KNOT ZONES AND SPIRAL IN ADIRONDACK RED SPRUCE 



781 



Field measurements were mathematically averaged for each diameter 

 class and a single point plotted for that average, as shown in figure I. 



SIAXtTCII l..,.„t 



Fic. 2. — Red spruce, showing zones of absolute clear, dead, and live knots in the tree bole, 

 for each diameter class, inside bark 



Curve A, top of clear zone, free from knots. Curve B, top of pin-knot zone, beginning of 

 J4inch knots. Curve C, top of ^ to i inch knot zone, beginning of linch knots. Curve D, 

 top of dead-knot zone and base of live crown. 



Attention is called to the regularity of variation of these points, which 

 determined the direction of the curves with certainty. The apparent 



