Periodical Literature 



115 



The rate of deterioration depends largely upon the age and size 

 of the tree. The larger the proportion of sap wood the more 

 extensive the damage during the first two or three years. Check- 

 ing, which is in many cases the most serious cause of deterioration, 

 is maximum in the young smooth-barked trees and in the topwood 

 of older trees. 



The wood of diseased trees may safely be used for any purpose 



where chestnut is suitable, since it is not injiu*ed by the disease. 



Strength tests conducted by the Forest Service indicate that 



sound wood from blight-killed trees is fully as strong as wood 



from healthy trees. Disease cankers or lesions on chestnut poles 



are no reason for rejecting material. In the experiments conducted 



at Mt. Gretna, Pa., it was found at the end of a year that all 



lesions on poles cut from blight-killed and infected trees were hard 



and sound even below the ground line where adjacent sapwood was 



rotted and burrowed by white ants. 



S. J. R. 



The Use of Blight-killed Chestnut for Poles, by J. C. Nellis. National Electric 

 Light Assn. Bulletin (N. Y.), Dec, 1914, pp. 693-695. 



Properties of 

 Wood 



A rough but convenient comparison of 

 the properties of many commercial woods is 

 condensed in the following tables : 



Hard 



Hickory 



Dogwood 



Sugar Maple 



Sycamore 



Locust 



Hornbeam 



Persimmon 



Medium 

 Ash 

 Oak 

 Elm 

 Beech 

 Cherry 

 Birch 

 Mulberry 

 Sour Gum 

 Longleaf Pine 



Hardness 



Soft 

 Chestnut 

 Tulip Poplar 

 Sweet Gum 

 Douglas Fir 

 Fir 



Yellow Pine 

 Larch 

 Basswood 

 Horse Chestnut 

 Hemlock 

 Cottonwood 

 Spruce 



Hard to Split 



Sour Gum 



Ehn 



Sycamore 



Dogwood 



Beech 



Holly 



Maple 



Birch 



Hornbeam 



Cleavability 

 Medium to Split 

 Oak 

 Ash 

 Larch 



Cottonwood 

 Basswood 

 Tulip Poplar 

 Hickory 



Very Soft 

 White Pine 

 Sugar Pine 

 Redwood 

 Willow 

 Paulownia 



Easy to Split 

 Chestnut 

 Pines 

 Spruce 

 Fir 

 Cedar 



