artesIAH Wat Eli in western Queensland. 
313 
Now, in such a stratum as Mr. Hay has imagined, the effect of 
pressure would simply be to close up the spaces between the solid 
grains, and diminish the stratum’s capacity for carrying water, and the 
surplus water would be forced into the underlying or overlying strata, 
if these were sufficiently permeable, or, if not, the surplus water would 
be forced out at the outcrop of the stratum. In any case, the water- 
carrying capacity of the stratum would be permanently impaired, or, if 
the pressure were great enough, entirely destroyed. 
Another idea is that there are in the bowels of the earth vast 
reservoirs of water — not filling up the interstices of porous strata, but 
actually filling up void spaces among the rocks — and that the presence 
of superincumbent rock is such that on these reservoirs being pricked 
by a bore the water rises as in the tube attached to a squeezed rubber 
bag. I can imagine the roof of such a reservoir tumbling in, in which 
case the water could only rise to an extent dependent on the bulk of 
the rock which had fallen into the water ; or supposing the whole 
mass of water to be displaced by an equal mass of rock, it must either 
occupy the space formerly occupied by the rock or get away laterally 
into crevices in the rocks above the former surface of the water, if 
such crevices are available, but at most would not rise above the level 
of the rock which had fallen in. To take the case of a shaft com- 
municating with extensive underground workings : — Let us suppose 
the workings to become filled with water and the roof suddenly to 
collapse. If the quantity of water were large enough to fill up the 
shaft and flow over, it would probably do so at first, and even flow 
over the mouth of the shaft ; but the water would simply stand in the 
shaft, supposing the latter to be water-tight, and there would merely 
be a tube filled with water, and in no sense an artesian supply. If, on 
the other hand, an underground reservoir were to remain unfilled 
by the tumbling in of the rocks above it, the rise of water in a bore 
tapping it would depend on the head of water supplying the reservoir, 
no matter how extensive the latter might be. My belief is, however, 
that such underground reservoirs are not common objects in nature. 
Caverns in limestone in which large streams disappear, to reappear at 
lower levels, are by no means unknown, but such caverns are for the 
most part confined to levels within the reach of the solvents conveyed 
by the atmosphere. 
# It is not within the scope of a single paper to consider the whole 
subject of artesian water. My object in addressing this Section has 
been to point out what light has been thrown on the question, so far as 
it affects Queensland, by recent investigations. We have shown that 
an intake at sufficient altitude to account for the flow of water in 
the artesian bores of the west exists along the eastern margin of the 
Lower Cretaceous ; and having found a simple explanation in agree- 
ment with known physical laws, I go no further in search of another. 
I have argued that the loss of water by the Darling River, and pro- 
bably a similar loss of water by the Western Queensland rivers, proves 
that the water-bearing strata must leak into the sea, and hence that 
unless the strata be periodically replenished the sea-level would ulti- 
mately become the level to which the water would rise. A drought 
sufficiently long to bring about this result would no doubt have for a 
prior result the destruction of the greater part of the land fauna of 
this part of Australia, including the genus homo . Ear short of this, 
