378 JOURNAI, OF FORESTRY 



possible to substitute a definite and practical rule based on the actual 

 inherent character of the wood structure. In the absence of such a 

 rule, a more or less chaotic situation in the southern pine trade had 

 developed. There was much misunderstanding among manufacturers 

 and consumers because of the lack of a reliable method for determin- 

 ing whether yellow pine lumber of any particular class was adapted 

 to the purpose intended, and the merchandizing of yellow pine and the 

 efficient use of structural timber has sufifered considerably. 



The use of the terms "longleaf" and "shortleaf" to segregate quality 

 classes was becoming more and more ineffective and confusing, and 

 owing to the very wide and overlapping margins of quality character- 

 istic of the southern pine species, structural timbers were getting into 

 bad repute. Substitution of material lacking in strength and durability 

 could not be eliminated and the quick failure of much southern pine 

 structural material was throwing discredit and loss upon the entire 

 yellow pine trade, and was demoralizing the market for structural tim- 

 ber in general. 



The application of research data met this intensely practical situation 

 and expressed itself in the specification including the density rule 

 adopted by the Southern Pine Association and later by the American 

 Society for Testing Materials. This specification reads as follows : 



Southern Yellow Pine. — This term includes the species of yellow pine growing 

 in the Southern States from Virginia to Texas, that is, the pines hitherto known 

 as longleaf pine (Pinus palustris), shortleaf pine (Pinus echinata), loblolly 

 pine (Pinus taeda), Cuban pine (Pinus heterophylla) and pond pine (Pinus 

 serotina). 



Under this heading two classes of timber are designated : (a) dense Southern 

 yellow pine and (b) sound Southern yellow pine. It is understood that these 

 two terms are descriptive of quality rather than of botanical species. 



(a) Dense Southern yellow pine shall show on either end an average of at 

 least six annual rings per inch and at least one-third summer wood, or else the 

 greater number of the rings shall show at least one-third summer wood, all 

 as measured over the third, fourth and fifth inches of a radial line from the 

 pith. Wide-ringed material excluded by this rule will be acceptable, provided 

 that the amount of summer wood as above measured shall be at least one-half. 



The contrast in color between summerwood and springwood shall be sharp 

 and the summerwood shall be dark in color, except in pieces having considerably 

 above the minimum requirement for summerwood. 



In cases where timbers do not contain the pith, and it is impossible to locate 

 it with any degree of accuracy, the same inspection shall be made over 3 in. 

 on an approximate radial line beginning at the edge nearest the pith in timbers 

 over 3 in. in thickness and on the second inch (on the piece) nearest to the 

 pith in timbers 3 in. or less in thickness. 



