WATER SUPPLY AND IRRIGATION. 159 
h 
theories are opposed on y by theory, and this shows the necessity 
that exists for obtaining, by systematic effort, data connected 
should be followed up in other parts of the Colony, the positions 
of all works of this character being determined and marked on a 
Map ; the level of the drift containing the water and the level to 
which that rises in the bore or shaft being shown in each case, 
and the levels reduced to a uniform datum. The strength of 
supply and quality of the water, with the influence of long con- 
tinued droughts or wet seasons should also be noted. In the 
of supply, and the back pressure in these drifts. The general 
inf Tmation, when a sufficient amount of it has been collected, 
might enable the courses of the drift channels to be traced, and 
Save much loss of time and capital in uselessly sinking upon salt- 
water leads, : 
; In the works constructed by the Government for reaching, 
,, Seating working two self-acting buckets, which discharge into 
® timber-framed, oe service tank communicating with the 
k. In carrying out th 
Great care has to be taken to have the slabbing thoroughly fitted, 
bios clay well puddled into all spaces at the back of same. Care 
