CHAPTER V 
PROPERTIES 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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