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 fibres 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. ; 

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

 torsion, 0'75 to 0'97 kgr. 



Resistance to shearing-stress, in the direction of the 

 fibres = 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 

 heaviest, nor the most supple and toughest of woods, but 

 it combines in a useful manner the average of these 

 qualities. 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 

 resistance which the beech offers to the saw, applied 



