104 



IRRIGATION FARMING. 



tie, and these are well cross-braced. On them rests a 

 cap piece 12x12 inches, and on this are ten longitudinal 

 stringers 16 feet in length, extending from one bent of 

 the trestle to the other. These stringers are 6x12 tim- 

 ber, and on them are nailed 2-inch floor planking placed 

 at right angles to the current. The side bracing of the 

 flume consists of 6x8 scantling 8 feet in length, though 

 at present these are planked for a depth of only 5 feet, 

 giving the flume that available depth. These pieces are 

 placed 4 feet apart between centers and are braced by 

 short struts at each bent of the trestle. 



Iron Flumes. One of the greatest objections to 

 the use of wooden irrigating flumes is the alternate 



shrinking and 

 swelling of the 

 wood and the con- 

 sequent w a r p i 11 g 

 and distortion of 

 the structures. To 



FIG. 81. SIDE VIEW OF SMALL Ii:oX FLUME. overcome ^3 fliffi- 



culty, and at the sc.me time to provide a durable substi- 

 tute, easy of transportation and erection, M. H. Lay- 

 bourn of New Windsor, Col- 

 orado, has designed and pat- 

 ented an iron flume, which 

 is illustrated herewith. 



Galvanized iron is uced 

 for the trough of the flume, 

 which is supported in various 

 ways, according to the exi- 

 gencies of the case, but gen- 

 erally by means of cast-ir n 



* J A . FI<;. 86. BND \ 1 1 \\ 



brackets placed on timber IRON r^nu 



supports. Figure 34 shows a small flume, supported on 

 single posts. In this, as in other cases, the upper edge 

 is stiffened by means of a board or plank, which also 



