NOTES ON THE VARIOUS SPECIES 257 



OAK 



The oak is so typical a tree that almost all of 

 the general rules apply perfectly to it. The wood 

 decays slowly and it is possible to make complete 

 and satisfactory excavations in a larger propor- 

 tion of cases in working on the oak than on almost 

 any other tree. The tree is also generally worth 

 the cost of the work, on account of its longevity 

 and its power of resisting storms and of accom- 

 modating itself to changing conditions. When 

 old it forms calluses slowly and wounds must be 

 kept well covered. The apparent soundness of 

 the surface of an exposed area of wood may mask 

 a considerable thickness of decay just below it. 



Though the common supposition that oak limbs 

 are exceptionally strong is well-founded, in some 

 cases extra caution must be employed in climbing 

 oak trees. The long limbs of open-land red oaks 

 are sometimes so infested with boring insects and 

 fungous decays, that they snap off without the 

 slightest warning, though apparently quite large 

 and strong enough to bear a considerable weight. 



SYCAMORE 



Sycamores are very frequently quite hollow. 

 As the tree bears pruning well, it is always wise to 

 consider the possibility of severe pruning as an 

 auxiliary to other restorative measures. The 



