IMPROVEMENTS IN APPARATUS FOR UTILISING THE UNCONSUMED GASES GIVEN OFF DURING COMBUSTION, PREVENTION OF SMOKE, AND THE ECONOMISING OF FUEL, FOR STEAM-BOILER FURNACES AND OTHER FURNACES AND PURPOSES."
Year: 1880

page_text: LETTERS PATENT to Richard Paulson, of 36, Streatfield Street, Burdett Road,
London, in the County of Middlesex, for an Invention of "IMPROVEMENTS
IN APPARATUS FOR UTILISING THE UNCONSUMED GASES GIVEN OFF DURING
COMBUSTION, PREVENTION OF SMOKE, AND THE ECONOMISING OF FUEL, FOR
STEAM-BOILER FURNACES AND OTHER FURNACES AND PURPOSES."
PROVISIONAL SPECIFICATION left by the said Richard Paulson at the
Office of the Commissioners of Patents on the 22nd December 1880.
RICHARD PAULSON, of 36, Streatfield Street, Burdett Road, London, in the
County of Middlesex. "IMPROVEMENTS IN APPARATUS FOR UTILISING THE
UNCONSUMED GASSES GIVEN OFF DURING COMBUSTION, PREVENTION OF SMOKE,
AND THE ECONOMISING OF FUEL, FOR STEAM BOILER FURNACES AND OTHER
FURNACES AND PURPOSES."
In carrying out my improvements I make the bars for the furnaces preferably of
cast metal (or alloy) having a deep flange or web extending along the under or
exposed side, which by rapidly radiating the heat imparted to them prevents them
being burnt or ingured by the action of the fire.
These bars have also a perforation extending from end to end through them, or
they may be cast in two or more pieces, each piece having a deep groove so as to
admit of a tube of metal being placed within the groove, and so that when placed
together and riveted, combined they make a perfect but hollow bar and retain the
tube in the interior. These bars when fixed do not mearly extend from the front of
the furnace to the back but are also prolonged and carried upwards at right
angles so as to rest against the bridge or butt usually placed at the back of the
furnace.
In locomotives, vertical and portable boilers, I prefer to arrange these bars
alternately across from side to side instead of from the front to the back, or they
may be ranged in a circle radiating from the middle of the furnace or firebox; in
all cases I carry the ends of the bars upwards so that they project into the furnace

page_text: above the surface of the fire. The object of this arrangement is that a fresh and
continuous supply of air is admitted into the fire or furnace in a heated condition
by being made to pass through the hot hollow bars, and in such a manner that it is
brought in contact and combines with the unconsumed hydro-carbons and gasses
given off during combustion, so that they are effectively consumed, a much greater
heat is thereby generated from a given quantity of fuel, and by means of this
arrangement equal effects may be obtained from slow combustion as previously
required rapid consumption of fuel. To enable me to effectively accomplish this
economy of fuel and also to regulate the admission of air as may be required
combined with the hollow bars as previously mentioned I arrange and add one or
more solid bridges of firebricks or metal in such a manner as to check, baffle,
and mingle the unconsumed gasses with the heated air admitted through the
hollow bars.
In Galloway, Cornish, and other boilers and furnaces where a considerable length
of bar is required, I prefer to make them in two lengths securely screwed or
joined together in the middle, and I support them by means of a cross piece
underneath extending to each side of the boiler, other cross pieces being also used
at each end.
At the ends of the bars furthest away from the furnace door where the part
extends upwards above the fire at right angles I make arrangements for admitting
a second current of air in such a manner that it strikes and mingles with the hot
air passing through the bars. To enable me better to do this underneath this
end of the bars I build or otherwise construct a seperate space haveing openings
left therein through which a second current of air passes, and by this means the
amount required can be regulated, this arrangements of two currents meeting here
being found in practice of the greatest advantage.
To prevent the hollow ends of these bars being liable to get choked with pieces
of fuel entering them I place a small triangular piece of metal just within the end
of each opening, so that although the air may pass freely, only such small particles
of fuel can enter as would readily fall down through the bars into the space before
mentioned underneath, in which 1 place, low down, a small door to admit of their
being removed occasionaly. In some instances, notably in marine boilers, I find
it advantageous to construct the second firebrick bridge in the form of an arch
across or at about the same height as the crown of the furnace; by this means the
heat is distributed more uniformaly throughout the whole of the return tubes or
flues.
