346 BOARD OF AGRICULTURE. [Pub. Doc. 



to this trouble we have the danger of water setthng behind these guards 

 and causing serious decay; it is also an ideal lodging place for insects 

 of all kinds, especially the gypsy moth. All these guards have been re- 

 moved, and where it was found necessary the cavities behind them treated 

 in the proper manner. 



The method used in treating all the cavities was to remove every sign 

 of decayed and decaying wood; then in case of a large cavity staples are 

 driven into the wood near the edge of the wound and a wire screen cut to 

 fit the opening fastened into place. A small space is reserved at the top, 

 through which the first installment of cement is poured, this consists of 

 a composition of cement, sand and coarse gravel. After this has set, the 

 outside dressing of fine cement and sand is applied and the finishing 

 touches are added. Great care has to be taken here not to have the cement 

 overlap the cambium layer or growing part of the tree. After this has 

 thoroughly set the whole thing is painted with tar. Before the cement is 

 run into the hole, the wood is treated with creosote, to prevent its attack 

 by the fungous ant, and to kill any that may not have been reached when 

 the dead wood was being removed. 



The last operation that we have had to do in the case of these trees is 

 to place new wire guards around them, to remove the curbing where it is 

 pressing too close to the tree and to remove the sidewalk for a given number 

 of square inches around its base. From this place all the cobblestones 

 and other refuse that have been used in construction of the sidewalk is 

 removed and a fresh supply of loam put in its place. This gives the tree 

 a chance to expand and grow, and a chance for a small amount of water 

 and air to penetrate the earth. As a tree needs both of these elements 

 for its continued health, we have done just so much more towards its 

 accomplishment, and probably added several years of life to these trees. 



All this work not only prolongs the life of the trees themselves but adds 

 to the health and beauty of the street. Trees are not only beautiful to 

 look at (when properly cared for), and an addition to any street, but are 

 in themselves an addition to the health of that street, as they take up 

 carbon dioxide and other noxious gases from the air, and after breaking 

 this up and absorbing the carbon to make cellulose for their own tissue 

 building, they give back to the atmosphere pure oxygen. They are also 

 great equalizers of temperature, making it warmer in winter and cooler in 

 summer, because of the great amount of water transpired through their 

 leaves and cells. They are a benefit to the city which takes good care of 

 them because they attract outsiders, and often are the cause of bringing 

 new industries to your city. 



So much for the shade-tree problem of a city forester. Besides this 

 so-called tree surgery worl^ there are a number of diseases and insect 

 pests to be handled and preventive methods used in caring for them. 



Where the elm-leaf beetle is established, or where gypsy or brown-tail 

 moths have obtained a foothold, a power sprayer outfit is very essential, 

 and a well-defined spraying campaign should be carried out from early 



