PRUNING TREES 167 



of light spruce or pine with hickory rungs, a good pruning 

 knife, plenty of coal tar, a fire-can to heat the tar, a pole- 

 brush, a small hand brush and plenty of good rope com- 

 prise the principal equipment of the pruner. 



SUGGESTIONS FOR THE SAFETY OF TREE CLIMBERS 



1. Before climbing a tree, judge its general condition. 

 The trunk of a tree that shows age, disease, or wood- 

 destroying insects generally has its branches in an equally 

 unhealthy condition. 



2. The different kinds of wood naturally differ in their 

 strength and elasticity. The soft and brash woods need 

 greater precautions than the strong and pliable ones. The 

 wood of all the poplars, the ailanthus, the silver maple 

 and the chestnut, catalpa and willow is either too soft or 

 too brittle to be depended upon without special care. The 

 elm, hickory and oak have strong, flexible woods and are, 

 therefore, safer than others. The red oak is weaker than the 

 other oaks. The sycamore and beech have a tough, cross- 

 grained wood which is fairly strong. The linden has a 

 soft wood, while the ash and gum, though strong and flexible, 

 are apt to split. 



3. Look out for a limb that shows fungous growths. 

 Every fungus sends fibers into the main body of the limb 

 which draw out its sap. The interior of the branch then 

 loses its strength and becomes like a powder. Outside 

 appearances sometimes do not show the interior condition, 

 but one should regard a fungus as a danger sign. 



4. When a limb is full of holes or knots, it generally 

 indicates that borers have been working all kinds of gal- 

 leries through it, making it unsafe. The silver maple and 

 sycamore maple are especially subject to borers which, 



