412 



expansion due to the absorption of moisture from the atmo- 

 sphere during damp weather. 



In order to further investigate the relation between the 

 expansion of the wood and its moisture contents two small 

 cylinders about 3 in. in diameter and 1 in. long were cut from 

 beams of each species. These were measured along marked 

 diameters, parallel and perpendicular to the rings, and 

 weighed. They were then kept immersed in water for two 



7r 



6 



I 



Q 



kj 



u 



kj 

 t^ 



PI. 



Pl.Z 



nOISTURE ON DRY WOOD. 







20 40 



60 



80 



100 120 140 



160 



Fig. 3. 



Showing contraction of wood on drying after immersion in water. 

 P.M. refers to P'tnus maritima. P.I. refers to Pirius insignis. 



P.C. refers to Pinas canariensis. 

 The suffix 1 indicates the curves showing contraction parallel 



to the rings. 

 The suffix 2 indicates the curves showing contraction perpendicular 



to the rings. 



clays, after which they were removed and again weighed and 

 measured. It was found that the moisture contents of the 

 hi sir/nix blocks now amounted to over 150 per cent, of the dry 

 weight of the wood. The maritima blocks did not absorb 



