98 WATER SUPPLY IN THE INTERIOR OF NEW SOUTH WALES. 
such a process of washing out the order in which the salts were 
deposited would be reversed, the more soluble such as chloride 
or common salt being dissolved out first, and the least soluble 
such as gypsum remain gia 
I know of no agency, except water in such a land-locked sea as 
the Caspian, capable of sat a all the conditions found in the 
yer assem 
has been put forward by Mr. Tenison-Woods, which 
way resemble the Darling formations, which consist of saliferous 
—: —— with gypsum and uncompacted sand or sand- 
ian, the stratification being always, as far as "I can judge, 
nearly horizontal. Quite recently it has been suggested to me by 
a gentleman whose opinion should have very great weight, that 
the plains might be a river formation, and I have given the idea 
a consideration; and though I cannot deal with the question 
, I may say that on comparing the suggestion with my own 
obserations, I find the difficulties in the way of accepting it 
japera 
Taking the facts as above stated, and apart from any theory or 
conclusion as to how the country assumed its present form, I will 
endeavour to show what are the probabilities of and the difficulties 
in the way of obtaining a supply of underground water, either 
artesian or by ordinary wells, festa: which the water would require 
to be lifted 
work which has been done by Mr. Russell, the Government 
“ae EW: in the last ten years, in connection with water supply 
in the interior of New So sky sire The conclusions reached, 
though at first disputed, a w, I think, generally accepted. 
They are, shortly, that the rainfall « of the Darling watershed is not 
adequately accounted for by evaporation, and the outflow of the 
‘that an, pnt in good years about 2, a The difference sm the 
Darling and the other rivers, even in New South Wales, 
_Fespect, is very marked, as in most parts of the world the ee 
of the rivers ranges from one-quarter to one-third of the total rain- 
fall of the area drained. This applies to rivers having a compara- 
tively ieahincs course like the Darling. Rivers with steep and hard 
oat 
