10 BULLETIN 788, U. S. DEPARTMENT OF AGRICULTURE. 
break streams adds weight to this conclusion, especially since it is 
true that the streams coming from the break rolls are composed of 
particles differing greatly in size and character, thereby making it 
difficult to secure a representative sample, or to divide it, for the 
purpose of moisture determination, into smaller portions composed 
of the different sizes and character of particles in their proper pro- 
portion. 
MOISTURE CONTENT OF DIFFERENT FLOUR STREAMS. 
Part 3 of Table II shows the percentage of moisture contained in 
the flour produced by the different grinding, or reduction, operations 
indicated in part 2. 
In practically all mills it is the practice to combine streams of 
small quantity and similar quality coming from different grinding 
operations before a separation of the flour product is made. The 
moisture percentages in some of the instances given here represent 
the moisture content of the flour product of combined streams, a fact 
which accounts for some of the apparent omissions and inconsisten- 
cles in the table. 
Probably the most interesting thing to note from the data given in 
part 3, as in the case of the data of part 2, is the reduction of the 
moisture content of the flour streams as the milling proceeded from 
first break to the end of the process, the break streams being 
highest and the low grade streams lowest. This point is illustrated 
more clearly by the curves shown in figure 2. 
The flour streams resulting from the break stock of mills Nos. 1 
and 3 showed a considerably higher moisture content than did those 
from the sizings, middlings, tailings, or low grade stock. The mois- 
ture content of the break flour of mill No. 2, on the other hand, did 
not appreciably differ from that of the sizings and middlings flour. 
This may have been due to the little difference in moisture content 
among the break, sizings, and middlings roll streams. 
Examination of parts 2 and 3 of Table II shows, except with respect 
to the break flour product of mills Nos. 1 and 3, a close correspondence 
between the moisture content of the flour product and that of the roll 
stream from which it was derived. The moisture content of the 
different break flour streams of mills Nos. 1 and 8, although higher 
than that of their middlings and sizings flour was, in some instances, 
as much as 2 per cent lower than that of the break roll streams from 
which they were produced. 
MOISTURE CONTENT AND YIELD OF MILL PRODUCTS. 
Part 4 of Table 2 shows the percentage of moisture contained in the 
different commercial products of each mill together with the percent- 
age of yield of each. The milling yields given here are based upon 
the actual weights of the products milled durimg a test run made 
iS i 
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