In steam boats and other boilers that require steam to be generated rapidly
occasionaly I make use of a fan placed so as to drive the air more rapidly through
the bars and furnace (thereby creating a most intense heat and flame). I also
make use of these means for various purposes, combined with the improved bars,
such as smelting and otherwise working various metals, such as iron, copper, and
alloys, also chemicals. I also use the exhaust steam, discharging it underneath
the furnace, so that the air circulating through and between the bars carries it
with it into the furnace. Where great heat is required I prefer (besides driving or
causing the air to pass more rapidly through the bars and furnace) to place a
chemical compound rich in inflamable gasses under the grate or furnace so that the
heat causes these gasses to rise and mingle with the air passing through the bars,
or the compound may be a mixture of parifine and sand, or any sutable poreous
material. I also, by means of contracting the opening at the back of the fire or
furnace, and also adding an expansion chamber, may cause the flame to impinge
upon any given point or substance. The ends of these bars may be cast seperately
from the bars themselves, and afterwards screwed or otherwise joined to them;
and also to protect them from the heat of the fire and from ingury they may have
a second or double opening at the exposed side nearest the flame, through which
air may be allowed to pass into the furnace.
The combustion of fuel and also the amount of air admitted may be 80
arranged as to be regulated with a damper or other means placed in the flues.

page_text: In smaller fires I in some instances prefer to make the bars of ordinary iron tubes,
and without the flange underneath, I also arrange them so that the air may be
admitted to them through the centre instead of at the ends. These bars are also
ranged side by side instead of alternately, or they may be carried back from the
front of the fire and combined with an opening so arranged that the unconsumed
gasses are made to pass over the ends of the upmost portion of them; the flame is
also in this instance made to travil back and impinge or otherwise act upon a
suitable iron plate or other medium so as to throw off and radiate the heat as
required. In some instances where articles are required to be acted upon, but to
prevent and protect them from ingury from the intense heat of these fires, I prefer
to place the object within, and enclosed within one (or it may be two or more)
metal chambers, so that although the flame may be in contact with the sides of the
outer the article is protected from ingury by the receptacle in which it is
contained.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Richard Paulson in the Great Seal Patent Office on the 22nd
June 1881.
RICHARD PAULSON, of 36, Streatfield Street, Burdett Road, London, in the
County of Middlesex. "IMPROVEMENTS IN APPARATUS FOR UTILISING THE
UNCONSUMED GASES GIVEN OFF DURING COMBUSTION, PREVENTION OF SMOKE,
AND THE ECONOMISING OF FUEL, FOR STEAM-BOILER FURNACES AND OTHER
FURNACES AND PURPOSES."
In carrying out my said Invention I make the bars for the furnaces preferably
of cast metal or alloy, having a deep web or flange extending along the exposed
or under side, which by rapidly radiating the heat imparted to them by the
fire prevents the bars from being burnt or injured. They have also one or
more perforations extending from end to end through them, or they may be
cast in two or more pieces, each having a deep groove so as to admit of a tube
of metal being placed within the groove, so that when placed together and
riveted or combined they make a perfect but hollow bar and retain the tube in
the interior. These bars do not merely extend from the front of the furnace to the
back, but are prolonged and carried upwards at right angles so as to rest against
the bridge or butt usually placed at the back of the furnaces. In locomotive,
portable boilers, and small fires (domestic) I prefer to arrange the bars alternately
across from side to side instead of from the front to the back, and for the latter I
make the bars of ordinary iron tubes in two parts, each piece being joined in the
middle in such a manner as to admit the air, their ends then bent upwards and
ranged along both sides of the fireplace so that the air passing through them is
admitted above the level of the fire as required. By these means a continuous
supply of air is heated in passing through these hot hollow bars or tubes, which on
entering into the furnace or fire at a suitable point is brought in contact and
combines with the unconsumed gases and hydrocarbons given off during combustion,
thereby causing them to ignite and be consumed. At the same time a much
greater heat is generated from a given quantity of fuel, and by this arrangement
equal effect may be obtained by slow combustion as formerly required a quick
draught and a rapid consumption of fuel. In order to enable me to more effectually
accomplish this object, and also to regulate the combustion and admission of air as
may be required, combined with the hollow bars as previously mentioned, I arrange
and add one or more solid or perforated bridges of firebrick or metal in such a
manner as to check, baffle, and mingle the unconsumed gases with the heated air
admitted to the furnace or fire through the hollow bars. In Galloway, Cornish,
