OAHU. 233 
northwestward the declivities lengthen out into a long dry plain, with- 
out forests, having a scarcely perceptible inclination, and terminating 
in a cliff of one to two hundred feet. 
Molokai is nine miles north of Lanai, and about the same distance 
north of west of Maui. It is a narrow island, thirty-five statute miles 
long and averaging seven in breadth, with an area of about two hun- 
dred and twenty square miles. It trends east and west. In a distant 
view from the south it appears like two unequal islands united by a 
strip of low land,—in this respect resembling Maui, though much less 
lofty in its heights. The western elevation is quite low, and the sur- 
face very dry. The eastern mountain rises to a height of 1500 feet, 
and is called Mount Olokui. On the north side there is a long range 
of vertical cliffs 1500 to 2000 feet in height; but in the opposite direc- 
tion the slopes are gradual, and are traversed by many valleys running 
seaward. In the sides of these valleys the stratified structure was dis- 
tinctly seen from the vessel as we passed by the southern shores, and 
the layers were observed to slope at a small angle away from the interior. 
There are many lateral cones, some of which were visible from the 
ship. 
Coral has been obtained on this island, as we were informed by Rev. 
Mr. Andrews, at a height of three or four hundred feet above the sea, 
which still exhibits the structure of recent specimens. It extends over 
a surface of more than twenty acres on the acclivity of the eastern 
mountain, two or three miles from the sea; and descending from the 
locality, it was traced almost to the sea. 
IV. ISLAND OF OAHU. 
1. GENERAL FEATURES. 
Oahu is twenty-eight statute miles west of Molokai, and trends 
west-northwest. It has the shape of a trapezium (see map), with 
the parallel sides facing northeast and southwest. The length of the 
trapezium is thirty-five miles, the breadth twenty-one, and the area 
six hundred square miles. The two parallel lines of coast, the 
northeast and southwest, are faced by ranges of mountains, and be- 
tween them lies a large tract of low, nearly level land. The island is 
thus a twin of mountains lke Maui, and the intermediate plain is 
properly the foot of the eastern range. We designate the mountains 
59 
