UTILIZATION OF FOREST PRODUCTS 185 



contain more wood than those of small pieces, while round sticks 

 give a higher wood volume than split ones of about the same size. 

 The relative price of various kinds of wood depends upon its 

 heating value and the rate at which it burns. Compared with 

 coal, the heating value of different species is about as follows: 

 one ton of coal is equal to a standard cord of hickory, oak, beech, 

 birch, hard maple, ash, elm, locust or cherry; a cord and a half 

 of soft maple; and two cords of cedar, poplar, or basswood. 

 For fire places old applewood is in great demand, and brings a 

 high price. 



Lime kilns and brick yards use a great deal of wood, which they 

 buy in four- or five-foot lengths. They can use very low-grade 

 material and, therefore, do not pay high prices for it. In northern 

 New England and New York the poorest of all wood, namely 

 dead and down trees, can be used to a large extent in boiling sap. 

 " Sugar wood," as it is called, has practically no stumpage value. 

 In fact, in most woodlots there is much of this kind of material 

 going to waste; and the owner would be benefited if he could 

 give it away. 



Tanning Bark. The purpose of tanning is to render the skin 

 permanently supple and durable by impregnation with tannin. 

 There are several methods of tannage in use including that 

 employing " vegetable tanning," 1 of which the forest produces 

 several products. Chief of these are hemlock and oak bark, and 

 chestnut wood. Hemlock bark has a tannin percentage of 13 

 per cent; chestnut oak bark, 12 per cent; chestnut wood, 8 per 

 cent. There is no tannin in the corky outer layers of bark. 

 Fresh bark contains on an average, 45 per cent water and shrinks 

 heavily during the drying process. While oak bark must be 

 peeled in the spring immediately when the sap begins to rise, 

 hemlock bark may be peeled at any time from May to September, 

 peeling best in July. Dying trees will not peel. One cord of 

 bark is produced on an average from 1500 board feet of hem- 

 lock. Bark is sold by the cord, but by a "cord" is meant 2240 

 pounds. 



1 Logging and Lumbering or Forest Utilization, by C. A. Schenck. 



