SAP-STAIN, MOLD, AND DECAY IN GREEN WOOD. 
31 
sultry weather. The tile chamber, when given a preliminary treat¬ 
ment, which consisted of intermittent steaming for three successive 
days to reduce the amount of viable fungous growth therein, pro¬ 
vided these conditions admirably. In this chamber the temperature 
was maintained at an average of 85° F., while the relative humidity 
varied from TO to 95 per cent. At the end of four weeks in the tile 
chamber the blocks were removed and their condition with respect 
to molding noted. 
The following observations were made from several series of exper¬ 
iments : 
The amount of drying which took place in the steam box was comparatively 
slight. This seemed to depend, however, upon the relative moisture content of the 
wood previous to steam- 
C 
ing. Green blocks usu¬ 
ally lost, while partly 
seasoned blocks often 
gained in weight. 
Beyond a certain 
length of time, dependent 
upon the moisture con¬ 
tent of the wood and 
the surface area of the 
blocks in relation to vol¬ 
ume, there seemed to be 
little gained, in so far as 
the reduction in weight 
was concerned, by con¬ 
tinued steaming. Six or 
nine hours’ s t e a m i n g 
seemed to be no more 
efficient than three hours 
in the case of the 2i by 
2\ by 10 inch blocks. 
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3 
Pig. 12.— Diagram illustrating one method of stacking 
green split billets. This method is used by one of the 
large wheel factories of the North. When ample storage 
space in well-ventilated sheds is available, this method 
is recommended. 
Steamed blocks subsequently dried more rapidly than those that were simply 
air-dried. 
Open piling or stripping in the steam box was preferable, in that it per¬ 
mitted a better circulation of the steam in the box and thus insured a more 
uniform treatment of the blocks. 
The amount of checking varied in the several lots when steamed under the 
same conditions. This may have been due to the fact that the blocks differed 
considerably in the relative proportion of sapwood and heartwood present. 
The greatest amount of checking occurred in those lots that were subjected 
to rapid cooling and surface drying by exposure to air currents from open doors 
and ventilators. Blocks allowed to cool in the steam box with doors closed 
seemed to suffer least in this regard. Slow cooling was, in some cases, brought 
about by opening a small hatch in the roof of the steam box at the conclusion 
of the steaming period. 
The total amount of checking which had taken place in the steamed blocks, 
both during the steaming process and the subsequent, period of air seasoning, 
extending over four months, exceeded but little that noted in those blocks which 
had been simply air seasoned for the same length of time. 
Steaming seemed to be effective in killing the fungi in the infected blocks 
when employed for a period of three hours. Cultures taken fi oiu ^ arious points 