and other boilers of this description where a considerable length of bar is required,
I prefer to make the bars in two or more parts or lengths securely screwed or
joined together, and supported underneath by a cross-piece extending to each side
of the boiler, other cross-pieces being also used at each end; and at the ends
furthest away from the furnace door, where they extend upwards above the furnace
or fire at right angles, I make arrangements for admitting a second current of air
in such a manner that it strikes and mingles with the hot air passing through the
hollow bars. In order to enable me to do this effectively, underneath this end of
the bars I build or otherwise construct a suitable space or chamber, the wall of
which having openings left therein through which the second currents of air first
pass, and by this means the amount required can be regulated, this arrangement of
two currents meeting here being found in practice of the greatest advantage. In
order to prevent the hollow ends of these bars being liable to get choked with
pieces of fuel entering them I usually place small pieces of triangular metal just

page_text: In
within the ends of each opening, so that although the air may pass freely, only
such small particles of fuel can enter as will readily fall down through the bars into
the space underneath before mentioned, and in which I place low down a small
door to admit of their being removed occasionally. In some instances (notably in
marine boilers) I find it advantageous to construct the second fire-brick or metal
bridge in the form of an arch, across or at about the same height as the crown of
the furnace; by this means the heat is distributed more uniformly throughout the
whole of the return tubes or flues. In steam-boat and other boilers that occasionally
require steam to be generated rapidly I make use of a fan or other means placed
so as to drive the air more rapidly through the bars and furnace, thereby creating
a most intense heat and flame. I also make use of these means for various purposes
combined with the improved bars, such as smelting and otherwise working various
For this purpose I may
metals, such as iron, copper, and alloys, or chemicals.
make use of the exhaust steam, or discharge it underneath the furnace, so that the
air circulating through and between the bars carries it with it into the furnace. In
adapting this principle to open fires, as used in dwelling-houses and for domestic
purposes, I use hollow tubes or bars combined with an opening or flues arranged at
the back or sides of the fire in such a manner that all unconsumed gases are made
to mingle and combine therein with the air made hot in passing through the
bars, thereby causing perfect combustion, and utilizing the aforesaid gases.
order to prevent them rising directly up the chimney in open grates as formerly
I prefer to place a crown or arch of metal above or in front of the fire or fitted
to the sides, so that it can be opened and closed or drawn down, so that only the
front and lower part of the fire can be left open and exposed. The greater heat
and flame thus created, after passing through the said openings as desired, may be
made to travel back or round the upper portion, so that its effects may not be lost
but the heat radiated into the room or as required. Should it be desirable that the
flame should also be seen I make the front of the stove or sides of prepared glass,
toughened," talc, or other suitably transparent material. In some cases I make
the front bars of the grate or stove hollow, and they may be arranged so as to allow
the outer air to be more freely admitted into the fire. In cooking ranges or stoves
to prevent the food being burnt or injured by the great heat obtained by this
process and Invention, at the same time to utilize it better, I make use of a deep
dish of metal, earthenware, or other suitable material, fitted with a grating in which
to lay the food to be cooked. Over this is then placed a closely-fitted cover, so
that the steam and vapours do not readily escape, but becoming superheated and
penetrating the food it may be cooked very rapidly without being burnt or losing
its favor. Further, this improved apparatus may be made applicable to any existing
fires or furnaces as may be required. Where great heat is required I can make
the fire to burn much more fiercely by forcing the air to travel more rapidly through
the fire and perforation in the bars, and also by means of contracting the outlet or
opening at the back of the furnace, adding an expansion chamber when required;
the flame may thus be made to travel a long distance, to impinge upon any given
The ends of
point or substance, and thus utilized to work or smelt metals or ores.
these bars may be cast separately from the bar itself, and afterwards screwed or
fitted to them as may be desired. They may also have a second casing placed over
their exposed ends to protect them from being burnt, and a space left through
which air may be admitted into the furnace, or they may be carried through the
fire-brick bridge and be curved upwards at the back between it and the second
bridge. The combustion may be regulated by means of a damper placed in the
flues or chimney. In some instances I make use of or place a chemical compound,
rich in inflammable gases, under the grate or furnace, so that the heat causes these
gases to rise and mingle with the air passing through the bars and furnace.
