In accordance with the remarks made on p. 224, the cost of fuel may be estimated at from 40 to 60 kilog. per 1000 kilog. of fired products, the firing taking place at a temperature of from 1100o to I 200° C.

Estimate Of A Continuous Kiln

The price varies according to the form of the kiln. In M. Bourry's opinion round kilns are preferable, as regards cost, for a daily production of from 3000 to 7000 bricks; for an output of 5000 to 10,000 there is very little difference between the two shapes; above that number, elongated kilns are more economical, and take up less room. For iron-plated kilns with sixteen compartments, like the one represented in Figs. 213 to 217, the following are the approximate dimensions: -

I. Outside measurement: Length, 34.8 m.; breadth, 7.5 m.; height, 2.75 m.

Dimensions of one compartment: Length, 4 m.; breadth, 2 m. ; height, 2 m.; cubic content, 12.6 cubic metres.

Rough masonary.......................224 cub. meters

400 cub. metres.

Brick "........... 176 "

2. Outside measurements (Figs. 213 to 217): Length, 35.8 m.; breadth, 9.9 m.; height, 3.4 m.

Dimensions of one compartment: Length, 4 m.; breadth, 3 m.; height, 2.7 m.; cubic content, 28.7 cubic metres.

Rough and brick masonry.......600 cub. metres.

It will be seen from these figures that the volume of the masonry is far from being proportional to the cubic content.

We shall now give the detailed estimate of the above kiln, adopting, for the sake of uniformity, the same prices as before:

Masonry........

600 cub. m. at 30 fr. =

18,000 fr.

Sand or clay for filling the hollows of the masonry 200 cub. m. at 1 fr. 50 =

300

Iron-work: 40 double iron plates bound by 20 iron tie-rods (.03 m.) with double nut ..................

6700 k.

224 cast-iron lids and shoulders for the coal holes .

3000

16 traps used as registers with shoulders and raising gear........

2000

3 cast-iron openings with double sheet-iron plate for the central channel......

300

12,000 k. at 30 fr. =

: 3,600

Sundries ................................

..............................

100

22,000 fr.

To this sum must be added for the chimney .

...................

5,000

The kiln works without being covered, but it is better to shelter it. A simple wooden shed covered with tiles, 40 m. long and 20 m. broad, costs about

8,000

Cost of kiln with chimney and building..................

• •

35,000 fr.

If storeyed drying-rooms are required, the price is increased.

A kiln constructed as above is very solid, elegant, and does not take up much room. A certain economy is effected by omitting the iron plating, and increasing the thickness of the walls. This is cheaply done by supporting the inside brick facing with buttresses between which clay is heaped up; the whole is covered with a facing of flint or rubble masonry.