460 KEELING ISLAND. [CHAP. sx. 



ind even conquered, by means which at first seem most weaR and 

 inefficient It is not that the ocean spares the rock of coral ; 

 the great fragments scattered over the reef, and heaped on the 

 beach, whence the tall cocoa-nut springs, plainly bespeak the 

 unrelenting power of the waves. Nor are any periods of repose 

 granted. The long swell caused by the gentle but steady action 

 of the trade-wind, always blowing in one direction over a wide 

 area, causes breakers, almost equalling in force those during a 

 gale of wind in the temperate regions, and which never cease to 

 rage. It is impossible to behold these waves without feeling a 

 conviction that an island, though built of the hardest rock, let it 

 be porphyry, granite, or quartz, would ultimately yield and be 

 demolished by such an irresistible power. Yet these low, insig- 

 nificant coral-islets stand and are victorious : for here another 

 power, as an antagonist, takes part in the contest. The organic 

 forces separate the atoms of carbonate of lime, one by one, from 

 the foaming breakers, and unite them into a symmetrical struc- 

 ture. Let the hurricane tear up its thousand huge fragments ; 

 yet what will that tell against the accumulated labour of myriads 

 of architects at work night and day, month after month ? Tims 

 do we see the soft and gelatinous body of a polypus, through the 

 agency of the vital laws, conquering the great mechanical power 

 of the waves of an ocean which neither the art of man nor the 

 inanimate works of nature could successfully resist. 



We did not return on board till late in the evening, for we 

 staid a long time in the lagoon, examining the fields of coral and 

 the gigantic shells of the chama, into which, if a man were to put 

 his hand, he would not, as long as the animal lived, be able to 

 withdraw it. Near the head of the lagoon, I was much surprised 

 to find a wide area, considerably more than a mile square, covered 

 with a forest of delicately branching corals, which, though stand- 

 ing upright, were all dead and rotten. % At first I was quite at a 

 loss to understand the cause ; afterwards it occurred to me that 

 it was owing to the following rather curious combination of cir- 

 cumstances. It should, however, first be stated, that corals are 

 not able to survive even a short exposure in the air to the sun's 

 rays, so that their upward limit of growth is determined by that 

 of lowest water at spring tides. It appears, from some old charts, 

 tliat the long island to windward was formerly separated by widt 



