Drying of Timber. 



79 



In Table III. are given the results of the first experiment. The 

 timber was messmate {Eucalyptus obliqua) , and the evaporating faces 

 were four inches square. The thicknesses ranged from half an inch 

 by half inches to three and a-half inches. The blocks were left to 

 dry on the laboratory table. The experiment commenced in the 

 middle of summer, and the effect of winter is seen by the decrease in 



Table III. 









Total losses 



of each thickness. 







Time in 

 Days 



3i in. 



Sill. 



2iin. 



2 in. 



1^ in. 



lin. 



hiu. 





<,M11S. 



JfUJS. 



{fills. 



Jims. 



Kins. 



gnis. 



gUJS. 



1 



9 



12 



11 



11 



11 



10 



11 



2 



15 

 22 



19 

 25 



17 

 23 



17 



21 



18 

 23 



16 

 21 



17 



3 



20 



5 



29 



33 



31 



31 



30 



28 



24 



7 



35 



45 



39 



47 



38 



47 



37 



47 



36 

 45 



34 



26 



11 



42 



26 



18 



61 



62 



61 



63 



60 



53 



28 



25 



72 

 81 



73 



82 



72 

 81 



74 

 83 



69 



59 

 62 



27 



32 



77 



27 



39 



87 



89 



87 



89 



81 



61 



26 



46 



93 



94 



92 



94 



84 



61 



26 



53 



99 



100 



98 



99 



89 











69 



112 



113 



112 



111 



96 











87 



123 

 142 



124 

 142 



122 

 139 



120 



98 

 102 



— 



— 



115 



134 







141 



148 

 168 



149 

 168 



145 



137 

 145 



101 

 102 







— 



195 



f 101 



— 



Each thickness loses approximately the same amount of moisture in a given time. 



loss of some of the blocks and a subsequent increase in weight. This 

 occurred in the inch and half inch specimens.. 



The total losses on the left of the heavy line for any particular 

 day are approximately equal. The table shows that up to a certain 

 point, the amount lost in a given time is quite independent of the 

 thickness. Each thickness loses the same amount until the reservoir 

 of moisture begins to be exhausted, and after that there is a different 

 type of curve for the loss of moisture. Experiments with Oak, Elm, 

 and Chestnut all gave similar results. In Fig. 7 is given a typical 

 family of curves of loss for a series of blocks, having 2" x 2'' faces, 

 and ranging fro-m half an inch by half inches to two and a-half inches. 

 The outer curve or envelope is the curve of loss for the thickest speci- 

 men. The equation to this curve is approximately, Z^6'75t's54, 

 where I is the total loss of weight in grams in time " i," 6 '75 is loss 

 In weight in grams for the first day, and " t " is time in days. The 

 irregularities of the secondary curves at the point of junction with 

 the main curve have been smoothed out. In this series only one 

 specimen was used for each thickness. The differences between the 



