THE USEFULNESS OF EARTHQUAKES. 223 



less immediately referable to subterranean action than 

 those which are produced during the progress of an 

 actual earthquake. I pass over, therefore, such phe- 

 nomena as the gradual uprising of Sweden, the slow 

 sinking of Greenland, and (still proceeding westward) 

 the gradual uprising of Nova Scotia and the shores of 

 Hudson's Bay. Eemarkable and suggestive as these 

 phenomena really are, and indisputable as the evidence 

 is on which they rest, they will probably seem much 

 less striking to the reader than those which I am now 

 about to quote. 



On the 19th of November, 1822, a widely felt and 

 destructive earthquake was experienced in Chili. On 

 the next day, it was noticed for the first time that a 

 broad line of sea-coast had been deserted by the sea 

 for more than one hundred miles. A large part of this 

 tract was covered by shell-fish, which soon died, and 

 exhaled the most offensive effluvia. Between the old 

 low-water mark and the new one, the fishermen found 

 burrowing shells, which they had formerly had to search 

 for amidst the surf. Eocks some way out to sea 

 which had formerly been covered, were now dry at half 

 ebb-tide. 



Careful measurements showed that the rise of the 

 land was greater at some distance inshore than along 

 the beach. The watercourse of a mill about a mile 

 inland from the sea had gained a fall of fourteen inches 

 in little more than a hundred yards. At Valparaiso, 

 the rise was three feet ; at Quintero, four feet. 



In February 1835, and in November 1837, a large 



