RAISED COEAL BLOCKS. 239 



distance of from 200 to 300 feet from the outer edge, the colour 

 of the water is as dark as in the channel of Kossol, which is 

 from 60 to 60 fathoms deep. But the most striking- peculiarity 

 of the western reef is the accumulation of immense blocks of 

 coral on the south-western point (see Map II.). These are, with- 

 out exception, dead, and their summits ai'e never covered even 

 at the highest tides, unless perhaps during storms. The largest 

 of these blocks lie on the south-west point, where they not un- 

 frequently measure ten feet or more in diameter; towards the 

 north and east they gradually grow smaller and less numerous, 

 and disappear altogether amid the sand and living coral before 

 the first island is reached on the eastern side; on the western 

 side, going northwards, they extend about ha'.fway. The 

 subjoined map makes this sufficiently clear. 



The position of these blocks, and their height above the 

 highest water line, it seems to me can only be regarded as 

 proof of a recent upheaval. It is true indeed, with regard to 

 similarly situated blocks on other reefs, that they have always 

 been said to have been piled up by violent storms ; but even 

 Wilkes remarked, as it appears to me with perfect truth, that 

 such enormous stones as are sometimes found on the margin of 

 the outer reefs could not possibly be tossed up so high by 

 waves. For the argument so often used, that in violent tem- 

 pests even large ships have been carried over the edge of a reef, 

 proves nothing ; since a ship will always float if it has enough 

 water under its keel, while a stone always sinks. The blow 

 of a wave may certainly be strong enough to roll such a block 

 a few paces forward on the reef; but even if the force wei'e 

 sufficient to rend blocks of ten feet or more in diameter from the 

 living reef, it certainly would be incapable of raising them over 

 the edge of the reef. In the case now in point the position of 

 the blocks is still more adverse to such an assumption ; for on 

 Kriangle they do not lie where the most violent attack of the 

 waves takes place during a storm, but precisely in those spots 

 most sheltered from it. By far the greater number of storms 

 in these islajids come from the east ; and even though, during 

 the short period of the western monsoon, storms may sometimes 

 sweep up from the west, it is not clear why in this case such 



