204 W. E. ABBOTT. 
on freely even as far down as five or six feet, or possibly in places 
even still further. This I recently found to be the case when I 
attempted at the height of the late drought to irrigate a small 
area of old cultivation land shewing no surface cracks. When 
the water was turned on through an eight inch pipe, after spread- 
ing a few yards, it broke through the old cultivated surface and 
disappeared at once in cracks from three to four inches wide, 
without effecting the surface in any way. Ina time of general or 
pronounced drought we do not usually have extremely hot weather, 
but fairly cool nights and bright clear days; anything like excep- 
tional heat, more particularly at night, is a sure indication that 
the drought is but local and likely to be of short duration. A 
dry, clear, and not abnormally hot atmosphere, is the invariable 
accompaniment of a general and prolonged drought, and it is the 
extreme dryness of the atmosphere which I regard as the indirect 
cause of increased outflow of water in springs and creeks, always 
observed at some stage in such droughts, and so noticeable in the 
drought which now seems drawing toa close. To understand 
the apparently uncaused increase in the flow of water in many, 
but not in all of our creeks and springs, occurring in most cases 
towards the close of a general drought, it will be necessary to 
refer to the character of the sources from which the flow of such 
creeks and springs is derived in normal seasons when they are 
permanent. 
The generally accepted theory of springs found in all books om 
the subject, is that on high ground there is an underground 
reservoir with very free openings to the surface, through which it 
is kept full by the rainfall. Then there is a narrow or restricted 
opening, not unlike a pipe line; which may be of any length, con- 
necting this reservoir with the outlet of the spring. The reservoir 
being filled by rainfall much more rapidly than it is emptied by 
the spring, gives the spring a permanent outflow not affected by 
the seasons. The Prospect Water Supply with its reservoir 
and pipe line to Sydney is an artificial reproduction on the surface 
of this kind of spring, but when we come to examine the sources of 
