12 BULLETIN 352, U. S. DEPARTMENT OF AGRICULTURE. 



Pulp mills may pay as high as $12 per thousand board feet, in the 

 log, and accept crooked logs. This fact is important in view of the 

 low "mill run" value of hemlock lumber, which is rarely much over 

 $15 per thousand board feet at the rnill, and for which crookedness 

 is a more or less serious defect. The pulp mills also prefer to receive 

 their wood peeled, and will often pay $1 more per thousand board 

 feet for peeled than for unpeeled logs. Peeled logs are cheaper to 

 transport and more durable than unpeeled ones, and there is no ex- 

 pense for rqssing. On the other hand, stripping tanbark from saw 

 logs often greatly reduces their value, due to the serious checking 

 which results. Bark peeling can be done more profitably when logs 

 are cut for pulp than for lumber. 



The value of hemlock cordwood in Wisconsin is about $3.50 per 

 cord when logs are selling at $8.50 per thousand board feet, and about 

 $4 per cord when logs sell at from $9 to $12 per thousand. The cost 

 of getting out cordwood is about $2.50 or $3 a cord. Until quite 

 recently hemlock pulpwood stumpage at many places in Wisconsin 

 has been valued at 50 cents a cord. 



TANNING. 



Hemlock bark has been used in tanning practically ever since the 

 beginning of the industry in America. Oak bark is preferred, since 

 it makes the leather softer, more pliable, and less permeable to water 

 than does hemlock; but there is not as much of it, and for many 

 years its annual consumption in tanning has been less than half that 

 of hemlock. With the introduction of tanning extracts, hemlock 

 and oak were the first native species to be used, but after the process 

 by which extract could be made from chestnut wood was perfected, 

 about 1900, the latter species became the leading source of supply. 

 In 1909 it supplied practically half the extract used, while the amount 

 supplied by hemlock had fallen to about 3 per cent of the total quan- 

 tity. The amount of hemlock bark made into extract was never a 

 large part of the total hemlock bark consumed in tanning; in 1900 it 

 formed about 1 per cent, in 1907 and 1908 slightly exceeded 8 per 

 cent, and in 1909 had fallen to less than 3 per cent. 



Table 5 gives the total annual consumption of tan bark and extract 

 in the United States, with the proportion supplied by each of the 

 leading native species, and the value per cord of hemlock and oak 

 bark. The figures are from census reports for different years. For 

 convenience, the percentage figures, when they include decimals, are 

 expressed as the nearest whole number. 



