THE FARMER'S SHORT-BOX MEASURHsTG FLUME. 3 



the weir box, a definite location for the gauges, and a uniform plan 

 of conducting the tests. 



Table 1 gives the standard weir-box dimensions and positions of 

 the gauges. The letters used refer to Figure 1. It will be noted that 

 the location of the gauges is the same for all the sizes of flumes. The 

 discharge over this type of weir is very nearly proportional to the 

 width of the flume, and therefore the condition of the flow is very 

 nearly independent of the width; consequently, the position of the 

 gauges need not be changed for the various sizes of flumes. The 

 gauge point, 1 foot upstream from the weir bulkhead, was so located 

 as to be outside the influence of the contraction lines of the water 

 entering the flume, and not too near the crest. Because of the dis- 

 turbed condition of the water below the crest the gauge point, 2 feet 

 downstream from the weir bulkhead, was placed as far below the 

 crest as the dimensions of the smallest flume would permit. The 

 elevation of the zero of the gauges is not given. It depends on the 

 height of the weir crest, and for convenience should be at the eleva- 

 tion of the crest. 



Table 1. — Standard dimensions for farmed s short-box measuring flumes. 







A 



B 



c 



Dis- 



D 



Dis- 



E 



F 



G 



H 



L 



P 



Size 

 of 



Capacity of 

 weir per 



Length 

 of box 



Length 

 of box 



tance 

 from 

 weir 



tance 

 from 

 weir 



Depth 



Depth 



Thick- 

 ness 

 of 



Length 



Length 



Height 



weir. 



second. 



weir 

 bulk- 



weir 

 bulk- 



bulk- 

 head 



to 

 upper 



bulk- 

 head 



to ' 

 lower 



of 

 flume. 



cut-off 

 wall. 



walls 

 and 



wing 

 walls. 



of weir 

 crest. 



of 

 crest. 







head. 



head. 







floor. 

















gauge. 



gauge. 















Feet. 



Cubic feet. 



Feet. 



Feet. 



Feet. 



Feet. 



Feet. 



Feet. 



Inches. 



Feet. 



Feet. 



Feet. 



1 



0.3 to 3.5 



2 



2.5 





2 





0.5 



4 



0.5 



1 





) 



1.5 



0.5 to 5 



2 



2.5 





2 





0.5 



4 



0.5 



1.5 



( 



) 



2 



0.7 to 7 



2 



3 





2 





0.5 



4 



0.5 



2 





) 



3 



1 tolO 



2 



3.5 





2 





1 



6 



1 



3 



f 



) 



4 



1.5 to 14 



2 



4 





2 





1 



6 



1 



4 



( 



) 



1 The distance E depends on the height of P and the capacity required. 



2 The height of the crest P depends on the fall available in the lateral. 



All the tests upon which the tables and charts are based were made 

 at the hydraulic laboratory at Fort Collins, Colo.^ The general 

 arrangement of the apparatus used in the calibration is shown in 

 Figure 2. The flume itself is similar to that shown in Figure 1, ex- 

 cept that auxiliary walls, with a side slope of 1 to 1, have been 

 attached to the upper end of the structure in order to approach more 

 nearly the condition in a lateral. The points for taking the gauge 

 readings are the same as in the standard measuring flume, but to 

 increase the accuracy the gauge readings above and below the crest 

 were taken by means of hook gauges located in the stilling wells 



t ' For a complete description of the hydraulic laboratory, see Engineering News, vol. 70, No. 14, pp. 

 662-665, Oct. 2, 1913, V. M. Cone. 



