e nib is now effected by a powerful current of air,
the large nib falling against the current, whilst the shell is carried
with it and drops into another compartment. It is amusing to stand and
watch the continuous stream of nibs rushing down, like hail in a storm,
into the screw conveyor.

[Illustration: SECTION THROUGH WINNOWING MACHINE.]

This is the process in essence--to follow the various partially
separated mixtures of shell and nib through the several further
separating machines would be tedious; it is sufficient for the reader
to know that after the most elaborate precautions have been taken the
nib still contains about one per cent. of shell, and that the nib
obtained is only 78.5 per cent. of the weight of raw beans originally
taken. Most of the larger makers of cocoa produce nib containing less
than two per cent. of shell, a standard which can only be maintained by
continuous vigilance.

[Illustration: CACAO GRINDING.
A battery of horizontal grinding mills, by which the cacao nibs are
ground to paste (Messrs. Cadbury Bros., Bournville.)]

The shell, the only waste material of any importance produced in a
chocolate factory, goes straight into sacks ready for sale. The pure
cacao nibs (once an important article of commerce) proceed to the
blenders and thence to the grinding mill.

(_g_) _Blending._

We have seen that the beans are roasted separately according to their
kind and country so as to develop in each its characteristic flavour.
The pure nib is now blended in proportions which are carefully chosen to
attain the result desired.

(_h_) _Grinding the Cacao Nibs to Produce Mass._

In this process, by the mere act of grinding, the miracle is performed
of converting the brittle fragments of the cacao bean into a
chocolate-coloured fluid. Half of the cacao bean is fat, and the
grinding breaks up the cells and liberates the fat, which at blood heat
melts to an oil. Any of the various machines used in the industries for
grinding might be used, but a special type of mill has been devised for
the purpose.

In the grinding room of a cocoa factory one becomes almost hypnotised by
a hundred of these circular mill-stones that rotate incessantly day and
night. In Messrs. Fry's factory the "giddy motion of the whirling mill"
is very much increased by a number of magnificent horizontal driving
wheels, each some 20 feet in diameter, which form, as it were, a
revolving ceiling to the room. Your fascinated