon which was
registered every vibration, no matter how
weak, that travelled over the continent
from distant California.
The statement was made at the Weather
Bureau that nearly every day during the
InOUlH vi cuIlhui ''
parts of the world were registered on the
seismograph. On January 80 and 81, when
Ecuador was visited by a seismic dis
tlrbance, excellent records were obtained
here. While the seismograph recorded
Enthusiastically at this distant point the
vibrations of the earth occasioned by the
disturbance in California, they were not
felt by people. One, of the Weather Bureau
nj Ill .lot the vibration on mo aVanlv
like the movement Of the waves Of the
ocean, and he pointed to the swaying OF
the indicator on the ~seismograph in support
Of his statement.
1t has always been the policy Of the
Weather Bureau to require its obs ervers
to take careful note of earthquake phe-
nomena of sufficient intensity to be felt at
stations, but no specific effort has been
made to provide generally the instrumental
means by which such phenomena could au-
tomatically be recorded and measured The
central station in Washington has however,
maintained a simple form of seismograph
in operation, since December. 1892, and
recently has greatly improved its equip
ment by the installation of one of the large
horizontal pendulums made by a firm in
Germany.
The new instrument ia of a superior type
and gives an accurate record of the move
ment Of the earth. The whole object sought
in the construction of this instrument is to
secure a steady mass, as it is called; hat
is, a mass that shall remain quite at rest
during an earthquake, not ~withstanding
the earth and the supports for the mass
are undergoing appreciable vibratory dis
placements. The kinetic property Of bodies
utilized in this connection is that which
gives rise to the so-called axis Of instan-
taneous rotation. Whenever any force is
applied in n one sided fashion to move a
body all points OF the body will not move
In the same manner, in fact, one point. or n
line OF points, will actually remain sensibly
- L.. Ill li..lnnnnnnnAn Thln