104 E. F. PITTMAN. 



was local, and could be explained by reference to the action 

 of geysers: that Artesian flow is, in most cases, due to the 

 earth's internal heat, the water being given off from cool- 

 ing igneous rocks: that the Artesian bore through the 

 upper impermeable strata relieves the pressure on the 

 heated water and that its expansive force aud imprisoned 

 gases compel it to rise to the surface. 



In a paper read before the Royal Society of New South 

 Wales in 1903, 1 Mr. Knibbs combated the views of Professor 

 Gregory and showed that 



"Hydrostatic head never disappears by friction": that "the 

 rate of hydrostatic head depends upon the rate of flow, and is very 

 small when the velocity is small," and that "the earth's internal 

 heat is not the chief cause of the ascent of the water, as proved 

 by the fact that the pressure is never relieved so far as to allow 

 of ebullition."' 



In 190G Professor Gregory published a very interesting 

 book, 2 in which he states at considerable length his reasons 

 for disagreeing with the conclusions of Australian geologists 

 in regard to the great Artesian basin. He asserts that the 

 water of our flowing wells is plutonic and not meteoric — 

 that it has, in fact never previously appeared at the sur- 

 face, and that its rise is due to the influence of temperature 

 and rock-pressure. 



It is not proposed to discuss here at any length the 

 general question as to the probability of very large bodies 

 of underground water being of plutonic origin, i.e., of their 

 having been given off by cooling deep-seated igneous rocks, 

 Suffice it to say that the view adopted by most American 

 geologists, viz. that "All underground waters have their 



1 The Hydraulic aspect of the Artesian problem, by G. H. Knibbs, 

 f.r.a.s., this Journal, Vol. xxxvu., 1903, pp. xxiv. - xliv. 



8 The Dead Heart of Australia by J. W. Gregory, f.r.s., d. sc, London, 

 John Murray, 1906. 



