POLE TO POLE AND PILLAR TO POST 21 



mum service. Generally speaking, the life of a 

 creosoted post is about twelve to sixteen years, or 

 twice that of one in the natural state. 



Without wood tunnel props, shaft lining and ties 

 for narrow gauge railroads the production of soft 

 coal in this country would stop tomorrow. Our 

 greatest remaining and hitherto undeveloped re- 

 sources of iron ore can be successfully tapped only 

 with the aid of wood, while many of our precious 

 metals are found in strata so soft that thousands of 

 wood supports can alone prevent a cave-in. Wood 

 props are also used to a varying extent in anthracite 

 coal mines, salt mines, lime quarries, and in every 

 industry where tunneling is necessary. Indeed, for 

 these purposes more than 200,000,000 cubic feet of 

 wood are consumed every year. 



The utilization of wood for the purposes enumer- 

 ated in this chapter bears a very interesting relation 

 to the solution of the whole wood supply problem. 

 The public is now beginning to regard trees as an 

 agricultural crop which must be planted and pro- 

 tected in the same way as any other, but there nat- 

 urally exists considerable hesitancy in planting a 

 crop which requires a lifetime to mature. Poles, 

 fence posts, mine props and the like, however, may 

 be cut from young trees fifteen to thirty years of 

 age. They are rightly products of the local wood- 



