A Discussion of the Smoking Stove 
My kitchen stove smokes all the time. The house is 
a T-shape, the larger part, setting north and south, 
with the kitchen running east. The roof of the kitchen 
on ly comes to the eaves of big house, as it is built from 
the* second floor. Flue runs out about 4% feet above 
roof, with pipe running inside of flue, and hole in the 
other side of flue,of kitchen pipe for dining room stove. 
Can you give me some idea of why it does not draw, 
and smokes so much? D. c. C. 
New York. 
E fficiency in heating.— with the coming 
of Winter the problem of satisfactorily warm¬ 
ing the home is again brought to our attention. This 
problem comes to us with increased force this year 
because of the high cost of fuel. Even though grown 
upon the place, fuel should he conserved because of 
the labor required to fit it for use. At the same time 
the efficiency demanded of every person by the 
present conditions makes comfort a requirement; 
no man can do his best who is not bodily comfort¬ 
able. The problem then 
resolves itself into one 
of securing the great¬ 
est output of comfort 
from every stick of 
fuel burned, and a 
properly constructed 
chimney is no mean 
factor in helping its 
solution. It is pretty 
generally understood 
that what wc know as 
“fire” is simply the 
union of two elements, 
carbon and oxygen; in 
the presence of heat: 
the carbon being found 
in the fuel and the 
oxygen coming from 
the air. A small 
amount of heat is ap¬ 
plied, usually by means 
of a match, to start 
the action, the fire is 
kindled, as we say, af¬ 
ter which it becomes 
automatic, the union 
of the two elements 
furnishing sufficient 
heat to continue the 
action as long as the 
supply of carbon and 
oxygen lasts. By the 
union of these ele¬ 
ments, however, a gas 
is formed—carbou di¬ 
oxide—which is fatal 
to combustion, and un¬ 
less removed the fire 
will “go out.” This 
gas, when at the same 
temperature, is slight¬ 
ly heavier than air. 
and tends to settle and 
collect in pockets. It is not poisonou 
CONSERVING HEAT.—With the open out-of- 
doors fire practically all of the heat generated passes 
off in the ascending air current and is lost. With 
the indoor fire, however, we wish to utilize as much 
of the heat as possible for warming tlie building; at 
the same time a certain amount of beat must be 
allowed to pass up the chimney in order that the 
column of gases contained by it may be kept warmer 
and thus lighter than the outside air, and by this 
means kept moving up the stack, removing the 
products of combustion and giving the fire 
“draught.” Here is where a perfect chimney makes 
for economy, for if properly constructed it will do 
this work at the expense of much less heat than will 
one that is loose and poorly constructed. 
CHIMNEY CONSTRUCTION.—For best results 
and to reduce this required amount of heat to the 
and stops 
combustion by shutting off the supply of oxygen— 
the fire is simply smothered. 
LAWS OF COMBUSTION.—From the foregoing 
one might draw the conclusion that a fire would 
very soon extinguish itself. Such is not the case, 
however, as the conditions tending to destroy the 
fire are met by natural laws. The waste gases 
evolved by combustion are heated by the fire, and 
because of this heating are expanded and made 
fighter than the surrounding air. They are conse¬ 
quently forced upward by the surrounding colder 
and heavier air in much the same manner that a 
cork is forced upward when submerged in a pail of 
water; at the same time the surrounding colder air 
rushes into the fire to take their place, thus supply- 
J ug the oxygen necessary to support combustion. 
This process is continuous as long as the supply of 
fuel lasts, and can be seen by watching any open 
fire. The ascending current of heated gases over it 
vill be marked by smoke, sparks and the upward 
streaming tlarnes, while the grass and other light 
objects surrounding the fire will denote the direction 
of the colder air currents toward it. This action has 
bo ?n described at some length, as it is the same 
tbiug that takes place in tlie confined fire of the 
stove or furnace, with tlie exception that the waste 
gases are confined and carried off by tlie smoke pipe 
and chimney, while tlie incoming air containing the 
necessary oxygen is regulated in quantity by tlie 
dampers, permitting the operator to control tlie fire. 
minimum tlie chimney should be built with a smooth 
round interior, ample in size, have thick walls and 
should extend from the basement to a point well 
above the ridge of the roof by the most direct route 
possible. A smooth round interior is specified be¬ 
cause this gives tlie most room for ascending gases 
with tlie least exposed wall surface to absorb and 
radiate beat and to cause friction. Heated air cur¬ 
rents move in spirals in the flue, and when the cross 
section of the chimney interior is other than round 
only a portion of it becomes effective. Rectangular 
flues are, however, in use that give efficient service, 
but where one is used it should approach a square 
as nearly as possible, and a larger size should be 
chosen because of the waste space mentioned. This 
is shown graphically in the drawing, Fig. 513. Tlie 
smooth inner surface of course permits tlie gases to 
flow upward with the least resistance due to friction. 
