Draining for Profit, and Draining for Health

by George E. Waring

"The kiln, in question, was constructed, in 1844, at a cost of £5.

"It was used four times in that year, burning each time between 18,000 and 19,000 draining pipes, of 1-3/4 inches in diameter.

"In 1845, it was used nine times, or about once a fortnight, burning each time the same quantity of nearly 19,000 pipes.

"In 1846, the same result.

"In 1847, it has been used twelve times, always burning the same quantity. In the course of the last year a trifling repair in the bottom of the kiln, costing rather less than 10 shillings, was necessary, and this is the only cost for repair since its erection. It is now as good as ever, and might be worked at least once a fortnight through the ensuing season.

"The result of this experiment of four years shows not only the practical value of this cheap kiln, but Mr. Hatcher, who superintends the brick and tile-yard at Benenden,[pg 186] where this kiln stands, expresses himself strongly in favor of this kiln, as always producing better and more evenly burned pipes than either of his larger and better built brick-kilns can do."

The floor of the kiln is first covered with bricks, placed on end, at a little distance from each other, so as to allow the fire to pass between them, and the tiles are placed on end on these. This position will afford the best draft for the flames. After the kiln is packed full, the door-way is built up, and a slow fire is started,—only enough at first to complete the drying of the tiles, and to do this so slowly as not to warp them out of shape. They will be thoroughly dry when the smoke from the top of the kiln loses its dark color and becomes transparent. When the fires are well started, the mouths of the fire-holes may be built up so as to leave only sufficient room to put in fresh fuel, and if the wind is high, the fire-holes, on the side against which it blows, should be sheltered by some sort of screen which will counteract its influence, and keep up an even heat on all sides.

The time required for burning will be from two days and a night to four days and four nights, according to the dryness of the tiles, the state of the weather, and the character of the fuel. The fires should be drawn when the tiles in the hottest part of the kiln are burned to a "ringing" hardness. By leaving two or three holes in the door-way, which can be stopped with loose brick, a rod may be run in, from time to time, to take out specimen tiles from the hottest part of the kiln, which shall have been so placed as to be easily removed. The best plan, however,—the only prudent plan, in fact,—will be to employ an intelligent man who is thoroughly experienced in the burning of brick and pottery, and whose judgment in the management of the fires, and in the cooling off of the kiln, will save much of the waste that would result from inexperienced management. After the burning is completed, from[pg 187] 40 to 60 hours must be allowed for the cooling of the kiln before it is opened. If the cold air is admitted while it is still very hot, the unequal contraction of the material will cause the tiles to crack, and a large portion of them may be destroyed.

If any of the tiles are too much burned, they will be melted, and may stick together, or, at least, have their shape destroyed. Those which are not sufficiently burned would not withstand the action of the water in the soil, and should not be used. For the first of these accidents there is no remedy; for the latter, reburning will be necessary, and under-done tiles may be left, (or replaced,) in the kiln in the position which they occupied at the first burning, and the second heat will probably prove sufficient. There is less danger of unequal burning in circular than in square kilns. Soft wood is better than hard, as making a better flame. It should be split fine, and well seasoned.

Arrangement of the Tilery.—Such a tilery as is described above should have a drying shed from 60 to 80 feet long, and from 12 to 18 feet wide. This shed may be built in the cheapest and roughest manner, the roof being covered with felting, thatch, or hemlock boards, as economy may suggest. It should have a tier of drying shelves, (made of slats rather than of boards,) running the whole length of each side. A narrow, wooden tram-way, down the middle, to carry a car, by which the green tiles may be taken from the machine to the shelves, and the dry ones from the shelves to the kiln, will greatly lessen the cost of handling.