66 THE SUBMARINE LEAKAGE, ETC. 



periods of rainfall and flood, and that, moreover, the waters of 

 this reservoir never reach sea level, even during times of 

 prolonged drought, as evidenced by the constant and undiminished 

 overflow of our artesian wells. Were cause and eftect so easily 

 explained, we should have before us one of the most remarkable 

 examples of natural phenomenon with which students of the 

 century have had to deal — one of the most interesting dynamical 

 problems of the age. It would, indeed, be a remarkable natural 

 process by which an artesian reservoir would never fall to the 

 level of the sea, even during long periods of intense dryness, 

 when there could be no local supply with which to replenish an 

 ever decreasing store." The conception of such a condition of 

 equilibrium is entirely Mr. Thomson's own. It is not difficult 

 to understand that when more fluid is poured into a receptacle 

 than it will hold it runs over, and there is nothing unnatural in 

 the fact that after a heavy wet season, when the absorbent strata 

 have been filled to their utmost capacity, the rivers run longer 

 than usual over the Western interior. Fluctuations m the 

 artesian wells will be looked for by all who admit that the first 

 cause of the supply is the periodical rainfall. To show that I 

 regarded such fluctuation as inevitable, I may quote from the 

 paper read in -January, 1895, at the meeting of the Australasian 

 Association :-—" The loss of water by the Darling River, and 

 probably a similar loss of w^ater by the Western Queensland 

 rivers, proves that the water-bearing strata must leak into the 

 sea, and hence that unless the strata be periodically replenished 

 the sea level would ultimately become the level to which the 

 water would rise. A drought sufficiently long to bring about 

 this result would, no doubt, have, for a prior result the destruc- 

 tion of the greater part of the land fauna of this part of 

 Australia, including the genus homo. Far short of this, how- 

 ever, we can conceive of the temporary diminution or cessation 

 of the flow of some at least, of our artesian wells." 



Since this was written fluctuations have been observed in the 

 pressure and output of a few of the artesian wells. Some have 

 even ceased, and after a time have recommenced to flow. The 

 only possible intermittent source of artesian water is the rainfall ; 

 but a series of observations on the fluctuations of pressm-e and 

 output in the wells, only initiated by the Government within the 



