Trees — The Character, Strnctitre, Sec. 55 



pine requires consideivably more load to bend it 1)y one 

 inch than a similar bar of iron of the same weight and 

 length. 



3. Timber can stand a far greater distorsion than metal 



without losing its power to regain its original position. 

 In this way timber gives a Avarning before reaching 

 breaking point. In many cases of damage or fracture 

 it is easier to replace, and it can be shaped and reshaped 

 with greater ease than metals. 



4. 12" wooden beams, though combustible, require a good 



deal of heat to destroy them, because the surface 

 becomes charred and protects the inner portion. Timber 

 beams will often remain in position, after a fire, and 

 carry a load, while iron and steel under the same heat 

 would twist out of shape and fall. 



5. Timber does not corrode like metal. It lasts longer, even 



without paint, in exposed situations. With metal, 

 access to moist air must be prevented. Impurities in 

 iron cause brittleness and weakness. Timber contimially 

 under water lasts longer than iron or steel. 



6. Timber is a poor conductor of heat and electricity ; it is 



pleasant to touch, is more artistic, and has a beauty 

 absent in metal, and has none of the iujvu'ious effects 

 of iron and steel. 



7. Pieces of wood may be strongly glued together. Metals, 



on the other hand, would i-e(pn're welding or soldering. 

 By too frequent reheating and forging, wrought iron is 

 weakened. 



8. Certain timbers may be used for casks, remaining un- 



affected, and imparting no disagreeable fiavoui- to their 

 liquid contents, where metals would be objectionable or 

 even poisonous. The elasticity of certain woods renders 

 them superior to any metal for the resonant parts of 

 musical instruments, 



