492 T. W. E. DAVID. 
hundred feet lower than that of the edge of the basin) would be 
about one in one hundred and six. As regards (3), the surface 
level would be practically flat, and as regards (4), there is at 
present, insufficient evidence to warrant any kind of inference. 
As regards the question as to whether the water in the artesian 
beds of New South Wales is hydraulic or hydrostatic it must be 
confessed that even now the question is far from settled. In any 
case the question does not probably materially affect the economic 
aspect of the artesian water question. Ifthe pressure is hydraulic 
there must be a natural outlet somewhere for the artesian water, 
and the water must have been undergoing for ages a slow process 
of circulation. The freshness of the artesian water has been 
quoted as an argument by many writers on this subject, the author 
included, in favour of the artesian water being able to circulate, 
but it must be remembered, that to a limited degree, the mud 
springs have afforded a means of circulation for this water for ages 
in the past, and the author is informed by Mr. E. F. Pittman, 
that numbers of extinct mud springs are to be seen on the Western 
Plains of New South Wales in the vicinity of existing mud springs, 
showing that the outflow of artesian water from them has pro- 
ceeded uninterruptedly for a vast period of time. The proportion 
however, of water discharged by the mound springs must be very 
small as compared with the enormous quantities of water which 
must percolate annually into the Cretaceous beds. It is probable 
in the author’s opinion, as stated in his previous paper, that the 
artesian water has outlets, and its pressure therefore, especially 
near these outlets is hydraulic, rather than hydrostatic, but of the 
three possible outlets previously suggested by him, (1) to the Gulf 
of Carpentaria under the Dividing Range at the head of the 
Flinders River in Queensland ; (2) to the Great Australian Bight 
vid Lake Eyre; (3) Under the present channel of the Darling- 
Murray to the Coorong coast, he now considers that the last 
mentioned may be abandoned. It follows then that the outlets, 
if any, must be situated at the Gulf of Carpentaria or at the Great 
Australian Bight under the Tertiary Limestones of the Nullarbor 
Plains ; or very probably in both these directions. 7 
