In even moderate-sized works the saving of time in handling and rehandling ware, in burning time and in fuel, in cracked and other shaky ware, would in one season more than pay for a cheaply constructed and furnace-heated drying-room. The system of steam-coil drying is preferable in many things to any other plan; but probably only large works would care to go to the expense of putting them in. Both of these plans have been fully tested, and they are not experiments, but successful and accomplished improve ments. The system of steam drying is employed in a brick-yard in Washington, D. C., and through its steam-heated driers there pass every twenty-four hours from eighty-six to ninety thousand bricks, and the bricks are often so soft when they go into the driers, directly from the machine, that they can scarcely be handled and rubbed without finger-marking. But the next day, be it rain or sunshine, the bricks are set in the kiln and successfully burned in less than the usual time. If the same quantity of bricks were dried to an equal degree by the wind, in the same period of time, they would be cracked and so generally shaky that no market could be found for them, but as it is, the stock produced is sound and in demand. In addition to the advantages which have been named from driers of this kind, there is one other, which may have nothing to do with money gained or lost, but which should be esteemed above all others; it is the satisfaction of knowing that all green stock along with some special design, some prized effort, is just as safe in these driers as if it were in the kiln and a faithful burner had it in charge. In all works producing either terra-cotta or brick, in which both the moulding and drying are done in the open air, too much liberty is taken with the weather by all hands. Everybody keeps on working until the rain is close upon him, and oftentimes actually falling, before any effort is made to save the stock that has been made, and then all hands, men and boys, hastily move a part to shelter, and at the same time ruin it. After keeping this up for a while, and getting water-soaked, they stop, and leave the remainder of the stock for the elements to finish, which is what they had best have done with that which they had disfigured, as no unshapely pottery of any kind ought ever to go into a kiln. Nobody is satisfied with it after it is burned, and the first loss in cases of this kind is always the best. It should be remembered by all persons about works of this class, and at all times, that everything in the shape of moulded clay is extremely perishable stock until it comes safely out of the kiln, and that in any case of threatened danger, the duty of everybody is to save and secure that which has been produced, and that may at any time be ex posed to loss. I have dwelt thus long on the drying and care of unburned terra-cotta, because it is a subject that has much to do with the production of, as well as the profit in this, and in kin dred branches of pottery. The drying processes described can be safely conducted every day in the year, if necessary. SECTION IV. BURNING. One of the hardest colors to obtain uniformity in the tint, is the elegant buff, and to secure this rich, pleasing color in terra-cotta, requires long burning, and a highly experimental knowledge of firing, as well as a thorough acquaintance with the clay, and its behavior in the kiln. Coal should not be used in firing light-colored terra-cotta, as, although the usual products of combustion are separate from the ware, sulphurous fuel darkens and tarnishes the surface. Wood should be used in burning light-colored terra-cotta; but for red or darker colored ware, no objection should be urged against the use of coal. Kilns for burning terra-cotta are generally circular in form, and are expressly built so as to obtain a greater degree and better distribution of heat than can possibly be obtained in an ordinary open brick-kiln. A perspective view of terracotta kilns and works is shown in the frontispiece of this volume. The principle of applying the heat in terra-cotta kilns by the overdraft system is much approved. In these kilns the heat is carried to the top through flues in the walls, and the kiln being covered, and the draft toward the bottom, the heat descends through the ware. In this class of kilns, the stock is not so liable to crack, break, warp, and twist, as in the Hoffman and other annular constructed kilns. But the principal gain in the circular overdraft kilns is, the impartial and equitable distribution of heat, thereby securing a greater uniformity in the color of the terra-cotta, which, in addition to the savings mentioned, makes them very desirable. The usual time required for burning terra-cotta is from five to seven days, which is dependent upon the condition of the ware when it is set into the kiln, as well as upon the purposes for which it is required. SECTION V. IMPROVEMENT IN THE CONSTRUCTION OF The object of the arrangement shown in Figs. 123 to 125 is to modify the construction of the doors of kilns for burning terra-cotta in such a way that the heat will be distributed equally through the door and the other parts, so that all of the kiln will have a uniform temperature. The invention is that of Mr. Alfred Hall, of Perth Amboy, N. J., a gentleman who has spent a lifetime in the manufac ture of terra-cotta, and it consists in so arranging a door for terra-cotta kilns, with flues in its inner part, communicating with and forming continuations of the ordinary flues in the kiln-wall, and connected with the furnaces by flues, that a uniform distribution of heat all around the kiln will be effected, and all the articles in the kiln will receive an equal degree of heat, and thereby be burned more satisfactorily than is usual. Fig. 123 is a front elevation of the improvement, shown as applied to a kiln. Fig. 124 is a sectional plan view of the forward part of the kiln. Fig. 125 is a sectional elevation of the door. A represents the furnace-doors, B the ash-pits, and C the door of the kiln D. To the side parts of the door-frame are attached plates E, which project at the sides of the door, and have eyes formed in their outer ends to receive pins F. The pins Falso pass through holes in the ends of the U bars or clevises G, between which ends the eyes of the plates E are placed. The bends of the bars G pass also through eyes in the forked ends of the right and left screws L. The screws L pass through right and left screw-holes in the ends of the bars M, which cross the door C, and have a longitud |