96 Modern Imp'ovements in Corn-Milling Machinery. j 
that they cannot be removed by the process just described. ' 
Such, for instance, are the Indian and Egyptian wheats. I 
These wheats require thorough washing in order to dissolve the i 
mud-clots and to free the grain from the attached dirt. Mingled 
with these wheats stones are frequently found. There are 
several types of washing-machines ; the best of them, in addition 
to active agitation of the wheat in water, are so contrived as to 
provide an upward current of water (into which the stream of \ 
wheat is directed) of suflBcient force to carry the wheat with it ■ 
to another part of the machine, and not so strong as to lift the 
heavier stones, which drop to a receptacle provided for them at 
the bottom, and thus a complete separation is effected. The 
wheat having been washed is allowed to drain, and is then 
passed into a centrifugal drying machine. This throws off" much j 
of the water, but does not dry the wheat sufficiently for imme- | 
diate grinding. Some apply jets of steam to the wheat in the I 
centrifugal drying-machine, with the object of driving out of the 
crevices any dirt that may have escaped the washing process. 
But in any case, if it be desired to grind the wheat within a 
short time, a dryer employing artificial heat must be used. It , 
remains to be mentioned that no mode has been indicated of ' 
removing stones from wheat if the wheat be not washed. There I 
are machines contrived, and extensively used, for the purpose, 
but none of them are perfectly effectual. i 
From what has been said it may be conceived how great are ' 
the difficulties which millers have in cleaning and purifying ; 
foreign wheats, and how great ingenuity has been put in action | 
and how much outlay incurred in overcoming these difficulties. ! 
In this respect our native wheats stand at a great advantage, as 
they are delivered almost clean to the mills, and do not call for 
the use of this elaborate machinery. It is to be feared that 
millers do not estimate at a sufficiently high rate the losses they 
sustain by the stuff" separated or lost in the cleaning process. ; 
Some foreign wheats are so foul that to clean them, and even 
then imperfectly, a removal of ten per cent, or more of the , 
original weight is necessary. In order that the miller may 
know what his loss is, wheat should be weighed after clean- 
ing, and the weight compared with the original ; its use at this 
point affbrds a good instance of the usefulness of the automatic , 
weighing-machine. i 
The wheat thus cleaned and purified may pass from the 
cleaning department into the mill. It will have been seen that i 
native wheats, so far as their mechanical treatment in the clean- 
ing pi-ocess is concerned, should be preferred to foreign sorts. 
It is not proposed in this paper to deal with tlie question of the 
extent to which the comparative value of English wlieat is 
