400 PRINCIPLES AND PRACTICE OF PKUNIN6 



drainage provided, yet no one can tell the difference after the cavity 

 has been filled or covered unless the tilling or covering be re- 

 moved. A cavity filled with cement or other material before the 

 decayed and diseased wood has been wholly removed is nearly com- 

 parable to a tooth from which the decayed matter has been only 

 partially removed by the dentist before it is filled. 



308. Misuse of the pruning hook. — Too commonly the ordinary 

 workman will get into the top of a tree and use his long pruning 

 hook to break off the small dead branches, in the same manner that 

 he would use a club for a like purpose. When so used, the pruning 

 hook will inevitably cause many injuries to the young bark of ad- 

 joining branches and make wounds through which disease and de- 

 cay germs may enter. In this manner many new openings for the 

 possible entrance of disease may be created in addition to the one 

 already existing in the dead branch, for it must be remembered that 

 merely breaking off the branch does not prevent decay from con- 

 tinuing at this point, while every new bruise or wound may furnish 

 a new point for decay to enter. 



309. Climbing devices. — On various occasions we have seen work- 

 men in the employ of well-known tree surgery firms repeatedly jab 

 their climbing spurs into the bark on horizontal limbs where it 

 would have been much easier for them to move about without us- 

 ing spurs at all. The use of climbing spurs on trees should be 

 avoided, or at least severely discouraged. It would be best if they 

 were never used. Every wound made by one of these spurs may be- 

 come the center of a new region of decay if conditions favorable 

 for the growth of decay organisms exist. The use of spurs should 

 be strictly prohibited on all parts of a tree subject to a contagious 

 disease above ground, especially if the disease is known to exist 

 in the vicinity. A man who uses spurs on the trunk or on limbs 

 that may readily be reached by a light ladder should never be al- 

 lowed to work on trees. Firms which permit their workmen to do 

 this should be classed as undesirable or dangerous firms to deal with 

 and accordingly avoided. Many trees have been irreparably dam- 

 aged and left in far worse condition after ignorant or indifferent 

 workmen equipped with climbing spurs and pruning hooks have 

 worked in them than if nothing had ever been done to them. The 

 edges of the soles and heels of leather shoes, to say nothing of 

 protruding nails, commonly cause considerable injury to soft and 

 tender bark. Probably the best and safest footwear, from the point 

 of view of preventing injury to the tree, is some form of rubber- 

 soled shoe, such as tennis shoes or "sneaks." All properly equipped 

 firms of tree surgeons have ladders that will reach 40 or .50 feet or 

 more into a tree. Ladders, ropes and rubber-soled shoes will al- 

 low a man to reach practically every part of a tree that can be 

 reached by climbing spurs. 



Reliable estimates indicate that it takes somewhat longer (per- 

 haps 25 per cent on an average) to do the required work on a tree 

 When ladders, roces and rubber-soled shoes are used instead qf 



