Meeson.— T/?c Bainfall of New Zealand. 667 



deluges of rain on the west coast, and then sheering ofi 

 eventually to the south-east. Even the south-west storms 

 that pass through Bass's Straits and skirt the coasts of New 

 South Wales are considered by Mr. Todd, of South Australia, 

 to turn when they reach the Tropic and make off to New 

 Zealand in the south-east, communicating their motion to or 

 being taken up, I presume, by the return trades. But pro- 

 bably very many of our north-west storms have an indepen- 

 dent origin near the coast of Queensland. 



We know that cyclones are always formed and travel along 

 by the sides of an anticyclone. Now, anticyclones are not 

 erratic, rapidly-moving twenty-miles-an-hour creatures like 

 cyclones, but decidedly sluggish, some of them hanging for 

 months indiiferently over sea or land almost motionless. 

 Certain latitudes are particularly anticyclonic. In the 

 Southern Hemisphere such a one in tlie winter season ex- 

 tends north-west of New Zealand, from about 20° to 35° south 

 latitude, brooding over the greater part of Australia and a belt 

 of contiguous ocean. Just north of New Zealand this belt 

 becomes thinner, and, as a consequence, the cyclones formed 

 south of Australia and Tasmania come to the North Island 

 from the south-west, and bring the copious winter rains., which 

 are a marked feature in that portion of the colony. Much of 

 this is also seen in the South Island ; but in Wangauui, Tara- 

 naki, and x\uckland Dr. Hann has calculated the frequency 

 of south-west in winter as 26 per cent, (greatest of all) ; in 

 autumn, 25 per cent, (also greatest) ; in spring, 21 per cent, 

 (second) ; and in summer, 18 per cent, (second). 



The anticyclone which hugs the Tropic of Capricorn more 

 or less right round the earth during the winter season, and is 

 "especially marked, as we should expect, over the central mass 

 of Australia, thins out and changes its character completely 

 as summer approaches over the three great masses of land in 

 the Southern Hemisphere. The mean pressure over Australia 

 falls from 30-2in. in July to 29-8in. in January. The anti- 

 cyclone north of New^ Zealand and east of Australia contracts 

 to a comparatively small area, and only affects or hangs over 

 the extreme northern tip of our colony. It leaves a continu- 

 ous belt of low pressure from the southern seas well into the 

 tropics. Now is the season — spring and summer — when the 

 north-west cyclones blow most persistently, their direction 

 being given by the sides of the great anticyclone. These 

 cyclones, born as would appear mostly between the anti- 

 cyclone and the coast of Queensland, in the neighbourhood of 

 the Tropic of Capricorn, strike New Zealand from north to 

 south, but heaviest in the middle of the South Island ; and 

 are drawn, if they do not previously exhaust themselves, by 

 the coast-line and the mountain-range, through and over which 



