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the surface of the country. They are for the most part 

 inclined at considerable angles, but show little disturbance, 

 and exhibit alternations of absorbent quartzites and impervious 

 slaty beds through vast thicknesses. So that altogether we 

 have in them the most favourable stratigraphical conditions for 

 the existence of springs, which occur wherever the gullies which 

 ravine the sides of our ranges intersect the line of junction of 

 a superior pervious bed and an inferior impervious one. Be- 

 cause of the prevailing easterly dip of the rocks, the larger 

 number of springs are located on the east slopes of the hills. 

 By a knowledge of the elements of hydrostatics, and by correct 

 observations on the secjuence and other phenomena of the rocks, 

 it becomes easy to predict with some degree of certainty the 

 depth at which water may be obtained from this source. To 

 obtain water in these rocks it is obvious that the search must 

 be conducted in those strata which rise to the surface to form a 

 collecting ground. "Where these older rocks are thrown into 

 synclinal folds, as in the AVilpena Pound, we have one of the 

 important conditions favourable for obtaining water on the 

 artesian principle. A sine qua non which must always be borne 

 in mind in dealing with this question as applicable to South 

 Australia is that water must be present in the rocks. 

 If no rain falls on the out-cropping surfaces, or if from their 

 highly impervious character no water can be conducted by them, 

 then an artesian boring must perforce be unsuccessful. 



The Chief Water-bearing Strata in ivhich the Suj^i^I^ is Not of 

 Local Origin. — Since 1878, when Mr. Eawlinson propounded 

 his view before this Society that the disappearance of the vast 

 bodies of river water, which collect on the inner watershed of 

 the bordering coast ranges of Australia, is to be accounted for 

 by their absorption into the porous beds of the Tertiaries 

 occupying the interior basin of the continent, I have taken 

 every opportunity to examine into the question raised by him. 

 "With respect to " the Barcoo, Cooper's Creek, and other large 

 streams which empty themselves at nowhere in particular in the 

 interior," there seems to be much reason for upholding the 

 generally received opinion that the disappearance of their flood- 

 waters is attributable to evaporation. Most certainly this 

 cannot explain the vast reduction of volume which the E-iver 

 Murray experiences in its onward course to the sea, and the 

 facts which I have collected point most conclusively to the 

 presence of a large body of underground freshwater at or about 

 the level of the river in the whole country extending eastward 

 from the Lower Murray River up to the Victorian frontier. 

 That the water in the wells in this area is not so fresh as that 

 of the river cannot be denied, but it is too pure to be accounted 

 for by soakage from the surface ; and there is further no 



