; 4 2 



THE APPLE 



a a 



diameter. The thickness of shell in the 12-inch pipe is i\ inches, 

 while that in the 6-inch pipe is a trifle more than 1 inch. Piping 

 of this kind, when well made and carefully laid, will withstand a 

 head of between 10 and 16 feet. The clay pipe is similar to that 

 used in cities for sewers, and, having stronger joints, withstands a 

 greater pressure ; but it costs more. 



A line of pipe is laid, about 2 feet below the surface, from the 



feed main and measuring box across the head of the orchard, and 



^ as each row of 



trees is passed 



Turnout Stone/ , • • • 



"^^SZfflSaCITZrilZm a standpipe is in- 

 serted. The gen- 

 eral plan is 

 shown in outline 

 in Pig. 64. Vari- 

 ous devices are 

 employed to con- 

 vey the water 

 from the pipe to 

 the surface of the 

 ground at the 

 head of each tree 

 row and divide 

 it evenly among 

 the furrows. One 

 of the most com- 

 mon consists of 

 a series of stand- 

 pipes, the top of 

 each set rising to 



13 



m (.$ 



M 



W 





i^ 



im 



m. 



Over flow 

 Stand 



m m w 



Fig. 64. The use of pipes in furrow irrigation 



the same elevation. At each change of elevation special standpipes 

 are used, and in these are inserted gates provided with overflows. 

 The manner of distributing the water from a standpipe to the 

 furrows of any one row is shown in Fig. 65. 



Occasionally a high-pressure pipe is substituted for that of 

 cement and clay. This is tapped at the head and in line with 

 each row of trees, and small galvanized-iron pipes are inserted. 

 These standpipes are capped by an ordinary valve, which regulates 



