out through the
perforations of the cylinder. Within the cylinder are compartments
equipped with winged plates, or ribs, that keep the coffee constantly
stirred up to facilitate the drying process. Another favorite is the
O'Krassa. It is constructed on the principle just described, but differs
in detail of construction from the Guardiola, and is able to dry its
contents a few hours quicker. Hot air, steam, and electric heat are all
employed in the various makes of coffee driers. A temperature from 65 deg.
to 85 deg. centigrade is maintained during the drying process.

[Illustration: O'KRASSA'S COFFEE DRIER COMBINED WITH DIRECT-FIRE HEATER]

When thoroughly dry, the parchment can be crumbled between the fingers,
and the bean within is too hard to be dented by finger nail or teeth.

_Hulling, Peeling, and Polishing_

The last step in the preparation process is called hulling or peeling,
both words accurately describing the purpose of the operation. Some
husking machines for hulling or peeling parchment coffee are polishers
as well. This work may be done on the plantation or at the port of
shipment just before the coffee is shipped abroad. Sometimes the coffee
is exported in parchment, and is cleaned in the country of consumption;
but practically all coffee entering the United States arrives without
its parchment.

[Illustration: THE SMOUT PEELER AND POLISHER, WITH CYLINDER OPEN SHOWING
CONE]

Peeling machines, more accurately named hullers, work on the principle
of rubbing the beans between a revolving inner cylinder and an outer
covering of woven wire. Machines of this type vary in construction. Some
have screw-like inner cylinders, or turbines, others having plain
cone-shaped cores on which are knobs and ribs that rub the beans against
one another and the outer shell. Practically all types have sieve or
exhaust-fan attachments, which draw the loosened parchment and silver
skin into one compartment, while the cleaned beans pass into another.

[Illustration: KRULL HULLING MACHINE (German)]

[Illustration: ANDERSON HULLING MACHINE (German)]

[Illustration: EUREKA SEPARATOR AND GRADER (American)]

[Illustration: CARACOLILLO (PEABERRY) SEPARATOR (American)]

[Illustration: ENGELBERG HULLER AND SEPARATOR (American)]

[Illustration: THE AMERICAN COFFEE HULLER AND POLISHER]

[Illustration: WELL KNOWN AMERICAN AND GERMAN HULLING AND SEPARATING
MACHINES]

Polishers of various makes are sometimes used just to re