Modem Imp'ovements in Corn-Milling Machinery. 97 
affected by its chemical composition or by the baking properties 
of flour made from it. It is desired to show its advantages and 
disadvantages from the mechanical point of view, and this seems 
to be the most convenient place to state in detail the difficulties 
of manufacturing it into flour, for it is in the modern milling 
process which is now to be described that the difficulties occur. 
The great drawbacks are the softness and looseness of texture of 
the endosperm, the farinaceous part of tlie corn, the large pro- 
portion of moisture which the grain holds, and the property 
which native wheat possesses, even if it be delivered in "good 
condition " and be stored in a well-protected warehouse, of 
absorbing moisture from the atmosphere. 
The largest proportion of the wheat-crop is now marketed 
in the damp winter months, and in those months consequently 
when wheat is in its worst condition. Immediately after a dry, 
hot harvest-time wheat is in as good condition as at any time, 
and also in the spring and early summer after it has been 
exposed in rick to the influence of the drying IMarch winds. 
But in winter the condition varies very much and very rapidly 
with changes of weather, and a decline in price of English 
wheat is often recorded " owing to poor condition," when there 
is no change in the actual position of the market. Nor can 
English wheat be stored in bulk for any long period without 
risk of deterioration. Absolute dryness and firmness of texture 
as opposed to toughness in any or however slight a degree is 
far more important in the "gradual-reduction" process than it 
was in the days of millstone-grinding, and for the reason that 
the millstone accomplished its work by a combination of crush- 
ing, tearing, and rubbing of a prolonged and violent kind, and 
thus was able to detach from the bran the floury particles of the 
grain in the shape of flour mixed with particles of bran, while 
in roller-milling it must be remembered that the object is to 
break the interior of the wheat into gritty particles and not into 
flour. 
The grooved roller-mills work with comparatively little 
pressure, and the grain is subjected to a cutting action of very 
short duration. The smooth rollers subsequently reduce the 
(^■ritty particles to flour by a crushing and rubbing action of a far 
gentler and less prolonged kind than that exercised by the mill- 
stone. In wheats that are dry the interior farinaceous portion 
of the corn is easily cut away from the bran ; in damp or tough 
wheats the flour particles adhere more closely to the bran, and 
appear, instead of being easily cut or scraped off" by the rollers, 
to be smeared into closer attachment with it. Further, such 
particles of the interior which have not fallen into flour in the 
original breaking process, when they come to be reduced by 
VOL. XXIV. — S. S. H 
