— 202 W. E. ABBOTT. 
accounts for his having put forward an explanation which ignores 
well known facts. 
Next we have the theory that the increased flow of water is 
due to barometric changes. Apart from the fact that Mr. H. C. 
Russell has shown that in the Bathurst and Orange districts, 
where the phenomena were very pronounced, there was no baro- 
metric change, it has always seemed to me that the explanation 
is inadequate. As far as my observations go, and I think they 
will be borne out by those of other observers, the increased flow 
invariably begins in creeks that have a drainage area of from a 
few hundred yards to a few miles in extent, and though it ultim- 
ately affects the larger creeks and rivers, this secondary effect is 
produced by the accumulated flow of the many little creeks work- 
ing down gradually from the upper watershed, and does not begin 
in the main creeks or rivers in their lower courses. 
In considering how barometric changes of pressure could pro- 
duce an increased flow of water, it will be clear that there must 
be a high pressure at the source of the spring and a low pressure 
at its outlet. A low or high pressure which was the same at both 
could produce no effect, and as it is impossible that there could be 
innumerable areas of high and low pressures at distances of only 
afew hundred yards or a few miles apart all over the country, 
and continuing permanent for weeks or months, I think this 
explanation is disposed of. Of course it is possible that a high 
and a low pressure following each other across the country might 
effect the source of supply and outlet of a spring alternately in 
some cases, but even then, I think the pressures would have 
changed long before the effect could be transmitted from the source 
to the outlet. 
Another explanation which has been put forward with some 
authority, is that the increased outflow of water is the result of 
the cracking of impervious dams of clay by which bodies of water 
had been held back in the gravels and sands of the smaller 
creek beds. The theory is that the long continued dry weather 
has caused these clay formations to crack to a point below the 
