for the Advancement of Science. 425 



er ? I have experienced m this place, as I have sfated, three ruinous 

 earthquakes,— that of 1822, which I passed in the house until the back 

 fell, that of 1829, and the present; and from observations on each oc- 

 casion and now again, particuhirly as in each case I have been calm 

 and resigned, I think I may be allowed to venture my conjecture in 

 common with others, in which I feel so confident that you are at liberty 

 t to submit them to your scientific friends if you please, and if any re- 



F quire further particulars I shall be happy to give them. 1 mwy, how- 



ever, add something more; — the barometer and ihermomeler indicaied 

 nothing, nor was there the least warning of any description ; but as in- 

 variably occurs after a heavy shock, we had on the third day after a 

 shower of twelve hours' rain, for vvfiich I had already prepared, aware 



of Its being the consequence, happen at whatever season it may. I 

 conceive, also, that I have felt less relaxed than before it. I cannot 

 understand al[ these things' imless electricity be the agent ; while the 

 atmosphere' must be aflecled in some way to shower down rain at sea- 

 sons when under ordinary circumstances it does ^not fall. Santiago 

 (the capital of Chile), Casa Blanca,and Quillota seem to have suffered 

 equally with Valparaiso; and the latter two places worse, while some 

 of the public buildings of the capita! are ordered to be pulled down. 

 My wife, who is at that place, mentions every subsequent shock tally- 

 ing exactly with those here. The shock of 1822 was, however, about 

 double in force and time; and I recollect well it was with difficulty I 

 could stand, — whereas on the present occasion I had no trouble. On 

 that occasion, the sea in the Bay of Valparaiso retired considerably, 

 and was several days in reaching its former level, — while on this no 

 such thing was observed. Your newspapers may make out a different 

 story, but you have here at least correct observations. The country is 

 advancing fast; but it is an awful fact to contemplate that the most 

 massive buildings of the country are the first to yield to the phenomena 

 referred to." 



The generally received impression is, that earthquakes have their 

 origin in consequence of violent subterranean action, doubtless of a 

 chemical character. Sometimes the violent eruptions of volcanoes are 

 accompanied by severe earthquakes; and in regard to those of Peru I 

 ^vill instance one o? this species, in which volcanic action was accom- 

 panied by a terrific earthqtiake, viz., the eruption in February, 1600, in 

 Ihe mountain range of Ornate, twenty-two leagues from Arequipa. On 

 the J5th of that month the volcano broke out with great fury and the 

 ground was in continual motion. On the 18ih, in the evening the move- 

 '^ents were more rapid, and at 10 p. m. there was such a shock that ft 

 ■awoke the soundest sleepers, and every five minutes during the night 

 shocks continued. On the morninsf of the 19th occurred a dreadful 

 shock, of which the Spanish MS. from which I extract this says, ' the 

 tnovements were now more rapid, and in the twenty-four hours there 

 were more than 200 shocks. The heavens were darkened with clouds 

 of eruptive matter, flashes of lightning were seen, and then there de- 

 scended much while ashes like a fall of snow, which covered the coun- 

 try around.' On the 28th of the same month happened the most dread- 

 ful shock of all. Tb* town of Quinistacas, four or five miles distant 

 from the volcano, with 100 inhabitants, was buried ; the town of Ornatt 



