266 HAWAIIAN ISLANDS. 
a region of frequent mists and rains, and the declivities are often 
marked with white, thready cascades, streaming down their almost 
vertical surface, sometimes through one, two, or even three thousand 
feet, in uninterrupted lines. The island is, consequently, well watered, 
and the lower country seldom fails in its productions. The district of 
Waimea, to the southwest, is the only exception to these remarks, and 
this is owing to its leeward situation. 
The soilof the island has the ordinary character of that derived from 
the basaltic material of these islands. It is usually of a deep red 
colour, from the iron contained, except where altered by vegetable 
growth and decomposition. ‘The depth over the shore plain is from 
three to eight feet, and the rock below is altered in colour and com- 
pactness toa much greater depth. Near Koloa the brown surface 
soil was a foot or two deep; and below this, it had the usual red or 
brownish-red colour, derived from uncombined oxyd of iron. The 
rocks of the walls of the valleys are generally so decomposed that it 
is dificult to obtain fresh specimens. The soil of the mountain de- 
clivities, where the moisture is constant, is rarely in any part red, as 
the iron from decomposition seldom appears in its condition of dry red 
oxyd, but is either a hydrate, or is united with carbonic acid, and cer- 
tain organic acids, crenic, apocrenic, and others. — 
GEOLOGICAL STRUCTURE OF KAUAI. 
Besides the mountains which compose the mass of the island of 
Kauai, we have mentioned the occurrence of an independent ridge 
along the eastern shores. ‘There is also a region of small craters, as 
perfect as many of the lateral cones of Hawaii, situated near Koloa. 
In addition, there are coral formations in progress on the shores, and 
others that have undergone a change of level. ‘These different points 
may be separately considered, as follows :—I., the structure of the in- 
terior elevations, and the shore plains subordinate; II., the eastern 
shore ridge; III., the lateral craters of Koloa; IV., the coral forma- 
tions; and after this may follow general deductions with regard to 
the origin of the island. 
