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AMERICAN FORESTRY 



No. 1. Cement filling 

 shattered by cold 

 weather and sway- 

 ing of the tree. 



No. 2. Cross section 

 showing method of 

 covering cavity with 

 sheet metal. 



No. 4. A long cavity with 

 nails and cement rein- 

 forcing rods in place 

 ready for filling. This 

 cavity should have been 

 bolted. 



No. 3. Section of tree trunk 

 showing simple method of 

 attaching a guy chain to a 

 hook bolt. 



No. 5. An open shal- 

 low cavity ready for 

 creosote and tar. 

 Shallow cavities of 

 this type are not 

 usually filled with 

 cement. 



PLATE NO. 6. A DAMAGED CEMENT FILLING, TYPES OF UNCEMENTED CAVITIES, AND CROSS 

 SECTION SHOWING METHOD OF ATTACHING A GUY CHAIN. 



ter is not injured in the operation (Plate 

 No. 4, figure 5 and plate No. o, figure 1 ) . 

 If the cement is allowed to become too 

 hard to trim with the trowel, it can still, 

 with more or less difficulty, be cut back 

 to the cambium line with a cold chisel 

 and hammer. It is a rule with most 

 tree surgeons to trim back the outer 

 surface of the cement to an eighth of 



an inch or more below the cambium 

 and then use a layer of stronger cement 

 (one part of cement to one or two of 

 sand) to raise it to the level of the 

 cambium, after the filling has partially 

 hardened. 



The thinner mixtures of cement will 

 set more firmly. If any mixtures thin- 

 ner than the one already mentioned are 



