TOBACCO. See NICOTIANA.

Tobacco-Pipes, Manufacture of. The art of making tobacco pipes, or, as it is commonly called, pipe-making, though one of the simplest species of pottery, is sufficiently curious to merit description. The process may be divided into six stages; viz. 1. Beating or preparing the clay; 2. Rolling; 3. Moulding; 4. Trimming; 5. Drying; and 6. Burning.

Preparation of the Clay.—The fine white clay employed by the pipe-makers is dug from the quarries in masses of about a cubic foot each. Before it can be used in the manufacture of tobacco-pipes, it must be reduced to the consistence of a tough paste. To effect this, after its outer surface has been cleared from dirt or dust, it is broken into small pieces about as large as a goose's egg, and thrown into a tub with such a quantity of soft water as experience has shown to be sufficient to bring it to the proper consistence. After lying till it has soaked up all the water, which usually requires from twelve to twenty-four hours, it is taken from the tub and laid on a strong wooden bench. Here it is beaten by a heavy four-square iron instrument, in such a manner as to cut it from one end to the other into very thin slices. It requires considerable address to perform this operation, and it is surprising how thin the workmen will sometimes cut the slices, and how equally they will thus divide the clay. This beating is continued, alternately folding up the clay and slicing it, till the whole is perfectly smooth. It is then ready for rolling.

Rolling.—The operation of rolling reduces the clay into pieces of a proper size and length for making pipes, and almost to their proper form. The roller sits at a bench with trimmer carefully passes up the hollow of the shank a wire similar to that employed in moulding, and holding the pipe by the hole, while the shank lies before him on the wooden block, he pares off with a blunt knife all the excrescences of clay, both from the shank and hole, and rubs the former, while lying on the block, with the grooved part of his iron, so as to render it as smooth as possible. He now cuts off the ragged piece at the extremity of the shank, withdraws the wire, and lays the pipe on the drying frame. One great object of the trimmer is to see that the pipe is completely perforated, which he discovers by blowing through it; and if he finds the hole choked up, he must open it by pushing the wire as far as possible. If this does not succeed, he breaks the pipe, as useless.

Drying.—The pipe has now received all the work that can be bestowed on it by the maker, previously to its being burned; but as the exposing of it to heat while soft and pliable would make it crack, it is necessary that it be properly dried. For this purpose, a frame is prepared, composed of three or four long pieces of wood, fastened to two end-pieces in such a manner that the middle of the frame shall be the lowest, to give the shanks of the pipes that curve which they generally possess. After being trimmed, the pipes are laid beside each other in this concave frame, with their holes hanging down over the edges of the frame, and their shanks bending within its hollow. In this position they are exposed to the air till they are dry and firm. They are then ready for burning or baking.

Burning.—For burning or baking the pipes, there is to be prepared a kiln of a simple but peculiar construction. It is built in the form of a cylinder, close at the bottom and on the sides, and open at the top. Below the bottom is a grate for receiving the fuel, and round the sides are constructed vertical or spiral flues, opening at the top, and communicating below with the grate. The sides of the furnace on its interior are pretty thin, and are formed of a cement composed of clay mixed with fresh cow-dung. In the middle of the cavity is placed a pedestal composed of the same materials, for the pipes to lean against. When the pipes are sufficiently dried, they are arranged round this pedestal, resting against it and against each other, with their holes next the bottom of the furnace. They are thus placed in successive layers, till the furnace be sufficiently full, when the open space at top is filled up with bricks placed over each other, so as to leave interstices for the free circulation of the air, and of the smoke and flame which issue through the flues. In these interstices are laid several pieces of broken dried pipes, to serve as pyrometers for ascertaining the state of the included pipes during the burning. The fire is now lighted, and kept up, till, on examining the pieces of clay laid in the interstices of the bricks, it is concluded that the pipes within the furnace are sufficiently baked. The fire is then suffered to go out, and the whole to cool till the next day, when the bricks are taken down, the pipes removed, and packed in barrels for sale. After being burnt, the pipes are sometimes glazed, which is done by rubbing them, while warm, with flannel and a little white flax. In some places the extremities of the shanks are rendered smooth by dipping them before burning in the ordinary potters' glazing, which prevents that adhesion to the lips so unpleasant in new unglazed pipes.