end always dries the most rapidly. When the pipes become somewhat dry, they may be laid in piles of several pipes in hight, according to their dryness; and, when dry enough to burn, five or six of even the largest size may be superimposed upon each other.

Some manufacturers dry their pipes upon hurdles or frames made of laths, in order to favor the admission of air; but this mode has scarcely any advantage over the simple drying board, and is far more expensive, and the pipes are more liable to be bent by being placed upon such racks.

Rolling and rimming the tiles is to be performed to secure a faultless product, and is done when they have lain long enough to be somewhat stiff, but still not hard enough to crack when handled and bent. This step in the progress of fabrication is too much neglected in this country, but in England is considered indispensable.

Rolling the pipes is thus performed: A round, smooth stick, one quarter or one third of an inch less in diameter than the clear capacity of the pipe, and long enough to reach through and afford a hand hold at each end, is passed through the opening, and the pipe gently rolled upon a smooth table two or three times to straighten it, and thus prevent any inequality which may have occurred during the progress of drying from becoming permanent. After rolling, the pipes are rimmed, by inserting into each end alternately and turning around the rimmer a wooden instrument, which is constructed of a round, smooth stick, just large enough to fill the end of the pipe, around the end of the shaft of which, and between it and the handle, is a collar, or square offset. This instrument, properly used, gives an exactly square end to the pipe, and insures their closely fitting together when laid down. The top or shaft of the instrument should be somewhat tapering,

so as to favor its insertion and only exactly fill the opening at the shoulder or collar. This shape favors its insertion and prevents the clay from being pushed into ridges when it is inserted.

The operations of rolling and rimming are very important to secure good tiles, and the expense is so slight that it will be more than repaid in the better quality of the product.

For convenience, a light table, about fifteen inches broad (where the tiles are twelve inches long), should be used. The tiles can be lifted off and on the drying board by means of the rolling pin, and the table moved forward. as the work progresses, and in this manner the process may go on very rapidly.

Tile burning. This is performed when the tiles are perfectly dry, and can only be done well by a person acquainted with the business. No extended description can supply a want of practical knowledge, but a word of admonition, in regard to important moments in the process, may be of great utility. One indispensable matter is a proper burning kiln. Almost any kind of lime or potters' kiln may be made use of, but an oven especially adapted will be found of great advantage.

In establishing a tile yard, it is usual to make and burn a clamp of bricks, in the first instance; then to use the scoving, the soft and other waste bricks for building the kiln. If the intention is to make from one to two hundred thousand in a season, a kiln 11 feet by 13 in the inside, and 10 feet high, will be a suitable size. A kiln of such dimensions will hold about 15,000 tiles, the number varying, of course, according to their size, beside bricks enough to fill to the top of the arches. The kiln must be built at one end of the shed, and directly in a line with it, so that the doorway into the side of the kiln, through which the

tiles are carried to

be set, may be on a line with the car track of the shed. Directly opposite this doorway there should be a similar opening on the other side of the kiln, through which the burnt tiles may be carried. The fire holes will be through the narrowest sides of the kiln, or those which correspond with the sides of the shed. For a kiln of the size named, there will be four fire holes, each end of which will be open. The walls of the kiln should not be less than two feet six inches in thickness at the bottom, and three feet is still better. They are carried up perpendicularly on the inside, but gradually becoming thinner toward the top, by drawing in on the outside. They are better built of tempered clay, mixed with a considerable proportion of sand, than of lime mortar. Some 25,000 bricks will be required to build such a kiln as the one described.

Tile kilns, of the following construction, will be found very appropriate for the purpose. There are two principal forms of construction in vogue in Europe-one of which is the high kiln, and the other the low kiln. The high kilns are commonly 20 to 24 feet long, 10 to 12 feet wide, and the arch 10 to 12 feet high, measured in the clear. The walls are made four courses of brick thick, and are supported by buttresses in the longitudinal walls. Between the buttresses, on each side, there are 8 furnace holes, 15 inches wide and about twice as high, and provided with a grate and ash box. They permit the firing to be done by means of wood, coal or turf. The door, placed at one end, should be wide enough to admit of wheeling in the tiles, and must be walled up when the burning is begun. Inside, between each pair of furnaces, there is a small flue, 3 to 4 inches square, which, passing up the wall and along the arch, terminates in low chimneys formed conveniently of tile pipe of proper size.

There are beside 6 or 8 rows of small smoke stacks, 4 to 5 inches in clear diameter, and 2 feet high, which pass through the arch, that may be opened or closed on the outside at pleasure, and by means of which the heat may be regulated according to requirement during the process of burning. Such a kiln resembles very much a common tile kiln. 40,000 or 50,000 pieces, of different dimensions, may be burnt in such a kiln, if space be economized, by placing the smaller pipes inside of the larger ones. The furnaces must be covered with an arch of masonry, else the pipes placed immediately upon the top of the furnace would be over-burnt.

The low kiln resembles a common potter's oven, and is now greatly in vogue, as it is easily built, and yields a well burnt product. Such a kiln consists of a long arch, 8 to 10 feet high, 14 to 16 feet long, and 10 to 12 feet wide in the clear. The walls and arch may be built very thin, if supported by iron arch bands-6 or 8 inch walls. being sufficient. But latterly the walls have been built thicker and supported by buttresses. At one end is placed the chimney, and at the other end the door for wheeling in the tiles. On each side of the door is built a furnace, of 18 to 20 inches breadth, and 10 to 15 inches hight, and a third furnace is fixed in the doorway when this is walled up. Immediately behind the doorway wall is placed the ash pit, 23 feet broad and 6 to 10 inches deep. The hearth of the oven lies a little higher than the opening of the ash pit, and behind this again there is a depression 9 inches wide and 6 deep, in which originate four flues, which, leading through the walls, terminate in the chimney. The chimney is not placed, as in the potter's oven, upon the arch, but at the end, so that the fire may be forced to pass over all the pipes, which are thus uniformly burnt in all parts. The chimney is about 15 to 18 inches clear in

diameter. In the walls and gable ends are vents, which during burning are walled up, but are opened when this is finished, so as to favor cooling.

Twenty to twenty-five thousand pipes of different sizes can be placed in such a kiln. When the tiles are wheeled in for arrangement, bricks are placed upright upon the hearth, and the pipes are set upon these perpendicularly, so that the fire may readily draw through the whole. When the kiln is filled, a sieve-like wall of a single course of brick, is built up to force the fire to spread equally through the entire oven, and at the same time to protect, in some measure, the first courses of tiles from the excessive action of the fire.

The following precautions must be observed in burning:

The tiles should not be placed in the oven before they are perfectly dry; but in case it is necessary to do so, they must be dried there, by being subjected, very gradually, to the heat of a slow fire, in order to dry them thoroughly, before heating them very much, as tiles burnt rapidly, in a damp condition, are nearly always bent and full of cracks.

The pipes are placed in the oven, perpendicularly upon the hearth and brick work which forms the furnace passages. Small pipes are put into larger ones, but not so nearly of a size, as to hinder a free play of the fire between them. Six inch pipe may be filled with three or four inch pipe, and these with inch pipe. This mode of placing is for the purpose of saving space. The upper tier of pipes may be placed horizontally, but the lower ones could not sustain the superincumbent pressure were they so placed.

It is very important to be provided with good fuel, and to keep the heat at an even temperature throughout the