ce (F, fig. 4) and the feed-roller (E) to either one or two
beaters, which are furnished with two or three blades. The beater (G)
flings the cotton against the bars of a grid (H) to loosen, and cause
the dirt to pass between the bars, after which the cotton is carried
forward upon an air current, in the same manner as in an opener, and
formed into a lap. In case two scutchers are required, the laps from
the first are fed into the second, where they are similarly treated;
in both machines the lever and pendent mechanism furnishes the means
by which uniformity is attained. A beater may consist of a straight,
smooth blade (as at G), or of a blade provided with stout teeth; in
the latter event the operation resembles combing rather than beating.
Two-bladed beaters revolve from 1200 to 1500 times per minute; those
with three blades from 900 to 1000 times per minute.

_Carding Engine._--The functions of a card (see CARDING) are: to place
the fibres parallel; to remove remaining impurities and immature
fibres; and to form mature fibres into a porous band, called a sliver.
A carding engine consists of three cylinders which are covered with
cards; the first, or taker-in (see fig. 5), is the smallest; the
second and largest is the main cylinder; and the third is the doffer.
If the main cylinder is surmounted with a series of small ones (as at
A), the engine is called a roller and clearer card. If a series of
fixed strips of card are placed above the main cylinder, the engine is
known as a stationary flat card. But if the strips move forward (as at
B), it is a revolving flat card. In a roller and clearer card the
small cylinders (E) are also covered with cards, but their teeth are
bent to oppose those on the main cylinder, and they revolve with a
different velocity. The taker-in is covered with saw teeth cut in a
strip of steel which is fixed in the surface of that cylinder; it
receives the cotton (I) from a feed-roller (C) that turns above a
smooth iron table (D) called the feed plate, and strikes out the
heaviest particles of remaining dirt. In passing through the fringe of
lap, the teeth comb the attached fibres but deliver the loose ones to
the main cylinder. The latter carries them into contact with the teeth
on the rollers (E), by whose lower surface velocity combing is again
effected. Short fibres become fixed amongst the teeth of (A) and (E),
but those ly