496 T. W. E. DAVID. 
1,139 feet, a level probably nearly as high as that of any portion 
of the Cretaceous intake in its neighbourhood, for the level of the 
intake in few places in Queensland attains a greater altitude than 
1,200 feet, excepting where it is capped with the Desert Sandstone 
(Upper Cretaceous), and the Muckadilla Bore is distant about 
fifty miles from the intake outcrop. The flow however, at the 
Muckadilla Bore is but feeble, and the pressure slight on account 
of this small difference in level. 
Charleville is distant about one hundred and forty miles from 
the probable edge of the artesian basin, and its surface level is 
966 feet, whereas that of the intake is probably not more than 
1,200 feet, which allows a fall of only one foot eight inches per 
mile, and the pressure of the water at the surface of the bore is 
exqual to 100 ibs. to the square inch, which would raise the level 
of the water at Charleville to about 231 feet, so that it should. 
stand at a level of 966 + 231 = 1197 feet, which is about equal 
to the level of the intake. Possibly however, part of the water 
may be derived from rain falling on the high ridge of Cretaceous 
rocks between Charleville and Mitchell, where the Rolling Downs 
Formation attains an altitude of about 1,380 feet, but this sup- 
position is extremely doubtful. 
At Cunnamulla, with a surface level of 627 feet, the pressure 
is 165 Ibs. to the square inch, so that the water would rise here to 
a level of 1,008 feet. Cunnamulla is about two hundred and twenty 
miles distant from the principal intake. 
At Noorama, the surface level being approximately 550 feet, 
the pressure of the water per square inch is 200 lbs., so that it 
would rise to approximately a level of 1,012 feet above the sea, 
which is nearly about the same level as that to which the water 
would rise in the Cunnamulla bore. At Weelawurra, about thirty- 
three miles E.S.E. from Cunnamulla, with a surface level of 625 
feet, the pressure is 150 ibs. per square inch, which would produce 
a column of water, the top of which would be about 972 feet above 
the sea, 
