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 at 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 ot 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 



