206 ESTABLISHMENT OF A GEOLOGICAL SURVEY, 
Government Astronomer New South Wales, concerning the 
River Darling and the water which should pass through it. 
Mr. Russell there gives an estimate of the water, based on rainfall 
statistics, which should be carried away by the Darling River, 
and also of the quantity of water which actually does pass. 
through the Darling River. The conclusion, which Mr. Russell 
arrives at, is that a very large portion of the rainfall of the 
basin of the River Darling must disappear beneath the surface. 
In England, owing to the increasing importance of the- 
water question, the Geological Survey have commenced to mark 
on their maps the areas covered by drift deposits distinguishing 
these by different colours, so as to show the permeability and im- 
permeability of the various surface deposits. A geological survey 
here in Queensland, by unravelling the structure of the country 
and marking on its maps the places where water-bearing” 
rocks exist, would show the broad features of the underground. 
water system, but the complete working out of this problem 
can only be effected by a long series of observations and 
inquiries 
I have now briefly sketched what has already been done to. 
elucidate the geology of this colony, and I have also pointed out. 
what I believe to be the most pressing wants at the present time: 
in indicating that the direction in which future work in the 
domain of geology should be conducted, is in the comple-- 
tion of the geological surveys of our mineral fields, and the 
investigation of the geological structure and rocks of the colony,. 
so that light may be thrown on the question of water supply. 
In urging the completion of the surveys of the mineral fields, 
I would insist that not only is it of importance that the State 
should be fully acquainted with the value of its mineral resources, 
but also that private individuals should be able to get any infor- 
mation they might require concerning mineral fields, and so 
every opportunity be given for the development of our mineral 
resources. Such information can now be obtained in England,, 
