Country and Climate 5 



first, of a coastal strip, backed by a mountain 

 range, beyond which a plateau gradually declines 

 to the low-lying central plains. The western di- 

 vision of Australia, a large part of which is still 

 practically unknown country, may also be de- 

 scribed as a low plateau, broken here and there by 

 well-marked mountain ranges of no great height. 



Considerable prominence has been given to the 

 position and character of the Dividing Range, be- 

 cause of its influence upon the climate of Australia. 

 The chief rain-bearing winds, blowing from the 

 eastward and meeting these highlands, provide 

 trie coastal districts with a plentiful rainfall. Be- 

 yond them the rainfall is scanty and irregular, 

 growing less in proportion to the distance from 

 the eastern coast. Hence the interior of Australia 

 suffers from dryness. The average rainfall of 

 more than half the continent is less than twenty 

 inches a year, and for the greater part of this area 

 an annual rainfall of ten inches and under is cus- 

 tomary in ordinary seasons. As the evaporation 

 caused by the sun's heat is very great in Central 

 Australia, it is obvious that the normal condition 

 of the soil there must be one of extreme aridity. 



The Dividing Range is naturally the main 

 watershed of the continent. The rivers flowing 

 to the eastern coast are necessarily short, but some 

 of them are of considerable volume and depth. 

 Of those flowing westward, the most important is 

 the Murray, which enters the sea through a large 

 shallow lake in South Australia. This river, with 



