E. F. PITTMAN AND T. W. E. DAVID. CxXXVII, 
between 3,058 and 3,500 feet, chiefly sandstone and shaly 
sandstones, = total of about 584 feet (say 600 feet) of 
porous beds. 
Wilby-Wilby Bore, north of Narren Lake, 1,114,800 
gallons. First flow 1,750 feet from sandstone 36 feet thick; 
second flow 1,940 feet from sand 10 feet thick; third flow 
2,160 feet from sandstone 20 feet thick. Bore was not 
carried to bed rock, minimum thickness of porous beds 66 
feet. Summary of ascertained thickness of porous beds:— 
Bulyeroi ... ae Sa a OCU Meet 
Woolabra ... ae er ar, CO Obes 
Tenandra ... ae ms ALO want (DOL) 
Warren»... bi mc apa ON Be 
Carinda ... = a Dee ee ey 
Kenmore ... Son iy ice AOD 
Mooramina a3 oe G24 DOE: cei 
Wilby-Wilby ay oe Oe re Bae 
Tulloona ... “ ae eo ais Y(avout) 
For the purposes of the calculation at the conclusion of 
this paper the mean thickness of the porous strata under- 
lying the artesian area of New South Wales has been esti- 
mated at 300 feet. 
The impervious rocks underlying the storage beds.—A 
knowledge of these can be obtained from studying the chips 
of rock resulting from the boring by percussion drills 
recovered from such bores as have reached bed rock, and 
in part their nature may be inferred from the character 
of the rocks forming the rim of the artesian area. As 
regards the latter, the eastern rim of the basin, where it 
touches the Queensland border consists of granite. Further 
south it is formed chiefly of Carboniferous rocks to near 
Narrabri. Thence to the Warrumbungle mountains the 
bed rock is partly Permo-Carboniferous with occasional 
granite areas and older sedimentary rocks. Thence as far as 
