26 BULLETIN 155, U. S. DEPARTMENT OP AGRICULTURE. 



but what has at some time put in more or less of it, and the demand 

 for this purpose continues to require a large output from the fac- 

 tories. It is also used a great deal in conveying water supplies for 

 manufacturing purposes and fire protection for factories and mills, 

 for railway tanks, for power plants, hydraulic sluicing operations, 

 etc., and during recent years there has been a great deal of it used 

 for irrigation purposes, particularly in the Northwestern States. 

 In the East it is used to some extent for municipal water supplies, 

 considerably for various purposes in the mining regions, and for oil 

 conduits, insulated wire conduits, steam pipe casing, etc. 



For municipal waterworks the low first cost of machine-banded 

 wood pipe as compared with that of cast iron or steel pipe has in 

 most instances been the consideration leading to its use, and many 

 communities which now have an abundance of water for domestic 

 purposes, fire protection, etc., would still be unsupplied had not some 

 such cheap type of pipe been available. 



While possessing some advantages other than that of low first 

 cost, machine-banded pipe, according to the experience of many 

 localities, has been found inferior in many respects to cast iron and 

 steel for city mains and connections. The complaint most fre- 

 quently expressed with reference to its use for this service relates to 

 trouble arising from leaks, which occur mainly at the joints. Such 

 leaks may develop as the result of decayed collars, from carelessness 

 in putting the pipe together, from increasing the pressure above 

 that for which the pipe was designed, or from other causes. While 

 in many cases even a considerable leakage may be permissible, in 

 others any material loss is highly objectionable. Leaks are particu- 

 larly objectionable where pipes are located in paved streets, and 

 owing to the difficulty in avoiding leaks, as well as because its life 

 is usually shorter than that of metal, wood pipe is usually replaced 

 before paving, and in the larger cities its use for distributing systems 

 is now being very generally discontinued. 



For service of a more or less temporary nature, such as hydraulic 

 sluicing, dredging, etc., where absolute tightness is not essential, but 

 where low cost, ease of transportation, facility of putting together, 

 removing, and relaying at small expense are desirable considerations, 

 machine-banded wood pipe is peculiarly well adapted. 



The use of machine-banded wood pipe in connection with irriga- 

 tion work is confined to the West, particularly the Northwest, where 

 hundreds of miles of it have been installed for delivery pipes of 

 small pumping plants, for inverted siphons, etc. In a number of 

 places the entire water supply is conveyed through such pipes, de- 

 livery being made to each unit of area, often as small as 5 acres or 

 less. And beyond this, many farmers use wood pipe instead of 



