MANUFACTURE OF BY-PRODUCTS. ed s 
An average of probably 5 per cent of the timber put into streams 
for driving is lost. On long drives and rough streams a small part 
of this damage is unavoidable. But it can probably be reduced on 
the average by more than half by peeling and drying out logs of 
kinds which do not float well, by stream improvements, and by rea- 
sonable care on the drive itself. 
ECONOMY IN THE MILL. 
An average of more than one-third of the wood in the log is’ 
wasted in the mill. It is practicable, under present conditions, to © 
reduce this nearly one-half. This means the use of thinner saws, 
or more band saws and resaws, and the disuse of gang saws. It 
means better machinery, more careful manufacture, and the sawing 
in round edge or “ waney” form of lumber which is worked over 
again before being finally used. It means the change of grading 
rules and market usage to admit random widths, odd lengths, and 
shorter and narrower pieces, and to allow defects which do not seri- 
ously reduce the value of the product for the use to which it is to be 
put, and it means fuller utilization of short boards, slabs, and waste. 
MANUFACTURE OF BY-PRODUCTS. 
Even when forest products are manufactured and used econom- 
ically great opportunity remains for the conversion of wood not 
utilized in logging or in the mill into useful by-products by chemical 
and other means. As timber becomes more valuable we approach 
more nearly that complete utilization in which every part of the 
felled trees will be used. 
Tf all the wood wasted in the manufacture of yellow-pine lumber 
in 1907 had been steam distilled for the production of wood turpen- 
tine, it would have yielded more than the total production of gum 
turpentine in that year. If all the wood wasted in the manufacture 
of lumber from spruce, hemlock, poplar, and cottonwood in 1907 
had been used for paper making, it would have furnished all the 
paper made from wood in that year. If all the wood which went 
to waste in the manufacture of chestnut lumber in 1907 had been 
used to make tanning extract, we would have produced twice as much 
as was produced from the chestnut cord wood used for this purpose. 
The waste in the manufacture of beech, birch, and maple lumber in 
1907 was nearly equal to the quantity of these woods cut for distilla- 
tion. The waste in the manufacture of oak lumber was twice the 
quantity of all hardwoods used for distillation. These are some of 
the great examples of the failure to use wood fully. 
[Cir. 171] 
