Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.3)

5G4 CORAL FORMATIONS. 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 weU-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 line 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-