and a due supply of air is admitted into the stove, a smoky chimney is
an exception; still the flue forms only a simple open funnel for the
passage of the smoke, and failures will inevitably often happen. A
construction on a good principle should render these defects as trifling
as possible. In our best houses--those constructed within the last
twenty or thirty years--two kinds of the common brick flue are mostly in
use. One is of the old-fashioned kind, having a section of 14 by 9 in.,
which was made originally of that size for the accommodation of the poor
sweeping-boys. This is now retained only for the kitchen fire, which
makes a large quantity of smoke, and for the rest of the fireplaces the
flue known as “Cubitt’s” flue is employed, which has a diameter each way
of 9 in. The author prefers the small flue, and always uses it in the
buildings he has constructed. There are many persons who still maintain
that the old-fashioned flue is the correct one, and it is still very
generally used. There is an old saying about the proof of the pudding.
In Belgrave Square, all the houses first designed and erected have the
old-fashioned flue, and there are scarcely a dozen of the old
chimney-pots left; all have been changed for tall-boys and other similar
contrivances; one house has about 24 in one stack. No. 49, built by
Cubitt about 35 years ago, and having the descending or sweeping flue,
has the stacks exactly as at first constructed, with the exception only
of a little doctoring to the kitchen flue. In the house opposite, No.
48, one of the first, the external stack alone, next the street, has no
less than 17 tall-boys, two of which appear to be broken off. On the
opposite side of the Square, in Chesham Place, is No. 38, built by
Cubitt about 30 years; it has all the original stacks untouched.
The Cubitt flue can be recognised by the small peculiar cap on the
chimney-pot, and several of these stacks remain in their original state.
In Eaton Place and Eccleston Square, where this flue is used, the roofs
tell the same story. In the first buildings erected by the author he
used the large flue, and he now finds several specimens of
chimney-doctoring on the roofs. In some large houses he lately erected
at Queen’s Gate, in which the sweeping flue is used, there are several
houses together without any disfigurement at all on the roof. He
considers that the appearance of a tall-boy on one of them would be
rather a proof that there was something wrong about the servants’
management of the fires, than an error in the construction of his flues.
A representation of this flue, and the manner of introducing it into a
building, is here given. Fig. 1
[Illustration: Flue construction.]
represents a portion of the chimney-flue construction of a first-rate
house; the lower chimney opening is in the basement, and above it are
two others, one on the ground floor, and one on the first floor. It will
be seen that there are three flues descending or taken down to the
basement. The third flue belongs to the room on the second floor. The
wall is two bricks thick, the flue 9 in. in diameter, and contained
within the wall with no chimney-breast projecting. Fig. 2 is a plan of
the flues on the ground floor, and fig. 3 of those on the first floor.
Fig. 4 is a section of the fireplace opening; this is 3 ft. in height
from the floor-line, the brickwork at top is splayed, and supported by
an iron bar; these openings are always filled up with 4½ straight joint
work, to be taken out when the mantelpiece is fixed. Fig. 5 is the
chimney-pot and its cap, the latter opening at top 7 in. by 9 in. only;
fig. 6 shows one of the sweeping doors, in which there are two to each
descending flue. The latter three figures are twice the scale of the
former. A plan and section of the chimney complete, with its marble
mantel and stove, is given in figs. 7 and 8. The flue passes completely
down at the back of the stove, the front is closed by an iron plate to a
height of 2 ft. On this is fixed the moveable door or register, shut
fully or partly over the flue when the stove is in use, and closed over
the stove when the flue has to be swept. The arrows show the mode of
admission of air to the front of the fire; it is brought through the
[Illustration: Fig. 7.--Plan of stove.]
floor and two openings in the back hearth from the outside of the house.
This is generally kept concealed,
[Illustration: Fig. 8.--Section.]
and in order to ensure a supply of air to the stove the room should be
kept completely closed.
To cause as full and perfect a combustion of the fuel as possible, a
draught or current of the external air should be always admitted to the
stove, and it could easily be placed under open management, so as to
admit either a large or small supply of air, as required. Numerous
patent processes to effect this are in use, but the most effective way
of doing it is that shown in figs. 7 and 8: it is too simple for a
patent.
[Illustration: Fig. 9.]
