IMPROVEMENTS IN ADMIT
Year: 1855

page_text: LETTERS PATENT to George Walker Muir, of Glasgow, in the County of
Lanark, and Matthew Gray, of Bonhill, in the County of Dumbarton,
Scotland, Engineers, for the Invention of "IMPROVEMENTS IN ADMITTING
Sealed the 30th October 1855, and dated the 24th May 1855.
PROVISIONAL SPECIFICATION left by the said George Walker Muir and
Matthew Gray at the Office of the Commissioners of Patents, with their
Petition, on the 24th May 1855.
We, GEORGE WALKER MUIR, of Glasgow, in the County of Lanark, and
MATTHEW GRAY, of Bonhill, in the County of Dumbarton, Scotland, En-
gineers, do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN ADMITTING & REGULATING THE ADMISSION OF AIR TO FURNACES'
follows:-
The improvements relate to means for regulating the admission of atmo-
spheric air to the products of combustion, in combination with a mode of
arranging plates for directing the currents of air so admitted, and preventing
the radiation of heat from the furnace.
The air is admitted to the fire-place through a series of openings, capable of
being partially or entirely closed by a sliding cover, directly connected to the
rod of a piston, which works in a closed cylinder. The weight of the cover
acting upon the piston gradually closes the cover over the openings.

page_text: The air after passing through the openings impinges upon two or more
successive sets or series of plates, horizontally, angularly, or vertically placed,
and so that the air deflected in one direction by one plate may be deflected in
a different direction by the succeeding; thus the air becomes heated in its
passage to the products of combustion, and the heat is prevented from
radiating outward.
The improvements also relate to means for admitting air by the furnace
bars, by arranging them in such a manner that when placed side by side they
present a furrowed, serrated, or -pyramidical face, upon which the fuel is
placed. We do this either by making the bearers to the bars stepped, so as
to raise or depress the bars relatively to each other, or they may be cast in
groups of the form required. By this arrangement the air is admitted to the
fuel more freely than when the bars are all in the same level, and present
a level surface for the fuel. The higher bars carry the air farther into the
body of fuel before it comes into contact with it.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Walker Muir and Matthew Gray in the Great
Seal Patent Office on the 24th November 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, GEORGE
WALKER MUIR, of Glasgow, in the County of Lanark, and MATTHEW GRAY,
of Bonhill, in the County of Dumbarton, Scotland, Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of May, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said George Walker Muir and Matthew Gray, Her special licence that we,
the said George Walker Muir aud Matthew Gray, our executors, adminis-
trators, and assigns, or such others as we, the said George Walker Muir, and
Matthew Gray, our executors, administrators, and assigns, should at any time
agree with, aut no other, 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 "IMPROVEMENTS IN
ADMITTING AND REGULATING THE ADMISSION OF AIR TO FURNACES," upon the con-
dition (amongst others) that we, the said George Walker Muir and Matthew
Gray, by an instrument in writing under our hands and seals, or under the

page_text: hand and seal of one of us, 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 we, the said George Walker Muir and Matthew
Gray, do hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained in
and by the following statement thereof, that is to say :-
The improvements relate to means for regulating the admission of atmo-
spheric air to the products of combustion, in combination with a mode of
arranging plates for directing the currents of air so admitted, and preventing
the radiation of heat from the furnace.
The air is admitted to the fire-place through a series of openings, capable of
being partially or entirely closed by a sliding cover, directly connected to the
rod of a piston, which works in a closed cylinder. The weight of the cover
acting upon the piston gradually closes the cover over the openings..
The air after passing through the openings impinges upon two or more
successive sets or series of plates, horizontally, angularly, or vertically placed,
and so that the air deflected in one direction by one plate may be deflected
in a different direction by the succeeding; thus the air becomes heated in
its passage to the products of combustion, and the heat is prevented from
radiating outward.
The improvements also relate to means for admitting air by the furnace
bars, by arranging them in such a manner that when placed side by side they
present a furrowed, serrated, or pyramidical face, upon which the fuel is
placed. We do this either by making the bearers to the bars stepped, so as
to raise or depress the bars relatively to each other, or they may be cast in
groups of the form required. By this arrangement the air is admitted to the
fuel more freely than when the bars are all in the same level, and present a
level surface for the fuel. The higher bars carry the air farther into the body.
of fuel before it comes into contact with it.
But that the nature of our said improvements, and the means which we
adopt in carrying the same into practice, may be fully understood, we will
proceed to describe the Drawing annexed.
DESCRIPTION OF THE DRAWING.

