44 RESOURCES OF CALIFORNIA. 
vicinity on the 29th of November, 1852. The low grounds 
near the Colorado cracked open with long, wide.fissures, from 
which water, sand, and mud, spouted up. The fissures were 
in some places so large, that they turned the river from its 
course; and the change was so sudden, that great multitudes 
of fish were left to die in the mud. At the same time, the 
mud-voleanoes of Lower California, distant forty-five miles 
southwestward from Fort Yuma, resumed their activity; for, 
although there is no record of their previous action, yet they 
probably existed before. A pool of hot, sulphurous water had 
been observed at the place by Americans since 1849. Imme- 
diately after the shock of 1852, the officers at Fort Yuma saw 
a great body of steam shoot up at least one thousand feet in 
the desert to the southwest; and when, soon afterward, some 
of them went out to examine into the cause of it, they found 
the mud-volcanoes on the site of the old pool, throwing up 
steam, boiling water, and mud, very much like the salses far- 
ther north. 
Earthquakes, according to the common theory of Califor- 
nians, are electrical in their origin, or closely connected with 
electrical influences. Many of the strongest shocks have been 
preceded by a condition of the atmosphere very similar to that 
which precedes: thunder-storms in other lands. When the 
weather is sultry and oppressive in San Francisco, people say, . 
“Look out for an earthquake!” And it usually comes—per- 
haps so faint as to be barely perceptible, and sometimes not 
until several hours after a change in the weather. 
The frequency of earthquakes in California has caused a 
number of persons, perhaps a hundred or more, to leave the 
state, and return to their former homes on the Atlantic side 
of the continent. And yet there they are in more danger from 
lightning than here from earthquakes, for there are fifty killed 
by lightning in the Mississippi valley for one killed by an 
earthquake in California. A year rarely passes that a dozen 
persons are not struck by thunderbolts within three hundred 
miles of St. Louis. [See Appendia, p. 464.] 
