DUTY AND DIVISION OF WATER 



357 



FIG. 102. Turnout and measuring weir. 



near the head of the secondary ditch to divert a part of 

 the water flowing in the main ditch. At the proper distance 

 down the secondary ditch an ordinary Cippoletti weir is 

 placed. The board containing the spillway notch is raised 

 or lowered hi accordance with the quantity of water to pass 

 over the weir. This device maintains the water flowing 

 over the weir at practically the same height, irrespective 

 of the quantity of water 

 in the main channel. 

 (Figs. 102, 103.) 



THE DISTRIBUTION 

 OF WATER 



215. Meaning of the 

 distribution of water. 

 After the duty of water 

 has been decided upon, 

 and the quantity of 



FIG. 103. Device for diverting a constant 

 quantity of water. 



