12 BULLETIN 1013, U. S. DEPARTMENT OE AGRICULTURE. 
tempered to the same final moisture content of 15 per cent, are as 
follows : 
With each increase of relative humidity or, in other words, with 
each increase in the extent to which the air within the mill became 
saturated with moisture, there was an appreciable decrease in the in- 
visible loss occurring during milling and a proportionate increase 
in the total yield of mill products. 
The higher total yields of mill products were associated with the 
higher relative humidities and with the wheats of lower moisture 
content, These higher yields in the former case were undoubtedly 
due to decreased evaporation during milling, of the moisture con- 
tained in the wheat and probably to the absorption of some moisture 
from the atmosphere by some of the mill stocks; and, in the latter 
case of lower moisture content wheats, to the greater amounts of 
water which it was necessary to add in tempering these wheats in 
order to bring their moisture contents to the required percentage. 
Each 10 per cent increase in relative humidity above 35 per cent 
increased the total weight of the products obtained about one-half 
of 1 per cent, and each decrease of 1 per cent in the moisture content 
of the wheat before tempering caused about six-tenths of 1 per cent 
increase in yield. Compared with the weight of the wheat before 
tempering, the samples containing from 9 to 9.9 per cent moisture 
showed a net gain in weight of total mill products for all relative 
humidities given, while the samples containing from 12 to 12.9 per 
cent moisture before tempering showed a net loss in weight of total 
mill products except for relative humidities higher than 60 to 69 
per cent. 
ISTo very pronounced relation between the moisture content of the 
flour and that of the wheat before tempering was shown, or in 
other words, no relation was shown of moisture content of flour to 
the quantity of temper water added to the wheat. On the other hand, 
a decided tendency was shown for the moisture content of the flour 
to increase as the relative humidity increased, a difference of 10 per 
cent in relative humidity, making an. average difference of approxi- 
mately one-half of 1 per cent in the moisture content of the flour. 
No definite relation between air temperature and total yield of 
mill products was established. 
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WASHINGTON : GOVERNMENT PRINTING OFFICE : 1921 
