The San Francisco calamity by earthquake and fire eBook
Charles Morris
Setting aside these general considerations, let us
return to the question of the disaster at San Francisco
on that fatal morning of April 18th. The shock
did not come unexpectedly. A month previous there
had been a severe earthquake in the Island of Formosa,
and many lives were lost there, while an enormous
amount of damage was done. Only a few days before
the event in San Francisco there was another earthquake
in the same island. Still greater havoc was caused
by it than by the earthquake in March, but fewer lives
were lost, the reason being that the people were warned
in time. Early in April the eruption of Mount
Vesuvius reached its height and devastated the country
around the volcano, covering an enormous territory
with ashes, and caused the loss of hundreds of lives.
On Tuesday night, April 17th, word was received from
Piatigorsk, Circassia, that there had been two severe
earthquake shocks the previous day in Northern Caucasia.
The same night a telegram from Madrid said that the
newspapers there reported that the long-dormant volcano
on Palma, the largest of the Canary Islands, was showing
signs of eruption, columns of smoke issuing from the
crater.
WIDESPREAD EARTH TREMORS.
While scientists as a rule doubt that there was any
connection between these volcanic phenomena and the
earthquake at San Francisco, yet reports from the
Mount Weather observation station in Virginia, a few
miles from Washington, show that the eruptions of Vesuvius
acted on the magnetic instruments by electro-magnetic
waves in such a way as to disturb the electrical potentials
at that place. Be this as it may, there is one
remarkable circumstance in regard to all this activity.
All the places mentioned—Formosa, Southern
Italy, Caucasia, and the Canary Islands—lie
within a belt bounded by lines a little north of the
fortieth parallel and a little south of the thirtieth
parallel. San Francisco is just south of the
fortieth parallel, while Naples is just north of it.
The latitude of Calabria, where the terrible earthquakes
occurred in 1905, is the same as that of the territory
affected by the recent earthquake in the United States.
This may or may not have some bearing on the question.
Whatever be thought of all this, one thing is certain,
the earthquake which laid San Francisco in ruins was
felt the world over, wherever there were instruments
in position to detect and record it. The seismograph
in the government observatory at Washington showed
that the first wave, on April 18th, came at 8.19—equivalent
to 5.19 at San Francisco; that at 8.25 there was a
stronger wave motion, and that from 8.32 to 8.35 the
recording pen was carried off the paper. The vibrations
did not entirely cease until 12.35 P. M., during this
period there having been nearly half an inch of to
and fro motion in the surface of the earth.
