ARID AGRICULTURE. 115 



tW carrying away the surplus, these gates do not 

 have to be very carefully made, but in the end it 

 always pays to make them well and so they may 

 l>r easily adjusted to allow the amount of water 

 required to now down the ditch. For permanent 

 gates on laterals heading in a large canal, iron 

 head gates clamped to enough sewer pipe to carry 

 the water through the canal bank are recom- 

 mended, both because they are lasting and 

 when once placed, there is less danger of 

 a washout, which may cause greater dam- 

 age or delay than there is with the ordi- 

 nary wooden head gate. For the diversion of 

 water into the different laterals on the farm, 

 small wooden boxes with head-boards running 

 between strips of wood tacked on the inside, are 

 sufficient. Holes should be drilled through the 

 handle of the gate so that it may be adjusted 

 at any height by putting in a wooden pin at the 

 proper hole. Sometimes trouble is caused by 

 gates not thus held dropping down and causing 

 the lateral to over-fill and flood all around it. 



Where the grade of a lateral is too great the 

 water \vill soon cut in deeply and the result is 

 that the lateral is too deep for easy irrigation. 

 Such washed out ditches are unsightly and are 

 objectionable on other accounts. To keep the 

 water from running too swiftly when the nat- 

 ural grade is great, drops or spill boxes are 

 ?ary. These are simply little falls made 