Fig. 9 shows a method of admitting air above the architrave of the
entrance door of the room. The opening is made about 2 ft. in length;
this, after a little time, becomes marked by the blacklets coming in
from the passage. The sweeping flue when the fire is lighted becomes
very hot; the smoke ascends speedily and soon leaves it. The flue
requires the stove to be formed expressly for it. Mr. Cubitt made the
stoves only for his own houses, and the author had some difficulty at
Queen’s Gate, in procuring stoves of the right pattern, for
manufacturers prefer their own shop patterns, and some of these would
have covered up half the descending flue. Those he used were supplied by
Messrs. Feetham of Clifford Street, who are well acquainted with the use
of the flue and stove. The flue is considered an excellent one; it is a
builder’s flue, constructed solely of brick, and is certainly the best
of the brick flues. The same attention was paid to it as was given to
every part of Mr. Cubitt’s buildings. It may be asked, “Are there no
other kinds of flues constructed of superior materials?” Yes, certainly
there are; particular attention has often been paid to the flue. There
is Hiort’s circular flue, formed in each course of four wedge-formed
bricks. Mr. Hiort held a very important position; he was Treasurer of
the office of Works at Whitehall, and his flue was extensively used in
some of the Government buildings and the houses in Carlton Gardens. It
did not bond well with the brickwork, so we have Mr. Moon’s improvement
upon it. This was considered not sufficient, and another patent was
taken out in 1844 by Messrs. Clark and Reed for its further improvement.
The flue was an excellent one, but on Mr. Hiort’s retirement from the
Government Board, it went out of use.
There is Seth Smith’s metallic chimney lining, which makes an excellent
flue; the lining is a pipe of from 5 to 10 in. in diameter, built in the
brickwork. About 150 of these flues are at the Pantechnicon. Mr. Smith
announced his determination of never building any house above the value
of 30_l._ per annum, without using them. They could be introduced, to
form perfect linings to chimneys in buildings already erected, and allow
the stack to be reduced in height, without having the unsightly
appearance of contractions made above them. The drawback to the use of
these tubes by builders was the price. Without any royalty, the 9 in.
tube cost 3_s._ 4_d._ per ft. run, the curved tubes 4_s._ 3_d._, the
starting tube 3_s._ 8_d._ The tubes were of the exact form of drain
pipes, and they were cheaper, and as effectual.
If Mr. Smith’s metal tubes had been introduced into a large brick flue,
they would have rendered the latter an efficient shaft for ventilating
every room in its upward course, openings being made for the purpose at
the upper part of the rooms. This mode of ventilation was applied to
hospitals on a large scale by the late Mr. Jacob Perkins several years
ago, with perfect success.
Denley’s flue, introduced in 1843, is believed to have been the
precursor of that used by the late Mr. Thos. Cubitt at Belgravia and
Pimlico, and there is a great resemblance between the two; but Mr.
Denley’s flue has nothing like the simplicity nor ease of construction
of Mr. Cubitt’s. The downward flues were merged into one at the
basement, and all the soot and cinders were collected or thrown down
into a fire-proof box, which must have stood out in the lower rooms,
from which they had to be removed. The flues were swept from the roof,
the register doors of the stoves being closed, and there was no
provision for sweeping the flues between the basement and the stoves.
Joined to his system for sweeping, was one of air flues which brought a
current of air direct from the exterior of the house to each fireplace.
We have several flue systems which have ventilating flues in connexion
with them. Boyd’s flue forms the wythes, or half-brick spaces between
the flues, of iron plates, and the open spaces thus gained make
ventilating passages. Mr. Doulton’s combined smoke and air flues are
manufactured in terra-cotta, in three sizes; the air flues follow the
line of the smoke flue, the passages being quite distinct, as in Mr.
Boyd’s. The heat from the smoke flue causes a current in the air-flue
which carries off the vitiated air admitted by openings near the
ceiling. The common drain pipes and the glazed fire-clay pipes make good
flues; the use of these pipe-flues has greatly increased during the last
few years; they improve the draught, and clean easily. Flues for
ventilation from rooms should, like Arnott’s ventilator, enter into the
smoke or a hot ventilating flue. Arnott’s ventilator requires careful
adjustment, to be balanced in such a way that it should stand closed on
a calm day.
The superior patented flues, as they are of considerable cost, and take
extra time in construction, are only used in the better class of
buildings, or in those erected under the express direction of the
owner. In speculative buildings they are never used. The time required
for their construction beyond that of the common brick flue, being
regarded by the builder as so much money lost.
