138 THE PINES 



there is enough resin in the heart wood to prevent their fall- 

 ing off as soon as the sapwood in them decays. Dense 

 shading of the lower limbs must begin, in early life and be 

 kept up until a satisfactory height of clean stem is secured. 



Lumber cut from trees grown in the open, or not suffi- 

 ciently crowded in early life, is much Jess valuable than that 

 from trees that were properly shaded and, consequently, 

 had dropped their lower limbs, thus permitting wood to 

 grow on the stem free from knots. Open-grown trees are 

 full of large knots and have a large proportion of sapwood. 

 Besides, the heartwood of such is very soft, weak, and brit- 

 tle, a condition which has led to a widespread belief that 

 second-growth White Pine can never furnish lumber that 

 can take the place of that found in our virgin forests, a 

 mistake that may take a long time to correct in the minds 

 of the consumer and woodworker. When crowded in early 

 life the annual layers will not be so thick as when grown 

 in the open and the character of the wood will be materi- 

 ally different in texture and strength. Age, however, seems 

 to have something to do with the character of White Pine 

 lumber. Probably some kind of chemical agency is at work 

 modifying the heartwood after it ceases to perform any 

 function towards supporting the life of the tree. No matter 

 what the cause for any change may be, if it occurs, close 

 planting and judicious thinning will unquestionably pro- 

 duce good lumber, while neglect of these will assuredly end 

 in failure. It is not unusual to see trees not more than five 

 or six inches in diameter breast high, free from limbs for 

 thirty, forty, or even more feet, in a naturally closely 

 planted grove of White Pines, thus laying the foundation 

 for clear lumber ; and whether natural seeding or artificial 

 planting prevails, the result should be the production of 

 such trees if success is to crown the efforts put forth. 



After the first few years of its life White Pine is a rapid 

 grower. Its annual rings, however, show a gradual and 

 constant decrease in thickness as age creeps on. This does 

 not necessarily imply that less wood is formed annually, 



