CXCII. GAUGING OF FLOW OF STREAMS AND ARTESIAN BORES. 
Lachlan river at Cowra, Murrumbidgee river at Hay and 
Gundagai, Murray river at Albury and Tocumwal, the 
author is of opinion that a single observation at °64 depth 
at each vertical gives a very close approximation to the 
mean velocity of that vertical; this agrees with the result 
obtained by T. G. Ellis. 
In order to obtain accurate results the meter is rated 
frequently, at least once a month and sometimes oftener, 
but by exercising great care in cleaning and oiling there 
is very little difference between the first rating and the last 
one made, after 18 months use in very muddy water, except 
at very low velocities. 
Gaugings are taken at various stages of the river and a 
mean curve drawn through the points plotted from indi- 
vidual gaugings, and from these the discharge at any height 
of the river is read off. If closely looked into it will be 
found that three curves can be drawn one for rising river, 
one for falling river, and one for stationary rivers, but for 
ordinary purposes this is an unnecessary refinement, and a 
curve is Simply drawn through all points disregarding the 
state of the river. From these curves rating tables for 
each gauge can be tabulated which shew the discharge for 
a given gauge reading, of course these will alter as the 
river bed alters so that discharge observations should be 
made frequently and the tables corrected. 
Artesian Bores. 
Acting upon instructions from the Principal Hngineer, 
Mr. L. A. B. Wade, A.M.I.C.E., the author some time ago 
started to make a detailed examination of the flows and 
pressures of the artesian wells of this State. Up to the 
present only the bores of the Moree district have been so 
done. According to the instructions each bore had to be 
freely flowing for 48 hours before the normal flow was 
measured. ; 
; 
q 
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