A treatise on smoky chimneys : their cure and prevention / By Frederick Edwards, jun.

  • Edwards, Frederick, Jun.
Date:
1868
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on smoky chimneys : their cure and prevention / By Frederick Edwards, jun. Source: Wellcome Collection.

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    of combustion, partly by the passage of undecomposed air up the chimney, and, partly by expansion from heat, the air in a room often becomes exceedingly rarefied, and if fresh air is not allowed to enter with some freedom, the air becomes in fact more rarefied than the air in the chimney itself. The inevitable consequence is that the air in the chimney being no longer supported by the pressure of air from the room, the balance becomes turned in the wrong direction, and air flows into the room from the chimney, bringing smoke and offensive vapour with it. The best chimney in the world may be readily made to smoke by the simple process of excluding the entrance of fresh air to a room. By far the best remedy is to provide a special supply of air to the fire, which ensures a constant supply with but little assistance from doors and windows. It is commonly effected by means of a tube communi- cating with an external wall, and passing between the joists to some opening in the neighborhood of the fire- place. The opening is sometimes in the hearth-stone, and is covered by an open grating, the bottom plate of the fender being pierced with a number of holes. At other times, the tube is carried behind the grate, and the air is allowed to enter the room by openings at bottom near to the fire, as shown at d} d, fig. 2. The latter arrangement may be considered to be the best, as dust and cinders are less likely to enter the open spaces than in the former. Many persons who have adopted the principle now sug- gested, have made the error of using tubes much too small. The tube should have an area of not less than that of the opening into the chimney when the register or regulator is in its usual position, with a good fire burning. This should give about twenty-eight square inches for a room containing a thousand cubic feet of air, and four
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