LASTING PROPERTIES OF WOOD 



To-day it has almost entirely disappeared. A few trees 

 were discovered in certain Chinese temples, where they had 

 been preserved as curiosities for centuries, but it is almost 

 extinct as a wild plant. The Bigtree group {Sequoia p. 47) 

 was a companion of the Ginkgo in its flourishing period. 

 So also were the Sago palms or Cycads. All the ordinary 

 trees, Pines, Oaks, Beeches, and the like, did not appear upon 

 the earth'*s surface till a much later period. 



The most important economic product of trees is the 

 timber which they furnish. Wood, as we have tried to show 

 in the last chapter, has been always of the greatest import- 

 ance to mankind. It is easily worked, durable, buoyant, and 

 light, and it is used for all sorts of purposes. 



Silver fir,^ which is accustomed, when growing, to be con- 

 tinually swayed and balanced by the wind, is preferred for 

 the sounding-board of pianos and for the flat part of violins, 

 whilst Sycamore or hard Maple is employed for the back and 

 sides of the latter. 



But there are enormous differences in different kinds of 

 woods. The colour of wood varies from white (Beech), 

 yellow (Satinwood), lemon-yellow and bluish red (sap and 

 heartwood of Barberry), to dark and light brown mottled 

 (Olive), black (Persimmon), and dark brown (Walnut). Some 

 woods have a distinct smell or perfume. Cedarwood, Sandal- 

 wood, Deal, and Teak, are all distinctly fragrant. The 

 Stinkwood of South Africa and the Til of Madeira have an 

 unpleasant smell. 



More important in practice are the differences in the hard- 

 ness and weight of wood. The Iron wood of India cannot be 

 worked, as its hardness blunts every tool. It requires a 

 pressin-e of something like 16,0001b. to force a square-inch 

 ' The Romans used it for ships' masts and spars. 

 58 



