with the flue behind the false back: through this passage the smoke
is to pass.
The fire-place is to be erected upon these hollows, by putting all
the plates in their places, and screwing them together.
Its operation may be conceived by observing the plate entitled,
Profile of the Chimney and Fire-Place.
_M_ The mantle-piece, or breast of the chimney.
_C_ The funnel.
_B_ The false back and closing.
_E_ True back of the chimney.
_T_ Top of the fire-place.
_F_ The front of it.
_A_ The place where the fire is made.
_D_ The air-box.
_K_ The hole in the side-plate, through which the warmed air is
discharged out of the air-box into the room.
_H_ The hollow filled with fresh air, entering at the passage _I_,
and ascending into the air-box through the air-hole in the bottom
plate near
_G_ The partition in the hollow to keep the air and smoke apart.
_P_ The passage under the false back and part of the hearth for the
smoke.
The arrows show the course of the smoke.
[Illustration:
_Plate VIII*._ _Vol. II. page 238._
_PROFILE OF THE PENSYLVANIA CHIMNEY & FIRE-PLACE._
_STAFFORDSHIRE FIRE-PLACE._
_Front View Side View_
_Published as the Act directs, April 1, 1806, by Longman, Hurst, Rees
& Orme, Paternoster Row._]
The fire being made at A, the flame and smoke will ascend and strike
the top T, which will thereby receive a considerable heat. The smoke,
finding no passage upwards, turns over the top of the air-box, and
descends between it and the back plate to the holes in the bottom
plate, heating, as it passes, both plates of the air-box, and the
said back plate; the front plate, bottom and side plates are also all
heated at the same time. The smoke proceeds in the passage that leads
it under and behind the false back, and so rises into the chimney.
The air of the room, warmed behind the back plate, and by the sides,
front, and top plates, becoming specifically lighter than the other
air in the room, is obliged to rise; but the closure over the
fireplace hindering it from going up the chimney, it is forced out
into the room, rises by the mantle-piece to the cieling, and spreads
all over the top of the room, whence being crouded down gradually by
the stream of newly-warmed air that follows and rises above it, the
whole room becomes in a short time equally warmed.
At the same time the air, warmed under the bottom plate, and in the
air-box, rises and comes out of the holes in the side-plates, very
swiftly, if the door of the room be shut, and joins its current with
the stream before-mentioned, rising from the side, back, and top
plates.
The air that enters the room through the air-box is fresh, though
warm; and, computing the swiftness of its motion with the areas of
the holes, it is found that near ten barrels of fresh air are hourly
introduced by the air-box; and by this means the air in the room is
continually changed, and kept, at the same time, sweet and warm.
It is to be observed, that the entering air will not be warm at first
lighting the fire, but heats gradually as the fire increases.
A square opening for a trap-door should be left in the closing of
the chimney, for the sweeper to go up: the door may be made of slate
or tin, and commonly kept close shut, but so placed as that, turning
up against the back of the chimney when open, it closes the vacancy
behind the false back, and shoots the soot, that falls in sweeping,
out upon the hearth. This trap-door is a very convenient thing.
In rooms where much smoking of tobacco is used, it is also convenient
to have a small hole, about five or six inches square, cut near the
ceiling through into the funnel: this hole must have a shutter, by
which it may be closed or opened at pleasure. When open, there will
be a strong draught of air through it into the chimney, which will
presently carry off a cloud of smoke, and keep the room clear: if
the room be too hot like-wise, it will carry off as much of the warm
air as you please, and then you may stop it entirely, or in part, as
you think fit. By this means it is, that the tobacco smoke does not
descend among the heads of the company near the fire, as it must do
before it can get into common chimneys.
