CXC. GAUGING OF FLOW OF STREAMS AND ARTESIAN BORES. 
In a large river it is impossible with the boats at one’s 
disposal to hold the meter rigidly. As before described, 
(see rod floats), the site is selected but only one section is 
to be measured, and as before a tagged wire is stretched 
across, two others are also stretched for holding the boat 
in any required position; the insulated wires with the 
meter and weights suspended pass over a sheave at the 
end of a pole projecting from the boat, so that the meter 
is well clear of the boat. 
Two methods may be used with sucha current meter as 
is adopted by the department, (a) multiple measurements 
(b) unit measurements. Method (a) is the more exact and 
when the water surface does not fluctuate is the method 
always adopted by the author. In this method the velocity 
at several points in each vertical is measured, at the surface 
and each one or two feet down to within °*4 feet of the 
bottom; from these a vertical velocity curve is drawn and 
the area of this divided by the depth gives the mean velocity 
of the vertical, as a rule the author gives a run of 100 or 
150 revolutions at each point. The verticals are 10 or 20 
feet apart across the cross section, depending upon the 
observer’s knowledge of the gauging site; they are closer 
together asarule near the banks. When the mean vertical 
velocities have been computed, the discharge is obtained 
as in the case of rod floats, being the sum of each partial 
area into its mean velocity. By this means it takes the 
author about two hours to gauge a stream like the Murray 
or Murrumbidgee; of course if a meter of the Revy type 
were used which has to be taken out of the water after 
each setting to read the dial, it would take much longer, 
in fact not nearly the same number of points could be 
observed, and again it has to be assumed that the meter 
takes up the velocity the moment it is released by the wire 
attached to the brake, and again that there is no slip of the 
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