ast named are the chief, the former
being 13,800 feet, the latter 13,600 feet, above the sea-level. Although
their height is so vast, the ascent to their summits is so gradual that
their circumference at the base is enormous. The bulk of each of them is
reckoned to be equal to two and a half times that of Etna. Some of the
streams of lava which have emanated from them are twenty-six miles in
length by two miles in breadth.
On the adjoining island of Maui is a still larger volcano, the mighty
Haleakala, long since extinct, but memorable as possessing the most
stupendous crater on the face of the earth. The mountain itself is
over 10,000 feet high, and forms a great dome-like mass of 90 miles
circumference at base. The crater on its summit has a length of 7 1/2
and a width of 2 1/4 miles, with a total area of about sixteen square
miles. The only approach in dimensions to this enormous opening exists
in the still living crater of Kilauea, on the flank of Mauna Loa.
A VOLCANIC ISLAND GROUP
The peaks named are the most apparent remnants of a world-rending
volcanic activity in the remote past, by whose force this whole Hawaiian
island group was lifted up from the depths of the ocean, here descending
some three and a half miles below the surface level. The coral reefs
which abound around the islands are of comparatively recent formation,
and rest upon a substratum of lava probably ages older, which forms the
base of the archipelago. The islands are volcanic peaks and ridges that
have been pushed up above the surrounding seas by the profound action of
the interior forces of the earth.
It must not be supposed that this action was a violent perpendicular
thrust upward over a very limited locality, for the mountains continue
to slope at about the same angle under the sea and for great distances
on every side, so that the islands are really the crests of an extensive
elevation, estimated to cover an area of about 2000 miles in one
direction by 150 or 200 miles in the other. The process was probably
a gradual one of up-building, by means of which the sea receded as the
land steadily rose. Some idea of the mighty forces that have been at
work beneath the sea and above it can be gained by considering the
enormous mass of material now above the sea-level. Thus, the bulk of the
island of Hawaii, the largest of the group, has been estimated by the
Hawaiian Surveyor General as containing 3,600 cubic miles of lava rock
above se
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