can be
revolved, and the dye-liquor, which is in the lower half of the wooden
casing, penetrates through the lattice work of the drum, and dyes (p. 044)
the material contained in it. The construction of the machine is well
shown in the drawing, while the mode of working is obvious from it and
the description just given. The machine is very successful, and well
adapted for dyeing loose or raw wool and cotton. The material may be
scoured, bleached, dyed or otherwise treated in this machine.

[Illustration: Fig. 12.--Delahunty's Dyeing Machine.]

The Obermaier Machine, presently to be described, may also be used for
dyeing loose cotton or wool.

[Illustration: Fig. 13.--Obermaier Dyeing Machine.]

#Dyeing Slubbing, Sliver or Carded Wool.#--It is found in practice that
the dyeing of loose wool is not altogether satisfactory, the
impurities they naturally contain interfere with the purity of the (p. 045)
shade they will take. Then again the dyes and mordants used in dyeing
them are found to have some action on the wire of the carding engine
through which they are passed; at any rate, a card does not last as
long when working dyed wools as when used on undyed cotton or wool
fibres. Yet for the production of certain fancy yarns for weaving some
special classes of fabrics it is desirable to dye the wool before it
is spun into thread. The best plan is undoubtedly to dye the fibre
after it has been carded and partly spun into what is known as
slubbing, or sliver. All the impurities have been removed, the wool
fibres are laid straight, and so it becomes much easier to dye. On the
other hand, as it is necessary to keep the sliver or slubbing straight
and level, no working about in the dye-liquors can be allowed to take
place, and so such must be dyed in specially constructed machines, and
one of the best of these is the

_Obermaier Dyeing Machine_, which is illustrated in figure 13.--In (p. 046)
the Obermaier apparatus dye-vat, A, is placed a cage consisting of an
inner perforated metal cylinder, C, and an outer perforated metal
cylinder, D; between these two is placed the material to be dyed. C is
in contact with the suction end of a centrifugal pump, P, the delivery
end of which discharges into the dye-vat A. The working of the machine
is as follows: the slubbing or sliver is placed in the space between C
and D rather tightly, so that it will not move about. Then the inner
cage is placed in the dye-vat as shown. The vat is