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Plate XII

D

much higher than B, and so the pressure on it is greater and more forcible, and beats down the frame to that part where it finds the least resistance. Carrying the machine first to the kitchen fire for preparation, is on this account, that in the beginning the fire and smoke naturally ascend, till the air in the close barrel C is made thinner by the warmth. When that vessel is heated, the air in it is rarefied, and then all the smoke and fire descends under it.

"The wood should be thoroughly dry, and cut into pieces five or six inches long, to fit it for being thrown into the funnel A." Thus far the German book.

of the three-sided box C, figure 5, which is cast in one piece.

D, figure 6, its cover, showing its under side with grooves to receive the upper edges S S S of the sides of C, figure 5, also a groove R, R, which when the cover is put on comes right over another Q Q in C, figure 5, between which it is to slide.

E, figure 7, the front plate of the box.

P, a hole three inches diameter through the cover D, figure 6, over which hole stands the vase F, figure 8, which has a corresponding hole two inches diameter through its bottom.

The top of the vase opens at 0, 0, 0, figure 8, and turns back upon a hinge behind when coals are to be put in; the vase has a grate within at N N of cast iron H, figure 9, and a hole in the top, one and a half inches diameter, to admit air, and to receive the ornamental brass gilt flame M, figure 10, which stands in that hole, and, being itself hollow and open, suffers air to pass through it into the fire.

It appears to me, by Mr. Leutmann's explanation of the operation of this machine, that he did not understand the principles of it, whence I conclude he was not the inventor of it; and by the description of it, wherein the opening at A is made so large, and the pipe E, D, so short, I am persuaded he never made nor saw the experiment, for the first ought to be much smaller and the last much higher, or it hardly will succeed. The car- G, figure 11, is a drawer of plate iron, that rying it in the kitchen, too, every time the slips in between the partitions 2 and 3, fire should happen to be out, must be so trou-figure 2, to receive the falling ashes. It is blesome, that it is not likely ever to have concealed when the small sliding plates Y Y, been in practice, and probably has never figure 12, are shut together. been shown but as a philosophical experiment. The funnel for conveying the vapour out of the room would besides have been uncertain in its operation, as a wind blowing against its mouth would drive the vapour back.

The stove I am about to describe was also formed on the idea given by the French experiment, and completely carried into execution before I had any knowledge of the German invention; which I wonder should remain so many years in a country, where men are so ingenious in the management of fire, without receiving long since the improvements I have given it.

Description of the Parts.

A, the bottom plate which lies flat upon the hearth, with its partitions, 1, 2, 3, 4, 5, 6, (Plate, figure 2.) that are cast with it, and a groove Z Z, in which are to slide, the bottom edges of the small plates Y, Y, figure 12; which plates meeting at X close the front.

B 1, figure 3, is the cover plate showing its under side, with the grooves 1, 2, 3, 4, 5, 6, to receive the top edges of the partitions that are fixed to the bottom plate. It shows also the grate W W, the bars of which are cast in the plate, and a groove V V, which comes right over the groove Z Z, figure 2, receiving the upper edges of the small sliding plates Y Y, figure 12.

I, I, I, I, figure 8, is a niche built of brick in the chimney and plastered. It closes the chimney over the vase, but leaves two funnels, one in each corner, communicating with the bottom box K K, figure 2.

Dimensions of the Parts.

Front of the bottom box,

Height of its partitions,...
Length of No. 1, 2, 3, and 4, each,
Length of No. 5 and 6. each,.

Fect In.

.2 0

.0 44 ...1 3

.0 81

Breadth of the passage between No. 2 and 3, ....0 6
Breadth of the other passages each,.
Breadth of the grate,..

Length of ditto,

.0 3

.0 6

.0 8

.1 0

.0 4

.0 10

.0 9

0 11

Bottom moulding of box, C, square,.
Height of the sides of ditto,.
Length of the back side,..
Length of the right and left sides, each,.
Length of the front plate E, where longest,.
Hole in ditto, diameter,
The cover D, square,...
Sliding plates Y Y, their length, each,..........10
Drawer G, its length,

....

their breadth, each,.

breadth, ..depth...

.......... .........

..depth of its further end only,..

....1 0

.0 3 ....0 44 ....0 1

Grate H in the vase, its diameter to the extremity

of its knobs,.

....at bottom less,

...0 5 ....0 4 .0 1

.0 5 0 04

.0 02

..0 0 ..1 6

Thickness of the bars at top.....
Depth of the bars at the top,
Height of the vase,....
Diameter of the opening O, O, in the clear, ......0 8

Diameter of the air-hole at top....

of the flame hole at bottom,.

