134 



NEW ENGLAND FARMER. 



[Nov. 18, 



of course be slight. This defect is often found j 

 in low buildings, or the up|)er story of high ones,, 

 and is not easily avoided ; for if the line be rais- ; 

 ed high above the roo( to strensrtheu its draught, ! 

 it is in danger of being blown down, and crusli- ^ 

 ing the roof beneath it. The remedy in this 

 case is to contract the opening of the chimney, 

 (which may be done as helbre observed by low- 

 ering the mantel) so as to oblige the entering 

 air to pass through or very near liic (ire, by 

 which means it will be considerably iienied, and 

 by its great rarefaction cause a poweitul draught, 

 and compensate for the shortness of its column. 

 The case of too short a funnel is more general 

 than would be imagined, and often fiuind where 

 one would not expect it ; for it is not uncommon 

 in ill contrived buildings, instead of having a 

 separate funnel lor each tire place, to bend and 

 turn the funnel of an upjier room so as to make 

 it enter the side of another flue that conies from 

 below. By this means the funnel of the upper 

 room is made short of course, since its length 

 can only be reckoned from the place whore it 

 enters the lower funnel, and that flue is also 

 shortened by .ill the distance i)et»cen the en- 

 trance of the second funnel and the top of the 

 slack ; for all that part being readily supplied 

 with air through the second flue, adds no strength 

 to the draught, especially as that air is cold 

 when there is no tire in the second chimnev. — 

 The only easy remedy here, is to keep" the 

 opening shut of that flue in which there is no 

 fire. 



Another very common cause of the smoking 

 of chimneys is, their overpowering one another. 

 For instance, it there be two chimneys in one 

 large room, and you make (ires in both of them 

 you will tind that the greater and stronger fire 

 will overpower the weaker, and draw air down 

 lis funnel to supply its own demand, which air 

 descending in llie weaker (unnel wi'ldrive down 

 its smoke, and force it into the room. If, instead 

 of being in one room, the two chimneys are in 

 two different rooms communicating by a door, 

 the case is the s,\uie whcnevpr the door is o[ien> 

 The remedy is, to take care that every room 

 have themeiin.s of sujiplying itself from without, 

 with the air its chimney may require, so that no 

 one of them may be obliged to borrow from a- 

 nollier, nor under the necessily of lending. 



Another cause of sni'iking is, when the (ojis 

 of chimneys are commanded by higher buildings 

 or by a hill, so that the wind blowing over such 

 eminences falls like water over a dam, some- 

 times almost perpendicularly on the tops of chim- 

 neys that lie in its way, and beats down the 

 smoke contained in them. The remedy com- 

 monly applied in this case is, a turn-cap made of 

 tin or plate-iron, covering the chimney above 

 and on three sides, open on one side, turning on 

 a sp.ndle, and which being guided or governed 

 by a vane, always presents its back to the wind. 

 Thirf method will generally be found elleclual, 

 but if not, raising the Hues where practicable, so 

 as their tops may be on a level with or higher 

 than the commanding eminence, is more to be 

 depended on. 



There is another case, in which the eminence 

 is to the leeward of the chimnev. Suppose the 

 chimney to bi so situated that its top is hebuv 

 the level of the ridge of the root, which, when 

 the wind blows againsl it. forms a kind of d;im 

 agaiusi lis progress. In Ibis case the wind being 

 obairucicd by tLiis dum, will, like water, pres"s 



and search for passages through it, and finding 

 the fop of the chimney below the top of the dam 

 or ridge, it will force itself down that funnel, 

 and if there be a tire in such chimney its smoke 

 is of course beat down and fills the room. The 

 only remedy for this inconvenience is to raise 

 the funnel higher than the roof, supporting it, 

 if necessary, by iron bars; for a turn-cap in this 

 case has no effect, the impeded air passing down 

 flirough it in whatever position the wind may 

 have placed its opening. 



Chimneys otherwise drawing well sometimes 

 smoke in consequence of the impropersi'uation 

 of a door. When the door and chimney are 

 |)laced on the same side of a room, if the door is 

 made to open iVom the chimney, and only partly 

 opened, a current of air is admitted and directed 

 across the opening of the chimney, which is apt 

 to draw out some of the smoke. 



Chimneys, which generally draw well, do 

 nevertheless sonietimes give smoke into the 

 room, it being driven down by strong «ind pas- 

 sing over the tops of their flues, (hough not de- 

 scending from any commanding eminence. To 

 iindrrsl.md this, it may lie considered (ha( the 

 rising light air, to obtain a free issue from the 

 funnel, must push out of its way, or oblige the 

 air that is over it to rise. In a lime of calm, or 

 of little wind, this is done visibly; for we see 

 the smoke that is brought up by that air rise in 

 a column above Ihe chimney. But when a vio- 

 leni current of wind jiasses over the top of a 

 chimney, its particles have received so much 

 force, which keeps Ihem in a horizontal direc- 

 tion, and follow each other so rapidly, that the 

 rising light air has not strength sufficient to ob- 

 lige them to quit that direction, and move up- 

 wards (o permit its issue. Add (o this, that some 

 of the air may impinge on that part of ihe inside 

 of (he funnel \vhich is opposed to its progress, 

 and be thence reflected downwards from side to 

 side, driving the smoke before it into the room. 

