tities can be dealt with at a time.

The first operation, viz. that of boiling in alkali, is carried out in
a "kier," a large, egg-ended, upright cylindrical vessel, constructed
of boiler-plate and capable of treating from one to three tons of yarn
at a time. In construction, the kiers used for yarn bleaching are
similar in construction to those used for pieces (see below). The yarn
to be bleached is evenly packed in the kier, and is then boiled by
means of steam with the alkaline lye (3-4% of soda ash or 2% caustic
soda on the weight of the cotton being usually employed) for periods
varying from six to twelve hours. It is essential that a thorough
circulation of the liquor should be maintained during the boiling, and
this is effected either by means of a steam injector, or in other
ways. As a rule low pressure kiers (working up to 10 lb. pressure) are
employed for yarn bleaching, though some bleachers prefer to use high
pressure kiers for the purpose.

When the boiling has continued for the requisite time (6-8 hours), the
steam is shut off, and the kier liquor blown off, when the yarn is
washed in the kier by filling the latter with water and then running
off, this operation being repeated two or three times. The hanks are
now transferred to a stone cistern provided with a false bottom, from
beneath which a pipe connects the cistern with a well situated below
the floor line. The well contains a solution of bleaching-powder,
usually of 2 deg. Tw. strength, and this is drawn up by means of a
centrifugal brass pump and showered over the top of the goods through
a perforated wooden tray, passing then by gravitation through the
goods back into the well. The circulation is maintained for one and a
half to two hours, when the yarn will be found to be white. The
bleaching-powder solution is now allowed to drain off, and water is
circulated through the cistern to wash out what bleaching powder
remains in the goods. The souring is next carried out either in the
same or in a separate cistern by circulating hydrochloric or sulphuric
acid of 2 deg. Tw. for about half an hour. This is also allowed to
drain, and the yarn is thoroughly washed to remove all acid, when it
is taken out and wrung or hydroextracted. At this stage the yarn may
be dyed in light or bright shades without further treatment, but if it
is to be sold as white yarn, it is blued. The blueing may e