SAP-STAIN, MOLD, AND DECAY IN GEEEN 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. r while the relative humidity 
varied from 70 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- 
ing. Green blocks usu- I I l i 
ally lost, while partly ^foft^ gljjg 
seasoned blocks often ^fofo^ j fWtfa<°\ 
gained in weight. fo ~zi m> _ _"Zs 
Beyond a certain 
L.I '" '' I ' ' I 
fiifaftiQi />P»ftnA vsfofa«K 
length of time, dependent I - - I I — - - .1 I, , . ,, 
, ' fofop*<*s /sr>ftifa<^ <7^^/?\<5^ 
upon the moisture con- r *J 1 f 1 I '™ tt ™\ 
tent of the wood and f*ft\fo<$\ fhfato<f\ ggg^ft 
the surface area of the /h xft fc> <& fa 7& 
blocks in relation to vol- \ ^^a fofi tfy fr MM f^^ 
ume, there seemed to be W ^ W^ kft^ fc fitf ^ ! 
little gained, in so far as I . - -. I I Z. Z I I . I I ~ .1 
the reduction in weight r^H Pf^ ^^ rf^M 
was concerned, by con- k J . iE J. k >i ^ &L 
nine hours' steamin^ FlG - 12, — Diagram illustrating one method of stacking 
, . c & green split billets. This method is used by one of the 
seemed to be no more large wheel factories of tne Nort h. When ample storage 
efficient than three hours space in well-ventilated sheds is available, this method 
in the case of the 2J by is recommended. 
2\ by 10 inch blocks-. 
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 from various points 
