The Venturi Flume 
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this type of structure. At present the only data available for the 
trapezoidal flume are found in the Journal of Agricultural Re- 
search, Vol. IX, No. 4, Apr. 23, 1917. 
The Venturi flume is very simple in operation, altho' two 
heads must be observed to determine the rate of discharge. It is 
recommended that the observations of head or depth be made in still 
boxes on gage wells, so placed that the water level in the throat, and 
also the point indicated in the converging section can be communi- 
cated to these boxes or wells by means of short lengths of pipe. 
The observations of head or depth can best be determined by means 
of a hook gage located in each well. However, a plumb bob or a 
weight of special design, tO' be referred to later, suspended on a 
graduated tape may be used in lieu of the hook gage. Investiga- 
tions, as well as observations under practical conditions, seem to 
indicate that heads determined by means of graduated scales fast- 
ened to the inside surface of the flume, countersunk until flush 
FIGURE 1. — Standard Plan for Venturi Flume with Rectangular Cross 
Section. 
