164 THE BOOK OF FORESTRY 



tree to be moved the better the result in some cases 

 large trees ten to twelve inches in diameter must be 

 planted along an avenue or in a park to give immediate 

 results. In such cases the ground is dug away from 

 the roots with great care, leaving a ball of earth and 

 roots eight to ten feet in diameter. This tree is then 

 carried on a specially constructed truck to its new 

 position, where a larger hole partially filled with rich 

 loam has been prepared. By root pruning these trees 

 a year or two before they are to be transplanted much 

 better results may be obtained. 



The general care and upkeep of the city's trees of 

 course are his concern. Trees must be sprayed with 

 poisonous solutions to kill the army of leaf-eating in- 

 sects which may consume all the leaves of a large tree 

 in a short time. So serious have become the attacks of 

 some of these pests that many cities have purchased 

 high-power spraying trucks which will throw a fine 

 spray of the poisonous material to the tops of the high- 

 est trees. Such measures are necessary not alone on 

 account of the unsightly appearance of the leafless tree 

 but also because several such attacks will kill the most 

 vigorous specimens. Throughout New England count- 

 less elms are killed each year by the attack of the elm 

 leaf beetle, while the presence of the imported moths 

 in Massachusetts makes it necessary! to spray large 

 areas of wood land. 



Tree Surgery. The pruning of trees and the filling 

 of cavities, often spoken of as tree surgery, are phases 

 of city forestry which need expert knowledge. Far too 

 much of this work has been done in our American cities 

 by men whose only qualification was assurance. The 

 result has been tree butchery plus a large bill for 

 services rendered. The proper pruning of trees requires 



