Drying of Timber. 



83 



considered. In Table V. are given the ratios of the loss of weight on 

 the first day to those on subsequent days. In this experiment the blocks 

 were dried at 90 per cent, humidity. 





T 



VBLE 



V. 













Time in Days. 





Teiup. 



4 





9 



15 



2n 



20 



4 





9 



16 



22 



30 



3.1 





6.6 



9.0 



11.8 



40 



2.9 





3.7 



5.6 



— 



50 



|3.6 

 l3.2 





7.0 



8.7 



— 







66 



7.8 



— 



Katies of loss at 90% Humidity. 



It will be seen that in the case of the specimen at 20°C. the ratios 

 are the same, except the last, as the time in days. In other words, 

 the curve of loss is a straight line. As will be seen in Fig. 9, when 

 this happens drying is very slow. It will also be seen that the higher 

 the temperature the less the ratio, although it may be noted that an 

 exception occurrs at 40 °C. This happened with every specimen at 40°. 

 There was no material available for a second experiment. The second 

 ■experiment at 50 °C. gave similar results to the first. 



In Table VI. are given the ratios of loss for specimens drying in 

 a 50 per cent, humidity. 



Table VI. 







Time 



in Days. 





Temp. 



4 



9 



16 



25 



20 



3.6 



7.4 



12.5 



17.1 



30 



2.9 



5.1 



6.4 



7.1 



40 



2.0 



3.0 



— 



— 



50 



/2.8 



44 



5 1 



— 





12.5 



3.6 



4.5 



— 



Eatios of loss at 50% Humidity. 



The ratios in the case of 20°C. are somewhat removed from the 

 values of the time in days. There is again a decrease in the ratios 

 with increasing temperature. In Table VII. are given the ratios of 

 loss for specimens drying at 10 per cent, humidity. 





Table VII. 











Time in 



Days. 





Temp. 



4 



y 



16 



26 



20 



3.5 



7.1 



10.1 



12.5 



30 



2.5 



3.9 



4.7 



5.0 



40 



2.0 



— 



— 



— 



50 



r 



.4 



— 



— 





3.2 



— 



— 



Eatios of loss at 10% Humidity. 



