4 BULLETIN 983, U. S. DEPARTMENT OF AGRICULTURE. 
After the amount of the bark is deducted there remains m the form 
of waste 5S 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 m ill s 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 amoimt. 
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 requirernents, 
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 binned 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 86.000,000 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 the lumber 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. 
