creates a vacuum inside the chambers. To fill this, liquor from the
dye-vat passes through the cops and into the chambers, and is in turn
drawn through the pump and returned to the dye-vat. In this way there is
a continual circulation of dye-liquors from the vat through the cops,
chambers and pump back to the vat again.

[Illustration: FIG. 14.--Graemiger Cop-dyeing Machine.]

The left upper chamber is practically a blank chamber. Those portions of
the cop carriers in contact with it are filled with cops, which are
placed on perforated spindles; the discs are given a quarter revolution
which brings the cops into the dye-liquor and in connection with the
left lower chamber and are dyed. At the same time the section of the cop
carriers now in contact with the left top chamber is filled with a new
lot of cops, another quarter of a revolution is given to the cop
carriers, which immerse the new lot of cops in the dye-liquor. The third
quarter of the cop plates is filled with cops. A third movement of the
cop plates now takes place; this brings the first lot of cops out of the
dye-liquor and in contact with the right upper chamber, where the
surplus liquor is drawn out of them and returned to the dye-vat. Another
revolution brings the cops back to their first position, they are now
removed and a new lot substituted. These proceedings go on
continuously. Although not quite free from defects the machine gives
very good results, the cops being very uniformly dyed through.

[Illustration: FIG. 15.--- Beaumont's Cop-dyeing Machine.]

=Beaumont's Cop-dyeing Machine.=--This is illustrated in Fig. 15. It
consists of a copper hemispherical dye-vessel, which is provided with a
tightly fitting lid, although this is not needed in all cases. The
bottom of the vessel is in communication with the suction end of a
centrifugal pump, while the delivery end of the pump is attached to the
upper end of the dye-vessel, the action of the pump being to secure a
constant circulation of dye-liquor from the bottom to the top of the
dye-vessel. Arrangements are provided by a peculiar and ingenious
contrivance fitted in one side of the dye-kettle for introducing steam
to heat the dye-liquor to any required degree. As in most forms of
cop-dyeing machines, the cops are placed on perforated metal spindles.
The cops and spindles are inserted in holes in a perforated metal plate,
and over them is placed a thin metal plate, technically called the
antifloat