564 



CORAL FORMATION 



April, 1836. 



of the coast of the mainland, it may be expected that any out- 

 lying islands would have formed lagoon islands. Now Bligh 

 and others distinctly state that some of the islands there are 

 precisely similar to the well-known lagoon islands in the 

 Pacific; there are also encircled islands, so that the three 

 classes supposed to be produced by the same movement are 

 there found in juxtaposition ; as likewise happens, but in a 

 less evident manner, at New Caledonia and in the Society 

 Archipelago. 



The New Hebrides hne of islands, may be observed to bend 

 abruptly at New Britain, thence to run nearly east and west ; 

 and, lastly, to resume its former north-west direction in 

 Sumatra and the peninsula of Malacca. The figure may be 

 compared to the letter S laid obliquely, but the line is often 

 double. We have shown that the southern part, as far north 

 as New Ireland, abounds with proofs of elevation, so is it 

 with the rest. Since the time of Bougainville every voyager 

 adduces some fresh instance of such changes throughout a 

 great part of the East Indian archipelago. I may specify 

 New Guinea, Wageeoo, Ceram, Timor, Java, and Sumatra. 

 Coral reefs are abundant in the greater part of these seas, but 

 they merely skirt the shores. In the same manner as we 

 have followed the curved line of elevation, so may we that 

 of subsidence. At Keeling Island, I have already mentioned 

 that there exist proofs of the latter movement : and it is a very 

 interesting circumstance, that during the last earthquake, by 

 which that island was affected, Sumatra, though distant 

 nearly 600 miles, was violently shaken. Bearing in mind 

 that there is evidence of recent elevation on the coast of the 

 latter, one is strongly tempted to believe that as one end of 

 the lever goes up, the other goes down : that as the East 

 Indian archipelago rises, the bottom of the neighbouring sea 

 sinks and carries with it Keeling Island, which would have 

 been submerged long ago in the depths of the ocean, had it not 

 been for the wonderful labours of the reef-building polypi. 



As I have remarked, the islands in this great archipelago 

 are only skirted with reefs ; and it appears from the state- 



