376 
NORTHERN CHILE 
CHAP. 
immediately cried out, “ How fortunate ! there will be plenty 
of pasture there this year.” To their minds an earthquake 
foretold rain, as surely as rain foretold abundant pasture. 
Certainly it did so happen that on the very day of the 
earthquake that shower of rain fell which I have described as 
in ten days’ time producing a thin sprinkling of grass. At 
other times rain has followed earthquakes, at a period of the 
year when it is a far greater prodigy than the earthquake 
itself: this happened after the shock of November 1822, and 
again in 1829, at Valparaiso; also after that of September 
1833 a t Tacna. A person must be somewhat habituated to 
the climate of these countries, to perceive the extreme 
improbability of rain falling at such seasons, except as a 
consequence of some law quite unconnected with the ordinary 
course of the weather. In the cases of great volcanic eruptions, 
as that of Coseguina, where torrents of rain fell at a time of 
the year most unusual for it, and “ almost unprecedented in 
Central America,” it is not difficult to understand that the 
volumes of vapour and clouds of ashes might have disturbed 
the atmospheric equilibrium. Humboldt extends this view to 
the case of earthquakes unaccompanied by eruptions ; but I 
can hardly conceive it possible that the small quantity of 
aeriform fluids which then escape from the fissured ground can 
produce such remarkable effects. There appears much prob¬ 
ability in the view first proposed by Mr. P. Scrope, that when 
the barometer is low, and when rain might naturally be 
expected to fall, the diminished pressure of the atmosphere 
over a wide extent of country might well determine the precise 
day on which the earth, already stretched to the utmost by the 
subterranean forces, should yield, crack, and consequently 
tremble. It is, however, doubtful how far this idea will 
explain the circumstance of torrents of rain falling in the dry 
season during several days, after an earthquake unaccompanied 
by an eruption ; such cases seem to bespeak some more 
intimate connexion between the atmospheric and subterranean 
regions. 
Finding little of interest in this part of the ravine, we 
retraced our steps to the house of Don Benito, where I stayed 
two days collecting fossil shells and wood. Great prostrate 
silicified trunks of trees, embedded in a conglomerate, were 
