278 HAWAIIAN ISLANDS. 
Conclusions relating to the Geological History of Kauat. 
The facts which have been presented in the preceding pages, at 
once suggest that the island of Kauai is another volcanic mountain 
like those of Hawaii or Maui, which different agents have altered, and 
degraded, till the original features have been obliterated. The whole 
island is not larger than either of the mountains Loa, Kea, or Hale-a- 
kala, as may be seen by making the comparison on the map of the 
group. Mount Kea has all the necessary material, therefore, for a 
Kauai, and it is only requisite to isolate it, and intersect it with gorges, 
to turn it actually into a Kauai. 
It is natural, landing upon an island of peaks and ridges, without 
order or apparent system, to look for separate volcanic cones in the 
several summits. But the steepness of these heights, as well as their 
structure, is evidence against such a view. It requires but little study 
of the other islands to ascertain that steep and lofty cones are not 
among the results of volcanic accumulation in the Hawaiian Group ; 
for the great slopes of the volcanic mountains are always gradual, not 
exceeding fifteen degrees. Moreover, there are the same facts in sup- 
port of the hypothesis of a single volcanic summit, as in the eastern 
division of Oahu. 
The shore plain, and its layers of rock beneath, have a gentle incli- 
nation away from the centre of the island, and this inclination is very 
uniform, being undisturbed by tiltings or irregularities of any kind. 
As we ascend, three to five miles from the coast, the plain begins to 
form the backs of the ridges; and we trace it on, till, towards the in- 
terior, the whole structure is so altered by degradation, that nothing 
appears to represent it, except the stratification of the rocks. These 
rocks, moreover, appear in much thicker layers, and, as near as could 
be judged from distant views, the stratified structure was as much 
wanting in the interior peaks as in those of ‘Tahiti. This important 
point will be remarked upon in our account of the Society Islands. 
What relation the high mountain plain of the western part of the 
island had to the crater or summit of the original volcanic cone or 
dome, we are not prepared to say. The cliff of two thousand feet, on 
the northwest, is, beyond doubt, another example of fracture, like that 
of Oahu, with a disappearance of the part broken off, beneath the sea. 