 The simplest and best remedy in this case is the 

 application of a chimney-pot which is a hollow 

 truncated cone of earthen ware placed upon (he 

 top of the flue. The intendon of this contriv- 

 ance is, that Ihe wind and eddies which strike 

 against the oblique surface of these covers may 

 be reflected upwards instead of blowing down 

 Ihe chimney. The remarkable chimneys ob- 

 served at Venice, in which the top of the flue is 

 largcd and rounded in the shape ofa funnel, seem 

 also intended as a remedy to this inctrnvenience, 

 that Ihe wind blowing over one of the edges in- 

 to the iuunel may be slanted out again on the 

 other side by its form. 



The bad constriiclinn of fire-places is another 

 cause of smoking chimneys. In such a case the 

 lire-place may be modified acco-ding to the |)lan 

 oi Count Huniford. Such modilication will, gen- 

 erally, not only (irevent smoke, but cause the 

 fire-plaie to sjive out a much greater quantity of 

 heat iban would be emanated from common fire 

 places. In Dr Gnrham's Klements of Chemical 

 Science, vol. i. page 131, we have the (ollowing 

 epitome ol Count Ri!mford''s directions for con- 

 structing fire-places ; 



'' One of the most useful imjirovemenls which 

 have been made in consequence of ihe knowl- 

 edge of ihe laws of radiant caloric, is that ol 

 Coiinl riumford, in Ihe construction ol fire-places. 

 He has [iroved that the warmth of fires is owing 

 principally to ihe radiation of heal. But previous 

 to his lime, the form, at least in this country, 



was exlremely unfavourable to the pas,sage of 

 the caloric info the room. The fire place was 

 '!ee|i, its mouth was wide, and the sides were 

 nearly parallel with each other. The conse- 

 ipiences were, that radiation was efiVctiial only 

 from the front, and that the air which had been 

 warmed by previous contact with surfiiccs in 

 the room, escajied through the chimnev. To 

 obviate these inconveniences. Ihe mouth of the 

 lire place was narrowed, its de[ith was dimin- 

 ished, the back was inclined forward, and ihc 

 sides wiTe made to diverge from each other by 

 a very large angle. Two essential advantages 

 were thus gained. The radiation of caloric 

 from Ihe fire became effectual from ihe sides as 

 well as the front of the fire, and a considerable 

 proportion of heated air remained in the apar't- 

 mcnl. Ev'perience has am[dy demonstrated Ihe 

 iilility of this mode of construction." 



There are causes besides the foregoing which 

 often induce chimneys to smoke. Among these, 

 the most common are Ihe suffering of soot to ac- 

 cumulate in the funnels ; hanging door? in such 

 a manner that when [>artly open a current of air 

 i« directed into and across the fire pdaces, &c. 

 Those who wish fiir further information on this 

 siibjpcl, may consult Ilees' Cyclopedia, ariicle 

 " Chiiiiiieii"' as well as (he (ihilnsophical papers 

 of Dr Franklin and Count Rumtord. 



It is im|iossible tor us to give any definite di- 

 rections for preventing the chimney of our cor- 

 respondent " Sam," from smoking, because ive 

 know nothing of its construction, location, &,c. 

 except the slight notices contained in his com- 

 munication. If "(he minisierand doc(or of the 

 parish," after examining the evil on the spot 

 I of its exhibition could not point out a remedy, 

 I it can scarcely be expected that we, without the 

 I advantage of [lersonal inspection, can do anything 

 : more than ^ucss what should be done in Ihe 

 I premises. We will, however, venture to tell 

 I" Sam" if his rooms are too tight to furnish air 

 for Ihe draught of his chimney, he should admit 

 I air near the upper part ; or u hat is still belter 

 I from a concavity at Ihe back of his chinmcy as 

 j above proscribed. It' his chimney flues aie crook- 

 ed, or siiort or not (igh(, he may find a remedy for 

 those evils by making (hem s(raigh(. tigh(, awl 

 j carrying (hem up separa(e ("rom each other. If 

 I wind forces its way down Ihe chimney and drives 

 ! the smoke into his rooms, (which as his " house 

 1 is situated on high ground near Ihe sea," we 

 I should coDJeclure may be Ihe case) he may per- 

 haps prevent this effect by Ihe applicalinn of a 

 chimney pot, as above directed. But although 

 the causes of smoking chimneys are very nume- 

 rous, ive believe that in most cases the simple 

 remedy pointed out by Dr Cooper as above, viz. 

 " Contract Ihe space immediately over Ihe fire 

 so that you may be sure of Ihe air being well 

 h».ited there, will prove pfTeclual. 



The im()orlance of the subject must he our 

 apology lor the lenijlh of this article. We have 

 known so much sufiering (rom smoky chimneys 

 that we think too much attention can scarceh be 

 paid to Ihe most probable means of removing 

 the cause of this calamity. 



TO THE KDITOR OF THE NEW ENCL.WD FARMER. 



NEW VARIETIES OF POTATOES. 

 Fassalboro\ (Me.) lllh mo. 8, 1825. 

 Dear Sir — I ha\v noticed in the iVew Eng- 

 land Farmer, voi. iv. page 31, a couijili.uii of 



