SHADE TREES. 



167 



the wood tissue. As the transpiration current remains practically normal 

 because checking of the wood is prevented, trees will support a large 

 amount of foliage even when badly girdled. Painter's oil is especially 

 suitable for bark wounds. These should be first properly shaped and 

 their surfaces scraped before applying the oil or other substances. Prac- 

 tically all disinfectants injure delicate tissue such as the cambium layer, 

 but it should be borne in mind that the cambium always dies back to a 

 certain extent when exposed to the air, and more of this dying back 

 results from dessication than from the use of antiseptics. All antiseptics 

 must be used with judgment, especially when the vital tissues are likely 

 to be seriously injured by their use. 



Chaining and Bolting Trees. 



It often becomes necessary to bolt or chain trees to render them more 

 secure and to prevent injury and disfiguration. As this process is not 

 necessarily always an expensive one it should be 

 much more commonly employed, many valuable 

 trees having been made practically worthless by 

 the loss of large limbs during wind storms, etc. 

 Although the elm is a very tenacious tree with 

 wood that is very difficult to work up into fuel, it 

 is very likely to split. For this reason it is advisable 

 to chain and bolt elms and any other trees which 

 show a tendency to weakness. For an outlay of 

 from S10 to $15 it is often possible to save a tree 

 worth S150 to $200 from destruction. 



Different devices are employed for strengthening 

 trees. Some of these are objectionable and do more 

 harm than good. It has been a common practice 

 to place chains around limbs to prevent then* split- 

 ting, but as the tree develops the chains become 

 imbedded in the bark, resulting in partial girdling, 

 and ultimately disfiguring and injuring the tree. 



Another equally objectionable method which invariably results in 

 girdling consists in placing strong bands of iron around limbs and trunks. 

 For making trees more secure some prefer to use an iron rod rather than 

 a chain, and although both have their place, in our estimation the chain 

 system is the better for most purposes. If it is necessary to fasten branches 

 near the point of forking where swaying is limited an iron rod is prefer- 

 able; but for connecting limbs a few feet apart more or less remote from 

 their junction with one another (where swaying is more pronounced) the 

 chain method is superior. A rod is likely to break when the tree is swayed 

 by the wind owing to its rigidity, whereas a chain, which is flexible, will 

 stand the strain better. Moreover, a chain is easier to place than a solid 

 rod, as less attention has to be given to boring the holes. However, if 



FIG. 28. Girdling by 

 chain placed around 

 tree. 



