296 CONCEPCIOX. [CHAP. xiv. 



and labour, overthrown in one minute; yet compassion for the 

 inhabitants was almost instantly banished, by the surprise in see- 

 jug a state of things produced in a moment of time, which one was 

 accustomed to attribute to a succession of ages. In my opinion, 

 we have scarcely beheld, since leaving England, any sight so deeply 

 interesting. 



In almost every severe earthquake, the neighbouring waters of 

 the sea are said to have been greatly agitated. The disturbance 

 seems generally, as in the case of Concepcion, to have been of two 

 kinds : first, at the instant of the shock, the water swells high up 

 on the beach with a gentle motion, and then as quietly retreats ; 

 secondly, some time afterwards, the whole body of the sea retires 

 from the coast, and then returns in waves of overwhelming force. 

 The first movement seems to be an immediate consequence of the 

 earthquake affecting differently a fluid and a solid, so that their 

 respective levels are slightly deranged : but the second case is a far 

 more important phenomenon. During most earthquakes, and 

 especially during those on the west coast of America, it is certain 

 that the first great movement of the waters has been a retirement. 

 Some authors have attempted to explain this, by supposing that 

 the water retains its level, whilst the land oscillates upwards ; but 

 surely the water close to the land, even on a rather steep coast, 

 would partake of the motion of the bottom: moreover, as urged 

 by Mr. Lyell, similar movements of the sea have occurred at 

 islands far distant from the chief line of disturbance, as was the 

 case with Juan Fernandez during this earthquake, and with Ma- 

 deira during the famous Lisbon shock. I suspect (but the subject 

 is a very obscure one) that a wave, however produced, first draws 

 the water from the shore, on which it is advancing to break : I have 

 observed that this happens with the little waves from the paddles 

 of a steam-boat. It is remarkable that whilst Talcahuano and 

 Callao (near Lima), both situated at the head of large shallow bays, 

 have suffered during every severe earthquake from great waves, 

 Valparaiso, seated close to the edge of profoundly deep water, has 

 never been overwhelmed, though so often shaken by the severest 

 shocks. From the great wave not immediately following the 

 earthquake, but sometimes after the interval of even half an hour, 

 and from distant islands being affected similarly with the coasts 

 near the focus of the disturbance, it appears that the wave first 

 rises in the offing ; and as this is of general occurrence, the cause 



