4 CONTENTS. 



The wood and its mechanical properties Continued. 



Factors that affect strength Continued. Page. 



Position in the tree 50 



Age 52 



Soil and situation 52 



Geographic location 52 



Species 55 



Defects 57 



Outlook for future supply 57 



Methods of perpetuating the supply 58 



Economic means 59 



Silvicultural means 60 



Summary 62 



