ARTESIAN WATER IN THE STATE OF QUEENSLAND, AUSTRALIA. 191 



vital importance. The progress of boring for 17 years, 

 culminating in the present large output, has revealed no 

 symptoms of a failure of the supply. I have no doubt that 

 so long as rain falls on the intake beds, water will flow 

 underground; but to ivhat extent? It is on this question that 

 I have recently been exercising my arithmetic. 



It may ba postulated, on geological grounds, that Queens- 

 land derives the whole of its underground supply from 

 Queensland alone, and it may be assumed that the wliole of 

 it comes from the eastern outcrop of the basal strata of the 

 Cretaceous formation. The assumption is based, first, on the 

 comparatively low altitude of the western margin ; and 

 secondly, on ^Ir. Cameron's observation that in the west the 

 basal strata do not come to the surface, but abut against the 

 older rocks, and are overlapped by the argillaceous rocks, 

 which succeed them in the Cretaceous series. Calculating 

 the area between tJie line where the " Blythesdale Braystone " 

 dips westward beneath the argillaceous beds and a line 

 representing the eastniost extension of any rock which could 

 possibly drain into the " Braystone," I have arrived at an 

 area of 55,000 square miles as the absolute maximum of 

 possible intake. The mean annual rainfall over this area 

 being taken as 27 inches, we get (allowing nothing for 

 evaporation) a total possible absorption of 127,776,000,000 

 cubic yards of water .per annum. Of this amount we are, 

 even now, recovering by means of artesian wells the 

 -j-Jr^rd part. It may be said that in i||- we have still a large 

 margin to be drawn upon. But there is a limit, and more- 

 over it is unimaginable that by any conceivable multiplication 

 of bores we could draw the Avhole supply to the surface, 

 since an unascertainable portion of it must always escape to 

 the sea. As for irrigating the whole artesian area, the entire 

 127,77H,000,00O cubic yards of water (if we could raise it, 

 which is impossible) would only be equal to an annual rain- 

 fall of 5^ inches, which every pastoralist knows to be 

 insufficient for the purpose. 



Discussion. 

 Mr. W. Gibbons Cox. — I have listened with particular interest 

 to -what Dr. Jack has said on the question of ai-tesian water ia 

 Queensland, than whom there is no man better able to treat the 