To fix this machine.

.0 14 .0 2

B 2, figure 4, shows the upper side of the Spread mortar on the hearth to bed the same plate, with a square impression or groove bottom plate A, then lay that plate level, for receiving the bottom mouldings TTT T'equally distant from each jamb, and project.

ing out as far as you think proper. Then put-one part of it passes round the far end of the ting some Windsor loam in the grooves of the cover B, lay that on: trying the sliding plates Y Y, to see if they move freely in the grooves Z Z, V V, designed for them.

Then begin to build the niche, observing to leave the square corners of the chimney unfilled; for they are to be funnels. And observe also to leave a free open communication between the passages at K K, and the bottom of those funnels, and mind to close the chimney above the top of the niche, that no air may pass up that way. The concave back of the niche will rest on the circular iron partition 1 A 4, figure 2, then with a little loam put on the box C over the grate, the open side of the box in front.

Then, with loam in three of its grooves, the grooves R R being left clean, and brought directly over the groove Q Q in the box, put on the cover D, trying the front plate E, to see if it slides freely in those grooves.

Lastly, set on the vase, which has small holes in the moulding of its bottom to receive two iron pins that rise out of the plate D at I I, for the better keeping it steady.

Then putting in the grate H, which rests on its three knobs h h h against the inside of the vase, and slipping the drawer into its place; the machine is fit for use.

To use it.

Let the first fire be made after eight in the evening or before eight in the morning, for at those times and between those hours all night, there is usually a draft up a chimney, though it has long been without fire; but between those hours in the day there is often, in a cold chimney, a draft downwards, when, if you attempt to kindle a fire, the smoke will come into the room.

But to be certain of your proper time, hold a flame over the air-hole at the top. If the flame is drawn strongly down for a continuance, without whiffling, you may begin to kindle a fire.

First put in a few charcoals on the grate H.
Lay some small sticks on the charcoals.
Lay some pieces of paper on the sticks.
Kindle the paper with a candle.

Then shut down the top, and the air will pass down through the air-hole, blow the flame of the paper down through the sticks, kindle them, and their flame passing lower kindles the charcoal.

When the charcoal is well kindled, lay on it the seacoals, observing not to choak the fire by putting on too much at first.

The flame descending through the hole in the bottom of the vase, and that in plate D into the box C, passes down farther through the grate W W in plate B 1, then passes horizontally towards the back of the chimney; there dividing, and turning to the right and left,

partition 2, then coming forward it turns round the near end of partition 1, then moving backward it arrives at the opening into the bottom of one of the upright corner funnels behind the niche, through which it ascends into the chimney, thus heating that half of the box and that side of the niche. The other part of the divided flame passes round the far end of partition 3, round the near end of partition 4, and so into and up the other corner funnel, thus heating the other half of the box, and the other side of the niche. The vase itself, and the box C will also be very hot, and the air surrounding them being heated, and rising as it cannot get into the chimney, it spreads into the room, colder air succeeding is warmed in its turn, rises and spreads, till by the continual circulation the whole is warmed.

If you should have occasion to make your first fire at hours not so convenient as those above mentioned, and when the chimney does not draw, do not begin it in the vase, but in one or more of the passages of the lower plate, first covering the mouth of the vase. After the chimney has drawn a while with the fire thus low, and begins to be a little warm, you may close those passages and kindle another fire in the box C, leaving its sliding shutter a little open; and when you find after some time that the chimney being warmed draws forcibly, you may shut that passage, open your vase, and kindle your fire there, as above directed. The chimney well warmed by the first day's fire will continue to draw constantly all winter, if fires are made daily.

You will, in the management of your fire, have need of the following implements: A pair of small light tongs, twelve or fifteen inches long, plate, figure 13.

A light poker about the same length with a flat broad point, figure 14.

A rake to draw ashes out of the passages of the lower plate, where the lighter kind escaping the ash-box will gather by degrees, and perhaps once more in a week or ten days require being removed, figure 15.

And a fork with its prongs wide enough to slip on the neck of the vase cover, in order to raise and open it when hot, to put in fresh coals figure 16.

