88 Modern Improvements in Corn-Milling Machinery. I 
equal, those wheats that have the least friable skins are better 
suited for the modern miller's use, even when he is equipped 
with machinery of the most recent type. 
The broad distinction between the " gradual-reduction " \ 
system and the old "low-grinding" system is that, whatever the j 
machinery employed, it is sought in " gradual reduction " to ' 
break the internal fai-inaceous part of the wheat-corn iiito gritty 
fragments, like coarse sand, keeping the bran as much intact and 
scraping it as clean as possible, and to produce' as little flour as 
possible in the initial processes ; while in the old system, as has 
been described, it was desired to make all the interior of the [ 
wheat into flour at the first grinding. The object of avoiding the i 
production of flour is this : whichever process be used the bran | 
will break up to some extent — this breakage cannot be avoided ] 
— and it will break or be cut into some frapfments amonof others , 
so minute, that in the process of sifting, these minute pai'ticles | 
of bran can, and do, pass through the same fine meshes of the 
sifting medium as the flour particles. If once they be mixed | 
with the flour there is no possibility of again separating them, j 
and the flour is thus spoiled. ' 
In any form of gradual reduction, and from any wheats, a 
certain small percentage of flour must be made in breaking ^ 
down the wheat, and that portion of the flour is injured by the | 
particles of bran that pass through the meshes of the sifting , 
apparatus and are mingled with it. The bulk of the interior 
of the corn is, however, obtained in gritty fragments, with 
which are found small bits of bran of the same size. These 
fragments, named "semolina" or "middlings," are submitted j 
to a " purifying " process, by which it is possible, more or less j 
completely, by the application of wind currents, either aloue or | 
in combination with sieves, to separate from the " semolina " or i 
" middlings " the bits of bran, they being of lighter specific I 
gravity. It is obvious that (theoretically) if the bran particles I 
be sucked, or sifted, or blown away, there will remain pure farina- | 
ceous fragments free from bran, and that these may by any 
appropriate grinding or crushing process be reduced to a pure 
flour. This is, in effect, what is done in the " gradual-reduc- 
tion " process. 
Difficulties, however, arise at every stage, and the process, 
while simple in principle, is very complicated when brought to 
the test of practical application. For instance, to avoid waste j 
of flour, it is needful that every particle of it should be scraped 
off" the bran ; but the bran is not readily detachable from the 
internal parts of the kernel of the wheat, and, in breaking down 
the corn, fragments of the interior are always obtained with 
pieces of bran attached to them. These fragments of farina- 
