288 T. W. E. DAVID. 



and Northern Hemispheres. These facts show that the impression 

 which has become somewhat popular, that Australia has as exten- 

 sive a supply of fresh water underground as other countries in 

 similar latitudes have above ground must be incorrect. These 

 underground supplies are entirely dependent on the rainfall, and 

 the average amount of water which might be annually drawn from 

 this source could not, therefore, exceed the average quantity of 

 rainfall which annually percolates into the water-bearing beds 

 below ground. In spite of the scantiness of its rainfall Central 

 Australia is not a desert, but may be described as a succession of 

 plains and tablelands with isolated flat topped hills, mostly grassed 

 or covered with shrubby salsolaceous plants or spinifex, but partly 

 consisting of stony downs and ridges of rolling sand almost bare 

 of vegetation excepting in the wet seasons. The two last men- 

 tioned varieties of country form however only a very small pro- 

 portion of the whole. It may be possible in the future to so- 

 improve certain localities in this central area by means of storage 

 of the surface water and use of the underground supplies, as to 

 make them habitable and useful not only for pastoral but also to 

 a limited extent for agricultural purposes, but anything like a 

 wholesale reclamation of it and rendering it suitable for agricul- 

 ture by either of the methods quoted above appears at present 

 impracticable, as about twenty inches of rain are needed annually 

 for irrigation, whereas the rainfall over a large area of Central 

 Australia, as already stated, is only from five to ten inches. 



Artesian Water in other Countries. — Before proceeding 

 to describe the artesian water supply of Australia and especially 

 of New South Wales, the Author wishes to draw attention very 

 briefly to a few facts about the artesian water supplies of other 

 countries, which may have a bearing upon that of our own. In the 

 Anglo-Parisian Artesian Basin the supply of the artesian water 

 has been proved to be directly dependent upon rainfall and to be 

 liable to diminution if the supplies drawn from the basin are in 

 excess of what the water-bearing strata receive by percolation. 

 The great number of wells in the London Basin has had the effect 



