417 
It is indeed difficult to identify the outcrops of tlie strata in wiicli tlie water lias 
been tapped, but at all events they cannot be at higher levels than the line where the 
sdgeof the liolling Downs Porination meets the Palaeozoic rochs on which the formation 
rests. The difficulty of the case is increased by the fact that the Eolling Downs Forma- 
tion is generally overlapped by the Desert Sandstone Formation, so as to obscure its 
junction with the Palaeozoic rocks. It is probable that the outcrops of the permeable 
strata are seldom more than five hundred feet above the level of the surface of the 
ground in the places where the permeable strata have been tapped, with the result of 
finding overflowing artesian water. 
Mr. J. Hugh Moor, Manager of Manfred Downs Station, on the Flinders, has 
courteously forwarded to me samples of the rock in which the water from his “ Is o. 2 
Well ’’was struck. A more favourable medium for the conveyance of water could 
scarcely bo imagined. It is a sandstone so open that water can be sucked through it as 
easily as through a piece of spongy iron. But oven if, instead of a stone filter (however 
open), the water had to pass through an iron pipe, there would still be such a loss by fric- 
tion in two or three hundred miles, that it could not rise quite to the level of its source. 
My belief is that the water flowing from an elevated source down the plane of a 
permeable stratum intercalated between two impermeable strata must rise, in a bore 
tapping the permeable stratum, to near the level of its source, and be aided in its rise 
by expansion due to heat acquired in its passage over a portion of the stratum now 
lying at a lower level than that at which it was tapped by the bore. 
The Desert Sandstone, which, where not denuded, always rests on the Eolling 
Downs Formation at high levels, and unconformably, is itself a great reservoir of water, 
which issues in springs from the cliffs at tho edges of the table-lands winch are its 
characteristic feature. Some of the water with which the Desert Sandstone is charged 
must find its way into any psrmeable beds in the Eolling Downs Formation whose 
outcrop may happen to be covered by the Desert Sandstone. 
The expansion of the water itself would probably be greatly assisted by the elasticity 
of imprisoned gases increasing in volume in proportion as they are relieved of pressure. 
It has been suggested that the pressure of water implied by Australian artesian 
wells may be derived from strata in the mountains of New Gruinea, or even of tho 
Himalayas. It must be recollected, however, tliat only open and porous strata can 
possibly act as conduits for water, and that strata of this character (gravels, conglomerates, 
grits, and sandstones) are necessarily local in their distribution, as they could not 
possibly be deposited in a deep sea far from the land. It is within the bounds of 
possibility, seeing how little we know of New Guinea, that the Eolling Downs 
formation may extend across the strait separating Queensland and New Guinea, and 
that the “ head of water” may be derived from the latter island, as we know at least that 
Cretaceous rocks occur in New Guinea.* From what has already been said as to the 
non-continuity of open and permeable strata across oceanic depths, it is, however, to 
say the least, highly improbable. As regards the continuity of Cretaceous rocks of the 
Dolling Downs age from Queensland to India, the idea is too extravagant to be enter- 
tained for a moment by any Geologist. 
Considering the paramount importance of the question of artesian water in the 
^Fest, I have thought it well to record briefly in the following pages such particulars as 
I have been able to ascertain regarding the wells already sunk. For a great deal of this 
information I am indebted to Mr. J. B. Henderson, M.I.C.E., Government Hydraulic 
Hngineer. 
*l^om the recent information collected by Mr. A. Gibb Maitland (see Chapter on British New 
Guinea), it must be admitted that this is hardly possible. 
2 c 