_The Manner of using this Fire-Place._
Your cord-wood must be cut into three lengths; or else a short
piece, fit for the fire-place, cut off, and the longer left for the
kitchen or other fires. Dry hickery, or ash, or any woods that burn
with a clear flame are rather to be chosen, because such are less
apt to foul the smoke-passages with soot; and flame communicates
with its light, as well as by contact, greater heat to the plates
and room. But where more ordinary wood is used, half a dry faggot
of brush-wood, burnt at the first making the fire in the morning,
is very advantageous, as it immediately, by its sudden blaze, heats
the plates, and warms the room (which with bad wood slowly kindling
would not be done so soon) and at the same time by the length of
its flame, turning in the passages, consumes and cleanses away the
soot that such bad smoaky wood had produced therein the preceding
day, and so keeps them always free and clean. When you have laid a
little back log, and placed your billets on small dogs, as in common
chimneys, and put some fire to them, then slide down your shutter
as low as the dogs, and the opening being by that means contracted,
the air rushes in briskly, and presently blows up the flames. When
the fire is sufficiently kindled, slide it up again.[46] In some of
these fire-places there is a little six-inch square trap-door of
thin wrought iron or brass, covering a hole of like dimensions near
the fore-part of the bottom plate, which being by a ring lifted up
towards the fire, about an inch, where it will be retained by two
springing sides fixed to it perpendicularly (_See the Plate, Fig.
4._) the air rushes in from the hollow under the bottom plate, and
blows the fire. Where this is used, the shutter serves only to close
the fire at nights. The more forward you can make your fire on the
hearth-plate, not to be incommoded by the smoke, the sooner and
more will the room be warmed. At night, when you go to bed, cover
the coals or brands with ashes as usual; then take away the dogs,
and slide down the shutter close to the bottom-plate, sweeping a
little ashes against it, that no air may pass under it; then turn
the register, so as very near to stop the flue behind. If no smoke
then comes out at crevices into the room, it is right: if any smoke
is perceived to come out, move the register, so as to give a little
draught, and it will go the right way. Thus the room will be kept
warm all night; for the chimney being almost entirely stopt, very
little cold air, if any, will enter the room at any crevice. When you
come to re-kindle the fire in the morning, turn open the register
before you lift up the slider, otherwise, if there be any smoke in
the fireplace, it will come out into the room. By the same use of the
shutter and register, a blazing fire may be presently stifled, as
well as secured, when you have occasion to leave it for any time; and
at your return you will find the brands warm, and ready for a speedy
rekindling. The shutter alone will not stifle a fire, for it cannot
well be made to fit so exactly but that air will enter, and that
in a violent stream, so as to blow up and keep alive the flames,
and consume the wood, if the draught be not checked by turning the
register to shut the flue behind. The register has also two other
uses. If you observe the draught of air into your fire-place to be
stronger than is necessary (as in extreme cold weather it often is)
so that the wood is consumed faster than usual; in that case, a
quarter, half, or two-thirds turn of the register, will check the
violence of the draught, and let your fire burn with the moderation
you desire: and at the same time both the fire-place and the room
will be the warmer, because less cold air will enter and pass
through them. And if the chimney should happen to take fire (which
indeed there is very little danger of, if the preceding direction be
observed in making fires, and it be well swept once a year; for, much
less wood being burnt, less soot is proportionably made; and the fuel
being soon blown into flame by the shutter, or the trap-door bellows,
there is consequently less smoke from the fuel to make soot; then,
though the funnel should be foul, yet the sparks have such a crooked
up and down round about way to go, that they are out before they get
at it). I say, if ever it should be on fire, a turn of the register
shuts all close, and prevents any air going into the chimney, and so
the fire may easily be stifled and mastered.
_The Advantages of this Fire-Place._
Its advantages above the common fire-places are,
1. That your whole room is equally warmed, so that people need not
croud so close round the fire, but may sit near the window, and have
the benefit of the light for reading, writing, needle-work, &c.
They may sit with comfort in any part of the room, which is a very
considerable advantage in a large family, where there must often be
two fires kept, because all cannot conveniently come at one.
2. If you sit near the fire, you have not that cold draught of
uncomfortable air nipping your back and heels, as when before common
fires, by which many catch cold, being scorched before, and, as it
were, froze behind.
3. If you sit against a crevice, there is not that sharp draught of
cold air playing on you, as in rooms where there are fires in the
common way; by which many catch cold, whence proceed coughs[47],
catarrhs, tooth-achs, fevers, pleurisies, and many other diseases.
