2 IS James 1). Dana, Esq., on 



10,400 feet above the sea; and can we believe it possible that 

 throughout this large area, when the two hundred islands now 

 sunk were above the waves, there were none equal in altitude 

 to the mean of these heights ? That all should have been 

 within nine thousand feet in elevation, is by no means pro- 

 bable. However moderate our estimate, there must still be 

 allowed a sinking of several thousand feet ; and however much 

 we increase it within probable bounds, we shall not arrive at 

 a more surprising change of level than our continents shew 

 that they have undergone. 



Between the New Hebrides and Australia, the reefs and 

 islands mark out another area of depression, which may have 

 been simultaneously in progress. The long reef of one hun- 

 dred and fifty miles from the north cape of New Caledonia, and 

 the wide barrier on the west, cannot be explained without sup- 

 posing a subsidence of one or two thousand feet at the least. 

 The distant barrier of New Holland is proof of as great, if 

 not greater, subsidence. 



Effect of the subsidence. — The facts surveyed give us a 

 long insight into the past, and exhibit to us the Pacific scat- 

 tered over with lofty lands, where there are now only humble 

 monumental atolls. Had there been no growing coral the 

 whole would have passed without a record. These permanent 

 registers, planted ages past in various parts of the tropics, 

 exhibit, in enduring characters, the oscillations which the 

 " stable " earth has since undergone. Thus Divine wisdom 

 creates, and makes the creations inscribe their own history ; 

 and there is a noble pleasure in deciphering even one sen- 

 tence in this Book of Nature. 



From the actual extent of the coral reefs and islands, we 

 know that the whole amount of high land lost to the Pacific 

 by the subsidence, was at least fifty thousand square miles. 

 But since atolls are necessarily smaller than the land they 

 cover, and the more so, the farther subsidence has proceeded ; 

 since many lands from their abrupt shores, or through vol- 

 canic agency, must have had no reefs about them, and have 

 disappeared without a mark, and others may have subsided 

 too rapidly for the corals to retain themsel ves at the surface, — 

 it is obvious that this estimate is far below the truth. It is 