The great desideratum in a flue is to make it pass off its smoke
quickly, and this the small size flue effects more certainly than the
larger one, as it warms sooner and keeps its heat longer.
An enthusiastic admirer of the descending or sweeping flue once told the
author that with a good fire in the grate, if a kettle of water could be
placed on the top of the chimney-cap the water would soon boil, even if
the flue were fifty feet high. The flues constructed of metallic or
earthenware casings retain also the heat longer, and keep hotter. It may
be imagined that with these flues, and the large quantity of gas lamps
in the streets, why the temperature of London should be always some
degrees higher than that of the country. In winter snow may be seen in
the suburban fields, but none is found in town.
Architects have often been blamed for not inventing a good system of
flue-construction, not only for the prevention of smoke in our
dwellings, but for the hindrance of its presence in the atmosphere.
Several, and most excellent attempts, have been made for the former, but
very few for the latter, which is one of far greater difficulty. Yet
this is one that admits of a cure, great as the evil is. The chimney
flue might be so improved as to effect a more certain and larger
ventilation of our houses, without any addition of ventilation flues.
The introduction of the French Mansard roof with us, one from a country
where coal fires are not in use, renders it almost imperative for the
chimneys belonging to such buildings to have a different construction,
for chimneys when placed against a building or roof that overtops them,
are sure, as they are at present made, to become smoky: the wind
returning owing to the high construction, and descending in the flues.
The following few designs are offered to cure these various evils.
Accepting as a fact that tall-boys, and the other iron and zinc
constructions, are useful appendages, there can be no reason why they
should be so used as to disfigure our buildings. Some of the finest
specimens of architecture in the Metropolis serve only as pedestals to
an ugly collection of cowls.
The author proposes to form the upper part of the flues in a building,
for a length of about 15 to 20 feet, entirely of iron or other tubing,
in square, round, or oblong sections, of a less diameter than the brick
flues to which they are attached. This tubing is gathered up in groups,
and carried out at an angle of 45° towards a centre stack: the tubes in
direct contact with each other, having no brick wyths, except one or
two to strengthen the stack.
It is obvious that if only one of the flues be in use, it would
moderately warm those next to it; and if the whole of the flues of a
building were constructed on this plan, and two or three were in use,
such a power would be obtained as would effectually ventilate every
room; the action would be continuous and imperceptible, and a fire could
be lighted in any one without the risk of return smoke from a cold or
damp flue.
Thus the heat now wasted in the atmosphere by the action of the common
flue, would be partly retained and turned to use, and the draught of the
flue very much improved.
This tubing could be readily introduced into either old or new
buildings, as the introduction does not involve taking down more than
twelve feet of the brickwork, measuring from the top of the coping. The
tubes could never become sufficiently heated to be dangerous, and less
brickwork would be required.
They might be made either of zinc or earthenware; cast-iron would be
objectionable on account of its weight. It will be seen that they admit
a better mode of sweeping than that now practised, and they could easily
have some kind of capping to prevent down-draughts.
These “stack flues” should commence from the attic or upper storey of a
building, at about six feet from the floor; sweeping doors should be
placed beneath them, so as to give the sweep command of the flue beneath
as well as above.
Each flue should be composed of three separate forms of tubing, by which
the various directions and turns necessary for the construction might be
obtained.
Fig. 10 gives the representation of the three forms; 1, is the first;
this is placed directly over the brick
[Illustration: Fig. 10.]
flue, and gathers it up to a size having an internal dimension of 6 +
4½. It is 21 inches in height. 2, the second piece, is on a curve; the
top and bottom lines, if carried on, would form an angle of 45°; it is
about 18 inches in height, and internal size 6 + 4½. The third, 3, is a
straight piece, internal size 6 + 4½, the lengths various. Fig. 11
gives a plan of four flues and an elevation of the commencement of two.
The sweeping doors are shown below. The flue without a door is the
ventilating flue for the basement. The ease with which this tubing can
be grouped is shown in fig. 12. The stack consists of five flues; the
tube, 2, connects them together below, and
[Illustration: Fig. 11.]
separates them above. The stack above the roof is 4 feet 9 inches in
length.
