vy press roller is arranged to bear on the cloth
on the full roller. When all the cloth has passed from one roller to the
other it is said to have been given "one end". The direction of motion
is now changed, and the cloth sent in the opposite direction through the
jig, and the piece has now received another "end". This alternation from
one roller to the other is continued as long as is deemed necessary,
much depending on the depth of colour which is being dyed--some pale
shades may only take two or three ends, deeper shades may take more.
When dyeing wool with acid colours which are all absorbed from the
dye-liquor, or the bath is exhausted, it is a good plan to run the
pieces several more ends so as to ensure thorough fixation of the dye on
the cloth.

It is not advisable in working these jigs to add the whole of the dye to
the liquor at the commencement, but only a part of it; then when one end
is given, another portion of the dye may be added; such portions being
always in the form of solution. Adding dyes in powder form inevitably
leads to the production of colour specks on the finished goods. The
reason for thus adding the dye-stuff in portions is that with some dyes
the affinity for the fibre is so great that if all were added at once it
would all be absorbed before the cloth had been given one end; and,
further, the cloth would be very deep at the front end, while it would
shade off to no colour at the other end. By adding the dye in portions
this difficulty is overcome and more level shades are obtained; it is
met with in all cases of jigger dyeing, but it is most common in dyeing
cotton or wool with basic dyes like magenta, auramine, methyl violet or
brilliant green, and in dyeing wool with acid dyes like acid green,
formyl violets, azo scarlet, or acid yellow.

Some attempts have been made to make jiggers automatic in their
reversing action, but they have not been successful; owing to the
greatly varying conditions of length of pieces, their thickness, etc.,
which have to be dyed, and it is next to impossible to make all
allowances for such varying conditions.

[Illustration: FIG. 20--Jig Wince.]

[Illustration: FIG. 21.--Cloth-dyeing Machine.]

=The Jig Wince or Wince Dye Beck.=--This dyeing machine is very largely
used, particularly in the dyeing of woollen cloths. It is made by many
makers, and varies somewhat in form accordingly. Figs. 20, 21 and 22,
show three forms by different makers. In any make