26 THE CLIMATE OF AUSTRALASIA 



diagrammatic simplicity. Between the latitudes 

 of 40 and 50 is the great belt of the variable 

 westerly winds, which blow uninterruptedly 

 round the world. To the north of the Southern 

 Ocean are the north-easterly trades, which are 

 developed unbroken only on the ocean. Along 

 the coasts the winds blow off shore during 

 winter, and inward during summer ; and in the 

 northern part of the Indian Ocean there are the 

 biennial monsoons, of which the winds are 

 reversed in direction at spring and autumn, and 

 indirectly affect the movements in the Southern 

 Ocean. 



These winds cause a steady drift of water 

 from west to east, along the Southern Ocean 

 and across the South Pacific. t Where corners 

 of land project southward into this great drift, 

 the water is heaped up against them ; and this 

 accumulation of water is relieved by currents 

 flowing outward in various directions. Most of 

 this water, as will be shewn later, escapes north- 

 ward as true ocean currents flowing along the 

 western coasts of Australia, South Africa and 

 South America, while some of that heaped up 

 against Westralia escapes as a current along the 

 southern coasts of Australia. 



tThe rate of this drift is shewn by the passage of bottles, casks of 

 blubber and other flotsam and jetsam, to be on an average 10 miles a 

 day. See Findley, Indian Ocean Directory, 1871, pp. 85-86. More 

 precise and recent data have been given by Russell's current-papers, of 

 which three crossed from Cape Horn to Australia, by voyages of 9517, 

 8617 and 9585 miles, at rates of 9, 7.9 and 10.3 miles respectively. 

 H. C. Russell, "Current Papers, No. 2." Proc. Royal Soc. N.S. 

 Wales, vol. xxx, (1897), pp. 202-210, pi. xii. 



