"286 T. W. E. DAVID. 



is regarded as controlling the waters, both in heaven and on earth ; hence 

 in the later mythology, his name is synonymous with ' the waters/ ' the 

 ocean/ For, just as the Vedic Varuna covers and encompasses the ter- 

 restrial sphere, so the Homeric mighty river Okeanos surrounds the whole 

 of the terrestrial lands. With all this compare the functions of Tang- 

 ;aloa, who, in some localities in Polynesia, is also lord of the sea. 



In the Greek mythology, Ouranos is the grandfather of Zeus, and 

 Varuna is thus more venerable and ancient than Dyaus, the lower sky. 



ARTESIAN WATER IN NEW SOUTH WALES. 



(Preliminary Notes.) 



By Prof. T. W. Edgeworth David, b.a., f.g.s. 



[Read before the Royal Society of N.S. Wales, November 4, 1891.~] 



Introduction. — The waterless character of the greater portion of 

 the vast interior of Australia, as well as the absence of any great 

 inland ranges commensurate with its immense superficial area is 

 a subject, which has been much dwelt upon in the narratives of 

 Australian explorers. Obviously the former want is chiefly a 

 •consequence of the latter. Three conditions are usually necessary 

 for maintaining a good water supply, viz., (1) abundant evapora- 

 tion in the surrounding ocean ; (2) carriage of the vapour-laden 

 air inland by suitable winds ; (3) condensation of the vapour by 

 elevated areas of cold ground. Of these conditions the first is 

 tolerably well fulfilled in Australia, but the second only partially 

 •so, and the third not at all, as far as relates to Central Australia. 

 Exact observations have not yet been made over a sufficiently 

 wide area to admit of an estimate being formed of the average 

 rate of evaporation taking place in the ocean surrounding Aus- 

 tralia, but probably it cannot be less than about a yard a year. 

 Consequently, if the whole of the water- vapour withdrawn by 



