562 TrauHactions.— Miner Uaiicoii,s. 



Among the circumstances which help to determine the 

 rainfall in any place, none is more important than the 

 elevation. Mainly because at a higher elevation the air, being 

 colder, will not carry so much moisture as the warmer air 

 lower down — rain is heavier up the side of a mountain than at 

 its base, and gradually increases up to a certain height at the 

 rate of 3 or 4 per cent, for each 100ft. of altitude. Yet, having 

 no statistics of rainfall in the mountains of New Zealand— 

 except at the Bealey, 2,155ft. high (Hochstetter), where one of 

 our heaviest falls is recorded — we have for the most part to 

 assume that the number of inches falling in the hills and 

 mountains will be the same as are recorded at the nearest 

 places, on the seashore, where records are kept. This must 

 be productive of great error, particularly as to the rainfall on 

 the west coast of the South Island. The observatory at Ho- 

 kitika is only 12ft. above the sea, but the rainfall 2,000ft. up 

 the western side of the Alps must be enormously heavier than 

 that at Hokitika, though even the latter is regarded by Loomis 

 as tropical ; yet we have to draw our map as though the rain- 

 fall all along the West Coast was the same as that at 

 Hokitika. The heaviest rainfalls in the world, such as that of 

 Cherra Poonjee, which is situated 4,000ft. high on the Khasia 

 Hills — 200 miles from Chittagong, north-east of Calcutta — 

 610in. in six months, and that of Mahabeleshwar in the West 

 Ghauts, 300in. in twelvemonths, occur at places where warm 

 humid winds strike against abrupt heights, corresponding in 

 position to the w^estern slopes of our Southern Alps at the ele- 

 vation of 2,000ft. or 3,000ft. Therefore in these latter places 

 it is quite likely that the rainfall is very much greater even 

 than that recorded on the western sea-coast. But what it 

 actually is must for some time to come be a matter of pure 

 conjecture, though the time will arrive when there will be in 

 New Zealand observatories corresponding in position to those 

 on Ben Nevis and, perhaps, Pike's Peak. Of course, be- 

 yond a certain height snow falls, instead of rain, and there is 

 no doubt, as has often been remarked, that the glaciers on 

 the western side of our Alps descend so low as compared with 

 those in many other parts of the world, and that our glaciers 

 altogether are so extensive, simply in consequence of the 

 excessive deposit of snow on the heights above them. A good 

 illustration of the fact that elevation materially affects the 

 amount of rainfall is seen in the case of the Bealey — over 

 ■2,000ft. high — where the number of inches recorded is greater 

 than elsewhere in the colony ; and this large precipitation— 

 though there are other circumstances which help to account 

 for it — is probably, in some measure, owing to exceptional 

 altitude. Mainly from an appreciation of these arguments, 

 Scott, in his "Elementary Meteorology," refrains from at- 



