Page:Popular Science Monthly Volume 2.djvu/490

474 chimneys that smoke unless a door or window be open. Our drawing-rooms should not be invaded by sooty chimney-sweepers, and all ought not to have to scramble for a place near the fire in a room to be warm, nor when there to have to rotate like a smoke-jack to prevent being frozen on one side while we are scorched on the other.

Such evils are to be obviated by simple means, and yet ninety-nine out of every hundred Englishmen submit to them supinely if not patiently. Whole streets, occupied by men of means, have their skyline fringed with demon-like excrescences which tell a sure tale of internal discomfort. Such was the case with that in which my own residence is situated. When I took my house upon lease, though it had been well built by an eminent architect for his own use, yet, in common with all its neighbors, it displayed a grim array of tall-boys and tortuous contrivances as chimney terminals. All these I swept away at once, without inquiry, feeling that, whatever might be needed, they certainly could not be. I then introduced an air-pipe to each fireplace through the floors, and, as I expected, found no smoky chimneys to complain of, though my neighbors still grumble at theirs, as I do of their futile and unsightly expedients to remedy them.

So much depends upon the proper construction of fireplaces and their flues, without which no appliance in the shape of a grate can have fair play, that I shall in the first place describe the points to be attended to in the erection of these portions of a building, and in palliating evils in those which already exist.

The first essential to insure a good draught is that the flue should be sufficiently rarefied. For this purpose it is desirable that it should not be in an outer wall; but, if it be necessarily so, the enclosing wall should be thick (at least 9 in. between the flue and the outer air) or else it should be protected by a double casing, with intermediate hollow space. Materials which absorb damp should be avoided for the construction, as they tend to the evaporation and loss of the heat generated; and the interior of the flue should be well pargetted, to further prevent the suction of external cold by the up-draught within. Another important point is that the flue be not too large, or currents of cold air descending will interfere with the ascending heated air. In old buildings flues are found of large size—as 18 in. by 12 in.—with wide throats, funnel-shaped, diminishing upward. But the fuel used in them was wood, and abundant, and men were more hardy, and minded not the roaring of wind in the chimney, or cowered over the embers within the vast embrasure of the fireplace, which formed an inner room of itself. There are those who would revive these large flues, on the ground that no cowls decorate their terminals. If, however, we are to recur to the practice of our ancestors, we might as well revert to that of a still earlier age, when the stately hall of Penshurst had its fire upon a hearth in the centre, and the graceful wreaths of smoke thence found exit by the lantern in the roof. We must needs then have