washer type are termed, do not
skin sufficiently by the open-piling treatment, and are generally
exposed on racks to a current of hot air in a drying chamber in order to
produce the skin, which prevents evaporation of water, and allows of an
impression being given by the stamp without the soap adhering to the
dies. It is of course understood that heavily liquored soaps are, as a
rule, unsuitable for the drying treatment, as the bars become unshapely,
and lose water rapidly.

_Stamping._--Bar soaps are usually stamped by means of a hand-stamp
containing removable or fixed brass letters (Fig. 15), with a certain
brand or designation of quality and the name of the manufacturer or
vendor, and are now ready for packing into boxes.

A very large bulk of the soap trade consists of the household quality in
tablet form, readily divided into two cakes. These are stamped in the
ordinary box moulds with two dies--top and bottom impressions--the
die-plates, being removable, allow the impressions to be changed. This
type of mould (Fig. 16) can be adjusted for the compression of tablets
of varying thickness, the box preventing the escape of soap. We are
indebted to E. Forshaw & Son, Ltd., for this illustration.

[Illustration: FIG. 16.--Box mould.]

The stamping machine may be worked by hand (Fig. 17) or power driven.
Where large quantities of a particular tablet have to be stamped, one of
the many automatic mechanical stampers in existence may be employed, the
tablets being conveyed to and from the dies by means of endless belts.
Such a machine is shown in the accompanying illustration (Fig. 18).

If necessary, the soap is transferred to racks and exposed to the air,
after which it is ready for wrapping, which is generally performed by
manual labour, although in some instances automatic wrapping machines
are in use.

Cardboard cartons are also used for encasing the wrapped tablets, the
object being that these are more conveniently handled by tradesmen and
may be advantageously used to form an attractive window display.

_Cooling._--Many attempts have been made to shorten the time required
for the framing and finishing of soap, by cooling the liquid soap as it
leaves the pan.

[Illustration: FIG. 17.--Soap-stamping machine, showing box mould.]

With milling base, this is successfully accomplished in the
Cressonnieres' plant, by allowing the hot soap to fall upon the
periphery of a revolving drum which can be cooled internal