256 CORALS AND CORAL ISLANDS. 



Loa and Mount ELea, of Hawaii, present a remarkable instance 

 of approximation, as they differ but two hundred feet ; but 

 the two sides of the crater of Mount Loa differ three hundred 

 and fourteen feet in height. Mount Kea, though of volcanic 

 character, has no large crater at top. Hualalai, the third 

 mountain of Hawaii, is 4,000 feet lower than Mount Loa. 

 The volcanic summit of East Maui is 10,000 feet high, and 

 contains a large crater ; but the wall of the crater on one 

 side is 700 feet lower than the highest point of the mountain ; 

 and the bottom of the crater is 2,000 feet below the rim of 

 the crater. Similar facts are presented by all volcanic regions. 



c. It further requires that there should be craters over 

 fifty miles in diameter, and that twenty and thirty miles 

 should be a common size. Facts give no support to such an 

 assumption. 



d. It supposes that the high islands of the Pacific, in the 

 vicinity of the coral islands, abound in craters ; while, on the 

 contrary, there are none, as far as is known, in the Marquesas, 

 Gambier, or Society Group, the three which lie nearest to 

 the Paumotus. Even this supposition fails, therefore, of giv- 

 ing plausibility to the crater hypothesis. 



Thus at variance with facts, the theory has lost favor, and 

 it is no longer sustained even by those who were once its 

 strongest advocates. 



The question still recurs with regard to the basement 

 of coral islands, and the origin of their lagoon character. 

 Shall we suppose, with some writers, that these islands 

 were planted upon submarine banks, within one hundred 

 and fifty feet of the surface of the sea ? As has been said, 

 there is no authority for the supposition. We nowhere find 

 regions over our continents with elevations so uniform in 

 height ; and submerged banks of this kind are of extremely 



