When coals are small and dusty it is well to sprinkle them with water, this cakes them and the steam generated assists to heat them into combustion; a little water, in fact, makes a fire burn more fiercely, because it is readily converted into steam, which increases heat. A large quantity of water extinguishes fire because it cannot be converted instantly into steam.

From these facts we may learn an important lesson. In cases of fire, a little water employed to extinguish it is worse than no water at all, as it increases the intensity of the fire instead of quenching it; a supply, rapid and abundant, which cannot be converted into steam, is required.

Smoke ascends the chimney, unless for our misery the flue smokes; it is carried up by the air, which, passing over the fire gets heated, becomes of course lighter, and flies up the chimney carrying the unconsumed particles of carbon with it; for, as we have said, warm air, expanded (as all things are) by heat, always ascends, the cold and heavier air sinks. This cold air presses the lighter (heated) air up the chimney.

We come now to the vexed question of smoky chimneys. There are, of course, scientific reasons for them. If fresh air is not let into the room as fast as it is consumed by the fire, a current of air comes down the chimney to supply the deficiency, and drives the smoke before it. This is one cause.

Again, if the funnel of the chimney - that is, the part up which the smoke goes - be very short, it will smoke, because the draught of a short flue is too slack to carry the smoke up the chimney. The longer the flue, the greater the draught; hence the use of chimney-pots.

Houses in valleys often smoke, because the wind striking against the hills, returns to the chimney and destroys its draught.

If the fireplace and the door are on the same side of the room, the chimney will be apt to smoke, because the current of air from the door will blow obliquely to the fireplace and drive the smoke into the room. It is best, if possible, for the room door to be opposite to the fireplace. Too large an opening of the fireplace, as in farm-houses and kitchens, will also cause smoke, because much of the air which goes up the chimney has never been over the fire, and this cold air chills the ascending hot air and checks its ascent. Contracting the space, or fixing a blower is the best remedy: a blower increases the draught by compelling the air to pass through the fire, and thus makes it so much hotter that it ascends more rapidly.

Such are some of the causes of smoky chimneys; we may add obstructions by soot, bricks out of the chimney and chinks which admit cold air; in short the management of the draught is the great thing in almost every case. Air must be supplied to the fire, and all contrivances to keep it out of the room, such as list or Indian-rubber round doors, sandbags, etc., are likely to make a chimney smoke. The draught of air from the door or window always sets towards the fireplace; a bed, chair, or sofa placed between them would be in a draught.

Cure For Smoky Chimneys

Inflate a large ox-bladder with air, and tie it by the neck to the middle of a stick, which place across the inside of a chimney, about two feet from the top, or at the foot of the chimney-top. The buoyancy of the air keeps the bladder continually in a circular motion, and thereby prevents the rush of air into the funnel from descending so low as the fireplace.

The grate should be fixed near the floor of the room, as the heat of the fire has very little effect on the air below the level of the grate. A poker laid across a dull fire will revive it, because the metal concentrates the heat and throws it on the fire, and air being drawn between the poker and the coals a slight draught is created.

In every occupied room there are two currents of air - one of hot air flowing out of the room, the other of cold air flowing into the room. The hot air escapes by the crevice at the top of the door, the cold air enters at the bottom.* But this is not the case when a fire is lighted in the room; an inward current is then drawn through all the crevices, and the heated air escapes up the chimney.

Professor Faraday has well explained the advantages of the open coal fire and chimney in comparison with the stove and flue. A parlour grate will consume forty pounds of coal in twelve hours; the combustion of this quantity of fuel renders 42,000 gallons of air unfit to breathe. But the chimney clears us of all this bad air which ascends it, while five times that quantity of air is carried up with it by the draught, and thus good ventilation is obtained by means of our ordinary fires.

If the combustion of the coals were perfect, we should have neither soot nor smoke. Dr. Arnott's patent stove was constructed that the combustion might be perfect. In a common fire it is estimated that five-sixths of the heat passes up the chimney.

The principle of the Arnott stove may be carried out by lighting a fire from the top. Here are instructions given for the arranging it, taken from the Builder: -

"Clean out your grate; cover the bottom with a sheet of paper cut out or folded to fit; place coals in the grate to the level of the top bar, keeping the larger ones to the front, to prevent waste. Light your fire on the top and allow it to burn downwards undisturbed. An ordinary fire prepared and lighted in this way will, according to the size and form of the grate, burn six, eight, or ten hours without any renewal of coal, burning brighter and warmer than if lighted from below, as fires are ordinarily made. The coal should be tolerably equal in size, something like McAdam stone; place the large to the front, the small to the back. The paper is put in the grate to prevent any air rising through the bottom bars. The fire is lighted on the top† and made to burn downwards to prevent rapid combustion, and to keep the heat on the surface of the coals, cinders, or coke; and if undisturbed, the combustion will be so complete that there will be no waste ashes. The grate must be cleaned each morning, and the paper must be renewed on the bottom of the grate when the fire reaches the lower layer of coal".

This fire is very advisable for a chimney which is incurably smoky; but though economical and clean, it lacks the bright sparkle and blaze of the old-fashioned fire.

A very good plan also, is to make a hollow at the back of the fire, before fresh coals are put on, and fill it in first with the cinders under the grate. Place the fresh coals on these cinders, and the gas given out by the coals will be consumed by them, and the smoke also. This is a very old-fashioned mode of making up a fire; the reason why it answered well was probably unknown to the housewives of other days, but their practical knowledge told them that this was the right way.

It should ever be borne in mind that fire cannot exist without air, and will not spread rapidly unless it is plentifully supplied with it. Therefore in cases of fire catching the furniture, etc., in a room, close all the doors and windows instantly, while every effort is made to extinguish it. In case of the dress catching fire, the same truth should be borne in mind. Never run out into the air. Running increases the flame by fanning it. Lie down and roll over and over on the ground, if you are alone; at all events lie down, as flame ascends, and will therefore not be so likely to injure the head or vital parts if the person on fire is lying down. But if possible roll yourself in a blanket, or the rug, or a table cover at once. The moment all air is shut off from fire it will go out. Remember also, that as heated air and vapour ascend, and cold air sinks, you will always (in the midst of most suffocating smoke) find air fit to breathe within a foot of the floor; DRAWL therefore rather than walk in escaping from a room full of smoke; a piece of flannel over the mouth would also enable you to breathe.

* This is the cause of our feet being cold if the draught is strong. † With wood and paper, as for other fires.