330 Geological Society. 
of the cracks was not uniform, though generally from south-east to 
north-west. The earth was not quiet during three days after the 
great shock, and more than three hundred shocks were counted 
between 20th February and 4th of March. The loose earth of the 
valley of the Bio Bio was everywhere parted from the solid rocks 
which bound the plain, being separated by cracks from an inch to 
a foot in width. 
In the Bay of Conception two explosions or eruptions were seen 
in the sea while the great waves were coming in. One beyond the 
island of Quiriquina appeared to be a dark column of smoke in 
shape like a tower; another rose in the Bay of San Vicente like 
the blowing of an immense imaginary whale. Its disappearance 
was followed by a whirlpool which lasted some minutes. It was 
hollow and tended to a point in the middle, as if the sea was pouring 
into a cavity of the earth. The water in the bay appeared to be 
everywhere boiling, bubbles of air or gas were rapidly escaping, 
and dead fish were thrown ashore in quantities. 
For some days after the 20th February the sea at Talcahuano did 
not rise to the usual marks by four or five feet vertically. ‘ Some 
thought that the land had been elevated, but the common and pre- 
vailing opinion was that the sea had retired. This difference gra- 
dually diminished till, in the middle of April, there was only a dif- 
ference of two feet between the existing and former high-water 
marks. The proof that the land had been raised exists in the fact that 
the island of Santa Maria was upheaved nine feet; but of this pre- 
sently. When walking on the shore, even:at high-water, beds of dead 
mussels, numerous chitons and limpets, and withered sea-weed still 
adhering, though lifeless, to the rocks on which they had lived, every= 
where met the eye—the effects of the upheaval of the land.” 
From the above extracts, then, it appears that in the opinion of 
Capt. FitzRoy some of the land was first raised in February four or 
five feet, and that it afterwards gradually returned towards its for- 
mer level, so that in about two months the temporary increase of 
its height was diminished by more than one half. 
The observations which follow respecting Santa Maria, an island 
seven miles long and two broad, in the Bay of Conception, deserve 
particular attention, and I shall give them in Capt. FitzRoy’s own 
words ; for although in so doing I anticipate a communication which 
I trust will hereafter be given in full to the Society*, I am only sup- 
plying the proofs of the elevation which was asserted as a fact in 
Capt. FitzRoy’s notes read before you during the last year. 
“It appeared that the southern extreme of the island had 
been raised eight feet, the middle nine, and the northern end up- 
wards of ten feet. The Beagle visited this island twice, at the end 
of March and in the beginning of April. At her first visit it was 
concluded, from the visible evidence of dead shell-fish, water-marks, 
and soundings, and from the verbal testimony of the inhabitants, 
* Since the above was written the whole memoir has appeared in the 
Nautical Magazine for March 1836. 
