384 PACIFIC ISLANDS. 
current of the Atlantic indicate the course of the flow of waters over 
the eastern part of North America, were the land under the sea, ex- 
cepting such deviations as the form of the land then above the water 
might produce. It is obvious that the valleys of the Pacific islands 
have nothing in their features attributable to such a cause. 
Running water of the land, and gradual decomposition.—Of the 
causes of valleys mentioned in the outset we are forced to rely for 
explanations principally upon running streams: and they are not 
only gouges of all dimensions, but of great power, and in constant 
action. ‘There are several classes of facts which support us in this 
conclusion. 
a. We observe that Mount Loa, whose sides are still flooded with 
lavas at intervals, has but one or two streamlets over all its slopes, and 
the surface has none of the deep valleys common about other sum- 
mits. Here volcanic action has had a smoothing effect, and by its 
continuation to this time, the waters have had scarcely a chance to 
make a beginning in denudation. 
Mount Kea, which has been extinct for a long period, has a succes- 
sion of valleys on its windward or rainy side, which are several 
hundred feet deep at the coast and gradually diminish upward, ex- 
tending in general about half or two-thirds of the way to the summit. 
But to westward it has dry declivities, which are comparatively even 
at base, with little running water. A direct connexion is thus evinced 
between a windward exposure, and the existence of valleys: and we 
observe also that the time since volcanic action ceased is approxi- 
mately or relatively indicated, for it has been long enough for the 
valleys to have advanced only part way to the summit. Degradation 
from running water would of course commence at the foot of the 
mountain, where the waters are necessarily more abundant and more 
powerful in denuding action, in consequence of their gradual accumu- 
lation on their descent. 
Hale-a-kala or Maui offers the same facts as Mount Kea, indicating 
the same relation between the features of the surface and the climate 
of the different sides of the island. On Eastern Oahu the valleys are 
much more extensive; yet still the slopes of the original mountain 
may be in part distinguished. And thus we are gradually led to 
Kauai, where the valleys are very profound and the former slopes 
can hardly be made out. ‘The facts are so progressive in character, 
that we must attribute all equally to the running waters of the land. 
The valleys of Mount Kea alone, extending some thousands of feet 
up its sides, sustain us in saying that time only is required for ex- 
