320 FOREST PRODUCTS 



Species. Years. 



Northern white cedar 12-16 



Western red cedar 12-16 



Southern white cedar " 1 1-15 



Chestnut 8-1 2 



White oak ' 7-1 1 



Cypress 11-15 



Longleaf pine 6-10 



Loblolly pine 4-6 



Redwood 12-15 



Western yellow pine 2-4 



Lodgepole pine 2-4 



Douglas fir 6-10 



Photograph by E. T. Chaptn Co 



FIG. 86. Method employed in piling and loading poles on cars. 



The life of untreated piling depends upon a number of factors, chief 

 of which are: (i) the kind of wood; (2) size; (3) amount of abrasion and 

 wear and tear to which it is subjected; (4) damage by marine borers 

 (teredo, limnoria, xylotrya, etc.) ; (5) exposure to elements which encour- 

 age decay. Piles retained entirely underneath the surface of water or in 

 the ground will last almost indefinitely. 