4. In case of sickness, they make most excellent nursing rooms; as
they constantly supply a sufficiency of fresh air, so warmed at the
same time as to be no way inconvenient or dangerous. A small one
does well in a chamber; and, the chimneys, being fitted for it, it
may be removed from one room to another, as occasion requires, and
fixed in half an hour. The equal temper too, and warmth of the air
of the room, is thought to be particularly advantageous in some
distempers; for it was observed in the winters of 1730 and 1736, when
the small-pox spread in Pensylvania, that very few children of the
Germans died of that distemper in proportion to those of the English;
which was ascribed, by some, to the warmth and equal temper of air
in their stove-rooms, which made the disease as favourable as it
commonly is in the West Indies. But this conjecture we submit to the
judgment of physicians.
5. In common chimneys, the strongest heat from the fire, which is
upwards, goes directly up the chimney, and is lost; and there is such
a strong draught into the chimney that not only the upright heat, but
also the back, sides, and downward heats are carried up the chimney
by that draught of air; and the warmth given before the fire, by
the rays that strike out towards the room, is continually driven
back, crouded into the chimney, and carried up by the same draught
of air. But here the upright heat strikes and heats the top plate,
which warms the air above it, and that comes into the room. The heat
likewise, which the fire communicates to the sides, back, bottom, and
air-box, is all brought into the room; for you will find a constant
current of warm air coming out of the chimney-corner into the room.
Hold a candle just under the mantle-piece, or breast of your chimney,
and you will see the flame bent outwards: by laying a piece of
smoaking paper on the hearth, on either side, you may see how the
current of air moves, and where it tends, for it will turn and carry
the smoke with it.
6. Thus, as very little of the heat is lost, when this fire-place is
used, _much less wood_[48] will serve you, which is a considerable
advantage where wood is dear.
7. When you burn candles near this fire-place, you will find that
the flame burns quite upright, and does not blare and run the tallow
down, by drawing towards the chimney, as against common fires.
8. This fire-place cures most smoaky chimneys, and thereby preserves
both the eyes and furniture.
9. It prevents the fouling of chimneys; much of the lint and dust
that contributes to foul a chimney being, by the low arch, obliged to
pass through the flame, where it is consumed. Then, less wood being
burnt, there is less smoke made. Again, the shutter, or trap-bellows,
soon blowing the wood into a flame, the same wood does not yield so
much smoke as if burnt in a common chimney: for as soon as flame
begins, smoke in proportion ceases.
10. And if a chimney should be foul, it is much less likely to take
fire. If it should take fire, it is easily stifled and extinguished.
11. A fire may be very speedily made in this fire-place by the help
of the shutter, or trap-bellows, as aforesaid.
12. A fire may be soon extinguished, by closing it with the shutter
before, and turning the register behind, which will stifle it, and
the brands will remain ready to rekindle.
13. The room being once warm, the warmth may be retained in it all
night.
14. And lastly, the fire is so secured at night, that not one spark
can fly out into the room to do damage.
With all these conveniences, you do not lose the pleasing sight nor
use of the fire, as in the Dutch stoves, but may boil the tea-kettle,
warm the flat-irons, heat heaters, keep warm a dish of victuals by
setting it on the top, &c.
_Objections answered._
There are some objections commonly made by people that are
unacquainted with these fire-places, which it may not be amiss to
endeavour to remove, as they arise from prejudices which might
otherwise obstruct, in some degree, the general use of this
beneficial machine. We frequently hear it said, _They are of the
nature of Dutch stoves_; _stoves have an unpleasant smell_; _stoves
are unwholesome_; _and, warm rooms make people tender, and apt
to catch cold_.--As to the first, that they are of the nature of
Dutch stoves, the description of those stoves, in the beginning
of this paper, compared with that of these machines, shows that
there is a most material difference, and that these have vastly the
advantage, if it were only in the single article of the admission and
circulation of the fresh air. But it must be allowed there may have
been some cause to complain of the offensive smell of iron stoves.
