404 R. T, Patton: 



wood will subsequently dry faster. As a matter of fact there are- 

 no pores in the wood to open, and hence from this point of view 

 the Avork of steaming is useless. The only pores in our hardwood, 

 timber are at the ends, and these are already open. To test the 

 efficiency of the process, 4 ft. lengths of 4 in. x 2 in. Mountain Ash. 

 were cut into 2 fts., and each weighed. One half was left in the 

 air and the other half placed in a steam bath at atmospheric 

 pressure. Pieces were left in the steam bath for periods ranging: 

 from 6 hrs. to 72 hrs. In all cases the weight of the piece when 

 taken out of the bath and cooled was just about the same as when 

 it went in, and this is what was expected. The pieces were- 

 weighed regularly, but both pieces, the steamed and the unsteamed, 

 lost moisture at the same rate. The idea of the steam opening- 

 the pores of the wood is pure fallacy. Howevei", after three months 

 the steamed pieces began to shrink more than the unsteamed, and 

 this went on until there was a marked difference in size between 

 the two halves of each original length of timber. Although the 

 steamed pieces were shrinking more than tlie unsteamed, yet botlt 

 pieces were losing moisture at the same rate. A typical example 

 may be given : — Nos. 7 and 8 were cut out of the same length of 

 timber. No. 7 was steamed for 24 hrs., and No. 8 was not 

 treated. 



Date. 



Weights of No. 7. 



Weights of No. 8. 



16.5.18 



61b. UJoz. 



61b. ISjoz. 



17.5.18 



61b. 15 oz. 



6 1b. 11 oz. 



19.5.18 



61b. 9oz. 



6 1b. 8oz. 



1.6.18 



5 1b. 15 oz. 



51b. UJoz. 



15.7.18 



5 1b. 



5 lb. 



9.9.18 



41b. 11 oz. 



41b. 10 oz. 



7.11.18 



4 1b. 7oz. 



41b. ^oz. 



The shrinking of the steamed specimens is probably due to the^ 

 steam slightly breaking down the structure of the wootl. So far 

 there does not appear to be any justification at all for steaming^- 

 timber. 



Many merchants stand the timber on end when naturally 

 seasoning. The argument is apparently that the sap runs 

 down . the length of the timber. When the trees are felled 

 sap does run out from the cut ends of the wood vessels, 

 but this sap was in the cavity of the vessel. The' moisture which id- 

 lest in seasoning is held in the wallfe of the cells. Hence this 

 cannot run down the stem. It can only be lost by diffusion. To- 

 test the question, however, several experiments were carried out,. 



