1835.] AND ERUPTIVE FORCES. 311 



a long time in eruption, and ten months afterwards were again 

 influenced by an earthquake at Concepcion. Some men, cutting 

 wood near the base of one of these volcanos, did not perceive the 

 shock of the 20th, although the whole surrounding Province was 

 then trembling ; here we have an eruption relieving and taking 

 the place of an earthquake, as would have happened at Con- 

 cepcion, according to the belief of the lower orders, if the 

 volcano of Antuco had not been closed by witchcraft. Two 

 years and three quarters afterwards, Valdivia and Chiloe were 

 again shaken, more violently than on the 20th, and an island in 

 the Chonos Archipelago was permanently elevated more than 

 eight feet. It will give a better idea of the scale of these phe- 

 nomena, if (as in the case of the glaciers) we suppose them to 

 have taken place at corresponding distances in Europe: then 

 would the land from the North Sea to the Mediterranean have 

 been violently shaken, and at the same instant of time a large 

 tract of the eastern coast of England would have been perma- 

 nently elevated, together with some outlying islands, a train of 

 volcanos on the coast of Holland would have burst forth in 

 action, and an eruption taken place at the bottom of the sea, near 

 the northern extremity of Ireland and lastly, the ancient vents 

 of Auvergne, Cantal, and Mont d'Or would each have sent up 

 to the sky a dark column of smoke, and have long remained in 

 fierce action. Two years and three quarters afterwards, France, 

 from its centre to the English Channel, would have been again 

 desolated by an earthquake, and an island permanently upraised 

 in the Mediterranean. 



The space, from under which volcanic matter on the 20th was 

 actually erupted, is 720 miles in one line, and 400 miles in another 

 line at right angles to the first : hence, in all probability, a sub- 

 terranean lake of lava is here stretched out, of nearly double the 

 area of the Black Sea. From the intimate and complicated man- 

 ner in which the elevatory and eruptive forces were shown to be 

 connected during this train of phenomena, we may confidently 

 come to the conclusion, that the forces which slowly and by little 

 starts uplift continents, and those which at successive periods 

 pour forth volcanic matter from open orifices, are identical. 

 From many reasons, I believe that the frequent quakings of the 

 earth on this line of coast, are caused by the rending of the strata, 



