CHAPTER IV 



AUSTRALIA 



Lying across the tropic of Capricorn, the vast Austra- 

 lian mass of land is primarily divided into an infra- 

 tropical and an extra- tropical portion ; but this 

 distinction is mostly felt along the margins of the 

 continent, and the desert centre varies little from south 

 to north. On nearly all sides the margins are higher 

 than the interior, and, forming barriers which lie athwart 

 the paths of the winds rushing in from the surrounding 

 seas, rob them of most of their moisture, leaving the 

 centre almost rainless. Broadly speaking, Australia 

 may be described as a desert with a fringe of vegetation ; 

 but whereas in the northern half the rainfall, which is 

 of the monsoon type occurs in summer, the extra-tropical 

 portion depends for its water mainly on the westerly 

 storms of the austral seas which, in winter, reach the 

 two southern points of the continent. Only the middle 

 of the east coast enjoys the benefit of the south-eastern 

 trade winds. Australia does not reach latitudes high 

 enough to experience any severe cold. The snows which 

 occasionally cover the loftier parts of the southern high- 

 lands are never of long duration. 



Northern Point of the Tableland. The northernmost 

 point of the continent is little known as yet. Along 

 the shores of the warm seas it enjoys a wet period of 

 five months' duration and a yearly average precipitation 

 of 65 inches. A few tracts of luxuriant tropical forests 

 are known, but it is uncertain if they are merely of 



