70 CELERY CULTURE 



pipes about 3 feet high every 16 or 18 feet along 

 their length. At the top of each upright is placed a 

 distributer, known as a deluge sprinkler, which will 

 spread the water very evenly over the entire sur- 

 face between the uprights. This system has its dis- 

 advantages; it is costly to install, the lines of pipe 

 and uprights are in the way of cultivation, and the 



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FIG. 26 — DELUGE SPRINKLER SYSTEM OF IRRIGATING 



pipes must be taken up at the end of each season 

 and relaid at the beginning of the next. 



The expense of pumping is greater than for the 

 open ditch system, as the water must be driven 

 through the pipes under a pressure of at least 50 

 pounds to the square inch in order that the sprink- 

 lers will distribute it uniformly. An eight to ten- 

 horse power pump, with a three-inch suction 

 and two and one-half-inch discharge pipe, will be re- 

 quired to operate 16 of these sprinklers at one time, 

 but these will thoroughly soak an area of about 20 

 square rods every 15 minutes, or i acre every two 



