612 



AMERICAN FORESTRY 



A PIECE Oi Wv 



iiRED WHITE OAK BOARD 



Most of the fiber is rotted away, leaving tlie thin ribbons, known as 

 medullary rays. 



dark, while a split surface would be marked with parallel stripes. 

 If the split ran straight through the middle these parallel stripes 

 would be of uniform width; if the 

 split were tangential or slabbed 

 off at right angles to a radius, 



there would be a wide band in the 

 middle with narrowing stripes at 

 either side. 



But logs are not perfectly 

 round; they are more or less flat- 

 tened and tapered; the growth 

 rings are not perfectly regular; 

 but vary in thickness and may be 

 undulating or decidedly wavy, 

 while branches and small limbs 

 cause local deformations. In con- 

 sequence, when a board is sawed 

 these various irregularities show 

 up in the grain. Boards cut tan- 

 gentially or flat sawn will have 

 the most conspicuous figure, 

 while those from the middle, or 

 radially sawn, may show nothing 

 but light and narrow stripes, the 

 edges of the seasonal growths. 



To these two general methods 

 of cutting a board from a log, the 



MOTTLE 



POPLAR 



ROE OR RIBBON GRAIN 

 SYCAMORE 



IN 



Yellow poplar board showing peculiar 

 mottle resulting from disturbance of the 

 cambium layer by woodpeckers. 



EFFECT OF A BRANCH ON THE 



GRAIN OF PINE 



It is from the crotches of mahogany trees 



that some of the finest figured material 



is obtained. 



The striping is due to differences in direc- 

 tion of fiber layers, the finer markings to 

 the rays. 



trade has given the names quarter- 

 sawed, that radially cut, and flat- 

 sawed, that is, tangentially cut. The name, quarter-sawing, comes from the 

 mill practice of dividing large logs into quarters and then cutting boards 



