4 BULLETIN 983, U. S. DEPARTMENT OF AGRICULTURE. 



After the amount of the bark is deducted there remains in the form 

 of waste 58 cubic feet of solid wood to 1,000 board feet of lumber cut, 

 or 2,320,000,000 cubic feet annually. As the average weight of a 

 cubic foot of air-dry wood is about 35 pounds, 4 this is a total annual 

 waste of 40,000,000 tons. Some of this total annual waste is used for 

 fuel at the mills, or may have a fair market value if the mills are 

 located in centers of population; but it is estimated that over one- 

 half, or 20,000,000 tons, is absolute waste, and that about 15,000,000 

 tons of this is from coniferous woods. 



According to data for 1907 submitted to the Forest Service by the 

 lumber manufacturers, 650 mills were reported to be cutting between 

 10,000,000 and 25,000,000 feet a year; 161 mills between 25,000,000 

 and 50,000,000 feet; 39 mills between 50,000,000 and 100,000,000 

 feet; and 2 mills over 100,000,000 feet annually. This is a total of 

 852 mills, each of which cuts 10,000,000 or more board feet a year. 

 For 1913, each of 974 mills was reported as cutting this amount. 

 This shows that the number of large operators is increasing instead 

 of decreasing, and that the supply of raw materials is so concen- 

 trated as to be available for any use to which it can be put. 



THE PRESENT VALUE OF WOOD WASTE. 



Most of the wood waste produced to-day is valuable only for fuel 

 for the production of power at the mill. In some places methods of 

 closer utilization have been worked out; but, compared with the total 

 amount of wood waste produced, the quantity of material so utilized 

 is negligible unless the mills are located in or very near large cities. 



Most mills produce waste in excess of their own power requirements, 

 and in large mills equipped with especially efficient power plants this 

 excess is from 50 to 65 per cent of the total amount produced. A 

 waste burner, therefore, is almost invariably necessary, and its use 

 involves not only a loss of large quantities of wood, but also a fixed 

 charge for its operation. The cost of burning waste varies widely 

 with the size and efficiency of the mill, but figures gathered by the 

 Forest Products Laboratory indicate that it ranges from 30 to 66 

 cents a cord. Assuming that 37 cubic feet are burned for each thous- 

 and feet board measure of lumber cut, this is a charge of from 11 to 

 22 cents a thousand feet on all of the lumber cut, and means that the 

 present cost of waste disposal amounts to about $6,000,000 annually, 

 in addition to the value of the wood. 



The wood waste available has great potential value, but its utiliza- 

 tion has not as yet reached the stage where the waste has much more 

 than a nominal value. 



4 The green weight, log scale, of yellow pine will range from 9,000 to 10,000 pounds to the thousand feet, 

 and the green weight of thelumber produced will range from 4,200 to 4,600 pounds. Allowing for the usual 

 15 to 20 per cent overrun, we ordinarily get about 4,500 pounds of waste to 1,000 feet of yellow pine cut. 

 The waste from other species will vary in the proportion of their respective weights to the cubic feet or to 

 the thousand feet, log scale. 



