SHADE TREES. 



161 



should be treated antiseptically to prevent deca5^ Strictly horizontal cuts 

 should never be left. They retain water so that rot is likely to result, and 



Fig. 21. — Showing the evolution of a cavity and method of treating it : (o) long stub left 

 from pruning; (6) beginning of decay; (c) more advanced stage; (d) cavity formed 

 in the wood; (e) longitudinal section of the trunk showing cavity; (/) cavity cleaned 

 out and ready for orifice covering. 



Fig. 22. — Method of pruning large limbs: (a) tree before pruning; (6) showing relative 

 distance of first cut from tlie tree trunk; (c) the same with limbs cut close and the 

 scars finished with mallet and chisel. 



the cleaner the cut the better it will heal. There is, moreover, less chance 

 for subsequent rotting. 



