104 PRACTICAL TREE REPAIR 



1. The decaying wood is completely removed, 

 the mouth of the cavity being enlarged as much 

 as may be necessary to accomplish this. 



2. The mouth of the cavity is so shaped as to 

 insure a proper retention of the filling, and as to 

 facilitate the healing of the wound. 



3. Braces are put in to strengthen the tree, re- 

 tain the filling, and prevent the opening of cracks 

 around it. 



4. The interior of the cleaned cavity is treated 

 and dressed in such a way as to prevent the rein- 

 fection of the wood by fungi, and, in so far as is 

 possible, to produce a water-tight connection be- 

 tween the filling and the wood. 



5. The cavity is filled, care being taken that the 

 surface of the filling is so arranged as not to inter- 

 fere with the natural healing of the wound. 



6. The surface of the filling is so treated as 

 to make it water proof. 



This outline may help to give unity to the rather 

 piecemeal handling of the subject-matter of the 

 chapter which is unavoidable from this point on. 

 We shall first discuss the tools which are used in 

 this branch of tree repair, then the materials, and, 

 finally the methods. 



TOOLS 



The tools used in cavity work are those nat- 

 urally suggested by the kind of work to be done. 



