EFFECTS OF ELEVATING FORCES. 513 



subsidence is not wanting. Thus in the Keeling or Cocos Islands, 

 situated in Lat. 11 50' S., and Long. 96 51' E., the old cocoa- 

 nut trees surrounding the lagoon, in which the water is as 

 tranquil as in the most sheltered lake, are undermined and 

 falling. The foundation posts of a store-house, which, according 

 to the inhabitants, had stood seven years before just above high- 

 water mark, were, at the time of Mr. Darwin's visit, washed by 

 the tide. The islands are occasionally shaken by earthquakes. 

 Such changes are by no means unfrequent in many parts of the 

 Pacific ; and, if the accounts of the natives are to be relied on. 

 many instances of the submergence of whole islands have occurred, 

 within the period of recent tradition. 



1082. The evidence in regard to the areas of elevation is still 

 more satisfactory. It is by no means uncommon to find beds of 

 recent Coral, at a considerable height above the sea level. Some- 

 times whole coral islets are thus upraised. Among these, 

 Elizabeth or Henderson's Island, examined by Captain Beechey, 

 is one of the most remarkable. This is about five miles in length 

 and one in breadth. It has a nearly flat surface ; and on all 

 sides, except the north, is bounded by perpendicular cliffs about 

 fifty feet high, composed entirely of dead coral. In some parts, 

 the height of the surface was nearly eighty feet above the water 

 level. The face of the cliffs presented a smooth surface, and was 

 destitute of any ridges or other indication of the action of the 

 sea at different levels ; so that it may be reasonably inferred, that 

 it was upraised by one convulsion. At a distance of a few 

 hundred yards of this island, no bottom could be gained with 

 200 fathoms of line. The most remarkable instance of this kind 

 on record is the one observed by Mr. S. Stutchbury in the island 

 of Tahiti. This island is composed of volcanic rocks ; and there is 

 in it a lofty mountain ridge with two summits, of which the 

 lower one is evidently the crater of a volcano, perhaps not very 

 long extinct. The principal peak rises to the height of about 

 10,000 feet ; and near its summit is a distinct and regular 

 stratum of coral-limestone, which cannot be distinguished from 

 that, which is being at present formed in enormous quantity 

 around the shores of the island. As there is no other deposit of 