Fig. 13 shows, in the upper plan, how the flue wall could be reduced in
thickness, made a brick and a half only, with a two-brick block at each
end; it contains coupled and tripled sets of tubes.
The middle plan shows nine flues grouped together, the centre being that
belonging to the kitchen. The last plan shows a group of six in a
two-and-a-half-brick wall; by the side of this are two flues of the
common construction, 14 inches by 9, made of this
[Illustration: Fig. 12.]
size to enable a boy to get up to the top and place his head out of the
chimney-pot.
The tube 1, fig. 12, can have its position reversed, as shown in fig.
14; six flues can thus be grouped together, as shown in the third plan,
fig. 13. The elevation of this stack is given in fig. 15.
[Illustration: Fig. 13.]
For a covering to these tubes figs. 16 to 20 show ornamental pots and
their sections. The only merit
[Illustration: Fig. 14.]
in these may be that they are of a more ornamental character than any
that have ever been introduced; they are formed of zinc, supported by a
stout dwarf iron railing. The intention is to permit the smoke to escape
in any direction, either upwards, sideways, or downwards, sheltering it
as far as possible from any action of the wind, and rendering of little
consequence whether the stack is high, low, unsheltered or
[Illustration: Fig. 15.]
otherwise. If any sudden gust of wind take place and the smoke be driven
back, the capping provides larger outlets for its escape than the small
aperture of the flue itself; in other words, it is easier for the smoke
to pass in any direction rather than return down the flue.
The stack flues are only, in fact, tall-boys boxed up and not put out in
the cold, and it is presumed they would be sufficiently powerful, from
their warmth, to ensure a good passing off of the smoke, and secure
ventilation to the building.
[Illustration: Fig. 16.]
[Illustration: Fig. 17.]
A forced ventilation to our dwellings, in ever so slight a degree, is a
matter of importance. By the proper construction of these proposed stack
flues it is presumed that any amount of ventilating power, self-acting
and continuous, could be obtained. Their introduction alone would be
beneficial; combined with the flue pedestal, to be described, the tubes
could be led into one general upward shaft; by either plan we should
have some command over the smoke, while the roofs of our buildings might
be made ornamental and picturesque. It would be a treatment of
bituminous coal alike artistic and novel, surprising to foreigners and
creditable to ourselves.
[Illustration: Fig. 18.]
It remains to show how the open character of the flue could be taken
away (this forms its chief evil), and how a chimney-stack may be formed
without chimney-pots. The late Lord Palmerston, when Home Secretary,
proposed the abolition of chimney-stacks, and the use of only one
chimney-stalk for each separate dwelling. In 1856, a commission was
appointed to inquire into the best modes of warming and ventilating the
apartments of dwelling-houses and barracks. Their report, given to the
General Board of Health, was published in 1857, and it afforded a
section illustrating “the principle on which it was proposed to
construct dwelling-houses.” There was only to be
[Illustration: Fig. 19.]
one flue, and this of metal 10 inches in diameter, enclosed in a large
brick flue, which was to serve for ventilation. In the metal flue were
to be inserted the flues of the several fireplaces; these were placed
back to back, and if the register doors of the stoves were open, a
person in one room might both see and converse with another in the
next; the music of a pianoforte in one room could be heard in them all;
this construction was taken up through four storeys, there being eight
fireplaces. For one fireplace alone it would have been perfect, but the
smoke from the two kitchen fires would have been sufficient to have
choked
[Illustration: Fig. 20.]
the flue and caused the smoke to enter into the whole of the eight
rooms.
The chimney-stack might possibly be lowered, and it certainly could be
constructed without chimney-pots, but each separate flue must have its
own outlet. A design for this, one that should take away the open
character of the flue, and fit the stack, possibly for the Mansard roof,
is here given.
In fig. 21, _a_ _a_ are the flues, delivering their smoke into a large
ventilating flue, _b_. The warm smoke would induce a current of air to
enter at _c_: any current will have a tendency to draw another with it,
so that the smoke leaving the flues _c_ _c_ would be taken out at _d_ by
the current of air at _c_.
[Illustration: Fig. 21.--The ventilating flue.]
This is the principle upon which all the best ventilating chimney-pots,
tall-boys, and cowls are made, and it is a very sure one. The jet of
steam in the funnel of the locomotive, drawing the smoke from the fire,
and creating a draught, is adopted on the same principle.
