CHAPTER V 

 PEOPEETIES OF WOOD AND THEIR USES 



IN spite of being the oldest building material, per- 

 haps with the exception of stone for caves were prob- 

 ably used as dwellings in the earliest times until very 

 recent years little accurate knowledge has been at hand 

 regarding wood. 



Its very common use made investigations seem un- 

 necessary and while steel and concrete are tested all 

 through the course of their manufacture, only recently 

 has the testing of timber been taken up as a business 

 proposition. Trees do not grow like crystals according 

 to mathematical laws. On the contrary, timber is any- 

 thing but uniform in structure and strength, for two 

 pieces taken from different parts of the same tree may 

 act quite differently and trees of the same species which 

 have grown in different parts of the country may differ 

 greatly in their qualities. Within the same locality the 

 kind of soils upon which trees grow affects the kind 

 of wood they produce. 



Each kind of wood has certain qualities which make 

 it unlike other species; these characteristics are color, 

 hardness, durability, grain, etc., and upon them depend 

 the value of a given species in the arts. For con- 

 struction work timber that is strong, durable, cheap 

 and of large size is demanded. Cabinet and furniture 

 makers require wood with a handsome grain that is 

 hard, will not shrink and capable of taking a beautiful 

 finish. Certain industries are based upon the chemical 



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