74 KEPOKT — 1891. 



cross our Islands are probably generated. Hence the fore- 

 casts of Mr. Wragge, the Government Meteorologist at Bris- 

 bane, have a special value for New Zealand. On our western 

 coasts these storms meet with a great impediment to their 

 further progress south-eastwards in the masses of the Southern 

 Alps, over which many of them fail to pass, and either spend 

 themselves in dashing against the mountains or, with that 

 affection for skirting mountain-chains and coast-lines for which 

 they are remarkable all over the world, go off to the south 

 and round the Island at Foveaux Strait. To what extent 

 the Southern Alps modify the character of the north-west 

 storm before it reaches the Province of Canterbury, and how 

 this modification is brought about, I have considered in 

 another paper. 



Dove divides the storms of the Temperate Zones into — 



1. Extensions of Torrid Zone storms ; 



2. Storms arising at the external edge of the Torrid Zone, 



from the meeting of the Eeturn Trades with surface 

 winds opposed to them ; 



3. Storms produced by the mutual lateral interference of 



polar and equatorial currents flowing in opposite 



directions. 

 Our north-west storms seem to belong to the classes 2 

 and 3, though occasionally we may have one which is simply 

 a prolongation of a Torrid Zone atmospherical disturbance. 

 Some of our storms are undoubtedly identical with those that 

 dash up against the south side of the Australian anticyclonic 

 area- — traceable sometimes so far to the north-west as 

 Mauritius — the region, be it remembered, of Indian Ocean 

 hurricanes — but sometimes apparently coming from points 

 much farther to the south, bringing bad weather to the ex- 

 treme southerly districts of Victoria and to Tasmania, and 

 then crossing over from Bass Straits to New Zealand in 

 twenty-four hours. Such storms, after leaving Australia, 

 always seem to make for the south-east. Even when at first, 

 after leaving Bass Straits, they hug the east coasts of New 

 South Wales and apparently make for the north-east, they 

 turn at right angles to their course before they go very far, 

 and mei'ge into the Eeturn Trades. 



It does not follow that, because much of our north-west 

 weather is cyclonic in character, all of it necessarily is so. 

 Some of it may be produced by broad gales which are defined 

 by Dove as strong winds, blowing in with tolerable steadiness 

 from one point of the compass. The phenomena, as far as 

 we in Canterbury are concerned, would be nearly the same 

 whether this were so or not, for the gyration of the wind on 

 one side of a cyclone is the same as that produced by the 

 ordinary currents of the atmosphere, and the effect of the 



