128 



IRRIGATION FARMING. 



flume. Where bench flumes are constru(5led it is best 

 to make the bench twice as wide as the flume in order 

 that there may be a footway alongside. In such flumes 

 the foundation is simply mudsills and cross-beams. 

 In sheathing a wooden flume it is best to use large 



FIG. 30— FLUME ACROSS A VALLEY. 



wire nails or cut spikes for the floor, but the sides 

 should be fastened with bolts through inside cleats at 

 the joints. If nails are used in the side planking they 

 will rot out and it will be found impossible to keep the 

 planks on. 



The weak spot in every flume is at either end where 



