34 Shrinkage, Sivelling, Warping of Cross-grained Woods 



Set G. 



The results of the measurements of yang 2 during its final process 

 of drying from a saturated condition arc given in Table G. 



The board at first decreased in length, but thereafter continued to 

 elongate. In this respect it differed from the tangential board yang 1, 

 but agreed with the radial board. The final loss of length was exceedingly 

 small, merely -012 per cent, of the maximum length, but the maximal 

 loss was -03 per cent. These figures are far less than those for yang 1, 

 and even less than for the radial board. 



The shrinkage in width of the ends was 6-29 per cent, of the maximum 

 width, and was thus greater than those of yang 1 (5-92) and the radial 

 board (5). 



When the shrinkage in area is assessed by the changes in length and 

 in width of the ends it will be seen that the loss of width atoned for the 

 shghtness in the shortening: for the shrinkage of area was 41-266 cm.^, 

 compared with 49-53 cm.^ in the case of yang 1. Yang 2 was only 

 about 48 cm. long, whereas yang 1 was about 61. Had yang 2 been 

 of the latter length its contraction in area would have been [circa) 

 52-43 cm. 2, thus slightly more than that of yang 1. 



The changes in length and width from May 28, 1915 to February 4, 

 1916, are worthy of special note as they occurred when the board was 

 so far dry that it gained or lost water solely according as the air became 

 moister or drier ; and during this phase the weight of the board varied 

 only between 570-075 and 570-48 g. 



Radially Cut Board. 



The first set of observations were made while this board was absorbing 

 309 g. of water. As a measuring rod was employed for the purpose 

 the longitudinal measurements were found to be useless. As regards 

 the transverse measurements the ultimate increase in width was 5-5 per 

 cent, of the maximum attained. This statistic is not of value as showing 

 the full radial expansion, for it was subsequently found that when first 

 measured (and weighed) the board was not fully dry in relation to the 

 laboratory air. Its original weight was 719 g., whereas at the conclusion 

 of the second set of observations the board had dried down to a weight 

 of 706-5 g. 



During the soaking, in contrast with the tangential boards, the 

 radial board remained flat and devoid of any twist. 



