Architecture

"In lighting a coal fire more wood should be employed than is commonly used, and fewer coals; and as soon as the fire burns bright, and the coals are well lighted, and not before, more coals should be added to increase the fire to its proper size."

"In the mean time, very little is done by these chimneys towards warming the room; for the air round the fire-place, which is warmed by the direct rays from the fire, does not continue in the room, but is continually crowded and gathered into the chimney by the current of cold air coming behind it, and so is presently carried off."

"The enormous waste of fuel in London may be estimated by the vast dark cloud which continually hangs over this great metropolis, and frequently overshadows the whole country, far and wide; for this dense cloud is certainly composed almost entirely of unconsumed coal, which having stolen wings from the innumerable fires of this great city has escaped by the Chimnies, and continues to sail about in the air, till having lost the heat which gave it volatility, it falls in a dry shower of extremely fine black dust to the ground, obscuring the atmosphere in its descent, and frequently changing the brightest day into more than Egyptian darkness."

"If you suspect that your chimney smokes from the too great dimension of its opening, contract it by placing moveable boards so as to lower and narrow it gradually, till you find the smoke no longer issues into the room. The proportion so found will be that which is proper... and you may employ the bricklayer or mason to reduce it accordingly."

"In both these sorts of fire-places, the greatest part of the heat from the fire is lost; for, as fire naturally darts heat every way, the back, the two jambs, and the hearth drink up almost all that is given them, very little being reflected from bodies so dark, porous, and unpolished; and the upright heat, which is by far the greatest, flies directly up the chimney. Thus five sixths at least of the heat (and consequently of the fuel) is wasted, and contributes nothing towards warming the room."

"The great fault of all the open Fire-places, or Chimnies, for burning... an open fire, now in common use, is, that they are much too large; or rather it is the throat of the Chimney or the lower part of its open canal, in the neighbourhood of the mantle, and immediately over the fire, which is too large. This opening has hitherto been left larger than otherwise it probably would have been made, in order to give a passage to the Chimney-sweeper; but I shall show... how a passage for the Chimney-sweeper may be contrived without leaving the throat of the Chimney of such enormous dimensions as to swallow up and devour all the warm air of the room, instead of merely giving a passage to the smoke and heated vapour which rise from the fire, for which last purpose alone it ought to be destined."

"I never view from a distance, as I come into town this black cloud which hangs over London without wishing to be able to compute the immense number of chaldrons of coals of which it is composed; for could this be ascertained, I am persuaded so striking a fact would awaken the curiosity, and excite the astonishment of all ranks of the inhabitants; and perhaps turn their minds to an object of economy to which they have hitherto paid little attention."

"3. To remedy this, the Sieur Gauger gives, in his book, entitled La Méchanique de Feu, published in 1709, seven different constructions of the third sort of chimneys mentioned above, in which there are hollow cavities made by iron plates in the back, jambs, and hearths, through which plates the heat passing warms the air in those cavities, which is continually coming into the room fresh and warm. The invention was very ingenious, and had many conveniences; the room was warmed in all parts, by the air flowing into it through the heated cavities; cold air was prevented rushing through the crevices, the funnel being sufficiently supplied by those cavities; much less fuel would serve, &c. But the first expense, which was very great, the intricacy of the design, and the difficulty of the execution, especially in old chimneys, discouraged the propagation of the invention; so that there are, I suppose, very few such chimneys now in use. The upright heat, too, was almost all lost in these, as in the common chimneys."

"To avoid the several inconveniences, and at the same time retain all the advantages of other fire-places, was contrived the PENNSYLVANIAN FIRE-PLACE, now to be described."

"Though the saving of fuel which will result from the improvements to the forms of Chimney Fire-places here recommended will be very considerable, yet I hope to be able to show in a future Essay, that still greater savings may be made, and more important advantages derived from the introduction of improvements I shall propose in Kitchen Fire-places."

"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 labor 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."

"[I]n building new houses... I would have the openings in my lower rooms about thirty inches square and eighteen deep, and those in the upper only eighteen inches square and not quite so deep; the intermediate ones diminishing in proportion as the height of funnel diminished. ...The same depth is nearly necessary to all, the funnels being all made of a size proper to admit a chimney-sweeper."

"Those who will take the trouble to consider the nature and properties of elastic s,—of air,—smoke,—and vapour,—and to examine the laws of their motions, and the necessary consequences of their being rarified by heat, would perceive that it would be as much a miracle if smoke should not rise in a Chimney, (all hindrances to its ascent being removed,) as that water should refuse to run in a syphon, or to descend in a river."

