Table 11.- -Analysis of variance of maximum twisting of poles at Newport pole farm 



Source of variation 

 in maximum distortion 



: Degrees of : 

 : freedom : 



Sums of 

 squares 



: Mean 

 : square 



: "F" 

 : value 



Grain direction (Gd) 



4 



15,307,797 



3,826,949 



*3.976 



Seasoning (S) 



3 



1,380,492 



460, 164 



.478 



Interaction (Gd x S) 



12 



2,561, 135 



213,428 



.222 



Within duplicates (error) 



20 



19,249,425 



962,471 





*F.05 = 2.87, F.Ol = 4.43. 



Nonorthogonal comparisons of the pole maximum distortion by their grain -direction class- 

 ification, irrespective of seasoning, are shown in table 12. This analysis indicates that only the 

 left spiral -grained poles differed significantly and that severe left-spiraled poles distorted the 

 most. 



Table 12. - -Nonorthogonal comparisons of maximum distortions of poles by their grain direction 



Nonorthogonal comparisons : 



Sums of squares 



; "F" value ^ 



of maximum distortions : 



(1 d.f.) 



Straight vs . right moderate 



89,252 



0.093 



Straight vs . right severe 



34,689 



.036 



Straight vs . left moderate 



1, 120,952 



1.165 



Straight vs . left severe 



9,711,014 



**10.090 



Right moderate vs . right severe 



235,225 



.244 



Left moderate vs . left severe 



4,233,306 



*4.398 



Right moderate vs . left moderate 



11,662,225 



**12.117 



Right severe vs. left severe 



8,584,900 



**8.920 



Right severe vs. left moderate 



761,256 



.791 



Right moderate) (left moderate 

 Right severe ) * (left severe 



18,382,656 



**19.099 





Error for calculating "F" value - 962,471 (d.f. = 20) from analysis of variance of 

 maximum distortion. 

 *F.05 = 4.35. 

 **F.01 = 8.10. 



These analyses establish the relation between distortion and spiral gram, particularly for 

 left-spiraled poles. However, the data fail to explain satisfactorily the stability of the right 

 spiral -grained poles. In an effort to isolate the factor or factors responsible, 10 of the study 

 poles were selected for dissection and subsequent examination (table 13). 



This sample was composed of four right -spiraled, four left-spiraled, and two straight - 

 grained poles. In general, the sample was selected on the basis of either maximum or mini- 

 mum distortion in the five slope -of -grain classifications. The four seasoning classes were 

 also included in the sample . 



11 



