6 Physko-Geognostic Sketch of the Island ofOahu, 



is heightened by the black colour of the rocks. With the ex- 

 ception of Mouna Raala, all the mountain summits in the 

 island belonging to the central ridges of the two chains, are 

 needle-shaped or conical. Raala is table-shaped. I put out of 

 view at present the isolated hills rising out of the plains. The 

 distance between the two parallel lines of direction of the moun- 

 tain-chains is sixteen miles. 



The only communication between the districts of Rotia in the 

 south and that of Koulaii on the north side of the island, is by 

 crossing over the precipice which forms the northern declivity 

 of the chain of Ronahuanui. The spots selected for this pur- 

 pose are the passes or fissures between two adjoining peaks of 

 the chain. Those most frequented are the Pari of Anuanu, at 

 the upper extremity of the valley of the same name, elevated 

 1144 feet above the level of the sea, and one about two to three 

 miles farther west, which, according to the reports of the natives, 

 for it is seldom resorted to by the white residents, is a still more 

 difficult passage than the former, and, when viewed from the 

 low lands of Koolaiiy appears of much greater elevation. 



The Plains or Loiv Lands of the island are of two kinds : the 

 belt of low land extending between the mountains and the sea, 

 generally of small breadth, and the elevated plain or plateau of 

 Eva, which is the only bond of connection between the eastern 

 and western chains. I am uncertain whether the extensive 

 quadrangular space occupying the north angle of the island, and 

 chiefly comprised in the district of Koolanloa, comes under the 

 denomination of an elevated plain similar to that of Eva, or 

 whether it consists of a tract of hilly country of inconsiderable 

 altitude, forming the northern termination of the chain of Rona- 

 huanui. I am inclined, however, to the latter view, from its 

 aspect in crossing the plain of Eva. 



The low land between the mountains and the sea is either di- 

 versified with hills and intersected with water-courses, when its 

 breadth is between two and three miles, as on the north side 

 of the island, between Railua and Rualoa ; or it is perfectly flat, 

 forming sandy downs, not more than five to six feet above the 

 sea, extending to the base of the hills, which rise suddenly in 

 tabular cliff's. Its breadth varies, but is never much more than 

 a mile ; and, in the vicinity of Laie and at Waimea, the rocky 

 cliffs approach within a few hundred yards of, or even run into. 