"I was much flattered on my return to England, in September 1798... to find that the improvements in the construction of chimney fire-places, which I had recommended in my Fourth Essay, published... 1796, were coming into use... It has been objected... that they sometimes occasion dust and ashes to come into the room when the fire is stirred. I have examined several fire-places... that have... that fault; but... found... their imperfections have arisen from faults in... construction. Either the grate has been brought out too far into the room, or the opening of the fire-place in front has been left too wide—or too high—or the workman has neglected to lower and to round off the breast of the chimney—or... several of these faults... together..."

"When the throat of a chimney is situated very high up above the mantle, and especially when the mantle and breast of the chimney, or the wall that reposes on the mantle, are very thin, workmen who are employed to alter chimnies, setting about the work with their minds strongly prepossessed with what they consider as the leading principle... that the throat of the chimney should not be more than four inches wide, they are very apt to bring the grate too far forward. In dropping their plumb-line from the breast of the chimney, they do not reach up high enough into the chimney, but take a part of the breast, where it still goes on to slope backwards, for the bottom of the perpendicular canal of the chimney. They also very often commit another fault, not less essential... in neglecting to bring down the throat of the chimney nearer to the fire, when... too high."

"Longlande, in Pierce the Plowman'sVision, feelingly alludes to the change as prompted by a mean and selfish wish to abridge the ancient hospitality observed towards the poor. "Elynge is that halle eche day in the wyke, Ther the lorde ne the lady liketh nat to sitte. Nowe hath eche ryche a reule to eten by hym silve In a privey parlour for pore mennys sake; Or in a chaumbre wyth a chymney, and leve the cheef halle That was mad for melis men to eten inne." The chimneyed chamber was spacious and lofty, and usually formed with a large bay window, looking into the court of the castle."

"It is remarkable that, while the open fireplace was one of the earliest contrivances invented to contribute to the health and comfort of man, the upright flue for carrying off the injurious products of combustion should have remained one of the latest."

"And in the choice of a grate, as in every thing else, beauty and elegance may easily be united with the most perfect simplicity.—Indeed they are incompatible with every thing else."

"Another way... is to take out an upper pane of glass in one of your sashes: set it in a tin frame, giving it two springing angular sides, and then replacing it with hinges below [Fig. 2], on which it may be turned to open more or less above. ...By drawing this pane in more or less, you may admit... air... Its position will naturally throw that air up and along the ceiling."

"In modern built houses where the doors and windows are... made to close with such accuracy that no crevice is left for the passage of the air from without... When there is a fire burning... as the air necessary to supply the current up the Chimney where the fire burns cannot be had in sufficient quantities... through the very small crevices of the doors and windows, the air in the room becomes rarefied, not by heat, but by subtraction of that portion of air which is employed in keeping up the fire, or supporting the combustion of the fuel, and in consequence of this rarefaction, its elasticity is diminished, and being at last overcome by the pressure of the external air of the atmosphere, this external air rushes into the room by the only passage left for it... by the open Chimney."

"A second cause of the smoking of chimneys is, their openings in the room being too large... Architects... have no other ideas of proportion in the opening of a chimney, than what relate to symmetry and beauty... while its true proportion, respecting its function and utility, depends on quite other principles... The proportion then to be regarded, is what relates to the height of the funnel. For... funnels in the different stories of a house are necessarily of different heights or lengths... [T]he openings of the longest funnels may be larger, and that those of the shorter funnels should be smaller. For if there be a large opening to a chimney that does not draw strongly, the funnel may... be furnished with the air it demands by a partial current... on one side of the opening... the other side free of any opposing current, may permit the smoke to issue there into the room."

"[C]onsider the fire-places heretofore in use, viz. 1. The large open fire-places used in the days of our fathers, and still generally in the country, and in kitchens. 2. The newer-fashioned fire-places, with low breasts and narrow hearths. 3. Fire-places with hollow backs, hearths and jambs of iron, (described by M. Gauger, in his tract entitled La Méchanique de Feu,) for warming the air as it comes into the room. 4. The Holland stoves, with iron doors opening into the room. 5. The German stoves, which have no opening in the room where they are used, but the fire is put in from some other room, or from without. 6. Iron pots, with open charcoal fires, placed in the middle of a room."

