CHAPTEK XI 
SEASONING AND IMPREGNATION OF TIMBER 
Objects and Advantages of Seasoning— Open Air Seasoning— Kiln Dry- 
ing— Charring— Artificial Methods of Preserving— Burn etti zing 
or Zinc Chloride Process— Boucherie's Process— Kyanizing— 
Powellized Wood— Creosoting— Long Life of Creosoted Timber— 
Haskynizing— Cost of Different Processes— Fireproof Timber. 
Open air Seasoning. — The object of seasoning timber is to 
extract as much moisture as possible from it, because, as 
we have seen, moisture is an essential factor in producing 
decay, and the reason why seasoned timber is not so liable 
to decay as unseasoned timber is that the moisture has 
been reduced below the limit required for the production 
and growth of fungus life. But it should also be borne in 
mind that fairly-dried timber is much stronger than green 
timber — all tests show this— and detailed reference is made 
to this point in another place, so that it is sufficient to 
say here that the strength of well-dried wood is increased 
considerably above that of the same timber when " green " ; 
so that it pays to season timber both from point of strength 
and longevity. 
Good pitch pine or Baltic timber, to be used in a quay or 
structure exposed to the atmosphere and having plenty of 
fresh air, need not be seasoned before use; the timber 
seasons in the work, it is usually of larger scantHng than 
that used for interior work, and it would be no use drying 
timber which was afterwards to be exposed to the elements; 
but for timber inside a dwelling-house, particularly for 
