In order to burn coal without smoke, it must be changed into coke. This cannot be done in an open grate, and the arrangement invented by Mr. Heim affords, in my opinion, a very satisfactory solution of the problem, as the thick heavy smoke, which is given off from the coal, is passed through the incandescent mass on its way to the chimney. There is no doubt whatever that the coal can be burnt without producing smoke, except during the first twenty minutes (say) after lighting, and a choice must be made between the cheerful appearance of an open fire, and the efficient consumption of the fuel in a closed sto\

The Falkirk Iron Company makes a stove, which is called a "Controlled-combustion Air-chamber Heating Apparatus". It consists of an internal stove and an ornamental perforated cast-iron external case, with an air-space between. The plan of the apparatus itself without case is shown in Fig. 471, a vertical section in Fig. 472, and a front elevation in Fig. 473. The bottom and sides of the fire-grate are of fire-brick. Fuel is inserted at the top, and the smoke-tlue descends at the back. The fire chamber is provided with vertical ribs outside, which project into the air-chamber between the stove itself and the external case. The surrounding air enters at the base of the apparatus, through the holes shown, and passes vertically upwards, and then through the ornamental casing, thus acting as a means of heating by warmed air. If the stove be placed over a hole in the floor, connected with an air-duct from the external air, more efficient ventilation will be secured. The makers state that a one-chambered apparatus, as illustrated, with the draught-valve at slow-combustion (or open only to 3/8 of an inch), will consume 2 lbs. per hour of gas-coke, and heat an apartment containing 40,000 cubic feet of air, at a cost of less than twopence for twelve hours. An evaporating pan placed under the base of the apparatus is found desirable to moisten the atmosphere. The heating-power of the stoves made by this firm vary from 10,000 to 140,000 cubic feet, according to the size of the apparatus. Such a stow is adapted for use in a large hall, and would warm the whole of the staircase and corridors with far less consumption of fuel than would be the case with an open grate.

Fig. 471   plan of one chambered controlled com bustion Heating Apparatus.

Fig. 471 - plan of one chambered controlled-com-bustion Heating Apparatus.

Fig. 472 Vertical Section of One chambered Controlled combustion Heating Apparatus.

Fig. 472 Vertical Section of One chambered Controlled-combustion Heating Apparatus.

Fig. 473   Front Elevation of One chambered Controlled combustion Heating Apparatus.

Fig. 473 - Front Elevation of One chambered Controlled-combustion Heating Apparatus.

The Shorland Grate is of the Gabon type with a Tealc hearth. A section it shown in Fig. 474. The back of the grate is of fire-clay, and projects well forward above the fire. Behind it is the warm-air chamber, to which the cold external air is admitted through a grid in the outside wall. From this chamber, it rises through two special warm-air flues, and is discharged into the room, at a height of about eight feet above the floor, through a hit-and-miss grating. It is of course easy to carry the pipe up through the floor, so as to deliver warm air into a room above. I have already drawn attention to the undesrability of drawing the external air into rooms in town-houses, without previously filtering it in some manner.

The makers .say: "In preparing new buildings to receive the Patent Manchester Grates, the best and simplest plan is to build common

Fig. 474   Vertical Section of the Shorland Grate and plan of Flues.

Fig. 474 - Vertical Section of the Shorland Grate and plan of Flues.

Fig .475   Front view of shorland's Fireplace

Fig .475 - Front view of shorland's Fireplace.

6-inch socketed clay drain-pipes in the solid brickwork of the chimney breast, as the building progresses, for the warm-air Hues, keeping them 18 inches apart. 4 inches from face of brickwork, and commencing 4 feet from floor (socket end upwards). Use square elbows to deliver the warm air into the room through the face of the breast, at about 8 feet from the floor. Then when the building is ready to receive the Manchester grates, they simply require connecting to the clay pipes by means of our own syphon pipes or other connecting pipes. The outside cold-air grids should also be built in as the building progresses." For size No. 1, the opening in the brickwork must be 48 inches high, 30 inches wide, and 14 inches from back to front, and the heating capacity is 3000 cubic feet of space, e.g. a room 20 feet long, 15 feet wide, and 10 feet high. Fig. 475 represents one of these fireplaces. It differs from Teale's in the form of the bars, as the space exactly above the grating is left open instead of having a solid piece to hide the ashes.

An arrangement, which, in my opinion, is of superior merit, is shown in fig 476. This is Shorland's Calorigen. It consists merely of an iron box containing a series of baffle plates, which is fixed directly at the back of the fire, in a room on the floor below that of the room to be warmed. As the warm-air pipe is of metal, it readily receives heat from the smoke. I would suggest that. wherever it can be done, a case of some kind should be provided in front of the outside grid, io which muslin could be stretched to filter the air to some extent before it enters the room.1

Fig. 476.   Shorland's Calorigen.

Fig. 476. - Shorland's Calorigen.