No fixed plan for the construction and equipment of a soap plant can be given. The specifications for a soap factory to be erected or remodeled must suit the particular cases. Very often a building which was constructed for a purpose other than soap manufacture must be adapted for the production of soap. In either case it is a question of engineering and architecture, together with the knowledge obtained in practice and the final decision as to the arrangement is best solved by a conference with those skilled in each of these branches. An ideal soap plant is one in which the process of soap making, from the melting out of the stock to the packing and shipping of the finished product, moves downward from floor to floor, since by this method it is possible to utilize gravitation rather than pumping liquid fats and fluid soaps. Convenience and economy are obtained by such an arrangement. The various machinery and other equipment for soap manufacture are well known to those connected with this industry. It varies, of course, depending upon the kind of soap to be manufactured, and full descriptions of the necessary machinery are best given in the catalogs issued by the manufacturers of such equipment, who in this country are most reliable. To know just what equipment is necessary can very easily be described by a brief outline of the process various soaps undergo to produce the finished article. After the saponification has taken place in the _soap kettle_ the molten soap is run directly into the soap _frames_, which consist of an oblong compartment, holding anywhere from 400 to 1,200 pounds, with removable steel sides and mounted upon trucks, in which it solidifies. In most cases it is advisable to first run the soap into a _crutcher_ or mixer which produces a more homogeneous mass than if this operation is omitted. Color and perfume may also be added at this point, although when a better grade of perfume is added it must be remembered that there is considerable loss due to volatilization of same. When a _drying machine_ is employed the molten soap is run directly upon the rollers of this machine, later adding about 1.0% zinc oxide to the soap from which it passes continuously through the drying chamber and is emitted in chip form ready for milling. After the soap has been framed, it is allowed to cool and solidify, which takes several days, and then the sides of the frame are stripped off. The large solid cake is cut with wires by hand or by a _slabber_ into slabs of any desired size. These slabs are further divided into smaller divisions by the _cutting table_. In non-milled soaps (laundry soaps, floating soaps, etc.), these are pressed at this stage, usually by automatic presses, after a thin hard film has been formed over the cake by allowing it to dry slightly. In making these soaps they are not touched by hand at any time during the operation, the pressing, wrapping and packing all being done by machinery.