PART I.—OF WOOD IN GENERAL 



CHAPTER I 



THE ORIGm, STRUCTURE, AKD DEVELOPMENT OF WOOD AISTD ITS 



USE TO THE TREE. 



Few, if any, of the products of nature are of such manifold utility 

 as wood. Though coal has in many lands largely replaced it as 

 fuel, and as a source of tar, though stone, brick, and iron or steel 

 have often been substituted for it as house-buildmg materials, 

 and the metals last mentioned for the construction of ships, new- 

 uses are constantly arising for it, such as railway sleepers, 

 pavements, and paper-making, so as to more than make up for 

 the saving effected by these substitutes. In England and the 

 United States, for example,, the consumption of wood per head 

 of the population during the last half-century has more than 

 doubled. 



Most people are aware that for these manifold uses a great 

 number of different woods are employed in the various countries 

 of the world — ^woods that differ in colour, grain, hardaess, weight, 

 flexibility, and other properties almost as widely as the trees by 

 which they are produced vary in foHage, flower, or fruit. It is, 

 however, not so generally recognized that the suitabiHty of wood 

 of any kind for some particular purpose depends mainly upon its 

 internal structure. This structure is determined not by man's 

 employment of the material, but by the vital requirements of the 

 tree when growing. 



Our present concern is with wood as a material in the arts, and 

 not with any merely botanical interest it may have, or with its 

 cultivation as a crop by the forester. In deahng with the means 

 of recognizing different kinds of wood we shall, therefore, not 

 depend in any way upon characters derived from bark, leaves, 

 flowers, or fruit — ^the characters, that is, of standing, or of un- 

 converted timber — ^but only on those of the wood itself as it 



1 



