PH VS tCAL GE0GKAP11V . 
71 
running east by north and west by south, and intersecting the 
longitudinal fissure near Mount Murchison. A few miles to the 
north of Lake lloto-iti the eastern chain is broken through, and 
a pass of little elevation leads into the valley of the ~W airau, the 
course of which from this point can be traced almost to the sea. 
The western chain is in like manner broken through by the Buller 
river, whose course can also be followed by the eye to its mouth 
on the West Coast. 
The longitudinal fissure above mentioned has an average alti¬ 
tude of 2,000 to 2,500 feet above the level of the sea, and exhibits 
a hilly plateau, on which, near the eastern chain, several regular 
conical and dome-shaped mountains rise to an altitude of 3,500 
to 4,000 feet above the sea level. This plateau is moreover inter¬ 
sected by streams which run in deep gullies, and, with the excep¬ 
tion of some grassy terraces and open patches on the banks of 
these rivers, is densely covered with forest. The openings through 
which the Wairau and the Buller flow are merely the valleys of 
rivers, narrowing where they receive no tributaries, to mere gorges, 
and breaking in a transverse direction through high mountain 
ranges. 
As I began my exploration at Lake Boto-iti, I shall adopt it as 
my starting point in describing the physical character of the eastern 
lateral chain, at the same time connecting with it the description 
of the sources of the Buller and its tributaries. This eastern chain 
attains its greatest elevation (rising abruptly on the eastern side 
of the longitudinal fissure) in the Spencer mountains, whose peaks 
attain an altitude of at least 10,000 feet, and are covered with 
perpetual snow. Three of these peaks are very conspicuous ; the 
central one, named by me Mount Franklin, lies in latitude 42 deg. 
1 min. South, and longitude 172 deg. 37 min. East. From this, as 
a centre, the various ranges branch ofi to the northward and south¬ 
ward. I found, upon a careful examination, that the main ranges 
below the above-mentioned peaks are 8,000 leet, and the ranges 
which branch from them (5,500 feet high. These ranges are 
covered, to an altitude of 4,000 to 4,500 feet, with dense forest, 
above which an Alpine vegetation begins, and the summits form 
meadows of short smooth snow-grass, the whole leminding me 
greatly of the wild Alpine scenery of Switzerland.. s 
The most easterly of the branching ranges which came within 
the limit of my researches, was the St. Arnaud range, so named 
by Mr. Travers when he passed through the. gorge of the W airau 
in 1854 and lies on the western side of that river, forming, until it 
reaches the Top-house, the watershed between the east and west 
coasts. This chain, beginning on the southern side of the old 
pass from Nelson to the Wairau, soon rises to an altitude of 
0 500 feet its western base forming the eastern shore of the , 
beautiful Alpine Lake Eoto-iti. On the south-western side ot 
this splendid water basin, a second range begins, forming, above 