page_text: rod
9,
a, a, in Figure 3 are the openings therein, for the purpose, when desired, of
admitting air through the door to promote the combustion of the fuel in the
furnace. These openings are capable of being closed by the parts b' of the
sliding frame b, which is retained with a capability of sliding in grooves c, c,
formed on the door, whilst it is by means of the connecting rods d, d, connected
to the cross head f, to which is also connected the upper end of the piston
the piston of which is fitted to the cylinder h. This cylinder h is closed,
and its ends are connected by the passage h'. In using a furnace with a door
arranged according to this part of our improvements, after each fresh supply
of fuel, we, after closing the door, raise the covers b, so as to open a free
passage for the air therethrough, and the slide is in part supported by the
water or other fluid in the lower part of the cylinder h, but the weight of
the slide causes the water to pass by the passage to the upper part
of the cylinder till the opening is closed. The time occupied in the falling
of the slide is capable of being regulated by the screw h², by which the
passage h' may be more or less closed. i, i, are plates, each having a series of
holes or longitudinal openings through which the air passes in its way from
the openings a to the furnace; and these openings are formed in the respective
plates, so as to cause the air passing through one to impinge on the surface of
the next plate before passing through the openings therein, by which the air
thus passing to the furnace becomes heated, and direct radiation of heat from
the furnace is prevented. We would state that although we prefer in carrying
out this first part of the Invention to apply the improvement to the fire door, we
do not confine ourselves to that arrangement.
Figure 4 shows a plan, Figure 5 a side view, and Figure 6 a section, of a
group of fire bars, forming part of a series arranged according to the second
part of our improvements. ',,,, are the bars, and in the casting they
may be connected together by the connecting pieces =. Sets of bars thus
formed may be placed together in the furnace so as to form a furrowed or
serrated surface, such as represented by the dotted line, Figure 7, or so as
progressively to rise from the sides to the middle, somewhat pyramidically, as
represented by Figure 8; in either case the fuel will be found to be the
thinnest where the bars rise the highest, by which it will be found that the
admission of air to the fuel will be facilitated.
In place of forming the bars so that when placed in the fire-place, and
whether cast in groups or singly, they will by their form assume the varying
heights referred to, we sometimes form the supporting bars with steps on their
upper surfaces, so that bars of the ordinary construction and all alike may
when placed thereon assumie a similar figure on their surface; or the bars may

page_text: be cast singly and of various depths, so that relatively to each other they
may when placed side by side form a furrowed or pyramidical section, and
this whether the bars be placed lengthwise or across the furnace.
Having thus described the nature of our said improvements, we do not
confine ourselves to the precise details herein shown and described; but
what we do claim is,―
First, the arranging and combining parts for admitting and regulating the
admission of air to furnaces, as explained.
Secondly, we claim the arranging furnace bars longitudinally or transversely
in the furnace to facilitate the admission of air to the furnace, as explained.
In witness whereof, we, the said George Walker Muir and Matthew
Gray, have hereunto set our hands and seals, this Twenty-second
day of November, in the year of our Lord One thousand eight hundred
and fifty-five.
Witness,
ANDREW BLACKWOOD.
GEORGE WALKER MUIR. (L.S.)
MATTHEW GRAY.
(L.B.)