BARK 



SAPWOOD 



Figure 53. Typical cross section of a log. 



readily distinguishable. Such an increment is known as an annual growth 

 ring or annual ring, and consists of an earlywood and a latewood band. 



(4) Earlywood (Springwood) and Latewood (Summerwood) . In many 

 woods, large thin-walled cells are formed in the spring when growth is 

 greatest, whereas smaller, thicker walled cells are formed later in the 

 year. The areas of fast growth are called earlywood, and the areas of 

 slower growth, latewood. In annual rings, the inner, lighter colored area 

 is the earlywood, and the outer, darker layer is the latewood. Latewood 

 contains more solid wood substance than does earlywood and, therefore, is 

 denser and stronger. The proportion of width of latewood to width of 

 annual ring is sometimes used as one of the visual measures of the quality 

 and strength of wood. 



(5) Grain and Texture . The terms "grain" and "texture" are used 

 in many ways to describe the characteristics of wood and, in fact, do not 

 have a definite meaning. Grain often refers to the width of the annual 

 rings, as in "close-grained" or "coarse-grained." Sometimes it indicates 

 whether the fibers are parallel to or at an angle with the sides of the 

 pieces, as in "straight-grained" or "cross-grained." Texture usually 

 refers to the fineness of wood structure rather than to the annual rings. 

 When these terms are used in connection with wood, the meaning intended 

 should be defined. 



b. Moisture Content of Wood . Wood may contain moisture as "free water" 

 in the cell cavities and as "absorbed water" in the capillaries of the cell 

 walls. When green wood begins to lose moisture in the seasoning process, the 



232 