This smell, however, never proceeded from the iron itself, which, in
its nature, whether hot or cold, is one of the sweetest of metals,
but from the general uncleanly manner of using those stoves. If they
are kept clean, they are as sweet as an ironing-box, which though
ever so hot, never offends the smell of the nicest lady: but it is
common to let them be greased, by setting candlesticks on them,
or otherwise; to rub greasy hands on them; and, above all, to spit
upon them, to try how hot they are, which is an inconsiderate filthy
unmannerly custom; for the slimy matter of spittle drying on burns
and fumes when the stove is hot, as well as the grease, and smells
most nauseously, which makes such close stove-rooms, where there is
no draught to carry off those filthy vapours, almost intolerable to
those that are not from their infancy accustomed to them. At the same
time nothing is more easy than to keep them clean; for when by any
accident they happen to be fouled, a lee made of ashes and water,
with a brush, will scour them perfectly: as will also a little strong
soft soap and water.
That hot iron of itself gives no offensive smell, those know very
well who have (as the writer of this has) been present at a furnace
when the workmen were pouring out the flowing metal to cast large
plates, and not the least smell of it to be perceived. That hot
iron does not, like lead, brass, and some other metals, give out
unwholesome vapours, is plain from the general health and strength
of those who constantly work in iron, as furnace-men, forge-men,
and smiths; that it is in its nature a metal perfectly wholesome
to the body of man, is known from the beneficial use of chalybeate
or iron-mine-waters; from the good done by taking steel filings in
several disorders; and that even the smithy water in which hot irons
are quenched, is found advantageous to the human constitution.--The
ingenious and learned Dr. Desaguliers, to whose instructive writings
the contriver of this machine acknowledges himself much indebted,
relates an experiment he made, to try whether heated iron would yield
unwholesome vapours: he took a cube of iron, and having given it
a very great heat, he fixed it so to a receiver, exhausted by the
air-pump, that all the air rushing in to fill the receiver, should
first pass through a hole in the hot iron. He then put a small bird
into the receiver, who breathed that air without any inconvenience,
or suffering the least disorder. But the same experiment being made
with a cube of hot brass, a bird put into that air died in a few
minutes. Brass, indeed, stinks even when cold, and much more when
hot; lead, too, when hot, yields a very unwholesome steam; but iron
is always sweet and every way taken is wholesome and friendly to the
human body--except in weapons.
_That warmed rooms make people tender, and apt to catch cold_, is a
mistake as great as it is (among the English) general. We have seen
in the preceding pages how the common rooms are apt to give colds;
but the writer of this paper may affirm from his own experience, and
that of his family and friends who have used warm rooms for these
four winters past, that by the use of such rooms, people are rendered
_less liable_ to take cold, and, indeed, _actually hardened_. If
sitting warm in a room made one subject to take cold on going out,
lying warm in bed, should by a parity of reason, produce the same
effect when we rise. Yet we find we can leap out of the warmest bed
naked, in the coldest morning, without any such danger; and in the
same manner out of warm cloaths into a cold bed. The reason is, that
in these cases the pores all close at once, the cold is shut out,
and the heat within augmented, as we soon after feel by the glowing
of the flesh and skin. Thus no one was ever known to catch cold by
the use of the cold bath: and are not cold baths allowed to harden
the bodies of those that use them? Are they not therefore frequently
prescribed to the tenderest constitutions? Now every time you go
out of a warm room into the cold freezing air, you do as it were
plunge into a cold bath, and the effect is in proportion the same;
for (though perhaps you may feel somewhat chilly at first) you find
in a little time your bodies hardened and strengthened, your blood
is driven round with a brisker circulation, and a comfortable steady
uniform inward warmth succeeds that equal outward warmth you first
received in the room. Farther to confirm this assertion, we instance
the Swedes, the Danes, and the Russians: these nations are said to
live in rooms, compared to ours, as hot as ovens[49]; yet where are
the hardy soldiers, though bred in their boasted cool houses, that
can, like these people, bear the fatigues of a winter campaign in so
severe a climate, march whole days to the neck in snow, and at night
entrench in ice as they do?
