36 OF WOOD IN GENERAL 



2. Very hard, requiring more than 3200 lbs, per square inch, 

 such as Hickory and good Oak and Elm. 



3. Hard, requiring from 2400 lbs.-3200 lbs., such as Ash, Wahiut, 

 Beech, Holly, Sycamore, and Sweet Chestnut. 



4. Medium, requiring from 1600 lbs.-2400 lbs., such as Douglas 



Snruce. 



5. Soft, requiring less than 1600 lbs., such as the majority of 

 coniferous woods. Pine, Spruce, Cedar, Poplar, Linden and Horse- 

 chestnut. 



6. Very soft, such as the so-called Cotton-tree of India {Bombax 

 malaUncum), which is so soft that a pin can be readily driven 

 into it with the fingers. 



Hardness and density or weight to a great extent vary together. 

 They also increase from the base of a stem up to its first branch, 

 and decrease from that point upward. 



Colour of wood.— The colour of the heartwood affords in 

 many cases a useful aid in identification, while mere differences of 

 tint are often indicative of quahty or soundness. The black 

 duramen of the Persimmon {Diosp^ros virginidna), of other species 

 of JDiospyros known as Ebonies, and of Laburnum {Cytisus 

 LaMirnum), the dark brown of the Wahiuts, the purpHsh-red of 

 Logwood (Hmmatoxylon campecMdnum), the lemon-yellow sapwood 

 and bluish-red heartwood of the Barberry {Berberis vulgaris), the 

 narrow yellow sapwood and greenish heart in Lignum-vitse (Gudia- 

 cum offlcindU), or the motthng of dark and light browns in the OHve 

 {dlea eurofdea), are obvious distinctions. 



The Northern Pine {Finns sylvestris) presents numerous varia- 

 tions in the colour of its wood, as well as in its mode of branching, 

 dependent probably in part upon the conditions under which it is 

 grown, and the superiority of "red deal" to the more resinous 

 honey-yellow varieties is well known in trade. Northern hill- 

 grown wood is commonly redder than that of the south grown in 

 plains, the finest being that of the Riga pines, with a close pyramid 

 of ascending branches, including the timber from Smolensk, Vitebsk, 

 Tchernigov, and Volhynia. 



The Locust or False Acacia of the United States [Bobinia 

 Pseudacdcia) includes at least four varieties of wood. The most 

 durable, most beautiful, and most valuable is the red : the 

 commonest, the green, a greenish-yellow wood (apparently the 

 only kind imported), is next in value ; the black is only recorded 

 in the Western States ; and the white is the least valuable. 



In West Virginia three varieties of the Tulip-tree (LirioMndron 

 tuUpifera) are distinguished as " White," " Blue," or " Yellow 

 Poplar," of which only the last named is commonly shipped to 



