90 



IRRIGATION l-ARMIXt;. 



that it is made on the ground, and the workmen 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- 

 tracting for such materials, the specifications should call 

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

 ber, free from all knots, worm holes, season checks, sap- 



FIG. 27. STAVE PIPE LINE IN POSITION. 



wood, splints, or other like defects, and cut from live 

 trees. In piping, ranging in diameter from eighteen 

 inches to three or four feet, the staves are usually pre- 

 pared from carefully selected 2x6 joists, and this joist 

 when dressed will make a stave about five and five- 

 eighths inches along i:< ouler arc, and about one And 

 nine->i\teenths inches thick. 



