16 



Table of Discharge for Rectangular Weirs Wltla Full Contractlonii. 



The above table is for rectangular weirs with crest 1 foot, 2 feet, and 3 

 feet long. It will be noticed that for this type of weir the discharge is not 

 exactly in proportion to the length of the weir crest, especially for the 

 greater depths of water on the crest. 



The form of construction of the weir will depend on the conditions 

 where it is used. It may be used on a ditch or a flume in which case it is 

 placed either as a weir board or a weir box across the canal or flume as 

 shown in the accompanying illustrations (Fig. 5, 6, 7, 8, 9) or it may be 

 used to measure the water taken out of a pipe in which case it is placed! 

 around the takeout valve as shown in Fig 11. 



