. Wood and forest . Ficr. 3s. Oiasrrain to Show the (GreaterSluinkaire uf SiinimcrCells, A, Spriny CeUs, C, D. ber of rings together shrink, the tangential shrinkage of the summerwood tends to contiact the adjoining rings of spring wood more thanthey would naturally shrink of themselves. Since there is more of ritOPiiUTIES OF WOOD. 45. the summer-wood substance, the spring-wood must yield, and the logshrinks circumferentially. The radial shrinkage of the summer-wood,however, is constantly interrupted by the alternate rows of spring-wood, so that there would not be so much radial as cir
. Wood and forest . Ficr. 3s. Oiasrrain to Show the (GreaterSluinkaire uf SiinimcrCells, A, Spriny CeUs, C, D. ber of rings together shrink, the tangential shrinkage of the summerwood tends to contiact the adjoining rings of spring wood more thanthey would naturally shrink of themselves. Since there is more of ritOPiiUTIES OF WOOD. 45. the summer-wood substance, the spring-wood must yield, and the logshrinks circumferentially. The radial shrinkage of the summer-wood,however, is constantly interrupted by the alternate rows of spring-wood, so that there would not be so much radial as circumferentialshrinkage. As a matter of fact, tlie tangential or circumferentialshrinkage is twice as great as the radial shrinkage. Putting these two factorstogether, namely, the length-wise resistance of the pith raysto the radial shrinkage of themass of other fibers, and sec-ond, the continuous bands ofsummer wood, comparativelyfree to shrink circumferentially,and the inevitable happens; thelog splits. If the bark is lefton and evaporation hindered,the splits will not open so wide. There is still another effectof shrinkage. If, immediatelyafter felling, a log is sawn in two lengthwise, the radial splitting may be largely avoided, Irat theflat sides will tend to become convex, as in Fig. 39. This is ex-plained by the fact that circumfe
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectforests, bookyear1912
