ed or lowered by means of the power-driven chain C. The goods to
be bleached are packed in wagons W outside the kier, and when filled
these are pushed home into the kier, so that the pipes p fit with
their flanges on to the fixed pipes at the bottom of the kier. The
heating is effected by means of steam pipes at the lowest extremity of
the kier, while the circulation of the liquor is brought about by
means of the centrifugal pump P, which draws the liquor through the
pipes p from beneath the false bottoms of the wagons and showers it
over distributors D on to the goods. By this mode of working a
considerable economy is effected in point of time, as the kier can be
worked almost continuously; for as soon as one lot of goods has been
boiled, the wagons are run out and two freshly-packed wagons take
their place. The following is the sequence of operations:--The goods
are first steeped over night in dilute sulphuric acid, after which
they are washed and run through old kier liquor from a previous
operation. They are then packed evenly in the wagons which are pushed
into the kier, and, the door having been closed, they are boiled for
about eight hours at 7-15 lb. pressure with a liquor containing soda
ash, caustic soda, resin soap and a small quantity of sulphite of
soda. The rest of the operations (chemicking, souring and washing) are
the same as in the old process.

[Illustration: FIG. 6.--The Mather Kier, cross section.]

[Illustration: FIG. 7.--The Mather Kier, longitudinal section.]

A somewhat different principle is involved in the Thies-Herzig
process. In this the kier is vertical, and the circulation of the
liquor is effected by means of a centrifugal or other form of pump,
while the heating of the liquor is brought about outside the kier in a
separate vessel between the pump and the kier by means of indirect
steam. The sequence of operations is similar to that adopted in the
Mather-Koechlin process, differing chiefly from the latter in the
first operation, which consists in running the goods, after singeing,
through very dilute boiling sulphuric or hydrochloric acid, containing
in either case a small proportion of hydrofluoric acid, and then
running them through a steam box, the whole operation lasting from
twenty to sixty seconds.

Bleached by any of the above processes, the cloth is next passed over
a mechanical contrivance known as a "scut