ARTESIAN WATER IN N. S. WALES AND QUEENSLAND. 419 
Wales, we might perhaps add an area of as much as 1,300 square 
miles with an annual rainfall of twenty-two inches. To allow 
however, for evaporation, one-half of this area might be taken 
for the Macquarie River = 650 square miles, and to this must be 
added the ancient gravels of the Bogan, Castlereagh, Namoi, 
Gwydir, and Dumaresq Rivers. The total area might be very 
approximately summed up as follows :— 
Macquarie River—65 square miles of gravel x 10 on 
account of area draining into sq. m. 
the gravels ... Ae is = 650 
Bogan River— 20 LOR: uF ey bee ee) 
Castlereagh River—30 x 10... ue iy. x = 300 
Namow River— 30% LO... ee we Joel i 
Gwydir River— 20 x 10... 1 wk eo ah == 00) 
Dumaresq River— 50 x 10... oa ee A = 500 
2,150 
These numbers must be taken as only very approximate, but 
they serve to show the possibility and even probability of the 
intake area being very much larger than forty-four square miles, 
and instead therefore, of the outflow equalling the annual supply, 
when the daily yield of the wells in New South Wales has reached 
38,000,000 gallons a day, it may be possible to increase the yield 
to fifty times that amount, that is to 1,900,000,000 gallons per 
day without exceeding the annual supply. Even if the amount 
be halved in order to allow for the Cretaceous Beds being partly 
covered by impervious beds, or having become locally tamped 
through fine sediment carried into it by the percolation through 
several periods of geological time, it would still be possible to 
increase the quantity of water supplied by the artesian wells of 
New South Wales by at least twenty times the present amount. 
It is hardly fair however, to apply a formula applicable to the 
‘Queensland artesian beds to those of New South Wales, where 
the conditions are somewhat different. 
