NAVAL STORES 



177 



by the storm under the two systems in one season. It is conclusive evi- 

 dence in favor of the cup system over the boxing method: 



Specifications for turpentining recommended by Schorger and Betts 

 are as follows: 



i. No trees under 10 in. in diameter shall be tapped; minimum 

 diameter to carry two faces, 16 in. ; no tree shall carry more than two faces. 



Photograph by Nelson C. Brown. 



FIG. 49. Western yellow pine tapped for naval stores products. Experimental area on 

 Coconino National Forest, Arizona. 



2. The faces on trees from 10 to 16 in. in diameter shall not exceed 

 12 in. in width, and the faces on trees above 16 in. in diameter shall not 

 exceed 14 in. in width. 



3. The height of the face shall not be increased by more than 16 in. 

 each year the tree is tapped. 



