334 APPENDIX. 



island, it is natural that this side of the reef, ex- 

 posed to the unremitting fury of the ocean, should 

 be formed chiefly by broken off blocks of coral, 

 and fragments of shells, and first rise above the 

 element that created it. It is only these islands, 

 respecting the formation and nature of which we 

 hitherto know any thing with certainty ; we are 

 still almost entirely without any observations on 

 those in the Indian and Chinese sea, which lie in 

 the regions of the six months' monsoons. From the 

 charts given of them, it is to be inferred that 

 every side is equally advanced in formation. The 

 lee-side of such a coral reef in the Pacific Ocean, 

 which is governed by the constant monsoons, fre- 

 quently does not show itself above the water, when 

 the opposite side, since time immemorial, has at- 

 tained perfection in the atmospheric region ; the 

 former reef is even interrupted in many places by 

 intervals tolerably broad, and of the same depth as 

 the inner sea, which have been left by nature like 

 open gates for the exploring mariner to enter the 

 internal calm and secure harbour. In their exter- 

 nal form, the Coral islands do not resemble each 

 other ; but this, and the extent of each, probably 

 depends on the size of the sub-marine mountain 

 tops, on which their basis is founded. Those 

 islands, which have more length than breadth, and 

 are opposed in their greatest extent to the wind 

 and waves, are richer in fruitful islands than those 

 whose situation is not so adapted to a quick form- 



