64 TREE PRUNING. 



had if grown under normal conditions ; the trunk 

 lengthens and thickens regularly, giving to the tree 

 an economic value for many purposes of construction, 

 and especially for the masts and spars of vessels. 



As a Pine grows, the lower branches die and dry up. 

 The resin with which these are impregnated prevents 

 their decay ; and these dead branches, embedded in the 

 new wood form the knots which interfere with the 

 growth of the tree and produce holes in the boards 

 and planks cut from it. Such defects can be greatly 

 diminished by cutting off all dead or dying branches 

 close to the trunk ; while a coat of coal-tar will pre- 

 vent or reduce the flow of resin from the wound. 



The practice of leaving a short stump to an ampu- 

 tated branch, adopted by some persons to prevent the 

 loss of sap, although less objectionable in the case of 

 coniferous trees, should never be 

 adopted. Such stumps must be 

 cut again the following year close 

 to the trunk, or cushions of wood 

 will form about their base, cover- 

 ing the trunk with protuberances 

 (Fig 53). These greatly injure 



pi?. 53. Effect on the foe appearance and value of the 



Pines of leaving the stump . 



of an amputated branch. tr66, aild nCCCSSltate, Should it 



be found desirable to remove later such excrescences, 

 wounds two or three times as large as an original cut 

 close to the trunk would have made. 



The custom of pruning Pines is very general in 

 France, and is often carried to excess. The removal 



