The hat bodies, before they are stiffened, should be steeped in a weak solution of soda, to destroy any acid that may have been left in them. If sulphuric acid has been used in the making of the bodies, after they have been steeped in the alkaline solution they must be perfectly dried in the stove before the stiffening is applied. When stiffened and stoved, they should be steeped all night in water to which a small quantity of sulphuric acid has been added. This sets the stiffening in the hat body and finishes the process. If the proof is required cheaper, more shellac and rosin may be introduced. The Blowing Machine. In the manufacture of the finest kinds of fur hats, namely, those with a flowing nap, the stuffs of which they are made must be thoroughly refined. The clipping and pulling operations, to which the skins were subjected previous to cutting off the fur, never free the fur entirely of the coarse hairs that are intermixed with the finer; and to separate the coarse from the fine, the fur, as it came off the skin, is placed under the action of the blowing machine, which consists of a long, close, narrow, wooden box, divided into a number of apartments, the divisions between each of them having an open space at the top or bottom, so that a blast of wind can be propelled through the whole length of the trunk. The fur is put into one of these receptacles at one end, where it is teased and tossed by revolving brushes set in the bottoms of several of them, and a revolving fan is placed at the head. The whole being set in motion by some first power, the blast of wind from the fan seizes the loose thrown up fur that is tossed by the revolving breakers and brushes, and the stream of flying fur is transmitted from division to division, along the whole length of the wooden box. In this operation, the fur is graded as it is blown along and deposited gradually in the respective places, lodging in the most regular order, from the one end of the wooden trunk to the other, the dust and dirt falling down below, the heavier portion of fur not being blown to the same distance as that of the finer, which reaches the farther end, where the finest of all is received entirely refined of its impurities. But the cutting and blowing of fur are both independent and distinct branches of business, although relatively connected with that of hatting, and the various grades of fur are bought by the hatters from the professional hat furriers or their agents. The Manufacture of Hats. Before commencing a detail of the processes of the trade, it will be necessary to bear in mind that hatting is universally divided into two great divisions, viz., the making, and the finishing departments, each of which as a matter of course has its subdivisions.