586 Geological Society, 



violence. At the time of the principal shock, the Corcovado was 

 quiet ; but when the summit of the mountain was visible a week af- 

 terwards, the snow had disappeared from the north-west crater. On 

 Yntales, to the south of the Corcovado, three black patches, resem* 

 bling craters, were observed above the snow-line after the earthquake, 

 though they had not been noticed previously to it. During the re- 

 mainder of the year, the whole of the volcanic chain, from Osomo to 

 Yntales, a range of 150 miles, exhibited, at times, unusual activity. 

 On the night of the 11th of November, Osomo and Corcovado threw 

 up stones to a great height ; and on the same day, Talcahuano, the 

 port of Concepcion, 400 miles distant, was shaken by a very severe 

 earthquake; and on the 5th of December the whole summit of 

 Osomo fell in. 



After these details of more particular phsenomena, Mr. Darwin 

 alluded to the great areas over which earthquakes have been simul- 

 taneously felt ; but he added, it is impossible even to guess through 

 how wide an extent, in the subterranean regions, actual changes 

 may have taken place. In order to enable the reader, who may be 

 more familiar with European than South American geography, to 

 comprehend the vast surface which was affected by the earthquake of 

 February 1835, he stated, that it had a north and south range, equal 

 in extent to the distance between the North Sea and the Mediterra- 

 nean; that we must imagine the eastern coast of England to be 

 permanently raised ; and a train of volcanos to become active in the 

 southern extremity of Norway ; also that a submarine volcano burst 

 forth near the northern extremity of Ireland; and that the long 

 dormant volcanos of the Cantal and Auvergne, each sent up a column 

 of smoke. 



The contemplation of volcanic phsenomena in South America, has 

 induced the author to infer, that the crust of the globe in Chili rests 

 on a lake of molten stone, undergoing some slow but great change ; 

 for if this inference be denied, he says, the only alternative is, that 

 channels from the various points of eruption must unite in some very 

 deeply-seated focus. This conclusion, however, he doubts, on ac- 

 count of the union of the different trains of volcanos on the one line 

 of the Cordillera, and more especially as many hundred square miles 

 of surface in Chili have been elevated during the same earthquake. 

 Moreover, these elevations have acted within a period geologically 

 recent, throughout the whole, or at least the greater part, of Chili 

 and Peru, and have upraised the land several hundred feet. He is 

 further of opinion, that the shocks coming from a given point of the 

 compass, and the overthrow of the walls, according to their position 

 with respect to this point, prove that the vibrations do not travel 

 from a profound depth, but are due to the rending of the strata not 

 far below the surface of the earth. 



In a geological point of view, the author conceives, the three classes 

 of phaenomena exhibited during this earthquake of February 1835, 

 viz. a submarine outburst — renewed volcanic activity, simultaneously 

 at distant localities — and a permanent elevation of the land, to be 

 of the greatest importance, as forming parts of one great action, and 



