202 PRACTICAL TREE REPAIR 



farther from the crotch. Light materials can be 

 used for rather heavy jobs if this principle is em- 

 ployed. 



As a rule the brace should not be pulled up taut. 

 If chain or wire is used a little slack should be left, 

 and long rod-iron braces should always be jointed. 

 The reason for this is that a branch can normally 

 sag a few inches without danger, and it is only 

 when this safe elasticity has been used up that the 

 brace is needed and should come into play. At 

 this point the strength of the brace is added to the 

 strength of the limb. If the natural sag of the 

 limb is not permitted, the brace must assume the 

 entire strain the moment an unusual burden is 

 placed on the limb. The amount of slack re- 

 quired depends, of course, on the distance of the 

 brace from the crotch. Where the purpose of the 

 brace is to close up a crack obviously no slack can 

 be allowed. 



Various materials are used for braces. Form- 

 erly, chain was much used. It has the advantage 

 of being rather easily applied, if hooked bolts are 

 used, but is expensive, conspicuous, and easily 

 rusted. Rod-iron is equally expensive, very diffi- 

 cult to adjust, often noisy, and requires frequent 

 trips to the blacksmith's while work is in progress. 

 Of late years the writer has come to depend on 

 heavy wire for light work and the various sizes 

 of steel wire rope for heavier work. This ma- 



