I92	MODERN PAPER-MAKING
a few turns, or, passing the board in hard rolls, spoil the wire. Brushes or
strips of old jacket are sometimes fixed in front of the guard board to loosen
these and allow the water to wash them away.
A very good combination is a swinging board and a rubber-covered squeeze
roll just after the couch roll clears the board. Then the board may be used as
a light cleaning agent and the roll will take the water out of the cover before
it touches the paper, far more eifectively than a board can. With this arrange-
ment higher speeds and more output can be obtained, without the necessity
of increasing couch-roll weight.

fta 70.—-MnxsPAUGH suction Rou, showing springs for holding Box up to shell and
adjusting sceews
Suction Couch Ro/k—The suction couch roll (Kg. 69) has now almost super-
seded the couch press, and although some people still use the press method
of o>uching7 it seems that the suction roll will soon be universally employed.
Tbe suction roll has many advantages over the plain couch, the chief of
wiidb. is thai there is no top roll and no jacket. The eliminating of jackets
saves a gpeat deal of time, and a great deal of spoilt paper, because jackets always
ga?e some trouble whea starting up new, and further trouble when becoming
worn. Hie dfobtttfoii of the top roll has entirely done away with crushing
of wet sttiC and tjbe damage done to the wire by the pressure of the nip, due
to lumps of staff ot foreign matter, has entirely disappeared.