76 



this some use pieces of sacks or canvas, others use pieces cf shingles or 

 small rocks, etc. A better improvement is the use of short tubes placed 

 in the bank of the head ditch. These tubes may be made of laths nailed 

 together and cut in two foot lengths or may be pieces of discarded pipes- 

 % inch to 2 inches in diameter. A lath tube having an inside opening 1 

 inch square placed 8 inches below the water level will give a discharge of 

 1 miners' inch. The flow through the tube can be regulated by a slide. 

 The surface of the water can be kept at the proper height by means of 

 check gates regulated by flashboards and spaced according to the grade of 

 the ditch. The accompanying sketches show the lath tube and the manner 

 of placing them, and also the check gates in the ditch bank. (Figs. 59, 60)_ 

 2. Wooden Head Flumes. 



Wooden flumes with small openings in one side give more accurate 

 division of the water and are used very extensively in Eastern Washington. 

 They can also be elevated above the ground to carry water over shallow 

 depressions which is an advantage over earthen ditches. However, the 

 height above the ground must not be over two or three feet or the water 

 falling through the opening into the furrows will cause excessive washing. 

 The flumes usually vary in width from 8 to 12 inches and from 6 to 10 

 inches in height, and the openings are controlled by metal or wooden slides. 

 3. Concrete Head Flumes. (Figs. 61, 62). 



The short life of wooden flumes has led most of the orchardists of 

 southern California to use either concrete flumes or cement pipes. A con- " 

 crete head flume is made of the same form as the wooden flume and gal- 

 vanized iron spouts or tubes from % to 1 % inch in diameter are inserted 

 in the side of the flume before the concrete has hardened, there being one 

 spout for each furrow (Fig. 63). On steep slopes where the velocity is 

 high, to give an even distribution through the spouts, checks made of short 

 pieces of lath are inserted below each opening as shown in. the accompany- 

 ing sketch. To hold the checks in place, one end of the lath fits into a 

 groove cut in the side of the flume by means of a trowel before the con- 

 crete is hard. 



The thickness of the floor for all sizes up to 24 inches in width is 2 

 inches. The side walls for all depths up to 12 inches are 2% inches thick 

 at the top and 3 inches at the bottom. The flumes are made almost any 

 size. The dimensions and cost of some of the sizes commonly used in 

 southern California are as follows: 



