THE USES OF WOOD 



339 



the freight charge by approximately seventy-five cents 

 calculated on the average shipment. The owner of the 

 lumber usually planes it at his own expense and saves 

 in freight more than the cost of planing. 



It is poor economy to ship lumber that is not fairly 

 dry. Some is piled to season in the open air, other for 

 quicker results is placed in kilns. The weight of a thou- 

 sand feet of lumber is reduced through drying by at 

 least 1,000 pounds, and the weight of some kinds is 

 reduced more than 2,000 pounds, and the freight cost is 

 lessened accordingly. The saving amounts to $1.50 a 

 thousand feet, on an average, if the weight is reduced 

 only 1,000 pounds. "Shipping weight" is a term in 

 use for lumber that has had its weight considerably 

 lessened by seasoning but which has not yet reached that 



it may be merely surfaced or planed and in that form 

 go to its ultimate use. Other lumber passes through 

 several processes before it is converted into finished 

 products. The amount of detail in such manufacture 

 depends upon the industry to which the lumber is sent. 

 A number of industries, in fact, most of them, employ 

 special machines and pass the wood through compli- 

 cated processes to convert it into commodities. 



In the United States Forest Service's investigations 

 of wood utilization, fifty-six industries were recognized 

 in which wood is employed as raw material for further 

 manufacture. The country's lumber output may be 

 divided into two general classes: first, that which is to 

 be used without further manufacture ; second, that which 

 is sent to shops and factories where it undergoes addi- 



A LUMBER YARD AERIAL RAILWAY 



The highest development of lumber movement in the yard is by the overhead railway. The lumber car is swung beneath the rail and moves 

 rapidly, clear of all obstructions, to the precise point desired, and the load is there released. Only the largest yards have this system of 

 railways. They are not profitable on a small scale. 



state of dryness fitting it for factory use. Before "ship- 

 ping dry" lumber is ready to be worked into finished 

 commodities, like furniture or vehicles, it must be sent 

 through the kiln or must spend a considerable time in 

 the open air. 



About forty-five per cent of the total quantity of 

 lumber turned out by the sawmills of this country, is 

 used in its rough form, without further manufacture, 

 for such purposes as railroad cross ties, trestles, bridges, 

 house frames, scaffolds and fences. The remaining 

 fifty-five per cent of the lumber production is further 

 manufactured before it reaches its final use. Most of 

 it passes through shops and factories, though some of 



tional processes. The second class includes a little more 

 than half of all the lumber produced by sawmills in 

 this country. The fifty-six industries to which it goes 

 do not receive equal amounts. One may demand a hun- 

 dred times as much as another. The largest call comes 

 from planing mills that make flooring, ceiling, cornice, 

 siding and similar stock which is used chiefly by builders. 

 More than half of all lumber going to factories for fur- 

 ther working is taken by the planing mill industry. So 

 numerous are the articles turned out by such mills that 

 it is not practicable to compile a list of them. 



Though the planing mill industry exceeds in impor- 

 tance all the rest of the fifty-six, some of the others are 



