218 Physiognomy of the Islands in the Pacific. 



tally by parallel linos of block rock. There are frequent cascades along 

 their course ; and at the head, they often abut against the sides of 

 he cen tral inaccessible heights of the island. The streamlet has 

 frequently its source in one or more thready cascades that make an 

 unbroken descent of one or two thousand feet down the precipitous 

 yet verdant walls of the amphitheatre around. 



II. A narrow gorge, having the walls vertical or nearly so, and a 

 flat strip of land at the bottom more or less uneven, with a streamlet 

 sporting along, first on this side and then on that, now in rapids, 

 and now with smoother and deeper waters. The walls may be from 

 one hundred to one thousand feet or more in height ; they are richly 

 overgrown, yet the rocks are often exposed, though everywhere more 

 than half concealed by the green drapery. 



These gorges vary in character according to their position on the 

 island. Where they cut through the lower plains (as the dividing 

 plain of Oahu) they are deep channels with a somewhat even charac- 

 ter to the nearly vertical walls, and an open riband of land at bottom. 

 The depth is from one to three hundred feet, and the breadth as 

 many yards. Farther towards the interior, where the mountain 

 slopes and vegetation have begun, the walls are deeply fluted or 

 furrowed, the verdure is more varied and abundant, and cascades 

 are numerous. 



This second kind of gorge, still further towards the interior, changes 

 in character, and becomes a gorge of the first kind, narrow^ing at the 

 bottom to a torrent's course, along which are occasional precipices 

 which only a torrent could descend. 



III. Valleys of the third kind have an extensive plain at bottom 

 quite unlike the strip of land just described. They sometimes abut 

 at head against vertical walls, but oftener terminate in a wide break 

 in the mountains. 



The ridges of land which intervene between the valleys, have a 

 flat or barely undulated surface, where these valleys intersect the 

 lower plains or slopes ; but in the mountains they are narrow at top 

 and sometimes scarcely passable along their knife-edge summits. 

 Some of them, as they extend inward, become more and more nar- 

 row, and terminate in a thin wall, which runs up to the central 

 peaks ; others stop short of these central peaks, and the valleys on 

 either side consequently coalesce at their head, or are separated only 

 by a low wall, into which the before lofty ridge had dwindled. The 

 crest is often jagged or rises in sharp serratures. 



The main valleys, which we have more particularly alluded to 

 above, have their subordinate branches ; and so the ridges in neces- 

 sary correspondence, have their subordinate spurs. 



As examples of the valleys and ridges here described, we intro- 

 duce a brief account of an excursion in the Hanapepe Valley on Kauai, 

 one of the Hawaiian Islands, and a second up the mountains of 

 Tahiti. 



