350 



FORESTRY INVESTIGATIONS U. B. DEPARTMENT Otf AGRICULTURE. 

 Weight and btrenqth of wood at different heights in the tree. 



Number tt ees used 



Average age of trees 



Numbei of feet from stump 







6 



10 



20 



30 



40 



50 .... 



60 



Strength of longleaf 

 pi ne (pounds per 

 square inch) 



Bending 



strength 



Compres- 

 sion end 

 wise 

 (with 

 grain). 



56 

 150 (o\ei! 



12, 100 



7, J50 



100 



too 



11, 650 



7 200 



9b 



9b 



10, 700 



6,800 



88 



93 



10, 100 



6,500 



Si 



6.9 



9,500 



0,300 



79 



80 



9, 000 



6,150 



75 



AJ 



8,600 



6,050 



71 



82 



Specific weight 



Lonulodf. 



22 



127 



.751 



lOh 

 . 705 



100 

 .674 



,96 



80 

 . 500 



84 

 560 



80 

 5,59 



77 

 528 



n 



Loblolly. 



14 

 113 



620 

 106 

 .595 

 100 

 578 



07 

 534 



90 

 ,508 



86 

 491 



83 

 ,470 



SO 

 470 



79 



Shot ilea,!. 



12 

 131 



.614 



10') 



.">85 



100 



.505 



07 



523 



90 



496 



85 



SI 

 455 



78 

 454 



7S 



Mean of 

 all three 

 species. 

 .Relative 

 weight. 



48 



106 

 100 

 97 

 00 

 S5 

 SI 

 7% 

 77 



Relative 

 strength of 



lougleat 



pine 



Mean of com 



pression and 



bending. 



56 



100 

 97 

 90 

 S6 

 S3 

 79 

 76 



20 



30 40 



Feet from Stump. 



SO 



&) 



JTiGr. 91 —Variation of weight with height of tree. 



