Kiln

“ Here the kiln was perfect. It was circular, and measured six yards in circumference, its shape being well-defined by small hand-formed masses of red brick-earth. The floor, about two feet below the natural surface of the ground, was paved with a layer of sand-stones, some of them cut into a circular shape, so as to fit the kiln, the upper surfaces being tooled, whilst the under remained in their original state. As at Anderwood, the ware was broken into small fragments, and was scattered round the kiln for five or six yards. ”

“ As the men were excavating on the site of the old Parliament Street Chapel at the lower corner of George Street, they came on an old kiln, in and near which they found jars, jugs, and flat-bottomed pots of mediæval manufacture, varying from six to sixteen inches in height and from two to nine inches in diameter; they are all of a red clay body, with the upper portion of the outside covered with green salt glaze. They afterwards found three other kilns and more pieces of the same description, and a number of fragments of encaustic tiles with coats of arms on, and one or two with inscriptions. ”

“ When Charcoal Nils had looked on for a while, he slunk back to the old pine-tree, and made its trunk echo to the sound of his three ax-strokes till one could hear them on the Harsberg. Then he went to the kiln, as though he had seen nothing, and all went on as before. The kiln was glowing with a handsome, even glow, and the tall woman was about and working as usual. ”

“ In these kilns the flames rush in at the fire holes, play on the built-up bungs of saggars, and escape through the top vent. In a two chamber kiln, as sometimes used for porcelain, the glaze is put in the lower chamber to receive the hottest fire, the biscuit in the upper getting a gentle fire. Where the fire enters directly into the kiln in any large volume, bags or small chimneys are built up inside the mouths to save the saggars from the worst of the fire. Of late the single-chamber, down-draught kiln has come into favour, as it is easily packed and economical of heat. ”

“ Kilns for drying corn are generally erected in lonely places, apart from the other dwellings, owing to their liability to catch fire. On the other hand, the kiln-logies or pits, are dreary, dark, deep receptacles, of circular form, narrow below and wide above, like hollow cones inverted. During the romping frivolities of the domestic circle in performing as many of the games as they can, lots are cast as to the maiden who must resort to the kiln at the dark hour of midnight, with her clue of blue thread in her hand, to meet with her sweetheart, or to hear his name. ”

“ With the remainder of my outfit we cleaned out and sealed off the walls of an old lime kiln, which had served ever since the first rock buildings rose on Las Palomas. The oven was cut in the same porous formation, the interior resembling an immense jug, possibly twelve feet in diameter and fifteen feet in height to the surface of the ledge. By locating the kiln near the abrupt wall of an abandoned quarry, ventilation was given from below by a connecting tunnel some twenty feet in length. ”

“ At the present time it is rare that any one attempts to build a kiln on a spot where no one has ever built before. Potteries are carried on just where they have been for ages, and the same clay is used which furnished the funeral urns of our ancestors. ”

“ The annealing kilns are large fire-brick chambers of small height but with sufficient floor area to accommodate four or six large slabs, and the slabs are placed directly upon the floor of the kiln, which is built up of carefully dressed blocks of burnt fire-clay resting upon a bed of sand ”

“ From the foregoing statements it will be observed that two quite different methods of manufacture are followed. In the first the cement 'mix' is molded into briquettes, which are dried, stacked in a kiln and burned. For the burning by this method three different forms of kiln are used: 1. The intermittent dome kilns that resemble in their operation common lime kilns. 2. Continuous kilns, of the Ditzsch or Schœfer patterns. 3. The Hoffman ring-kiln. These kilns are economical in fuel, but expensive in time and labor. ”

“ For then the men, women, and children would gather and build the kilns—pits scooped in the sand, measuring about seven feet across and three feet deep in the centre. While the men finished lining the sides of the kiln with stones, the women and girls would leap into it with armfuls of furze; which they lighted and so, strewing the dried ore-weed upon it, built little by little into a blazing pile. The great sea-lights which ring the Islands now make a brave show ”

“ Sands. “They are mostly used by nursery-gardeners, because they take so little room.”
“How long do they take to dry?” asked Mary, looking longingly at her little jug.
“About a day; so we will leave your jug with the others, and go to the kiln to see how they will be burnt to-morrow.”
The kiln was round, with a big doorway, called a wicket.
The pots and pans are put inside, great care being taken that they should not touch each other, or they would stick like loaves of bread. ”

“ It is the duty of the workmen belonging to the glaze kiln to make the saggers during the intervals of their work; or if there be a relay of hands, the man who is not firing makes the saggers.
The English kilns differ from those of France and Germany, in their construction, in the nature of their fuel, and in the high temperature required to produce a surface sufficiently hard for a perfectly fine glaze. ”

“ The wall of the kiln is carried up nearly straight for 6 feet, when it is drawn in, so as to become bluntly conical. Upon the top a plate of iron is fastened in the manner of the keystone of an arch, and bands of iron are passed round the kiln and drawn tight with screw bolts and nuts to strengthen it. ”

“ The better or peculiar kinds of bricks, as well as tiles of all kinds, are burnt in kilns instead of clamps. These kilns, though of a peculiar form, according to the purpose to which they are applied, yet do not differ in principle from the lime-kiln, &c. In the kiln, the fire is not intermixed with the bricks, but is applied beneath; nor are ashes mingled with the clay of which kiln-burnt bricks are made. ”

“ One method of drying was finely to bed the kiln with wheat straw laid on the hair-cloth, the hops being spread 8 inches thick over this, 'and then you shall keepe a fire a little more fervent than for the drying of a kiln full of malt,' the fire not to be of wood, for that made the hops smoky and tasted the beer, but of straw! Worlidge, strangely, recommended the bed of the kiln to be covered with tin, as much better than hair-cloth, for then any sort of fuel would do as well as charcoal, since the smoke did not pass through the hops. ”

