Evening star., 1933-03-26
BY BAILEY WILLIS,

Geolosst and Authority on Earthquakes
~ u the coast of sunny Southern
California, where the mission
fathers used to pray and the
" jazz bands play today. the
earthquake kobold follows his
ancient habit. Although constantly at
work, he strikes heavier blow only at
intervals of century or so in any one
place. Two weeks ago he struck harder
than common, and Long Beach fell.
Back in 1912 he hit the same place and
the mission church of San Juan Capis-
trano tottered Led by their priest, a
frightened flock rushed in to implore
protection-and they were buried in the
ruins. That was on october z. Old
chronicles recite the story of successive
blows on October 8, October 81 and De-
cember 81 and of after-shocks continu-
ing for four-and-a-haf months.
Today this region is populated by
millions where thousands could scarcely
have been counted century ago. Safety
first should be the immediate slogan.
Shattered building should be razed.
weak one should be strongly braced or
tied together with iron bars or bands
and repairs should be made promptly
to provide against danger from recur-
rent after-Shocks.
Fortunately, it is the habit of the
earthquake kobold to take a long rest
after an effort such as this recent one.
Following 1912 he was inactive until
1857, when he and his comrades work
ing on the San AndreaS rift united for
an effort mightier than any that ever
have been recorded in California. The
center of that disturbance was near
Tehatchapi, at old Fort TETON. and
its effects were felt with startling in
tensity north as far as San Juan Bau-
tista and south to the Mexican border.
The local shock which has just occurred
at Long Beach. by comparison. was no
more than single hammer blow dellV-
cred under the margin OF the ocean
near San Pedro Point.
Those who listen to the tapping OF
the kobolds heard them constantly at
work and knew that at any time they
might strike a heavier blow. There had
been one such in 1892. In 1920 the
town of Inglewood had been shaken.
The watchers gave the alarm, but they
were not generally needed.
Nevertheless. engineers responsible Tor
the great structures of steel and con-
crete took notice and designed their
structures to resist earthquake vlbra-
tions. The Los Angeles City Hall, con-
spicuous among other buildings OF its
kind, stands as monument to modern
engineering ability and as an expression
of the skill that has learned to meet
the dangers. in some degree success
fully. In the bracing of its steel frames.
the rigidity of its concrete walls and
the unity of the whole structure, which
is firmly bonded together, it illustrates
what is possible with trained technique
using modern materials.
The great tower rises slenderly
through 27 stories-a white. shining
mark for an earthquake blow. 1t
swayed to and fro as old brick build
ings in the next block cracked open
but it did not fall Had 1t been de-
signed simply to stand up straight and
look well, as so many steel and con-
crete structures were before 1920. 1t
would now be a tangled ruin like those
that Uttered the streets of Toxic IN
1923. In that very violent shock Amer
ican structural engineers received a
compelling object lesson. Not in every
case did steel and concrete fall. There
were six buildings all designed by an
American-taughtJ japanese, Prof. Iacnu
Naito. professor of engineering at the
Imperial University in Toxic. which
stood unchanged except by fire. Nalto
principles of unity-frameS. walls and
floors all tied together, ship fashion.
But it was not simply unity in struc-
ture He had carried the principle OF
the "one-hoss shay" into his design.
The frame was just as strong as the
walls, the walls were just as strong
as the floors and the floors were just
as strong as the frame. There was
nothing that could fail, the weight OF
the structure considered, and from this
skillful engineer the world learned anew
an old lesson-that in unity there Is
strength.
The lesson Of 1923 Is understood.
Through the untiring efforts Of Henry
Dewen and John D. Galloway, Cali
fornia engineers, supported by the So
ciety Of American Civil Engineers, the
Japanese experience has been made
methods of design to some extent have
been embodied in general building
code The evil influences that promote
shoddy building-carelessly or GRIM
inally, as the case may be-are scotched
though not killed; but their end is
!, brought nearer by this latest disaster,
and if greed, scamping and graft should
be among its fatalities none would
mourn them.
Earthquakes, however, are too few
and too far between to be satisfactory
as engineering experiments. They are
also somewhat difficult to observe with
precision at close range. 1t Is more
convenient to study artificial earth
quakes, kept under control, to find out
| what a shock does to a structure and
how it can be resisted. To that end a
three-ton steel-shaking table is used.
Vibrating under the blow of half-ton
pendulum or in response to an unba!-
anced flywheel, it reacts as the earth
does when the earthquake kobold
strikes. Equipped with delicate record
ing devices, it tells exactly what is
happening to the model building
anchored to it.
Thus the great shaking table at STAN
ford University as yet the only one OF
its kind, through the ingenuity Of Prof.
Lydik Jacobsen, has demonstrated that
We can build to resist earthquakes, ac-
cording to the principles of unity and
rigidity, up to 10 or II stories in
height and still build at reasonable
cost. But beyond that point it would
be more economical to support the rigid
superstructure from the ground up on
flexible columns extending down
tIllUuSu dliu ulucpeIlQeIlt Ol tilc pdSC-
ment floors, so that it may stand still
or sway gently as the ground oscillates
to and fro under it.
Engineers thus are seeking the best
solution of the practical problem of
how to combine adequate earthquake
resistance with reasonable cost, and
they have made such progress that no
new structure need be wrecked by
| some future earthquake, nor need lives
be lost except In insecure buildings
built as the Pharoahs built.