One of the most serious evils in domestic life is often found in chimneys that will not properly draw the smoke of a fire or stove. Although chimneys have been building for a thousand years, the artisans of the present day seem strangely ignorant of the true method of constructing them so as always to carry smoke upward instead of downward. It is rarely the case that a large house is built in which there is not some flue or chimney which "will not draw." One of the reasons why the stove described as excelling all others is sometimes cast aside for a poorer one is, that it requires a properly constructed chimney, and multitudes of women do not know how to secure it. The writer in early life shed many a bitter tear, drawn forth by smoke from an ill-constructed kitchen-chimney, and thousands all over the land can report the same experience.
The following are some of the causes and the remedies for this evil:
The most common cause of poor chimney draughts is too large an opening for the fire-place, either too wide or too high in front, or having too large a throat for the smoke. In a lower story, the fire-place should not be larger than thirty inches wide, twenty-five inches high, and fifteen deep. In the story above, it should be eighteen inches square and fifteen inches deep.
Another cause is too short a flue, and the remedy is to lengthen it. As a general rule, the longer the flue the stronger the draught; but in calculating the length of a flue, reference must be had to side-flues, if any open into it. Where this is the case, the length of the main flue is to be considered as extending only from the bottom to the point where the upper flue joins it, and where the lower flue will receive air from the upper side flue. If a smoky flue can not be increased in length, either by closing an upper flue or lengthening the chimney, the fire-place must be contracted so that all the air near the fire will be heated and thus pressed upward.
If a flue has more than one opening, in some cases it is impossible to secure a good draught. Sometimes it will work well, and sometimes it will not. The only safe rule is to have a separate flue to each fire.
Another cause of poor draughts is too tight a room, so that the cold air from without can not enter to press the warm air up the chimney. The remedy is to admit a small current of air from without.
Another cause is two chimneys in one room, or in rooms opening together, in which the draught in one is much stronger than in the other. In this case the stronger draught will draw away from the weaker. The remedy is, for each room to have a proper supply of outside air; or, in a single room, to stop one of the chimneys.
Another cause is the too close vicinity of a hill or buildings higher than the top of the chimney, and the remedy for this is to raise the chimney.
Another cause is the descent into unused fire-places of smoke from other chimneys near. The remedy is to close the throat of the unused chimney.
Another cause is a door opening toward the fire-place on the same side of the room, so that its draught passes along the wall and makes a current that draws out the smoke. The remedy is to change the hanging of the door, so as to open another way.
Another cause is strong winds. The remedy is a turn-cap on top of the chimney.
Another cause is the roughness of the inside of a chim-ney^ or projections which impede the passage of the smoke. Every chimney should be built of equal dimensions from bottom to top, with no projections into it, with as few bends as possible, and with the surface of the inside as smooth as possible.
Another cause of poor draughts is openings into the chimney of chambers for stove-pipes. The remedy is to close them, or insert stove-pipes that are in use.
Another cause is the falling out of brick in some part of the chimney so that outer air is admitted. The remedy is to close the opening.
The draught of a stove may be affected by most of these causes. It also demands that the fire-place have a tight fire-board, or that the throat be carefully filled. For neglecting this, many a good stove has been thrown aside and a poor one taken in its place.
If all young women had committed to memory these causes of evil and their remedies, many a badly-built chimney might have been cured, and many smoke-drawn tears, sighs, ill tempers, and irritating words avoided.
But there are dangers in this direction which demand special attention. Where one flue has two stoves or fireplaces, in rooms one above the other, in certain states of the atmosphere, the lower room being the warmer, the colder air and carbonic acid in the room above will pass down into the lower room through the opening for the stove or the fire-place.
This occurred not long since in a boarding-school, when the gas in a room above flowed into a lower one, and suffocated several to death. This room had no mode of ventilation, and several persons slept in it, and were thus stifled. Professor Brewer states a similar case in the family of a relative. An anthracite stove was used in the upper room; and on one still, close night, the gas from this stove descended through the flue and the opening into a room below, and stifled the sleepers.