The Enemies of Trees 

 INJURIES TO TREES FROM ELECTRIC WIRES 



The damage done to roadside trees offsets to an alarming 

 degree the benefits derived by the pubHc from the telephone 

 and the trolley. The poles are set in the line of the trees, and 

 the wires threaded between them. The limbs that might strike 

 the wire when the wind is high are hacked oflf. Miles of road are 

 lined with trees ruthlessly beheaded and utterly ruined under 

 the direction of the foreman in charge of the pole setting. The 

 workmen proceed rapidly through a section of country, passing 

 from one property to another. They keep an eye out for ob- 

 jections; the owners could make them a great deal of trouble. 

 But rarely is there concerted action, unless it be a mass meeting 

 to bewail the damage after it is done. Then things settle down, 

 and the poor maimed trees do their best to heal their wounds 

 and to grow new tops. As they reach up they encounter 

 the wires, and this interferes with the service. The offend- 

 ing trees are shorn again. They finally become stunted old 

 pollards, throwing up groves of straight water sprouts, 

 year by year, if they are by nature inclined to sprout from 

 stubs. 



"Burns" that cost the lives of large limbs are proved to 

 result from contact with electric wires passing through treetops. 

 Proofs are also indubitable that trees are killed by the same 

 cause. Investigations made by the Experiment Station of the 

 Massachusetts Agricultural College in 1903 led to the following 

 conclusions (Bulletin No. 91): 



1 . The high resistance offered by trees serves as a protection 

 against death from an electrical contact.* 



2. There are cases where the direct current, used in operating 

 street railways, has killed large shade trees. 



3. Electrical currents act as stimulants to growth up to a 

 certain degree of intensity. Beyond that degree, growth is 

 retarded, and the death current is the maximum. 



4. The greatest damage caused by alternating and direct 

 currents is by local burnings. The stronger the voltage the 

 greater the injury. 



5. There is practically little or no leakage from wires during 



* Wood is a non-conductor when dry, but when wet it is a partial conductor. After a 

 rain one often sees sparks in trees caused by electric wires that touch the branches. 



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