76 



IRRIGATION FARMING. 



The gate (i) is built of two-inch plank securely- 

 bolted to four gate standards 2x8 inches and of length 

 equal to the depth of the canal for which it may be de- 

 signed, and as many gates, each three to four feet 

 wide, may be placed in the principal frame, termed 



FIG. 16 — AUTOMATIC WASTE GATE. 



wasteway, as the magnitude of the anticipated flood 

 water may require. The gate is hung on substantial 

 hinges at the top to a horizontal beam 4x12 inches, as 

 shown in the figure. Near the bottom the gate is sup- 

 ported by two levers (2), which are four inches square, 

 placed between the gate standard, through which a 

 round bolt is placed, as shown in plan. Both gate 

 standards and the ends of levers are lined with cast 

 plates to prevent the bolts from being pressed into the 

 wood, to allow the gate to move with the least possible 

 friction. The opposite ends of the levers (2) join in a 

 single lever (5), likewise with a bolt joint and cut 

 plates. These levers (3) are connecfled with two levers 



