THE DIFFEEENT PROPERTIES OF WOODS 195 



Elasticity. — Elasticity is the property possessed by many 

 woods so that when bent out of shape they will spring back 

 to their former position. Elasticity is essential where woods 

 are subject to strains that tend to change their shape. The 

 rims and spokes of a buggy wheel, the thills and tongues of 

 wagons, an ax handle, a bow, oars to a boat, all must be 

 made of woods that have elasticity. If woods are bent too 

 far out of shape they will not return exactly to their former 

 positions, but will have a permanent set. 



Table of Elasticity of the Common Woods 



Flexibility. — Flexibility is the property some woods pos- 

 sess by which it is possible to bend them without their break- 

 ing. Hickory is flexible, pine is brittle. It depends largely 

 on toughness in the wood or the ability of the fibers to hold 

 together. Young shoots are more easily bent than old wood, 

 moist wood than dry wood. When wood that is green oi 

 that has been moistened by steaming or soaking is bent and 

 then dried in that position, it will always tend to retain 

 its new shape. The rims of buggy wheels, hoops, shafts, 

 shinny sticks, the curved handles to canes and umbrellas are 

 examples of woods that have been bent and dried in position. 

 Lumber that has been dried flat will usually not warp. Boards 



