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beheld for the first time the regular cone of the Tongariro volcanoe 
rising at an angle of 30°, and bearing the special name of Nga- 
urulioe; and I plainly saw the curly clouds of white steam whirling 
up from the crater. The natives assert, that they have never seen 
black smoke; that, however, the clouds of steam are often much 
larger, especially in winter-time. The Tongariro was clear of snow, 
while of the Ruapahu nothing was seen but its snow-clad summit. 
In perfectly clear weather Mount Taranaki , also , is said to be 
visible from here. We were, as yet, about 50 miles distant from 
those volcanic cones, and in the same direction, through sombre 
wood-grown mountains, lay our onward route. 
But before straying off* into that region of forests and swamps, 
we must add a few remarks concerning the Mokau river. 
The Mokau is, next to the Waikato , the most important river 
of the West Coast, emptying into the sea without forming an 
estuary. Its mouth is half-way between the Kawliia Harbour and 
New Plymouth. Its size is equal to the W aipa. Both rivers have 
the same length, their course being about 80 English miles; and 
both have their source upon the Rangitoto range at an elevation 
of about 2600 feet. Thence the Waipa flows in a northerly, the 
Mokau in a south-westerly direction. The upper Mokau valley with 
its numerous smaller side-valleys spreads between ranges of wood- 
clad hills into wide plains, partly marshy, partly covered with 
grass, and very fertile. 
Section at the upper Mokau River. wairere jaus. 
a. Clay-slate, b. Tertiary clay. c. Tertiary limestone, d. Trachytic tuff with pumicestone. 
The bottom of the valley is composed of tertiary clays , im- 
pervious to water, above which at the slope of the hills tabular 
limestones protrude , the heights themselves being formed of tra- 
chyte-tuff. At the Wairere falls below the tertiary clays slates of 
the same description as those at the Taupiri form the masses of 
rock, over which the river falls. Below the falls the valley becomes 