"Those [grates] whose construction is the most simple, and... the cheapest, are beyond comparison the best, on all accounts.— Nothing being wanted in these Chimnies but merely a grate for containing the coal, and in which they will burn with a clear fire;—and all additional apparatus being, not only useless, but very pernicious, all complicated and expensive grates should be laid aside, and such as are more simple substituted in the room of them."

"The most obvious remedy... is to provide for the supply of fresh air necessary for keeping up the fires by opening a passage for the external air into the room by a shorter road than down one of the Chimnies..."

"[T]he form of the breast of the Chimney is... of... great importance... The worst form it can have is that of a vertical plane, or upright flat;—and next... worst... is an inclined plane.—Both... cause the current of warm air from the room, which will... sometimes find its way into the Chimney, to cross upon the current of smoke, which rises from the fire, in a manner, most likely to embarrass it in its ascent, and drive it back.— The inclined plane which is formed by a flat register placed in the throat of a Chimney produces the same effects; and this is one reason, among many... which have induced me to disapprove of register stoves."

"Much... of the force of draft in a funnel depends on the degree of rarefaction in the air it contains; and that depends on the nearness to the fire... in entering the funnel. If it can enter far from the fire on each side, or far above the fire in a [too] wide or high opening, it receives little heat in passing by the fire, and the contents of the funnel is by that means less different in levity from the surrounding atmosphere, and its force in drawing consequently weaker."

"The current of air, which, passing under the mantle, gets into the Chimney, should be made gradually to bend its course upwards, by which means it will unite quietly with the ascending current of smoke, and will be less likely to check it, or force it back into the room.—Now this may be effected with the greatest ease and certainty, merely by rounding off the breast of the Chimney or back part of the mantle, instead of leaving it flat, or full of holes and corners; and this... ought always to be done."

"If the room be so tight as that all the crevices together will not supply so much air as is continually carried off, then, in a little time, the current up the funnel must flag, and the smoke, being no longer driven up, must come into the room."

"1. The first of these methods has generally the conveniency of two warm seats, one in each corner; but they are sometimes too hot to abide in, and, at other times, incommoded with the smoke; there is likewise good room for the cook to move, to hang on pots, &c. Their inconveniences are, that they almost always smoke, if the door be not left open; that they require a large funnel, and a large funnel carries off a great quantity of air, which occasions what is called a strong draft to the chimney, without which strong draft the smoke would come out of some part or other of so large an opening, so that the door can seldom be shut; and the cold air so nips the backs and heels of those that sit before the fire, that they have no comfort till either screens or settles are provided (at a considerable expense) to keep it off, which both cumber the room, and darken the fire-side. A moderate quantity of wood on the fire, in so large a hearth, seems but little; and, in so strong and cold a draft, warms but little; so that people are continually laying on more. In short, it is next to impossible to warm a room with such a fire place; and I suppose our ancestors never thought of warming rooms to sit in; all they purposed was, to have a place to make a fire in, by which they might warm themselves when cold."

"This may be easily done by drawing down about an inch the upper sash of a window; or, if not moveable, by cutting such a crevice through its frame... it will be well to place a thin shelf... to conceal the opening; and sloping upwards, to direct the entering air... In some houses, the air may be admitted by such a crevice... near the ceiling and over the opening of the chimney. ...[T]he entering cold air will there meet with the warmest rising air from before the fire, and be soonest tempered by the mixture. The same kind of shelf should also be placed here."

"[T]he height to which the new back and covings ought to be carried... will depend not only on the height of the mantle, but also, and more especially, on the height of the breast of the Chimney, or of that part of the Chimney where the breast ends and the upright canal begins.—The back and covings must rise a few inches, five or six... higher than this part, otherwise the throat of the Chimney will not be properly formed;—but I know of no advantages that would be gained by carrying them up still higher."

"But Chimnies so circumstanced may very frequently be prevented from smoking even without opening any new passage for the external air, merely by diminishing the draught... up the Chimnies... by altering both Fire-places upon the principles recommended... in the foregoing..."

"[W]here the throat of the Chimney has an end... where it enters into the lower part of the open canal of the Chimney, there the three walls which form the two covings and the back of the Fire-place all end abruptly. ...[T]hey should end in this manner for were they to be sloped outward and raised in such a manner as to swell out the upper extremity of the throat of the Chimney in the form of a trumpet, and increase it by degrees to the size of the canal of the Chimney, this manner of uniting the lower extremity of the canal of the Chimney with the throat would tend to assist the winds which may attempt to blow down the Chimney, in forcing their way through the throat, and throwing the smoke backward into the room; but when the throat of the Chimney ends abruptly, and the ends of the new walls form a flat horizontal surface, it will be much more difficult for any wind from above, to find, and force its way, through the narrow passage of the throat..."

