424 APPENDIX. 



management for private owners has in many places become 

 possible only through the wood pulp industry.' 1 '' 



This would indicate that in Germany it is the small-sized 

 material, the tops, which go into this manufacture, while with 

 us the logs are used, the tops are left in the woods, and no 

 provision for re-growth is made. 



P. 28. Substitution of Other Materials. Whatever the 

 reasoning regarding the possible substitution of other mate- 

 rials for wood, the historical evidence so far has been the 

 other way : new and more extensive use of wood has accom- 

 panied the development of these other materials. 



The increase of wood consumption parallel with the increase 

 of consumption of its substitutes, coal, iron, and stone, simply ac- 

 centuates the influence of the great modern industrial develop- 

 ment and increase of civilization, which means increase in wants. 



P. 28. Tanning Bark. The leather industry, which in the 

 year 1900 produced, with a capital of over $356,000,000 

 and a wage of over $105,000,000, a product valued at over 

 $615,000,000, relies for the tanning, in spite of the in- 

 creased use of substitutes, still mainly on the bark of two 

 kinds of trees, namely, oak and hemlock. Of the amount 

 spent for tan materials ($17,000,000), nearly $12,000,000 is 

 for such bark and bark extracts, denoting a consumption of 

 about i million cords of tan bark, as against about half that 

 consumption in 1880. 



The consumption of hemlock bark is nearly three times as 

 great as that of oak. Consequently the largest production is 

 to be found in western Pennsylvania and New York, where 

 the largest supplies of this material are to be found, these two 

 States producing about half the cordage consumed. One ton 

 of hemlock bark will tan about 300 pounds of sole and 400 

 pounds of upper leather. The usual harvest of hemlock bark 

 averages 12 to 15 cords per acre, worth $6 to $7 per cord. 

 As long as the timber is used afterwards, which is now prob- 

 ably done in most places, this utilization of a by-product is 

 one of the important economies in forest utilization. 



