ll troubles are (p. 057)
avoided, and plush fabrics can be satisfactorily dyed in them.

[Illustration: Fig. 21.--Copper Cased Dye Beck. Mather & Platt.]

Figure 21 shows a dye-bath built of iron, cased with copper, suitable
for dyeing most colours on woollen cloths.

[Illustration: Fig. 22.--Read Holliday's Hawking Machine.]

In the jig and wince dyeing machines the pieces necessarily are for a
part of the time, longer in the case of the jigger than in that of the
wince, out of the dye-liquor and exposed to the air. In the case of
some dyes, indigo especially, this is not desirable, and yet it is
advisable to run the cloth open for some time in the liquor so as to
get thoroughly impregnated with the dye-liquor.

The so-called hawking machine, figure 22, is an illustration of Read
Holliday's hawking machine, made by Messrs. Read Holliday & Sons, of
Huddersfield. There is the dye-vat as usual; in this is suspended the
drawing mechanism, whose construction is well shown in the drawing.
This is a pair of rollers driven by suitable gearing, between which
the cloth passes, and by which it is drawn through the machine. A
small roller ensures the cloth properly leaving the large rollers, (p. 058)
then there is a lattice-work arrangement over the pieces are drawn. In
actual work the whole of this arrangement is below the surface of the
dye-liquor in the vat. The piece to be dyed is threaded through the
machine the ends stitched together, then the arrangement is lowered
into the dye-vat and set in motion, whereby the cloth is drawn
continuously in the open form through the dye-liquor, this being done
as long as experience shows to be necessary. This hawking machine will
be found useful in dyeing indigo on wool, in mordanting and dyeing
wool with the Alizarine series of dyes.

CHAPTER IV. (p. 059)

THE PRINCIPLES AND PRACTICE OF WOOL DYEING.

The various methods which are used in dyeing wool have, of course,
underlying them certain principles on which they are based, and on the
observance of which much of the success of the process depends.
Sometimes these principles are overlooked by dyers, with the result
that they do not get good results from their work. It must be obvious
to any person with any technical knowledge that all processes of
dyeing either wool or silk, or cotton or any other fibre, must take
into consideration the properties of the fibre on the