In the management of this stove there are certain precautions to be observed, at first with attention, till they become habitual. To avoid the inconvenience of smoke, see that the grate H be clear before you begin to light a fresh fire. If you find it clogged with cinders and ashes, turn it up with your tongs and let them fall upon the grate below; the ashes will go through it, and the cinders may be raked off and returned into the vase when you would burn them. Then see that all the sliding plates are in their places and close shut, that no air may enter the stove but

through the round opening at the top of the vase. And to avoid the inconvenience of dust from the ashes, let the ash drawer be taken out of the room to be emptied: and when you rake the passages, do it when the draft of the air is strong inwards, and put the ashes carefully into the ash-box, that remaining in its place.

If, being about to go abroad, you would prevent your fire burning in your absence, you may do it by taking the brass flame from the top of the vase, and covering the passage with a round tin plate, which will prevent the entry of more air than barely sufficient to keep a few of the coals alive. When you return, though some hours absent, by taking off the tin plate and admitting the air, your fire will soon be recovered.

The effect of this machine, well managed, is to burn not only the coals, but all the smoke of the coals, so that while the fire is burning, if you go out and observe the top of your chimney, you will see no smoke issuing, nor any thing but clear warm air, which as usual makes the bodies seen through it appear waving.

fit of its heat, whereas in common chimneys a
great part goes away in smoke which you see
as it rises, but it affords you no rays of warmth.
One may obtain some notion of the quantity
of fuel thus wasted in smoke, by reflecting on
the quantity of soot that a few weeks firing
will lodge against the sides of the chimney,
and yet this is formed only of those particles
of the column of smoke that happen to touch
the sides in its ascent. How much more must
have passed off in the air? And we know that
this soot is still fuel: for it will burn and flame
as such, and when hard caked together is in-
deed very like and almost as solid as the coal
it proceeds from.
The destruction of your

fuel goes on nearly in the same quantity whether in smoke or in flame: but there is no comparison in the difference of heat given. Observe when fresh coals are first put on your fire, what a body of smoke arises. This smoke is for a long time too cold to take flame. If you then plunge a burning candle into it, the candle instead of inflaming the smoke will instantly be itself extinguished. Smoke must have a certain degree of heat to be inflammable. As soon as it has acquired that degree, the approach of a candle will inflame the whole body, and you will be very sensible of the difference of the heat it gives. A still easier experiment may be made with the candle itself. Hold your hand near the side of its flame, and observe the heat it gives; then blow it out, the hand remaining in the same place, and observe what heat may be given by the smoke that rises from the still burning snuff. You will find it very little. And yet that smoke has in it the substance of so much flame, and It is certain that clean iron yields no offen- will instantly produce it, if you hold another sive smell when heated. Whatever of that candle above it so as to kindle it. Now the kind you perceive where there are iron stoves, smoke from the fresh coals laid on this stove, proceeds therefore from some foulness burning instead of ascending and leaving the fire or fuming on their surface. They should while too cold to burn, being obliged to detherefore never be spit upon, or greased, nor scend through the burning coals, receives should any dust be suffered to lie upon them. among them that degree of heat which conBut as the greatest care will not always pre-verts it into flame, and the heat of that flame vent these things, it is well once a week to is communicated to the air of the room, as wash the stove with soap lees and a brush, rins- above explained. ing it with clean water.

But let none imagine from this, that it may be a cure for bad or smoky chimneys, much less, that as it burns the smoke it may be used in a room that has no chimney. It is by the help of a good chimney, the higher, the better, that it produces its effect; and though a flue of plate iron sufficiently high might be raised in a very lofty room, the management to prevent all disagreeable vapour would be too nice for common practice, and small errors would have unpleasing consequences.

The Advantages of this Stove.

1. The chimney does not grow foul, nor ever need sweeping; for as no smoke enters it, no soot can form in it.

4. The flame from the fresh coals laid on in this stove, descending through the coals already ignited, preserves them long from consuming, and continues them in the state of red coals as long as the flame continues that surrounds them, by which means the fires made in this stove are of much longer duration than in any other, and fewer coals are therefore necessary for a day. This is a very material advantage indeed. That flame should be a kind of pickle, to preserve burning coals from consuming, may seem a paradox to many, and very unlikely to be true, as it appeared to me the first time I observed the fact. I must therefore relate the circumstances, and shall 3. The whole of the fuel is consumed by be- mention an easy experiment, by which my ing turned into flame, and you have the bene-reader may be in possession of every thing VOL. II.... 3 G

2. The air heated over common fires instantly quits the room and goes up the chimney with the smoke; but in the stove, it is obliged to descend in flame and pass through the long winding horizontal passages, communicating its heat to a body of iron plate, which, having thus time to receive the heat, communicates the same to the air of the room, and thereby warms it to a greater degree.

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