158 HAWATIAN ISLANDS. 
of a triple island, the three summits, Loa, Kea, and Hualalai, com- 
prising the island; a subsidence of 6000 feet would make three 
islands of the three mountains, and Loa and Kea would still be 8000 
feet in elevation. ‘These facts are of special interest in a geological 
point of view, and help us to an insight into the past history of the 
islands, which will be considered and explained in the sequel. 
I. ISLAND OF HAWAIL 
Hawaii is the most extensive seat of volcanic action in the Pacific, 
and one of the most remarkable regions of eruption in the world. 
Besides the three lofty summits which have been mentioned, there _ 
are great numbers of craters in all conditions, scattered over the slopes, 
some overgrown with forests, while about others, streams of lava, 
now hard, and black, may be traced along their course for miles. 
Areas, hundreds of square miles in extent, are covered with the 
refrigerated lava floods, over which the twistings and contortions of 
the sluggish stream as it flowed onward are everywhere apparent; 
other parts are desolate areas of ragged scoria. But a few months 
before our visit, a surface of fifteen square miles had been deluged 
with lavas, which came by an underground route from the crater 
Lua Pele. As we have therefore on Hawaii the most recent igneous 
action, we commence our survey of the group with this island. 
1. GENERAL FEATURES. 
The form of Hawaii is nearly triangular, with the three sides 
fronting severally, west, southeast, and northeast. The western side is 
about 85 geographical miles in length, the southeast 65, and the north- 
east 75 miles; the area is 3800 square miles. ‘The whole surface pertains 
to its three lofty summits, forming their declivities or foot, excepting 
a single ridge on the north called Kohala. 
The voyager approaching Hawaii, while admiring the sublimity of 
its swelling heights, is struck with the unbroken surface of the island. 
Lofty peaks, and alternating valleys and ridges are so generally cha- 
racteristic of mountain scenery, that he views the even and gentle 
slope of the summits Loa and Kea with a degree of amazement. 
