truction of an
ordinary gas singeing apparatus is seen in section in fig. 3. Coal gas
mixed with air is sent under pressure through pipe a into the burners
b, b, where the mixture burns with an intense heat. The cloth travels
in the direction of the arrows, and in passing over the small nap
rollers c comes into contact with the flame four times in succession
before leaving the machine.

[Illustration: FIG. 3.--Gas Singeing Apparatus.]

Gas singeing is also used for plain goods, and being cleaner and under
better control has largely replaced plate singeing.

At this stage the goods which have been browned on the surface by
singeing are ready for the bleaching operations. A great many
innovations have been introduced in recent years in the bleaching of
calico, but although it is generally admitted that in point of view of
time and economy many of these processes offer considerable
advantages, the old process, in which a lime boil precedes the other
operations, is still the one which is most largely employed by
bleachers in England. In this, the sequence of operations is the
following--

_Grey Washing._--This operation (which is sometimes omitted) simply
consists in running the pieces through an ordinary washing machine (as
shown in fig. 5) through water in order to wet them out. On leaving
the machine they are piled in a heap and left over night, when
fermentation sets in, which results in the starch being to a large
extent hydrolysed and rendered soluble in water.

_Lime Boil._--In this operation, which is also known as _bowking_
(Ger. _beuchen_), the pieces are first run through milk of lime
contained in an ordinary washing machine and of such a strength that
they take up about 4% of their weight of lime (CaO). They are then run
over winches and guided through smooth porcelain rings ("pot-eyes")
into the kier, where they are evenly packed by boys who enter the
vessel through the manhole at the top. It is of the greatest
importance that the goods should be evenly packed, for, if channels or
loosely-packed places are left, the liquor circulating through the
kier, when boiling is subsequently in progress, will follow the line
of least resistance, and the result is an uneven treatment. Of the
numerous forms of kier in use, the injector kier is the one most
generally adopted. This consists of an egg-ended cylindrical vessel
constructed of stout