OAK TIMBER. 141 



elasticity = 129-8 kgr., and the breaking limit 0-406 

 kgr. 



The absolute tenacity in the transverse direction is 

 given as 0-44 to 0-61 kgr. 



In the case where pressures are applied in the direc- 

 tion of the length of the fibers the limit of elasticity = 

 2-09 to 2-22 kgr. ; the modulus of elasticity, 933 to 1,250 

 kgr. ; and the absolute resistance, 2-58 to 3-64 kgr. 



Flexibility. The limit of elasticity = 1'77 to 2*71 

 kgr. ; modulus of elasticity, 620 to 735 kgr. ; resistance 

 to bending, 4-53 to 6-18 kgr. 



Torsion. Oak warps considerably unless carefully 

 seasoned. Limit of elasticity = 0-4 to 0-54 kgr. ; modu- 

 lus of elasticity, 612*5 to 785 kgr. ; resistance to torsion, 

 0-75 to 0-97 kgr. 



Eesistance to shearing- stress, in the direction of the 

 fibers = 0-61 to 0*97 kgr. ; perpendicular to them, 1-9 

 to 3-49 kgr. 



(7) Resistance to Splitting. Oak is easily split into 

 tolerably smooth and even staves, and is much employed 

 for this purpose. 



(8) Hardness. Oak is neither the hardest and heavi- 

 est nor the most supple and toughest of woods, but it 

 combines in a useful manner the average of these quali- 

 ties. Good oak is hard, firm, and compact, and with a 

 glossy surface, and varies much ; young oak is often 

 tougher, more cross-grained, and harder to work than 

 older wood. According to Gayer, if we call the resist- 

 ance which the beech offers to the saw, applied trans- 



