81 



ECONOMIC PRODUCTS. 



THE economic products of Coniferous Trees come chiefly under two 

 heads, TIMBER and RESINOUS SECKETIONS ; the uses to which the 

 bark, foliage, fruits and seeds are applied, are to these relatively 

 unimportant. 



CONIFEROUS TIMBER 



THE timber yielded by the stems of coniferous trees is of universal 

 importance. It possesses qualities that render it exceedingly service- 

 able for building and other constructive purposes, as durability, 

 strength, lightness, elasticity, fineness of grain, etc. It also abounds 

 in quantity immensely in excess of that of any other Order of Trees, 

 so that it * is also the cheapest and most easily obtained. In the 

 northern hemisphere, the timber used in building may be said to 

 be almost exclusively coniferous, obtained from the Fir and Pine 

 tribe, and in populous countries as Great Britain, Holland, Belgium, 

 etc., where it does not exist, or cannot be grown in quantity sufficient 

 for the supply, and where natural forests have long since almost 

 disappeared, it forms an important article of commerce. 



The physical properties of coniferous wood are the result -of its 

 anatomical structure and specific gravity, the former being the chief 

 factor in determining its strength, elasticity, fineness or coarseness of 

 grain, and the latter its weight, hardness, durability and heating 

 power. 



The anatomical structure of coniferous wood is, in all its most im- 

 portant details, essentially the same as that of the broad-leaved 

 (dicotyledonous) trees and shrubs, a conception of which 

 may be easily obtained from an examination of the 

 stem or "branch of any of our native trees, and one 

 that has completed at least three years' growth will be 

 the best for the purpose. If a cross section of such 

 a stem be made, and the surface of the section be 

 made sufficiently smooth, the following arrangement of 

 the parts will be readily recognised by the naked eye : 

 1, A central pith which is larger or smaller according 

 to the kind of tree or shrub to which the branch 

 belongs, large in the Elder, small in the Sycamore, a 



imere point in the Oak. 2, Around the pith is a 

 series of rings or concentric circles, the number of 

 mki!i,!llllM'Hil such rings corresponding precisely with the ago in 

 ii>34 years of the stem examined. 3, The rings are 

 4i. Transverse and crossed by lines of a paler colour, all radiating from 

 the central pith; these lines are Medullary Rays. 



