frequently so poor that the expectation of life of trees is frequently 



one-fourth to three-fourths of the normal. 



The increase of electric railroads, electric 

 lighting systems and telephone lines which have 

 their wires located, usually adjacent to the tree 

 belt necessitates a large amount of disfiguration 

 by pruning, and the close proximity of wires to 

 trees too frequently causes a serious injury to 

 them, in other ways. A tree that has been 

 severely pruned or disfigured by a mass of wires 

 is scarcely better than none. The telephone 

 companies are satisfied if they can cut their way 

 through the tree, the electric companies often 

 take in addition to this privilege that of burning 

 their way through. There are numerous in- 

 stances where trees are planted under a mass of 

 wires which are responsible for malformation 

 and restricted growth, and it is only a question 

 of time when either the trees or the wires must 

 give way. In cities, where it has become expe- 

 dient to bury the wires, we have one solution of 

 the problem, but in towns this expensive process 

 is not practiced to any great extent. In case 

 of telephone wires a greater use of the cable 

 would obviate much trouble ; electric light 

 wires, however, cannot be disposed of in this 

 manner. The best possible way to get rid of 

 them and, in fact, all overhead wires, if they 

 cannot be buried, is to locate them as much as 

 possible in the rear of buildings on private 

 property. 



Electrical injuries to trees cause the most 

 Fig. 2. Shoiijinp in- , . „„ i • j r ,. • 



jury by //;/^;/7^«V complanit I here are two kinds of currents in 



spjcrs on a j^wwi' use in towns and cities, namely, the alternating 

 7naple tree. ^^^^ ^^^^ direct. The voltage of the former may 



range from 1200 to loooo volts. That of the latter is usually about 

 500 volts. These two kinds of currents produce different physiolog- 

 ical effects upon vegetable life ; the alternating current being appar- 

 ently less disastrous to plant life than the direct current, and when 



