204 PRACTICAL TREE REPAIR 



bolts are used. It must be just the size of the 

 bolt-head and its floor must be at right angles to 

 the hole, regardless of the bark. It may be shal- 

 low or deep, but must be sunk through the bark 

 and at least an eighth of an inch into the wood. 



', ^ -. \N(/t&nd washer 

 \ \ \ sunk in round 

 \ x , x \coffer ,,,,], 



Diagram of bolt through a limb, and views from above of 

 both ends of the bolt 



If the head is sunk in to the level of the cambium 

 it will be quickly grown over, but that is an ad- 

 vantage of appearance only. A similar coffer, ex- 

 cept that it is round, to receive the washer, must be 

 made at the other end of the hole. Now run a 

 wire or stick through the hole and get the length 

 of the bolt. The bolt being selected or prepared, 



