I20 IRRIGATION FARMING. 



SO as to form a continuous pipe, which leaves no ob- 

 struction to the flow of water. The beauty of this 

 system is that it is made on the ground, and the work- 

 men do not have to be especially experienced. 



It is always economy to purchase the staves already 

 dressed, and thereby save in freight charges. In con- 

 tra<5ling for such materials, the specifications should 

 call for sound, well-seasoned, close and straight grained 

 lumber, free from all knots, worm-holes, season checks, 

 sap-wood, splints, or other like defe<5ls, and cut from 

 live trees. In piping, ranging in diameter from eigh- 

 teen inches to three or four feet, the staves are usually 

 prepared from carefully seledled 2x6 joists, and this 

 joist when dressed will make a stave about five and 

 five-eighths inches along its outer arc, and about one 

 and nine-sixteenths inches thick. 



In laying the pipe the trench is usually excavated 

 at least eighteen inches wider than the outer diameter 

 of the pipe, to provide standing room for the work- 

 men ; the number of staves needed to form the pipe are 

 placed in piles along the trench and a foreman with 

 five workmen form a gang. The tools used by a gang 

 are a twelve-pound sledge, an oak driver banded on 

 one end, four two-pound hammers, two chisels, four 

 crank wrenches, two inside forms of coiled gas-pipe, 

 and two outside U-shaped forms of the same material. 

 A completed line of stave pipe with an abandoned 

 flume just above it is pictured in Fig. 28. In this in- 

 stance the pipe was laid above ground, as can just as 

 well be done in countries where the winters are mild. 

 The capacity of a thirty-inch stave pipe is computed 

 on thirty inches diameter as follows : 



