Measuring Water, Speeds, etc. 



97 



sensible velocity of motion until it approaches 

 the overflow. Ascertain the depth C to D. 



It is to be especially noted, however, that 

 the depth of the overflow must be taken, not 

 on the edge (B), but at some distance back 

 from the weir (A), before the water begins to 

 curve downwards, which it does before reaching 

 the weir. After ascertaining this depth, the 

 following table should be made use of : 



Table of Discharge for each foot of width of 

 Sill in Cubic Feet per minute.* 



One cubic foot of water=6'24 gallons=28 ! 3 litres= '0283 cubic metres 

 =62-5 Ibs. 



