FOREST UTILIZATION 15 



III. By hewing "out of the pan," a method used for valuable heavy 



boles. Uncertainty of fall is counterbalanced by a gain in the 

 length of the bole. The bole thus obtained is said to show 

 less heart shakes. 



IV. By using the two-handed cross-cut saw alone, without the help 



of the axe, a method not advisable for the reason that the 

 fall of the bole cannot be directed. 



V. By joint use of cross-cut saw and axe. The axe cuts a kerf on 

 the falling side, the depth of which is 1/4 to 1/5 of the diam- 

 eter, and the innermost point of which lies on a level with 

 the saw kerf. When the saw begins to pinch, drive wedges 

 behind the back of the saw. Withdraw the saw when the 

 tree begins to shake heavily and force it to fall by wedging. 



Advantages of this method are : the trees are easily directed at 

 a small loss of timber. 



Disadvantages are: several tools and several men are required. 

 In very thick woods and on very rocky, steep slopes, the use 

 of the saw is not advisable or possible. Careless wedging may 

 cause the bole to split at the butt. The saw and the wedge 

 are said to be responsible for heart shakes. 



B. Obtaining bole with stump and roots : 



It is essential to thoroughly sever the main roots with axe, mattock 

 and pick. The tree is then forced over by a tree-felling machine, 

 or with a rope fastened to a high limb. 



Advantages are : longer bole ; gain of lumber 8 % to 10 %. Possi- 

 bility of obtaining knees for ship building (tamarack and white 

 oak). The tree falls gently, its fall being checked by the roots 

 so that the bole shows less splits, cracks and wind shakes. The 

 bole is less apt to break and can be allowed to dry out gradually. 

 Further, root-breeding insects don't find any incubators and agri- 

 cultural use is facilitated. 



Disadvantages are: greater expense, more tools, axes ruined in cut- 

 ting roots, extra saw cut required to sever the butt log from the 

 roots and, above all, the delay in finishing the logging job. 



C. Criteria of a good method : 



I. Danger to workmen. 



II. Total net value obtained. 



III. Wastefulness. 



IV. Possibility of throwing the tree in the desired direction. 



D. Pollarding before felling: 



The branches or the tree tops in European logging are frequently 

 lopped off before felling, for the following reasons : 

 I. The younger generation of trees surrounding the tree to be 

 cut receives less injury. 



II. Lopped trees touch the ground all along the bole at one and 



the same time. Hence no danger j& the boles breaking or 

 splitting. In addition, a reduced crown causes the tree to 

 fall with decreased force. 