"
It should be understood that the Invention is applicable to all classes of furnaces
or stoves, et cetera, where bituminous coal or other smoke-producing fuel is used,
its object being to prevent the escape of such smoke and gases into the surrounding
atmosphere, and not only this but also to utilize and consume them, thus greatly

page_text: economising and reducing the quantity of fuel required to obtain certain results.
There are, it is well known, numerous chemical, mechanical, and electric phenomena
associated with the evolution of heat; but the readiest means of effecting the object
before-mentioned is to be found in the rapid combination of the oxygen contained
in the atmosphere with some combustible body. Many and varied attempts have
heretofore been made to accomplish the results aimed at in this Invention by
various devices, such as introducing fresh air at the doors over the fuel or into the
back of the furnace by means of a hollow bridge, et cetera. Jets of steam have also
been used to assist in decomposing the gases given off by the burning fuel, which
to a certain extent ameliorates the nuisance; but as far as my extensive practical
experience and knowledge extends former arrangements have failed to give complete
satisfaction and abate the smoke without at the same time causing injury to either
the boiler from rapid and unequal expansion or to other parts acted upon by
the heat, whilst according to my Invention the objects before mentioned are
accomplished without the liability of injury to the parts acted upon by the
heat.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed two Sheets of Drawings, the same letters of
reference indicating corresponding parts in all the Figures.
Figs. 1, 2, and 3, Sheet 1, represent respectively a vertical longitudinal section, a
horizontal section, and a transverse vertical section of an ordinary Cornish boiler
having my said Invention applied thereto; and Fig. 4, Sheet 1, & Figs. 5 & 6,
Sheet 2, represent respectively similar views of an ordinary marine boiler with my
Invention applied thereto. A, A, shews the position of the hollow bars; A 1, the
deep flange or hollow web underneath; b, b, are the ends of the same, made so as
to project above the normal level of the fire in front of the fire brick bridge C that
is usually placed in such boilers; C1, C2, & C 3, are other bridges showing one of the
forms and constructions placed there and used by me in carrying out the Invention;
D is a space formed by means of fire-bricks or metal sheets D 1 arranged at a short
distance from the bridge C, at the rear end of the ash pit D, and partly used to
support the ends of the bars a, a; E 1, E 1, are openings left in D 1 for the admission
of the second currents of air; E 2 is a small door used for the purpose of facilitating
the removal occasionally of any ashes or fuel that may fall through the openings in
the bars above. In operation the action is as follows:-The outer atmospheric air
enters the furnace in the direction shown by the arrows. Part of it passes through
the openings made for that purpose in the hollow bars a, a; another part between
them into direct contact with the burning fuel, and the remainder passes underneath
through the ashpit E, and thence through the openings E1, E1, to meet and mingle
with the first current of air after it has passed through the hollow bars a, a, and
thence through the openings in b, b, so as to be delivered into the furnace above
the fire by each separate bar in a divided state, as desired, meeting and mingling
with the escaping gases, and chemically combining with them, and thus on to the
bridge C1, through or over which it passes. This bridge I prefer to make as an
arched diaphragm, its purpose and object being to baffle and contract the smoke,
and cause the unconsumed gases to pass downwards as they make their way along
the flue, after which they are allowed to expand in the chamber G. I occasionally
place a third bridge C 2 & C3 behind the second C1, so that should any of these
gases by any chance escape combustion in the first expansion chamber G by
repeating the process and the number of the bridges they are again intercepted,
baffled, and combined, so that perfect combustion is the result, the gases
retaining by the time that they reach the chimney little heat, and nothing but the
incombustible gases passing into it, since nearly all the heat has been imparted to
the surfaces of the boiler exposed to its action. By these means the utmost
maximum is obtained from a minimum of fuel consumed, fully equal results being
obtained from slow combustion as would otherwise require a quick draught and
rapid combustion of fuel; at the same time, much less injury to the boiler and

page_text: other parts takes place (if any injury, except that due to ordinary wear), the
temperature being almost uniform. And in order that this object may be further
carried out I propose using a damper or dampers, which, placed in the flues, may
be used to regulate the draught; or the said damper or dampers may be so arranged
as during the operation of stoking to be worked by a lever, and by the action of
opening the furnace door, or other suitable means to be worked automatically, thus
preventing the rush of cold air into the flues and furnace while cleaning the fires
or adding fuel to them.