The mentioning of those northern nations, puts me in mind of a
considerable _public advantage_ that may arise from the general use
of these fire-places. It is observable, that though those countries
have been well inhabited for many ages, wood is still their fuel,
and yet at no very great price; which could not have been, if they
had not universally used stoves, but consumed it as we do, in great
quantities, by open fires. By the help of this saving invention our
wood may grow as fast as we consume it, and our posterity may warm
themselves at a moderate rate, without, being obliged to fetch their
fuel over the Atlantic; as, if pit-coal should not be here discovered
(which is an uncertainty) they must necessarily do.
We leave it to the _political arithmetician_ to compute how much
money will be saved to a country, by its spending two-thirds less of
fuel; how much labour saved in cutting and carriage of it; how much
more land may be cleared by cultivation; how great the profit by the
additional quantity of work done, in those trades particularly that
do not exercise the body so much, but that the workfolks are obliged
to run frequently to the fire to warm themselves: and to physicians
to say, how much healthier thick-built towns and cities will be,
now half-suffocated with sulphury smoke, when so much less of that
smoke shall be made, and the air breathed by the inhabitants be
consequently so much purer. These things it will suffice just to have
mentioned; let us proceed to give some necessary directions to the
workman who is to fix or set up these fire-places.
_Directions to the Bricklayer._
The chimney being first well swept and cleansed from soot, &c.
lay the bottom plate down on the hearth, in the place where the
fire-place is to stand, which may be as forward as the hearth will
allow. Chalk a line from one of its back corners round the plate
to the other corner, that you may afterwards know its place when
you come to fix it; and from those corners, two parallel lines to
the back of the chimney: make marks also on each side, that you
may know where the partition is to stand, which is to prevent any
communication between the air and smoke. Then, removing the plate,
make a hollow under it and beyond it, by taking up as many of the
bricks or tiles as you can, within your chalked lines, quite to
the chimney-back. Dig out six or eight inches deep of the earth
or rubbish, all the breadth and length of your hollow; then make
a passage of four inches square (if the place will allow so much)
leading from the hollow to some place communicating with the outer
air; by _outer air_ we mean air without the room you intend to warm.
This passage may be made to enter your hollow on either side, or in
the fore part, just as you find most convenient, the circumstances
of your chimney considered. If the fire-place is to be put up in
a chamber, you may have this communication of outer air from the
stair-case; or sometimes more easily from between the chamber floor,
and the ceiling of the lower room, making only a small hole in the
wall of the house entering the space betwixt those two joists with
which your air-passage in the hearth communicates. If this air
passage be so situated as that mice may enter it, and nestle in the
hollow, a little grate of wire will keep them out. This passage
being made, and, if it runs under any part of the earth, tiled
over securely, you may proceed to raise your false back. This may
be of four inches or two inches thickness, as you have room, but
let it stand at least four inches from the true chimney-back. In
narrow chimneys this false back runs from jamb to jamb, but in large
old-fashioned chimneys, you need not make it wider than the back of
the fire-place. To begin it, you may form an arch nearly flat, of
three bricks end to end, over the hollow, to leave a passage the
breadth of the iron fire-place, and five or six inches deep, rounding
at bottom, for the smoke to turn and pass under the false back, and
so behind it up the chimney. The false back is to rise till it is
as high as the breast of the chimney, and then to close over to the
breast[50]; always observing, if there is a wooden mantle-tree, to
close above it. If there is no wood in the breast, you may arch over
and close even with the lower part of the breast. By this closing the
chimney is made tight, that no air or smoke can pass up it, without
going under the false back. Then from side to side of your hollow,
against the marks you made with chalk, raise a tight partition,
brick-on-edge, to separate the air from the smoke, bevelling away to
half an inch the brick that comes just under the air-hole, that the
air may have a free passage up into the air-box: lastly, close the
hearth over that part of the hollow that is between the false back
and the place of the bottom plate, coming about half an inch under
the plate, which piece of hollow hearth may be supported by a bit
or two of old iron-hoop; then is your chimney fitted to receive the
fire-place.