In scientific language, the established law both of pneumatics and
hydraulics is that when two currents of fluid matter passing in the same
direction, but in separate channels, arrive at any point of confluence,
the stronger current draws the other along in its course, and with a
considerable portion of its own velocity. Thus the force of the wind,
which checks in other instances the action of a chimney-draught, is made
to produce a stronger draught, exactly in proportion to the violence
with which it blows.
Returning to fig. 21, a current of air, instead of coming in at the
opening _c_, might come in at _d_. It would then have a tendency to blow
down the flues _a_ _a_: to prevent this, the opening _d_ could be
closed, and an upright stalk placed at _e_,--this should have a downward
shaft, a place for soot, and a sweeping door.
There is still another mode of treatment; fig. 22 represents the flues
grouped, each with a separate ventilating flue, the smoke delivered
being at the side of each.
The stack might be covered with zinc in the ornamental style with which
that metal is now treated.
It is probable that if a stack on this principle was placed parallel to
the side of one of these Mansard roofs, it would be secure from the
ill-effects of any wind returning against it. The author will not vouch
for its success, but it is offered here to the attention of architects
and builders as an experiment worthy of trial.
[Illustration: Section.]
[Illustration: Elevation.]
[Illustration: Fig. 22.--Plan.]
It has been affirmed that the smoke of towns, however disagreeable it
may be to the inhabitants, neutralizes the poisonous effect of the gases
caused by sewers, &c. If it was possible wholly to remove carbon
evolved by smoke, our towns would almost be uninhabitable, and they
represent that any scheme for getting rid of smoke must be combined with
one for getting rid of the exhalations from sewers at the same time. If
the two evils were brought together, they would neutralize each other,
and both could then be got rid of at one operation. The best scheme for
this is a matter of important consideration, but few have been proposed.
It may be asked, what has a work on Picturesque Architecture to do with
either smoke or sewer gases? The author in reply considers that
buildings never will look picturesque while they are covered with great
patches of soot. An eminent sculptor once affirmed that the statues of
London were improved by their soot covering, because it made them stand
boldly out against the sky. But those beautiful decorated smoke towers
which stand on the roof of the Houses of Parliament, and which are as
black as Erebus, look anything but pleasing, standing amidst the whiter
front of the rest of the building. Besides, tall-boys are beginning to
make their appearance on the roof under the Victoria tower, and these
certainly form no part of the architecture, but appear monstrously ugly;
consequently smoke and its abolition are clearly questions to be
considered in relation to Picturesque Architecture.
A plan for removing smoke from the atmosphere of towns, and at the same
time ventilating buildings and sewers, was proposed in 1849 by Mr.
Flockton, surveyor to the town trustees of Sheffield,[F] a town as much
begrimed with sooty smoke, only in a smaller way, as the Metropolis.
The proposal was, that under the footways along the side of every street
and lane, flues should be constructed of sufficient capacity to carry
off all the smoke and other atmospheric impurities, these flues all
converging, upon a general plan, to tall shafts or chimneys at some
distance from the town, and supplied with furnaces. These, when the
fires were once ignited, would give a fire produced by the combustion of
the inflammable gases accompanying the smoke, and which would burn
spontaneously in a similar manner to the combustion of foul air from old
shafts connected with coal mines. The combustion might be assisted by
jets of coal gas, in a fire of coke.
In very large towns it would be necessary, Mr. Flockton added, to divide
the whole into districts, and to erect towers in the centre of each, to
which all the flues should converge. He published a plate, showing two
large dwelling-houses, with a street between, the common sewer in the
middle of the carriage way, and the smoke flues on each side under the
footpaths, also showing the connexion between the sewer and flue. The
alteration proposed to houses already erected consisted in converting
ascending into descending flues; turning the smoke from the chimney-top
into the latter, and from thence into the street flue. This operation
would have necessitated the pulling down and rebuilding of the flue
walls. The street smoke flues, in order to carry off the smoke from a
few thousand chimneys, would require to have been made of a size even
larger than the sewer itself. Provision must have been made for clearing
out the soot, for the smoke would have been cooled and the soot would
accumulate in large quantities in them.
The same scheme, with similar constructions, was proposed by a foreign
gentleman, who took out a patent for it in 1850 (No. 13,061). His plan
was a very grand one; he did not propose alterations in existing
buildings, but pulled them down and gave designs for a new city.