IRRIGATION AND DRY-FARMING 



697 



FIG. 76. Essential features of construction in one method of overhead 

 spray irrigation. Water is supplied under pressure from under- 

 ground pipes and is distributed from small nozzles (N) along the 

 axis of the pipe. Different forms of nozzles are used for different 

 purposes (see detail). Gauge (G) shows pressure, (*S) is pipe sup- 

 port, and (L) is lever for turning the discharge pipe, which is fitted 

 with a freely moving sleeve joint. 



