960 CORALS AND CORAL ISLANDS. 
Loa and Mount Kea, 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 5,440 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, so 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 tacts, the theory has lost favor, and 
it is now seldom urged. 
The question still recurs with regard to the basement 
of coral islands, and the origin of their lagoon character. 
