WOOD OF SOUTHERN PINES. 



Ill 



first ten to twenty years' growth, and in all cases the first lew rings about the pith have but little 

 sunimerwood. In general, the summerwood per cent varies in the several species ;is well as in the 

 individual with the weight of the wood, which is least in the spruce pine, greatest in Cuban and 

 longleaf pine, and stands between these in loblolly and shortleaf. It furnishes a very useful 

 criterion to distinguish between these groups, and especially to select strong timber. 



In the limb, the sum iner wood is most abundant in the knot (all wood practically partaking of 

 the character of summerwood, at least as far as the thickness of cell walls is concerned) and in the 



1 23 4 5 6 7 8 9 10 11 12 13 14 15 16 1 



Decades of Rings Trorn periphery . 



28 19 20 21 



Fid. 19 Variation of snnimerwood per cent with rate of growth (width of ring) in tree No. 3, longlcaf pine. 



NOTE. Only the heavy line represents Mummerwood per cent; the others indicate the actual width of the rinj;H ('ipprr pair) and of the 

 Uaml of summerwood {lower pair). 



part next to the stem, decreasing with the distance from the trunk. As might be expected, it also 

 forms a larger per cent of the wood of the tmderside of limbs and the concave portions of bent 

 trunks. 



GRAIN OF THE WOOD. 



Though usually quite straight grained, the wood of these species is by no means always so. 

 Spiral growth, leading to "cross- grained" lumber, occurs frequently, is usually more pronounced 

 in the basal portions of the tree, and commonly varies from pith to bark in the same log. Wavy 

 grain resembling that of the maple (curly maple) has not been observed, but an irregular wavy 

 grain, due to the fact that the surface of the trunk for many years is covered with small, low 

 eminences, 1 to a few inches across, is frequently seen, especially in longleaf pine, and leads to 

 remarkably pretty patterns. Unfortunately the contrast of spring and summer wood being so 

 very pronounced, the figures are somewhat obtrusive and therefore not fully appreciated. 



