with the cambium (growing layer of the tree). Before filling 

 large cavities, flat-headed wire nails 2 1 / to 3 inches long are 

 driven about half their length into the interior, to hold the 

 cement. The cement is reinforced with iron rods and cross 

 bolts. The filling is then built up in blocks of 8 to 12 inches, 

 each block being separated by sheets of heavy tar paper. 

 Large solid fillings of cement are apt to be cracked when the 

 tree sways in the wind. When it is not advisable to go to the 

 expense of filling, much good is done by treating the cavity as 

 recommended above, following with an extra coating of tar. 

 Split crotches should have all decayed wood removed from the 

 split, and creosote and tar applied. Bring the limbs back to 

 their proper position, using rope and tackle if necessary, and 

 hold them in place by means of bolts through each limb, con- 

 nected by chains. Counter-sink the head of the bolt. Thor- 

 oughly coat with tar the cuts made for the bolt, and the edges 

 of the crack. Cavity filling is advisable only when the tree is 

 a highly valued specimen. Old unsightly cripples and trees of 

 poor species are much better taken down and replaced with 

 new trees of desirable kinds. The need of tree surgery at a 

 future time will be very largely removed by promptly attend- 

 ing to the fresh injuries of today. 



Beware of fake doctors. There are reliable tree surgeons, 

 and many who are not. The owner should investigate before 

 employing outsiders to repair his trees. If the owner chooses 

 to do the work, it is mainly a matter of common sense to make 

 needed repairs. However, if it is desirable to employ an ex- 

 pert to do the work, the owner should investigate his stand- 

 ing before employing him, and should closely superintend the 

 work to see that it comes up to the specifications of the writ- 

 ten contract. 



Co-ordination of effort is necessary in any community, large 

 or small, to obtain the greatest beauty and benefit from shade 

 trees. In this way it is possible to secure uniformity in the 

 use of species, proper pruning, and efficient control of insect 

 and fungus invasions. A number of states have laws govern- 

 ing the planting of street and roadside trees. If there is no 

 shade tree commission or city forestry systematically develop- 

 ing the tree welfare of your community, interest yourself in 



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