CONSERVING WARMTH.—The necessity for 
warmth secured by thickness need hardly be com¬ 
mented upon. If tlie heat of the ascending column 
of gases can be conserved by warm, tight construc¬ 
tion of the chimney, it follows that the column can 
start with a lower initial temperature and still reach 
the top with heat enough to make it lighter than the 
surrounding air. For this same reason—warmth— 
a chimney built inside the house is more efficient 
than an exterior flue; its wall arc protected and give 
off less heat. 
SECURING DRAFT.—A chimney should project 
well above the ridge or highest poii.-t of the building 
in order to secure the beneficial effect of the wind 
blowing across its top. Two feet is usually given as 
the minimum amount of this protection. Free pas¬ 
sage of air over tlie top produces an aspirating effect 
or “suction” which increases the draught in the 
chimney. On the other hand, if the ridge is above 
the chimney top, as shown in the cut. eddy currents 
are likely to he formed, as indicated by the arrows, 
which may blow directly down the chimney, causing 
puffs of smoke and sometimes ashes as well to he 
blown from the stove in windy weather. Tall trees 
near a building will sometimes give tlie same effect. 
A chimney smoking from this reason alone seldom 
does so steadily; the trouble manifests itself in 
windy, gusty weather, and usually when the wind 
is in a certain quarter, depending upon the location 
of the obstruction causing the trouble. The remedy 
is of course an increase 
in tlie chimney height 
in a case of this kind. 
CAUSES OF SMOK¬ 
ING.— Some of the 
most frequent causes 
of smoking are shown 
in the drawing. At 
“A” is shown a very 
common cause of smok¬ 
ing and poor draught 
Two smoke pipes are 
connected directly to 
the same chimney fine. 
If one stove happens 
to lie unused, or pre¬ 
sents less resistance to 
the passage of air 
through it than the 
other one does, there 
is likely to be poor 
draught and attendant 
smoking in tlia other. 
The cause of trouble is 
usually indicated by 
this fact. Smoking 
from a similar cause 
is sometimes brought 
about through the con¬ 
dition shown at "B.” 
In this chimney two 
flues are provided, but 
a leak has developed 
between them, due to 
a break in the dividing 
wall, permitting air to 
pass from one to the 
other. Loose - fitting 
connections where the 
pipe enters the chim¬ 
ney, a loosely fitting 
clean-out door at the 
bottom, or chinks in 
chimney itself are all 
causes that tend to produce smoking by permitting 
air to enter tlie chimney in a manner that cannot be 
controlled. All incoming air. except that controlled 
by dampers, should pass through tlie fire. A con¬ 
stricted opening is another frequent cause of srnok- 
ing. This may he the result of too small a flue 
opening in the first place, or from a number of other 
causes giving the same effect. A chimney built with 
an offset may have a pile of soot, leaves, birds’ nests 
or even bricks wedged in tlie throat and almost com¬ 
pletely filling it. This condition is shown at “C.” 
Fig. 513. The same thing will frequently happen in 
a straight chimney where the sutoke pipe enters near 
the bottom, the debris accumulating until the open¬ 
ing is nearly closed. Again, the pipe may he pushed 
too far into tlie chimney, as shown at “D,” resulting 
in a greatly constricted passage. 
LEAKING CREOSOTE.—Another frequent source 
of trouble with tlie chimney and piping, and one 
that is very disagreeable, is the leaking of “creo¬ 
sote.” This trouble is especially likely to occur 
where wood not thoroughly dried is used, where the 
heating plant is of large capacity, as it should he. so 
that under normal conditions the draughts are kept 
closed, permitting little heat to reach the chimney, 
and in cases where there arc long runs of horizontal 
pipe. Under normal conditions this “creosote” 
passes out with tlie burned gases as a vapor, and 
causes no inconvenience, hut where the conditions 
are such as are noted above tlie •smoke current may 
he cooled sufficiently to permit condensation within 