I sometimes make the bridge C1 for marine and other boilers of hollow metal,
which may be perforated, and also communicate by means of tubes with the outer
atmosphere, and thereby be kept cool. The principle and action from the shape of
these bridges is somewhat on the system of an injector on an enlarged scale, the
gases being contracted and expanded alternately. Where steam is required to be
generated quickly or at short notice I make use of any suitable means, such as a
fan injector or blast of steam, to force a stronger current of air and create a
quicker draught, this arrangement being made to act only temporarily or con-
tinuously, as required. Figs. 7 & 8, Sheet 2, illustrate in vertical and horizontal
section respectively a mode of applying the Invention to an ordinary locomotive or
portable boiler, referring to which it will be seen that the hollow bars are in this
instance placed alternately from side to side across the fire box, so that the ends b, b,
thus project on each side of the furnace above the fire, a small space or gap b', the
width of a bar, being left between each two consecutive bars, and serving the
double object of allowing the heat to still act upon the sides of the fire box, but not
so intensely and injuriously as before. For locomotives I prefer to make the
bars a, a, with two perforations extending through them, to prevent an undue
current of air passing through when the engine is running at a great speed. For
the same reason, and to prevent the flame acting injuriously upon the tubes, and
also to effectively mingle the air admitted with the products of combustion, I make
use of an arch of fire-brick (or hollow metal) H, as in the marine boilers. The
larger openings in the projecting ends of these bars b, b, I prefer to place at the sides
or front instead of at the top, so that there is less risk of particles of fuel entering
and lodging therein. I also propose making enclosed spaces D, such as shewn in
Fig. 1, under each end of the bars if required.
Figs. 10 & 11, Sheet 2, show the Invention applied to an upright or vertical
boiler, Fig. 10 being the transverse vertical section, and Fig. 11 the horizontal
section on the line R, R. The hollow bars I prefer to place and arrange as in the
locomotive type of boiler, that is to say, from side to side, although I may make
them to radiate all round the sides of the boiler or firebox. J shows the shape and
position of the hollow metal bridges or cones, as I prefer to make it, one or more
of which may be used. This cone or bridge may also be made use of not only to
check and baffle the gases but also to regulate the draught of the furnace.
I may also apply this Invention to the furnaces of muffles or annealing pots for
glass or metal, in doing which I prefer to make the ends of the bars that project
above the fire very narrow, so that there shall be a space left between each of
them; or I arrange them so that a portion of them are carried from the front to
the back and part from the back to the front, that is to say, about one third of
them placed one way and two thirds the other; or I make the bars to be placed
alternately across from side to side.
The firebrick or metal bridges may in any case not only be made to contract the
gases passing, but be so arranged as to split and divide them at the same time if
required, but not so as to cause injury to the boiler or other surfaces by allowing
the heat to be brought in contact too freely with the plates, tubes, or flues. Also I
arrange the said hollow bars in such a manner that a rocking motion may be
imparted to them if required by any of the usual and well-known arrangements of
levers or other suitable means. In some cases I also provide a hopper to contain
the fuel, so that the furnace may be readily supplied without at the same time so
frequently opening the furnace doors. In order that the shape and construction of

page_text: the furnace bars may be more perfectly understood I have shewn in Fig. 12 & 13
a side and end sectional elevation respectively of one of the bars detached. I have
also shewn a modification of the bar in Fig. 14, from which Figures it will be seen
that I sometimes make the bar in two sections, or solid, with a hollow web only and
a perforation above. I occasionally place a plate of metal or casting, or it may be
fire-brick, extending to each side of the furnace, so that the ends of the bars are
protected, as it were, in a double hollow bridge; also admit a current or currents of
air through suitably arranged openings therein, and allow it to enter the fire in the
same manner as previously described. I propose utilizing the great and intense
heat that I can obtain by the use of this apparatus, and by forcing a current of air,
previously heated or otherwise, by using a fan, injector, or other means, to smelt,
work, and anneal metals, ores, or alloys, or to convert ordinary pig iron into steel.
In doing the latter I find it advantageous to cause powdered or pulverized
anhydrate of lime to be carried with the blast into the furnace in such a manner
that it shall unite with the phosphorus contained in the iron, forming phosphuret
and siluret of lime, which can easily be removed with the slag. This blast of air
may be single or divided so as to aid in supplying pulverized or liquid fuel to the
furnace. The Invention is also specially adapted for chemical works and to
consume the noxious vapours, also gas retorts, bakeries, et cetera, or for the purposes
of cremation.