"2. Most of these old-fashioned chimneys in towns and cities have been, of late years, reduced to the second sort mentioned, by building jambs within them, narrowing the hearth, and making a low arch or breast. It is strange, methinks, that though chimneys have been so long in use, their construction should be so little understood till lately, that no workman pretended to make one which should always carry off all smoke, but a chimney-cloth was looked upon as essential to a chimney. This improvement, however, by small openings and low breasts, has been made in our days; and success in the first experiments has brought it into general use in cities, so that almost all new chimneys are now made of that sort, and much fewer bricks will make a stack of chimneys now than formerly. An improvement so lately made may give us room to believe, that still farther improvements may be found to remedy the inconveniences yet remaining. For these new chimneys, though they keep rooms generally free from smoke, and, the opening being contracted, will allow the [house] door to be shut, yet, the funnel still requiring a considerable quantity of air, it rushes in at every crevice so strongly, as to make a continual whistling or howling; and it is very uncomfortable, as well as dangerous, to sit against any such crevice. Many colds are caught from this cause only, it being safer to sit in the open street; for then the pores do all close together, and the air does not strike so sharply against any particular part of the body."

"As the two walls which form the new covings... are not parallel... but inclined, presenting an oblique surface towards the front of the Chimney, and as they are built perfectly upright, and quite flat, from the hearth to the top of the throat, where they end... an horizontal section of the throat will not be an oblong square; but its deviation from that form is a matter of no consequence; and no attempts should ever be made, by twisting the covings above, where they approach the breast of the Chimney, to bring it to that form."

"In an edition of the author's writings on electrical and philosophical subjects, published in London in the year 1769, the following note is appended to this tract. "Soon after the foregoing piece was published, some persons in England, in imitation of Mr. Franklin's invention, made what they call Pennsylvanian Fire-places, with improvements; the principal of which pretended improvements is, a contraction of the passages in the air-box, originally designed for admitting a quantity of fresh air, and warming it as it entered the room. The contracting [of] these passages gains indeed more room for the grate, but in a great measure defeats their intention. For, if the passages in the air-box do not greatly exceed in dimensions the amount of all the crevices by which cold air can enter the room, they will not considerably prevent, as they were intended, the entry of cold air through the crevices.""

"The earth is every where surrounded with a great body of air, that is called the atmosphere. This air is a thin elastic fluid, possessing some qualities peculiar to itself, but subjected in general to the same physical laws with other fluids; and of consequence it hath a constant tendency to preserve an exact equilibrium in all its parts; so that if at any time the weight of it at one place is diminished, the heavier air rushes from all sides towards that point, till the equilibrium be again restored."

"Whether the new back and covings are constructed of stone, or... bricks, the space between them, and the old back and covings of the Chimney ought to be filled up... with loose rubbish, or pieces of broken bricks, or stones, provided the work be strengthened by a few layers or courses of bricks laid in mortar; but it will be indispensably necessary to finish the work where these new walls end... at the top of the throat of the Chimney, where it ends abruptly in the open canal of the Chimney by a horizontal course of bricks well secured with mortar."

"All twists, bends, prominences, excavations, and other irregularities of form, in the covings... never fail to produce eddies in the current of air which is continually passing into, and through an open Fire-place in which a fire is burning;—and all such eddies disturb, either the fire, or the ascending current of smoke, or both; and not unfrequently cause the smoke to be thrown back into the room.—Hence... the covings... should never be made circular, or in the form of any other curve; but always quite flat."

"[N]ear half the children that are born and bred in London die under two years of age. ...[T]he constant and unremitting Poison is communicated by the foul Air, which, as the Town still grows larger, has made regular and steady advances in its fatal influence. ...[W]e are accustomed to read with great composure of the deaths of thosands of infants, suffocated every Year by Smoke and Stenches which good policy might in a great measure remove."

