384 Transactions. — Geology. 
height of the snow line is the position of the line of mean annual tempera- 
ture of 32° F., its absolute height at any particular point depends on many 
local causes, as well as on the general one of the decrease in temperature 
in ascending from the sea level. We are not, however, without data for ascer- 
taining the average height of the snow line with sufficient accuracy for our 
present purpose. Pembroke Peak, near Milford Sound, is 6,710 feet high, 
and not only is it always covered with snow, but a small glacier comes 
down from it towards Harrison Cove. The quantity of snow on this 
mountain is, no doubt, owing to local causes, and it would be incorrect to 
take the snow line in Otago at so low a level as this would give. On the 
other hand 8,000 feet would be too high an estimate, for there is no mountain 
in Otago, whatever be its aspect or steepness, that attains to this altitude 
without having snow upon it in places all the year round, and I think that 
7,000 feet might be taken as the average height of the snow line in Otago. 
In the North Island we have in Ruapehu an excellent standard for esti- 
mating the height of the snow line there. This mountain is 9,195 feethigh, 
and its summit is always snow-clad, consequently we cannot take the height 
of the snow line in the centre of the North Island at more than 9,000 feet. 
If now, taking these two as fixed points, we calculate the altitude of the 
snow line at those places, where it is necessary that we should kmow it in 
order to follow out the argument, we find that at Mount Franklin, in the 
Nelson province, it would be 8,000 feet; at Wellington 8,300 feet, and at 
Auckland, 10,000 feet, which is rather higher than the snow line im corre- 
sponding latitudes in the Andes. 
The next point is to try to estimate the amount of elevation that would 
be necessary to bring back the glaciers to their former size. Mr. A. D. 
Dobson, after a careful examination of the Nelson district, says* :—‘“‘ During 
the period the line of perpetual snow must have been very much lower 
down the mountains than it is at present. I should be inclined to think 
that it was about on a level, which is now only about 4,500 feet above 
the sea.” This, if we take 8,000 feet as the present height of the snow 
line, would require an elevation of 8,500 feet to bring about. In my former 
paper on this subject I said that ‘‘ an elevation of 2,000 to 8,000 feet would 
be sufficient to account for all the phenomena;’’} and Mr. W. Travers says in 
his paper that it would require an elevation of not less than 4,000 to 5,000 
feet.{ But Mr. Travers estimates the height of the snow line in Nelson at 
9,000 feet ; and, if we reduce this to my estimate of 8,000 feet, it will be 
necessary to deduct 1,000 feet from the elevation he requires. This will 
* « Trans. N.Z. Inst.,” Vol. IV., page 339. 
+ “Trans. N.Z. Inst.,” Vol. V., page 385. 
} “Trans. N.Z. Inst.,” Vol. VI., page 299. 
RO ge we 
