ESSAYS-1 [111]
heats on one side of the body, and the cold blasts on the other, so often felt in houses in this country, are infinitely more detrimental to health than the supposed closeness of the air in a room warmed more equally, and by a smaller fire.
All these advantages, attending the introduction of the improvements in Fire-places here recommended, are certainly important, and I do not know that they are counterbalanced by any one disadvantage whatsoever. The only complaints that I had ever heard made against them was, that they made the rooms TOO warm; but the remedy to this evil is so perfectly simple and obvious, that I should be almost afraid to mention it, less it might be considered as an insult to the understanding of the persons to whom such information should be given; for nothing surely can be conceived more perfectly ridiculous than the embarrassment of a person on account of the too great heat of his room, when it is in his power to diminish AT PLEASURE the fire by which it is warmed; and yet, strange as it may appear, this has sometimes happened!
Before I proceed to give directions for the construction of Fire-places, it will be proper to examine more carefully the Fire-places now in common use;--to point out their faults;-- and to establish the principles upon which Fire-places ought to be constructed.
The great fault of all the open Fire-places, or Chimnies, for burning wood or coals in 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 hereafter 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.
Were it my intention to treat my subject in a formal scientific manner, it would be doubtless be proper, and even necessary, to begin by explaining in the fullest manner, and upon the principles founded on the laws of nature, relative to the motions of elastic fluids, as far as they have been discovered and demonstrated, the causes of the ascent of smoke, and also to explain and illustrate upon the same principles, and even to measure, or estimate by calculations, the precise effects of all those mechanical aids which may be proposed for assisting it in its ascent, or rather for removing those obstacles which hinder its motion upwards;--but as it is my wish rather to write an useful practical treatise, than a learned dissertation, being more desirous to contribute in diffusing useful knowledge, by which the comforts and enjoyments of mankind may be increased, than to acquire the reputation of a philosopher among learned men, I shall endeavour to write in such a manner as to be easily understood BY THOSE WHO ARE MOST LIKELY TO PROFIT BY THE INFORMATION I HAVE TO COMMUNICATE, and consequently most likely to assist in bringing into general use the improvements I recommend. This being premised, I shall proceed, without any further preface or introduction, to the investigation of the subject I have undertaken to treat.
As the immoderate size of the throats of Chimnies is the great fault of their construction, it is this fault which ought always to be first attended to in every attempt which is made to improve them; for however perfect the construction of a Fire-place may be in other respects, if the opening left for the passage of the smoke is larger than is necessary for that purpose, nothing can prevent the warm air of the room from escaping through it; and whenever this happens, there is not only an unnecessary loss of heat, but the warm air which leaves the room to go up the Chimney being replaced
All these advantages, attending the introduction of the improvements in Fire-places here recommended, are certainly important, and I do not know that they are counterbalanced by any one disadvantage whatsoever. The only complaints that I had ever heard made against them was, that they made the rooms TOO warm; but the remedy to this evil is so perfectly simple and obvious, that I should be almost afraid to mention it, less it might be considered as an insult to the understanding of the persons to whom such information should be given; for nothing surely can be conceived more perfectly ridiculous than the embarrassment of a person on account of the too great heat of his room, when it is in his power to diminish AT PLEASURE the fire by which it is warmed; and yet, strange as it may appear, this has sometimes happened!
Before I proceed to give directions for the construction of Fire-places, it will be proper to examine more carefully the Fire-places now in common use;--to point out their faults;-- and to establish the principles upon which Fire-places ought to be constructed.
The great fault of all the open Fire-places, or Chimnies, for burning wood or coals in 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 hereafter 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.
Were it my intention to treat my subject in a formal scientific manner, it would be doubtless be proper, and even necessary, to begin by explaining in the fullest manner, and upon the principles founded on the laws of nature, relative to the motions of elastic fluids, as far as they have been discovered and demonstrated, the causes of the ascent of smoke, and also to explain and illustrate upon the same principles, and even to measure, or estimate by calculations, the precise effects of all those mechanical aids which may be proposed for assisting it in its ascent, or rather for removing those obstacles which hinder its motion upwards;--but as it is my wish rather to write an useful practical treatise, than a learned dissertation, being more desirous to contribute in diffusing useful knowledge, by which the comforts and enjoyments of mankind may be increased, than to acquire the reputation of a philosopher among learned men, I shall endeavour to write in such a manner as to be easily understood BY THOSE WHO ARE MOST LIKELY TO PROFIT BY THE INFORMATION I HAVE TO COMMUNICATE, and consequently most likely to assist in bringing into general use the improvements I recommend. This being premised, I shall proceed, without any further preface or introduction, to the investigation of the subject I have undertaken to treat.
As the immoderate size of the throats of Chimnies is the great fault of their construction, it is this fault which ought always to be first attended to in every attempt which is made to improve them; for however perfect the construction of a Fire-place may be in other respects, if the opening left for the passage of the smoke is larger than is necessary for that purpose, nothing can prevent the warm air of the room from escaping through it; and whenever this happens, there is not only an unnecessary loss of heat, but the warm air which leaves the room to go up the Chimney being replaced