Chapter I. 

 THE STRUCTUEE OF WOOD. 



"W'lieii it is remembered tliat the suitability of wood lor a par- 

 ticidar purpose depends most of all upon its internal structure, it 

 is plain that the woodworker should know the essential characteris- 

 tics of that structure. While his main interest in wood is as lum- 

 ber, dead material to be used in woodworking, he can properly un- 

 derstand its structure only by knowing something of it as a live, 

 growing organism. To facilitate this, a knowledge of its position 

 in the plant world is helpful. 



All the useful woods are to be found in the highest sub-kingdom 

 of the plant world, the llowering plants or Phanerogamia of the 

 botanist. These flowering plants are to be classified as follows : 



I. Gj'mnosperms. ( Naked seeds. ) 



1. Cycadaceae. (Palms, ferns, etc.) 



2. Gnetaceae. (.Joint firs.) 



3. Conifers. Pines, firs, etc. 



Plianerogamia, 

 (Flowering plants) 



II. Angiosperms. (Fruits.) 



1. Monocotyledons. (One seed-leaf.) 

 Palms, bamboos, grasses, etc. ) 



2. Dicotyledons. (Two seed-leaves.) 



a. Herbs. 



b. Broad-leaved trees. 



Under the division of naked-seeded plants (gyranosperms), prac- 

 tically the only valuable timber-bearing plants are the needle-leaved 

 trees or the conifers, including such trees as the pines, cedars, spruces, 

 firs, etc. Their wood grows rapidly in concentric annual rings, like 

 that of the broad-leaved trees; is easily worked, and is more widely 

 used than the wood of any other class of trees. 



Of fruit-bearing trees (angiospernrs), there are two classes, those 

 that have one seed-leaf as they germinate, and those that have two 

 seed-leaves. 



The one seed-leaf plants (monocotyledons) include the grasses, 

 lilies, bananas, palms, etc. Of these there are only a few that reach 



