300 FOREST PRODUCTS 



2. The timber must be accessible and available in such quantities 

 that it can be placed on the market at a reasonably low price. 



3. It should be light in weight in order to transport and erect the 

 poles with comparative facility, but still more importantly to secure low 

 freight rates. 



4. The wood should be sufficiently strong to resist the stresses and 

 strains incident to carrying a load up to 80 wires, some of which may be 

 No. 8 B. W. G. copper wire under the pressure of high winds, slet t, ice 

 storms, etc. 



5. The pole should be cylindrical, straight, with gradual taper, and 

 free from excessive checks or other defects which will detract from its 

 strength or shorten its life. At the present time the market is preferring 

 poles (at least of certain species) which have large butts. 



6. The surface of the pole should be susceptible to use with climbing 

 irons. This is rather a minor consideration and yet some workmen have 

 difficulty in climbing poles of certain species and object to their use. 



7. When the poles are to be treated, the wood should be capable of 

 penetration by creosote or other preservatives. The percentage of poles 

 being treated is rapidly increasing so this has an important bearing. 



In general, the some qualifications as outlined will hold for piling, but 

 in addition to these properties, the timbers must be capable of being 

 driven without breaking or splitting; they must withstand very heavy top 

 loads; they must be sufficiently straight so that the axis is kept within 

 the pile, and they must be clear and sound throughout. 



SPECIES AND AMOUNT USED 



The various species of cedars combine the above qualifications to a 

 remarkable degree. The two principal species used for poles, northern 

 white cedar or arbor vitae (Thuja occidentalis) and western red cedar 

 (Thuja plicata) make up about 65 per cent of all the woods used for 

 pole purposes in this country. The chief sources of these poles are in the 

 cedar districts of the Lake States, northern Idaho and western Wash- 

 ington. Most of our cedar poles now come from the Lake States, where 

 large quantities of northern white cedar are cut, but the best poles for 

 size, shape, durability and strength come from the western red cedar of 

 the " panhandle " of Idaho. Excellent poles are also cut of the same 

 species in western Washington, but the tree naturally grows to better 

 pole sizes in northern Idaho. Some southern white cedar or juniper 

 (Chamaecyparis thyoides) is cut for poles in New Jersey, Virginia and 

 North Carolina, but the amount is small compared to the other cedars 



