i6o 



IRRIGATION FARMING. 



from a ditch company. It is self -registering and is 

 said to be absolutely accurate. The design is shown 

 in Fig. 45. It is not a headgate, but is to be used as 

 a meter, and is placed in the main ditch below the head- 

 gate or in private laterals below the tap-gates. The 

 gate is placed in a frame or box in the ditch, so that 

 the water flows through the aperture created when 

 the slide is raised. In measuring the flow the slide is 



FIG. 45 — THE STOKES MEASURING GATE. 



lowered into the water until the flange on the side is at 

 the level of the surface. The amount of water is then 

 indicated on the scales. The water must stand steadily 

 at the flange and flow freely away below the gate. 

 These conditions may be secured in a ditch of any grade 

 by the use of a weir-board if necessary. In order to 

 turn out a given quantity of water into a ditch or 

 lateral all that is necessary is to raise the slide until 

 the indicators point to the required amount and then 



