m TEE COCOS'KEEIINO ISLANDS. 



35 



CHAPTER IIL 



SOJOURN IN THE COCOS-KEELING ISLANDS— 



Coral reef formntion— Obsenrations on the elevation or aubsidenoe of the 



Keeling atolL 



As the Keeling atoll was the reef most carefully examinefl and 

 €l escribed by Mr. Darwin, and that with which, in prnpnuiicli ng 

 his famous theory of coral reefs, he has compared the others he 

 describes, I felt specially pleased at being able to go over 

 his owTi ground with his book in my hand, and gain a clearer 

 understanding of several points which I hafl fonnd it difficult 

 to comprehend. 



Unfortnnately the weather during my visit was not suffi- 

 ciently favonrable to enable me to examine so closely as I 

 could have desired the corals of the enter margins or to make 

 the series of seaward soundings I had intended. 



The first questions that present themselves to the traveller 

 in midst of his amazement on first reaching that peculiar 

 production of the warm seas — an island-speckled ring of coral 

 holding its own against the wave^ — are, How came itintoljeing 

 here, Wliy of this singular form, and How docs it continno to 

 exist? Mt. Darwin was the first to attempt any far-reaching 

 solution of these difficult questions, a]iplicable to coral forma- 

 tions overall the work! As true reef-building corals,, it is well 

 known, can flourish only beneath a very limited depth— some 

 twenty fathoms — of water, a great apparent difficulty existed 

 " respecting the foundations on which these atolls ai'e based, 

 from the immensity of the spaces over which they are inter- 

 spersed and the apparent necessity for believing that they are 

 all supported on mountain summits, which, although rising very 

 near to the surface of the sea, in no one instance emerge above it. 

 To escape this latter most improbable admission, which implies 

 the existence of submarine chains of mountains of almost the 



If 2 



