34 CORAL-REEFS. 



away. On the western side, also, of the atoll, where I have 

 described a bed of sand and fragments with trees growing 

 out of it, in front of an old beach, it struck both Lieut. 

 Sulivan and myself, from the manner in which the trees 

 were being washed down, that the surf had lately recom- 

 menced an attack on this line of coast. Appearances 

 indicating a slight encroachment of the water on the land, 

 are plainer within the lagoon : I noticed in several places, 

 both on its windward and leeward shores, old cocoa-nut 

 trees falling with their roots undermined, and the rotten 

 stumps of others on the beach, where the inhabitants assured 

 us the cocoa-nut could not now grow. Captain Fitzroy 

 pointed out to me, near the settlement, the foundation 

 posts of a shed, now washed by every tide, but which the 

 inhabitants stated, had seven years before stood above high- 

 water mark. In the calm waters of the lagoon, directly 

 connected with a great, and therefore stable ocean, it seems 

 very improbable that a change in the currents, sufficiently 

 great to cause the water to eat into the land on all sides, 

 should have taken place within a limited period. From 

 these considerations I inferred, that probably the atoll had 

 lately subsided to a small amount ; and this inference was 

 strengthened by the circumstance, that in 1834, two years 

 before our visit, the island had been shaken by a severe 

 earthquake, and by two slighter ones during the ten 

 previous years. If, during these subterranean disturbances, 

 the atoll did subside, the downward movement must have 

 been very small, as we must conclude from the fields of 

 dead coral still lipping the surface of the lagoon, and from 

 the breakers on the western shore not having yet regained 

 the line of their former action. The subsidence must, also, 

 have been preceded by a long period of rest, during which 

 the islets extended to their present size, and the living 