Fig. 17, Sheet 2, shows a modification of the Invention adapted to cooking
ranges or stoves. It will be seen that I here dispense preferably with the flange or
web a¹ and make the bars of ordinary iron tubing, although I do not restrict
myself to its use, as it is evident that the bars might be made hollow in various
ways, or by bending or otherwise. I join these bars in the middle in this instance,
leaving an opening so as to admit a current of air through them; the outer ends
are then bent upwards, so that they can be ranged along each side of the furnace
or fire. I may also make a plate or fire-brick protection as in the furnaces,
extending along each side of the fire, which fire may be so constructed that it may
be enlarged or contracted at pleasure by moving a suitably arranged loose-back.
The hot air after passing through the hollow bars is made to mingle with the gases
as they enter the flues either at the back or sides, and that they may be thoroughly
and effectively consumed I place a series of bridges C, 1, 2, 3, 4, of metal or fire-
brick, not only so as to check and baffle them but also cause them to be contracted
and expanded alternately, as hereinbefore described as applied to furnaces. By this
means the flame created can be made to travel a considerable distance, imparting
great heat to the surfaces that it is brought in contact with. But in order that
the food may not be burnt, and at the same time to utilize this heat to the best
advantage, I make use of a hollow dish of metal or earthenware M, having a
grating on which to place the food to prevent its touching the bottom of the dish.
Over all I place a closely fitting cover M¹, so that the steam and vapours given
off do not readily escape, but becoming superheated materially assist in cooking
the food thoroughly and rapidly in less than half the time usually required and
that without burning it. Fig. 18, Sheet 2, shows the application of the Invention
to ordinary grates or stoves for domestic purposes. It will be seen that I here
make the whole of the bars hollow, not only those that support the fuel but also
those in front; and instead of allowing the smoke and unconsumed gases to ascend
directly up the chimney I make the whole or the greater part of them to be
diverted, so as to pass through an opening K left for that purpose at the back of
the fire, over which I usually place a metal or other grating 1, passing which they
enter a flue L, in which I place a number of bridges C, 1, 2, 3, as in the cooking
stoves (Fig. 17) to act in the same manner and for the same purpose. I do not
always force the whole of the gases in this direction, but sometimes make a second
opening at the top in which I place a small damper by means of which the fire can
be regulated. Furthermore, I make a slide or screen of metal P, or it may be talc
or any other suitable transparent material framed or placed therein, such as
toughened glass. This slide is made so that it can be drawn down and expose

page_text: only the lower bars of the fire; a much quicker draught can thereby be induced, so
that the fire is started when first lit or fresh fuel added much more readily, at the
same time the flame can be seen through the transparent screen. Fig. 19, Sheet 2,
shows another modification, the stove being round or square and the bars so placed
that they radiate from and are divided by a hollow bridge perforated and
supported underneath, so that it can rotate. Fresh fuel being added to the front
part it can be then turned round to the back, thus the other part is brought to the
front. By this means, and also by placing cone-shaped bridges C, 1, 2, 3, in the
flue L above the fire the gases are much more readily consumed. The flame thus
created may then be made to descend downwards through the outer chambers L³,
causing the heat to be radiated into the room or apartment. It may then be
conducted by a suitable flue under the floor of the room, so that the stove may thus
be placed in the centre of the apartment.
It is at once obvious that I can apply a very slight modification of the principles
previously shewn to furnaces for domestic use for stoves for drying purposes or
greenhouses, one of the chief features of the Invention being the facility with
which it may be successfully fixed and applied to almost any or every description
of existing furnaces or fires as now in use, and its suitability for all description
of fuel.
Having now described the and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that I do not claim seperately any one of the
parts hereinbefore described and shewn in the accompanying Drawings, but what
1 consider to be novel and original, and therefore claim as the Invention secured
to me by the hereinbefore in part recited Letters Patent is, -
The combination of the peculiar fire bars and fire bridges or their equivalents,
herein described, so as to act as such in conjunction or not with auxiliary air spaces
or chambers communicating with the passages from the fire bars, the several parts
being constructed, arranged, and combined together so as to operate substantially
in the manner and for the purposes hereinbefore described and as illustrated in
the accompanying Drawings.
In witness whereof, I, the said Richard Paulson, have hereunto set my hand
and seal, this Twenty second day of June, in the year of our Lord One
thousand eight hundred and eighty one.
RICHARD PAULSON. (L.S.)