THE LIFE OF THE TREES IS 



If a tree had no limbs, and merely laid on each year a 

 layer of wood made of parallel fibres fitted on each other 

 like pencils in a box, wood splitting would be child's play 

 and carpenters would have less care to look after their 

 tools. But woods differ in structure, and all fall short of 

 the woodworker's ideal. The fibres of oak vary in shape 

 and size. They taper and overlap their ends, making the 

 wood less easily split than soft pine, for instance, whose 

 fibres are regular cylinders, which lie parallel, and meet end 

 to end without "breaking joints." 



Fibres of oak are also bound together by flattened 

 bundles of horizontal fibres that extend from pith to cam- 

 bium, insinuated between the vertical fibres. These are 

 seen on a cross-section of a log as narrow, radiating lines 

 starting from the pith and cutting straight through heart 

 wood and sap wood to the bark. A tangential section of a 

 log (the surface exposed by the removal of a slab on any 

 side) shows these "pith rays," or "medullary rays" as 

 long, tapering streaks. A longitudinal section made from 

 bark to centre, as when a log is "quarter-sawed," shows 

 a full side view of the "medullary rays." They are often 

 an inch w-ide or more in oak; these wavy, irregular, gleam- 

 ing fibre bands are know^n in the furniture trade as the 

 "mirrors" of oak. They take a beautiful polish, and are 

 highly esteemed in cabinet work. The best white oak has 

 20 per cent, to 25 per cent, of its substance made up of these 

 pith rays. The horny texture of its wood, together with 

 its strength and durability, give white oak an enviable 

 place among timber trees, while the beauty of its pith rays 

 ranks it high among ornamental woods. 



The grain of wood is its texture. Wide annual rings 

 with large pores mark coarse-grained woods. They need 



