AN IMPROVED MODE OF CONSTRUCTING FIRE FLUES AND AIR PASSAGES
Year: 1856

page_text: LETTERS PATENT to Thomas Evans Blackwell, of Clifton, Bristol,
Engineer, for the Invention of "AN IMPROVED MODE OF CONSTRUCTING
FIRE FLUES AND AIR PASSAGES."
Sealed the 16th December 1856, and dated the 20th September 1856.
PROVISIONAL SPECIFICATION left by the said Thomas Evans Blackwell
at the Office of the Commissioners of Patents, with his Petition, on
the 20th September 1856.
I, THOMAS EVANS BLACKWELL, of Clifton, Bristol, Engineer, do hereby
declare the nature of the said Invention for "AN IMPROVED MODE OF CON
STRUCTING FIRE FLUES AND AIR PASSAGES," to be as follows:-
This Invention relates to an improved mode of constructing fire and air
flues, the object being to improve the draft and prevent the accumulation of
soot in the flues. To this end, instead of constructing the flues of ordinary
bricks, or of round or oval pipes built into brickwork as heretofore, I employ
hollow blocks of fire clay moulded into a rectangular figure in plan on the
outside, and with the internal angles of the space rounded off. These blocks
I so proportion that they will readily build in with ordinary bricks, and
prevent the necessity for filling up spaces with bats and rubble. Instead of
forming the flue in the wall, I may build up the fire-clay blocks against the
wall, the outer form of the blocks affording sufficient facilities for securing
them to the main structure. I propose to mould the blocks of various sizes,

page_text: and with one, two, or more passages in them to form one or more flues. For
the purpose of causing a divergence (when required) in the direction of the
flues built on this principle of construction, I propose to mould skew and
curved blocks with passages through them, corresponding to the passages in
the square blocks with which they are to be used.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Evans Blackwell in the Great Seal Patent Office on
the 20th March 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
EVANS BLACKWELL, of Clifton, Bristol, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of September, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Thomas Evans Blackwell, Her special licence that I, the said Thomas
Evans Blackwell, my executors, administrators, and assigns, or such others as
I, the said Thomas Evans Blackwell, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United Kingdom
of Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "An IriprovED MODE OF CONSTRUCTING FIRE FLUES AND AIR
PASSAGES," upon the condition (amongst others) that I, the said Thomas
Evans Blackwell, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed and cause the same to
be filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Thomas Evans Blackwell, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawing hereunto annexed,
and to the letters and figurcs marked thereon (that is to say):-
This Invention relates to an "improved mode of constructing fire and air
flues or passages" in dwelling-houses, offices, and other buildings, the object

page_text: being to improve the draft of chimneys by preventing the accumulation of soot
in the flues, and to facilitate the ventilation of apartments.
Instead of constructing the flues of ordinary bricks, or of round or oval
pipes built into brickwork as heretofore, I employ hollow blocks of fire-clay
moulded into a rectangular figure in plan on the outside, and with the
internal angles of the spaces filled up. These blocks I so proportion that they
will readily bond with ordinary bricks, and prevent the necessity for filling up
spaces with bats and rubble when they are built up into a wall.
In the accompanying Drawing, Fig. 1 represents, in plan view, the kind of
block which I propose to employ in carrying out my Invention; Fig. 2 is a
front elevation of the same; and Fig. 3 is a cross section; the form of the block,
however, I propose to modify according to circumstances, keeping in view the
principle of bonding with the brickwork to which they are to be applied, or of
which they will form an integral part. A, A, (Figures 1 and 3) is a central
space, forming the fire flue, and proportioned according to the ordinary con-
structions in brickwork; and B, B, B, are openings made through the block
for the purpose of ensuring its lightness, and also for the introduction of keys
or dowels when necessary, while the whole takes the proportional dimensions
requisite for bonding with the brickwork. When, however, I desire to build
up air flues together with the fire flues, I avail myself of these cavities, or
some of them, and employ them as air flues, connecting them together by
lateral passages, as shewn by dots at Fig. 1, or leaving them separate, as
thought most desirable. The air flues are formed by building up blocks of
this construction, and I connect them with the apartment or apartments
desired to be ventilated, by making openings in the sides of the flues as shewn
at Fig. 2, which may be fitted with a suitable ventilator valve, or with a
removeable covering. An up-draft will thus be created, which will ensure the
rapid discharge of deleterious gases from the apartment thus connected with
the air flue. Or, in place of merely ventilating an apartment, the air flues thus
constructed may be employed for conveying warm air to closets, sleeping-rooms,
and other apartments. For this purpose access of air must be permitted to
the lower part of the flue, and the proximity of the flue to a fire flue, which is
or may be in frequent or constant use, will ensure the heating of the ascending
current in the air flue, and this current being directed and regulated by means
of valves, dampers, or otherwise, can be readily thrown into any adjacent
apartment.
Instead of forming the flues within walls, I may build up the fire-clay
blocks against a wall; the outer form of the blocks affording sufficient
facilities for securing them to the main structure. The blocks I propose to

page_text: mould of various sizes, and with one, two, or more openings in them, to form
any required number of contiguous fire flues, and either with or without
cavities, which may be converted as above explained into air flues. For the
purpose of causing a divergence (when required) in the direction of the flues
built on this principle of construction, I propose to mould blocks with skew
and curved passages through them, corresponding in gauge and position with
the passages in the blocks to which they are to be applied.
Having now set forth the nature and object of my Invention of "An
Improved Mode of Constructing Fire Flues and Air Passages," and explained
the manner of carrying the same into effect, I wish it to be understood, that
under the above in part recited Letters Patent I claim, constructing the fire
flues and air passages of buildings of hollow blocks, so formed that they will
bond in with ordinary brickwork, as above explained.
In witness whereof, I, the said Thomes Evans Blackwell, have hereunto
set my hand and seal, the Twentieth day of March, in the year of our
Lord One thousand eight hundred and fifty-seven.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
THOS E. BLACK WELL. (L.S.)