On the Seasoning of Hardwoods. 351 



It will \ye seen that the specimen steamed for 48 hours has lost 

 sliglitly more than, the others. This is often the case, as tannin 

 and kino are dissolved out of the wood. 



While the drying rate is not affected, the amount of shrinkage is 

 seriously affected. Two typical cases are given. The timber wa.s 

 6 in. X 1 in. messmate. The first specimen was steamed for six 

 hours, and then put out in the air to dry. Ihe corresjionding 

 piece was left in the air. 



steamed Unsteamed 



c, • 1 f Breadth - l^in. - ^iin. 



Shrinkage ^ -^^ ''- 



<. Depth - a^jUi- - g'si^- 



The second specimen was steamed for 12 hours. 



Steamed Unsteamed 



ei • 1 ( Breadth - ^Sii- - ^Jin. 



ShriuKage ] Y 



<- Depth - Aiii- - 3^2 in. 



It will be seen that the steaming has greatly increased the amount 

 of shrinkage. The cause of this extra shrinkage is not yet known, 

 but it may be due either to the steam affecting the union of the 

 cells or the constitution of the cell wall may l>e affected. 



A very interesting result was obtained by cutting a length of 6 

 in. X 1 in. tim1>er into 10 in. lengths, and subjecting each piece 

 to a different mode of treatment before putting it out in the air 

 to dry. 



The result of one experiment is as follows : — 



Treatment 



7/11/18 



9/11/18 



19/11/18 



29/11/18 



16/12/18 



8/1/19 



28/1/19 



14/219 



The weights are given as percentages of the original weights. 

 It will be noticed that the piece treated at 10 lbs. pressure of 

 steam is the lightest. This is due to various substances being dis- 

 solved out of the wood. The interesting feature of the experiment 

 lies in the fact that all the pieces have dried approximately at the 

 same rate. With the exception of the second weighing, the diffei-- 

 ence lietween any pair of weights never exceeds 3% at any 

 weighing, and in this 3% diff'erence must bo included the loss of 



