pulp, etc.,
works by massing the constituents in two or three cylindrical strata,
and after action severing and removing these separately.

BREWING.--In brewing, centrifugals are quite useful. After the wort has
been boiled with hops, albuminous matters are precipitated by the
tannic acid, which must be extracted. Besides these the mixture
frequently contains husk, fiber, and gluten. The machine (Pat.
315,876), although quite unique in construction, has the same principle
of working as a sugar centrifugal, and need not be described. There is
one point, however, which might be noticed--that air is introduced at
about the same point as the material, and has an oxidizing and
refrigerating effect.

Class I. includes also centrifugals for the following purposes: The
removal of must from the grape after crushing, making butter,
extracting oils from solid fats, separating the liquid and solid parts
of sewerage, drying hides, skins, spent tan and the like, drying coils
of wire.

HORIZONTAL CENTRIFUGALS.--Only vertical machines have been and will be
dealt with. Horizontal centrifugals, that is, those whose spindles are
horizontal have been made, but the great inconvenience of charging and
discharging connected with them has occasioned their disuse; though in
other respects for liquids they are quite as good as vertical
separators. Their underlying theory is practically the same as that
hereinbefore discussed.

CLASS II., CREAMERS.--Centrifugals of the second class separate liquids
from liquids. There are two main applications in this class--to
separate cream from milk and fusel oil from alcoholic liquors. When a
liquid is to be separated from a liquid, the receptacle must be
imperforate. The components of different specific gravity become
arranged in distinct concentric cylindrical strata in the basket, and
must be conducted away separately. In creamers the particles of cream
must not be broken or subjected to any concussion, as partial churning
is caused and the cream will, in consequence, sour more rapidly.

The chief cause of oscillations in machines of this class, where the
charge is liquid, is the waves which form on the inner surface. They
may be met by allowing a slight overflow over the inner edge of the rim
of the basket; or by having either horizontal partitions, or vertical,
radial ones, special cases of which will be noticed. Oscillations may
also be met in the same manner as in sugar machines, by allowing the