DUTY AND MEASUREMENT OF WATER. 



117 



small service head. It needs no oversight or su- 

 pervision, as it can be locked until a change of volume 

 is desired. The irrigator himself can with his pocket 

 rule demonstrate to his entire satisfaction that he is 

 getting the amount of water in inches for which he 

 is paying. 



Weirs. To determine the flowing capacity of 

 small streams, ditches or laterals the rectangular weir, 

 such as is illustrated in Figure 41, may be employed, 



FIG. 40. FOOTE'S MEASURING FLUME. 



thanks to the ingenuity of James Leffel of Ohio. The 

 illustration represents a weir dam across a small stream. 

 When it is convenient to use a single board, as is shown 

 in the sketch, one may be selected sufficiently long to 

 reach across the stream, with each end resting on the 



