SEASONING AND IMPEEGNATION OF TIMBER 273 
advantage, and is seldom practised except on a small scale 
in a builder's yard. The planks are almost universally laid 
horizontally in tiers, being often kept separate by laths, and 
in the case of logs and larger timber each layer is or should 
be placed in reverse directions. 
Pine timber, when cut, contains in round figures 40 to 60 
per cent, of its weight of moisture, the larger proportion 
of which is within a couple of inches of the outside, and it 
is advisable that for good interior work not more than 10 to 
Fig. 39. — Common Method of Stacking Planks for Seasoning. 
12 per cent, be left, although this is a condition of dryness 
rarely attained by timber when it is put into buildings. 
In three months 16 per cent, of their moisture has 
been abstracted from oak sleepers by open air exj)osure 
in Arkansas, U. S., and in the drier climate of New Mexico 
pine sleepers have lost 42 per cent, in six weeks. 
Absolutely dry wood cannot be attained by any process, 
for chemical destruction takes place before that occurs ; 
moreover, as we have already stated, timber will always 
absorb the amount of moisture contained in the surround- 
ing atmosphere, and it is useless drying it below that limit. 
T. T 