“ Then the donkey patters off for another load, the boy sitting sideways on its pack and shaking his heels—that makes it go.
To the left stands a kiln in process of being packed with millions of the clay dice, which, baked hard, dove-tailed together, and forming a smooth, polished surface, will keep many a room cool. The kiln next door to it, is full of pots and pans of all shapes and sizes, but its opening is plastered up with clay, and they are not to be seen. Into the great fiery furnace underneath, a man is thrusting dry brown bushes, and dried prickly pear, and whatever rubbish will burn. ”

“ The brisk and long flame which it yields dips into the tunnels, penetrates the kiln, and circulates round the sagger-piles. The heat augments rapidly, and, at the end of 13 or 15 hours of this firing, the interior of the kiln is so white, that the watches can hardly be distinguished. ”

“ Emptying the kiln.—The kiln is allowed to cool very slowly. On taking the ware out of the saggers, the biscuit is not subjected to friction, as in the foreign potteries, because it is smooth enough; but is immediately transported to the place where it is to be dipped in the glaze or enamel tub. A child makes the pieces ring, by striking with the handle of the brush, as he dusts them, and then immerses them into the glaze cream ”

“ Length of time lumber should be left in the kiln.—No one should undertake to operate a kiln unless he understands perfectly the particular make of the kiln that he is handling, for if the ventilation is not correctly regulated, the entire charge of the kiln may become mildewed, casehardened, checked, discolored, or dried unevenly. No rule can be given for the time which lumber should be left in the kiln, as it depends upon the condition of the lumber, temperature, kind of lumber, dimensions, and ventilation. ”

“ So important a part does the kiln play in perfecting a piece of pottery—putting the final touch upon it: the touch that shall make or mar—that the potter realises he must plan, before anything else, either to own a good kiln or to know of one where his pieces can be sent to be fired. ”

“ Kilns and burning form the pivot upon which the art of the potter turns. M. Doat has said, "A potter can no more express himself without his kiln than can a violinist without his violin," and yet there are some who try to make out by sending their work to some nearby pottery to be burned. Let it be at once understood that he who finds it impossible to procure and manage a kiln had best take to some other craft. ”

“ A site for the new factory was found in Warmstry House, a fine old mansion that had belonged to the Windsor family, situated some hundred yards to the north of the cathedral, and the kilns were erected in the grounds which sloped down to the river. The biscuit kiln and the glazing-kiln were enclosed in long roofed buildings apparently without conspicuous chimneys. Only the great kiln for the ‘segurs’ takes the conical shape that we associate with pottery-ovens. ”

“ In clamp burning the bricks are built up close together, and the bottom ones only are heated with burning breeze or cinders, the heat spreading to those at the top. A kiln is a sort of large chamber in which the bricks are loosely stacked with spaces between them for the heat to pass through, and they are baked by fires placed either in arched furnaces under the floors of the kiln, or in fire holes made in the side walls. ”

“ While as for the little town children, the buildings which they see all round them made of sun-dried bricks and earth, the barrels and the thousand and one household utensils formed of exactly the same material, or perhaps of clay very roughly baked in a primitive kiln, seem to them hardly more artificial and man-made than the corn in the walled gardens outside the city, which they see watered twice a week. ”

“ The kiln for burning the limestone into lime is a cup-shaped concavity, surrounded with solid brick-work, open at the top, and terminating below by an iron grate. It has a stone door that may be opened and closed for charging and emptying the furnace when required. This furnace I formerly charged with alternate strata or layers of small coal and limestone, the latter being broken previously into pieces not larger than a man’s fist, until the kiln was completely filled. ”

“ It is well where stock is kiln-dried direct from the saw or knife, after having first been steamed or boiled—as in the case of veneers, etc.,—to get them into the kiln while they are still warm, as they are then in good condition for kiln-drying, as the fibres of the wood are soft and the pores well opened, which will allow of forcing the evaporation of moisture without much damage being done to the material. ”

“ The kiln is circular, built on a foundation of brick or stone, and strengthened with bands of wrought iron. At all four sides of the central chamber, where the pottery is placed, are fire-boxes where the coal is fed on to a grate below the level of the floor of the chamber. ”

“ Kiln-drying which is an artificial method, originated in the effort to improve or shorten the process, by subjecting the wood to a high temperature or to a draught of heated air in a confined space or kiln. ”

“ Each one has the benefit of the heat of all the lower ones. The Japanese do not make any extensive use of seggars. To keep the pieces free from dust or falling particles of the vault, the inside of each kiln is glazed before the firing begins. The pieces are placed one above another upon fire-clay stands. The small kilns for the preliminary firing are in the potter’s yard, but the kilns above described belong to the community, and are rented to the manufacturers.{78} ”

“ The fuel is thrown directly into the kiln, and not into a fireplace. It is arranged along the lower side in a narrow space divided from the rest of the kiln by fire-clay slabs set upright. The fire begins in a furnace attached to the lowest kiln. The hot air rushes through the air-holes into the next kiln, which is thus heated before its own firing begins, and so on throughout the entire range, the kilns furthest up the line having thus to stand the highest temperature. ”

“ In packing a kiln with biscuit or glaze much care, thought, and expedition have to be exercised. An experienced setter is essential in a factory if the pots are to have every chance in the fire, for all kilns vary and have their hot and cool corners. First, the floor is well bedded with quartz sand or flint that will not vitrify but will provide a good setting for the bottom saggars. These saggars are fire-clay boxes, round or oval, rarely square, and without lids, in which the pots are placed. Piled one above another they form the bungs, the bottom of one supplying the top of that beneath. ”