300 shocks were
counted between the 20th February and the 4th of March. The loose earth
of the valley of the Biobio was everywhere parted from the solid rocks
which bound the plain, there being an opening between them from an inch
to a foot in width.

[Illustration: Fig. 70.]

"For some days after the 20th of February, the sea at Talcahuano," says
Captain Fitz Roy, "did not rise to the usual marks by four or five feet
vertically. When walking on the shore, even at high water, beds of dead
mussels, numerous chitons, and limpets, and withered seaweed, still
adhering, though lifeless, to the rocks on which they had lived,
everywhere met the eye." But this difference in the relative level of
the land and sea gradually diminished, till in the middle of April the
water rose again to within two feet of the former high-water mark. It
might be supposed that these changes of level merely indicated a
temporary disturbance in the set of the currents or in the height of the
tides at Talcahuano; but, on considering what occurred in the
neighboring island of Santa Maria, Captain Fitz Roy concluded that the
land had been raised four or five feet in February, and that it had
returned in April to within two or three feet of its former level.

Santa Maria, the island just alluded to, is about seven miles long and
two broad, and about twenty-five miles southwest of Conception. (See
Map, fig. 70.) The phenomena observed there are most important. "It
appeared," says Captain Fitz Roy, who visited Santa Maria twice, the
first time at the end of March, and afterwards in the beginning of
April, "that the southern extremity of the island had been raised eight
feet, the middle nine, and the northern end upwards of ten feet. On
steep rocks, where vertical measures could be correctly taken, beds of
dead mussels were found ten feet above high-water mark. One foot lower
than the highest bed of mussels, a few limpets and chitons were seen
adhering to the rock where they had grown. Two feet lower than the same,
dead mussels, chitons, and limpets were abundant.

"An extensive rocky flat lies around the northern parts of Santa Maria.
Before the earthquake this flat was covered by the sea, some projecting
rocks only showing themselves. Now, the whole flat is exposed, and
square acres of it are covered with dead shell-fish, the stench arising
from which is abominable. By this elevation of the land the southern
port of Santa Maria has been almost destroy