Meeson. — The Rainfall of Neiu Zealand. 563 



For this comparison, as %Yill be seen, places are chosen as 

 nearly as possible on the same parallel. There is thus a 

 marked diminution of rainfall on the eastern side of the 

 Islands, and tliis diminution is greatest where the mountains 

 are highest. "The excess of precipitation on the [west?] 

 coast is clearly illustrated," says Sir J. Hector, " by the descent 

 of the glaciers on the opposite sides of the range : those on 

 the west slope descend to a line where the mean annual tem- 

 perature is 50^, while on the eastern slope they descend only 

 to the mean annual temperatm-e of 37^. The winter snow- 

 line on the Southern Alps is 3,000ft. on the east side, while 

 that on the western rises to 3,700£t." 



The small amount of rain in Marlborough, Canterbury, 

 Otago, and Hawke's Bay — i.e., generally on the east side of 

 our Islands — is paralleled in many other parts of the world 

 similarly situated as regards the prevaiHng winds and neigh- 

 bouring mountain-ranges. In Patagonia, east of the Andes ; 

 in Sweden, east of the Dovrefeld Mountains ; in British North 

 America, east of the Rockies : in eastern Europe as compared 

 with western (Dr. Kriimmel : Gesellschaft fiir Erdkunde, 1878) ; 

 and, as already observed, in the eastern counties of Great 

 Britain as compared with the western, we see precisely similar 

 phenomena. Also in the Atacania Desert of Peru, for in that 

 latitude the prevailing \\-inds are east, and so the precipitation 

 occurs on the Brazilian and Paraguayan slopes of the Andes, 

 while the western slopes in North Chili and Peru are di"y. 

 "What western rain we do get in Canterbury comes mostly 

 from the south-west, because the South Island lies from south- 

 west to north-east, and its main range runs in the same general 

 direction ; therefore the western rains can only, as a rnle,reuch 

 us by coming round the south end of the Island, and, as the 

 equinoctial winds gyrate from north-west by west to south- 

 west, we thus sometimes get the benefit of the rains carried 

 by the fag-end of western storms. The ordinary south-west, 

 however, is more like a polar than an equinoctial wind, being 

 accompanied by high barometer and low thermometer, and 

 winds from higher latitudes cannot, as a rule, bring heav^' 

 annual rainfall because, coming as cold winds, and there- 

 fore carrying little moisture to wanner regions, their tem- 

 perature rises, and so their capacity for holding moisture 

 increases. 



The excessive fall at the Bealey is probably, as already 

 observed, owing to its altitude, and the contiguity of a pass 

 (Arthur's, 3,038ft. high) sufficiently low to let much of the 

 north-west weather cross over the Southern Alps. 



It has been observed that in England a range of hills l,o00ft. 

 high running athwart the south-west or rainy wind will have 

 the largest precipitation on the eastward or leeward side ; 