"And what is all this, but that Hellish and dismall Cloud of SEA-COALE? which is not onely perpetually imminent over her head... so universally mixed with the otherwise wholsome and excellent Aer, that her Inhabitants breathe nothing but an impure and thick Mist, accompanied with a fuliginous and filthy vapour, which renders them obnoxious to a thousand inconveniences, corrupting the Lungs, and disordering the entire habit of their Bodies; so that Catharrs, Phthisicks, Coughs and Consumptions, rage more in this one City, than in the whole Earth besides."

"Whilst these are belching it forth their sooty jaws, the City of London resembles the face rather of Mount Ætna, the Court of Vulcan, , or the Suburbs of Hell, than an Assembly of Rational Creatures... For when in all other places the Aer is most Serene and Pure, it is here Ecclipsed with such a Cloud of Sulphure, as the Sun itself... is hardly able to penetrate... and the weary Traveller, at many Miles distance, sooner smells, than sees the City to which he repairs."

"[N]ot from the Culinary fires, which for being weak, and lesse often fed below, is with such ease dispelled and scattered above, as it is hardly at all discernible, but from some few particular Tunnells and Issues, belonging only to Brewers, Diers, Lime-burners, Salt, and Sope-boylers, and some other private Trades, One of whose Spiracles alone, does manifestly infest the Aer, more than all the Chimnies of London put together besides."

"Workmen should be consulted, and encouraged to make experiments, whether a particular construction of the Chimnies would not assist in conveying off the Smoke, and in fending it higher into the air before it is dispersed."

"It seems that those who have hitherto built or caused chimneys to be erected, have only taken care to contrive in the chambers certain places where wood may be burnt, without making a due reflection that the wood in burning ought to warm those chambers, and the persons who are in them; at least, it is certain that but a very little heat is felt of the fire made in the ordinary chimneys, and that they might be ordered so as to send forth a great deal more, only by changing the disposition of their jambs and wings."

"1. Air is rarefied by heat, and condensed by cold, that is, the same quantity of air takes up more space when warm than when cold. This may be shown... Take any clear glass bottle (a stript of the straw is best), place it before the fire, and, as the air within is warmed and rarefied, part of it will be driven out of the bottle; turn it up, place its mouth in a vessel of water, and remove it from the fire; then, as the air within cools and contracts, you will see the water rise in the neck of the bottle, supplying the place of just so much air as was driven out. Hold a large hot coal near the side of the bottle, and, as the air within feels the heat, it will again distend and force out the water. Or, fill a bladder not quite full of air, tie the neck tight, and lay it before a fire as near as may be without scorching the bladder; as the air within heats, you will perceive it to swell and fill the bladder, till it becomes tight, as if full blown; remove it to a cool place, and you will see it fall gradually, till it becomes as lank as at first."

"To be able to kindle a fire speedily, and make it, if you please, flame continually, whatever wood is burning, without the use of bellows; to give heat to a spacious room, and even to another adjoining, with a little fire; to warm one's self at the same time on all sides, be the weather ever so cold, without scorching; to breathe a pure air always fresh, and to such a degree of warmth as is thought fit; to be never annoyed with smoke in one's apartment, nor have any moisture therein; to quench by one's self, and in an instant, any fire that may catch in the tunnel of a chimney; all these are but a few of the effects and properties of these wonderful machines, not withstanding their apparent simplicity. Since I used this sort of chimney, I have not been troubled one moment with smoke, in a lodging which it rendered before untenable as soon as a fire was lighted; I have always inhaled, even during the sharpest seasons, a fresh air like that of the spring. In 1709, water that froze hard everywhere else very near the hearth, did not congeal at night in my chamber, though the fire was put out before midnight; and all that was brought thither in the day soon thawed; neither did I ever perceive the least moisture in winter, not even during thaws."

"A plate of iron or copper bowed or bended after such a manner as is not at all disagreeable to the sight; a void behind, divided by certain small iron bands or partition plates, forming several spaces that have a communication one with another; a little vent hole in the middle of the hearth, a register plate in the upper part of the funnel; and for some shafts, a capital on the top, make up the whole construction and workmanship of our modern chimney. Now, can there be anything more simple or plain, or more easy to execute?"

"[A]ny new proposal for saving the wood, and for lessening the charge and augmenting the benefit of fire, by some particular method of making and managing it, may at least be thought worth consideration."

"1. Fire... throws out light, heat, and smoke (or fume.) The [first] two... move in right lines, and with great swiftness; the latter is but just separated from the fuel, and then moves only as it is carried by the stream of rarefied air; and without a continual accession and recession of air, to carry off the smoky fumes, they would remain crowded about the fire, and stifle it."