SOME RECENT ENGINEERING EXPERIENCES. 973 
The artesian basin, which occupies such a large portion of the 
provinces of Queensland and New South Wales, extends also into 
the north-eastern corner of the province of South Australia and 
the south-eastern corner of the Northern Territory. On the map 
the provincial boundaries appear to divide it into four portions of 
approximately 374,000 square miles in Queensland, 60,000 square 
miles in New South Wales, 110,000 square miles in South Aus- 
tralia, and 42,000 square miles in the northern territory. 
Geologically I believe it stands as a whole, and constitutes one of 
the largest and most remarkable artesian basins known. 
Scientists, of course, desire to study this basin in its geological 
aspect, and a brief reference to the borings by which our portion 
is being exploited by my department will supply the South 
Australian contribution to the mass of interesting facts which are 
being gathered concerning this wonderful natural storage of 
water. 
There is abundant evidence which may be cited in proof of the 
contention that the marine shale beds under which the water is 
found in South Australia correlate with those of the portions of 
the basin within Queensland and New South Wales. Many of 
the fossils have been determined as identical, and further proof is 
coming to light almost every day. From a boring in progress at 
Dulkanninna, in South Australia, and from a depth of 1,166 feet, 
an interesting fragment of a large ammonite has just been found, 
which is no doubt identical with ammonites daintreei of the 
Hughenden beds, Queensland, and which has been figured by Mr. 
Jack, the Government Geologist, Queensland, and R. Etheridge, 
Curator of the Australian Museum, Sydney, and determined as 
of lower cretaceous age ; therefore, without doubt, to this age may 
be referred the whole of the shale beds in South Australia and 
the northern territory, under which is found such a remarkable 
and splendid supply of artesian water under hydrostatic pressure 
sufficient to bring it over the surface. So far as these strata have 
been proven, their thickness ranges from a few feet on the edge 
of the basin to 3,000 feet at about 100 miles northwards towards 
Queensland. There is every reason to suppose that about the 
boundary line between Queensland and South Australia, in the 
neighbourhood of Birdsville, the thickness of these strata will 
prove to be nearly if not quite 4,000 feet. 
In South Australia seventeen Government borings have been 
put down within the area of this secondary basin. Towards the 
edge of the basin the depths range from 228 to 365 feet, and from 
some of these comparatively shallow borings the daily flow 
reaches a maximum of 14 million gallons of water at a tempera- 
ture of about 96 degrees Fah. 
The shale-beds thicken rapidly as the shore line of this old 
cretaceous sea is left, and at 30 or 40 miles the borings have 
