Practical Hints 



THE more familiar aspect of wood is of no less importance than 

 the structure. The user of wood has from time immemorial 

 relied upon the evidence of his unaided senses to tell one kind 

 from another and, just as in other Arts, this rule-of-thumb method 

 will always remain the chief factor in the discrimination of 

 timbers. Science with its precise definitions and accurate 

 instruments steps in only where common-sense stops short. 

 A carpenter has no need for text-books to tell him the 

 difference between Oak and Walnut, any more than a child 

 has need for a work on Botany to tell a Daisy when he sees 

 it, nor does the expert timber-merchant need anything beyond 

 his impressions coupled with his experience, until he meets with 

 a wood that he has never seen before. Here something more 

 is needed. By noting minute details usually overlooked, so 

 many more characters are added to the obvious features that 

 a timber may be recognizably described. Certain misleading 

 resemblances can thus be detected. For instance, the familiar 

 American or Canary Whitewood (Fig. I) may be met with quite 

 black, as witness a specimen in the Museum at Kew. Ebony, 

 which should be black, is oftener brown with black stripes, and 

 generally requires the assistance of black polish to assume its 

 " ebon hue." Colour, though of prime importance, is so 

 variable as to be unreliable at tunes. The coarseness of 

 grain has already been dealt with, and can only furnish 

 assistance when the known range of size of the pores, their 

 shape, and relation to the section observed, are all carefully 

 harmonized. The weight is a useful criterion if it be carefully 

 ascertained when the wood is dry. Judging from various tables of 

 the weights of timbers, it appears to be assumed in many quarters 

 that each kind of wood has its own special weight per cubic foot, 

 whereas it is difficult to find two pieces of wood of the same 

 specific gravity, and the maximum and minimum for a species 

 seems to get further apart as more specimens are examined. 

 In the descriptive portion of this work the figures given are those 

 which happen to be on record, but these limits are certain to be 

 modified by more extended trials. 



The different physical qualities of wood are more or less bound 

 up together. The weight, the hardness and the density generally 



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