236 REPOET— 1891. 



the bed-rock or reef of the miner. These channels are levelled 

 up and masked by the porous and more or less saturated sedi- 

 mentary beds which compose the undulating surface of the 

 plains. In these leads or channels more copious supplies must 

 have collected, and these will drain away in the direction in 

 which the country falls, which is towards the south-west. 



These underground watercourses, or, as the miners would 

 describe them, these wet leads, will run out into the plains for 

 greater distances than a hundred miles. Indeed, when we 

 remember that the streams are undiminished by evaporation 

 or the demands of vegetation, and that they have been the 

 recipients of all the leakage of the hills throughout all the 

 ages that have passed since the sea retired, it appears to me 

 that the deeper leads must be saturated with water right 

 from the mountain-foot to the Australian Bight. For, however 

 slow the circulation of the system may be, as the water has 

 never ceased to run in at the upper ends of the region, and as 

 it does not rise to the surface as springs, it must run out at 

 the lower end into the sea, escaping in the form of submarine 

 springs. As a matter of fact, along the south coast of Australia 

 between Warrnambool and the Murray mouth the sea literally 

 bubbles up with fresh water which has leaked up through the 

 sea-sands. These subterranean streams will be worth tracing, 

 and worth tapping, across the wide dry plains. Mr. McKinney's 

 paper on the rivers of New South Wales, which, was con- 

 tributed to this section in 1888, bears directly on this subject, 

 and is well worthy of consultation in this connection. 



I may remind you that the French have ascertained that 

 the terrible Desert of Sahara is underlain by saturated sands, 

 and by means of artesian wells they are creating, artificially, 

 oases in the limigry sandhills, and in this way cultivated fields 

 are steadily invading one of the most sterile districts of the 

 earth. The same result can be effected upon ihe dry interior 

 plains of Australia. But it will be necessary to record every 

 bore that is put down, to fix the position on the map of the dry 

 as well as of the wet ones, and to note the formations in which 

 the water occurs, and the depths at which it is tapped. In 

 this way we shall gradually acquire an acquaintance with the 

 underground circulation of the continent of great economic 

 as well as scientific value, and we shall add a fresh feature to 

 the geography of Australia. 



There is another direction in which work ought to be done ; 

 but in this case the onus must rest on New Zealand. Your 

 glaciers require to be systematically gauged as to their lengths, 

 as indicated by their terminal moraines, as well as to their 

 volumes, and rates of motion. And not your glaciers only, but 

 also your mountain-lakes. For both glaciers and lakes are 

 measures of the annual or periodic fluctuations in the tempera- 



