72 



Reuben T. Patton: 



As will be seen from Fig 4, as soon as drying commences a 

 gradient is established. It does not matter at what temperature or at 

 what humidity the wood be dried, a gradient is established. Gradients 





















































0/\K 

























■iftiis 



















at 



i.„ 



oicnct 



Vltlit 



/ 



.^■*-^ 



^ 

























/ 



/ 







\ 























/ 











\ 





















/ 











\ 



















/ 













\ 



















/ 





/^ 





./Bda 







\ 











3 









/ 



r 







N 



\ 













S 

 «- so 







1 



/ 











\ 



\ 











o 







'■ 





>^ 



^~ 



^< 





\ 



\ 











i 40 





/ 





/ 









\ 



\ 



y 















/ 



/ 











a daiii 



\ 



\ 



\ 













/; 



' 







/ 





\ 



\ 



\ 















// 



1 





!/ 









\ 



\\ 



\ 









20 



/ 



/ 





/ 











\ 



A 



\ 











/ 



/ 



/ 















V 



s 









/e 



^ 



















\ 



\ 











"^ 





















\ 

































,.J 







Thickness in iii'-hes. 

 Graphs iLLusTiiATiNG the Pkogrkssive Drying of 



3 IN. TiMBKK AT 40°C AND 50'?., HuMIDITY. 



have been found in all timbers examined. A series of birch blocks 

 were dried at room temperature, and room humidity, and after 55 

 days they gave the following gradient from the evaporating surface 

 to the centre of the block: — 



Percentage of moisture in each I inch. 

 16 23 29 34 37 39 



Drying was very slow, nevertheless a graidient was formed. 



If a graident be formed, then there can be no such condition as fibre 

 saturation. It is believed that no shrinkage takes place until this so- 

 called fibre saturation point is reached. As a matter of fact, in all 



