TRANSACTIONS OF SECTION A. 73 



observing stations therein established, the waste of waters 

 round about, and the small number of ships navigating it and 

 bringing in their weather reports, must make it extremely dif- 

 ficult to draw isobars of a thoroughly reliable nature in our 

 colony. 



Now, the cyclones, formed at various points in the north- 

 west gale like eddies in a mighty stream, sometimes are so 

 large as to absorb the whole current and stretch over vast 

 areas. But, just as Loomis shows (Nature, 11th July, 1878) 

 that American storms in the Northei'n Hemisphere originate 

 in a district near the Eocky Mountains, two-thirds of them 

 north of lat. 36°, and move on to the east through tlie general 

 circulation of air in that direction, and as Dove considers that 

 many of the storms of the Temperate Zones are tropical ones 

 diverted from their path at or about lat. 30° north and south, 

 and as the English meteorologists recognise certain fairly- 

 definite storm-tracks across the Atlantic, ramifying frequently 

 from certain definite spots and skirting the North Atlantic 

 anticyclone w^hile journeying usually in a north-east direction, 

 so it perhaps should be possible for us to arrive at some con- 

 clusion as to the starting-points and general paths of our New 

 Zealand cyclones, though the means that we have of doing so, 

 for reasons already indicated, are exceedingly limited. Even 

 in Europe, with its army of observers, its delicate appliances, 

 and numerous stations, it is very difficult to trace the connec- 

 tion, by continuously advancing minima, between tropical 

 cyclones and their prolongations into the Temperate Zone. 

 Here, therefore, the work must be considerably harder. 



In the North Atlantic there is a great anticyclone stretch- 

 ing over the intertropical area and the more southern part of 

 the North Temperate Zone. x\long the northern edge of this 

 is the birthplace of the innumerable cyclones of every size and 

 intensity which incessantly move to some point east or north- 

 east along the shores of and crossing the British Isles — to be 

 worn out in the polar regions north of the Scandinavian 

 peninsula. Similarly, in the Southern Hemisphere and in 

 corresponding latitudes there is formed in winter a more or 

 less continuous anticyclone, producing the fine weather of 

 Australia at that season, interrupted, however, occasionally 

 by bad spells, squalls, and thunderstorms, and thoroughly 

 broken in the summer season, when the vast mass of the 

 Australian Continent, with its atmospherical rarefaction in 

 the Torrid Zone (when the sun is south of the Equator), 

 must exercise large attractive action on all sides. This anti- 

 cyclone at the latter season contracts very much, and leaves 

 a breadth of low pressure over the Pacific between New 

 Zealand and Queensland, in the vicinity of which a consider- 

 able number of the north-west storms which dash against or 



