618 C. Darwin, Esq., on Volcanic 



same manner as they do that of Peru and Chile. Thus, at Valparaiso in 1822, 

 the movement was felt along- 880 miles of the shore of the Pacific; andatCon- 

 cepcion, in 1835, for the greater length of more than 1000 miles ; but on no 

 occasion has the shock been transmitted across the Cordillera to a nearly equal 

 distance. In 1835 the rocking of the ground was so gentle at Mendoza, that 

 an old man, one of the inhabitants, (and every one in these countries is pos- 

 sessed with an almost instinctive power of perceiving the slightest tremor,) 

 told me, that for some time he mistook the movement of the ground for a 

 giddiness in his head, and that he called out to his friends that he was going 

 to die. At Concepcion, Valparaiso, Lima, and Acapulco*, the residents 

 believe that the disturbance generally proceeds from the bottom of the 

 neighbouring sea; and thus they explain the unquestionable factf, that the 

 inland towns are generally much less injured than those near the coast. It 

 does not appear, that the disturbance proceeds from any one point, but from 

 many ranged in a band ; otherwise the fact of the linear and unequal exten- 

 sion of earthquakes would be unintelligible. Thus, in 1835, the island of 

 Chiloe, the neighbourhood of Concepcion, and Juan Fernandez, were all 

 violently affected at the same time, and more so than the intermediate di- 

 stricts. In mountainous countries, such as New Andalusia, Peru, and Chile, 

 when earthquakes follow coast lines, they may be said to extend parallel to 

 the littoral chain of mountains. 



The last consideration I shall enter on, as indicating' the cause of earth- 

 quakes, is, that in South America they have sometimes (if not, as 1 believe, ge- 

 nerally;};) been accompanied by elevations of the land; but this, judging from 

 the Lima shock of 1746, does not appear to be a necessary concomitant, at 

 least to a perceptible amount. It might at first be thought that, at Concepcion, 

 the uplifting of the ground, which accompanied the first and great shock, 

 would by itself have accounted for the whole phenomenon of the earthquake. 

 The great shock, however, during the few succeeding days, was followed 

 by some hundred minor ones (though of no inconsiderable violence), which 

 seemed to come from the same quarter from which the first had proceeded ; 



* At Acapulco, Humboldt says, the shocks come from three different quarters, the west, 

 north-west, and south. (Polit. Essay on the Kingdom of New Spain; English Translation, Vol. 

 iv. p. 58.) 



t Almost every author, from the time of Molina, makes this observation. See Molina's Com- 

 pendio de la Hist, del Reyno de Chile, Vol. i. p. 52. 



X My belief is grounded on the fact that, on the same coasts, and within the same period, in 

 which a vast number of earthquakes are recorded, there exist proofs of an elevation of the land ; 

 although the rise is not known to have been connected with any particular earthquake. 



