8 TIMBEE 



quickly dies, as it can derive no further nourishment from 

 the soil. Although absolutely necessary to the growing 

 tree, sapwood is objectionable to the timber user, as it is 

 the first part to decay. What is called the pith was once 

 the seedling tree, and in many of the pines and firs, 

 especially after they have been seasoning for a good while, 

 this is distinctly noticeable in the centre of the tree, and 

 detaches itself from the surrounding wood. 



On looking at the cross section of most timbers of 



SUMMER WOOD 

 SPRING WOOD 



FIG. 1. Pine Timber. 



commerce we see what are called the annual rings, repre- 

 senting generally a year's growth; these are especially 

 clear and distinct in the pines and firs, and are approxi- 

 mately circular ; they form the pleasing patterns noticeable 

 on boards, Figs. 1 and 2. It will be seen that they consist 

 of alternate light and dark bands gradually shading into one 

 another, or dark lines with a light coloured space between ; 

 the distance apart of the rings tells us whether the trees 

 are of quick or slow growth, those with rings far apart 

 generally indicate quick growing timber, those with rings 

 close together a timber of slow growth, but even in trees 



