852 NORTHERN CHILE. (CHAP. XVI. 
atmosphere and of the trembling of the ground: I was much 
struck by this, when mentioning to some people at Copiapé that 
there had been a sharp shock at Coquimbo: they 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 earth- 
quakes, 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, at Tacna. A person must be some- 
what 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 ordi- 
nary 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 aériform 
fluids which then escape from the fissured ground, can produce 
such remarkable effects. There appears much probability in 
the view first proposed by Mr. P. Scrope, that when the baro- 
meter 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 
