AN IMPROVED METHOD OF SUPPLYING AIR TO GAS AND OTHER LIGHTS
Year: 1856

page_text: LETTERS PATENT to Richard Archibald Brooman, of 166, Fleet Street,
in the City of London, Patent Agent, for the Invention of "AN IMPROVED
METHOD OF SUPPLYING AIR TO GAS AND OTHER LIGHTS."-A communication.
Sealed the 9th December 1856, and dated the 19th July 1856.
PROVISIONAL SPECIFICATION left by the said Richard Archibald
Brooman at the Office of the Commissioners of Patents, with his
Petition, on the 19th July 1856.
I, RICHARD ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of
London, Patent Agent, do hereby declare the nature of the said Invention for
"AN IMPROVED METHOD OF SUPPLYING AIR TO GAS AND OTHER LIGHTS," (com-
municated to me by a foreigner residing abroad,) to be as follows:-
This Invention consists in so arranging gas and other burners that only just
sufficient quantity of air to support combustion may be supplied to the flame,
and that in a heated state, whereby a better light is obtained, and flickering
and cross currents are avoided. This is effected by preventing the direct
entrance of the outer air to the flame from beneath, and by supplying through
orifices at the upper part or top of the shade or globe of the light the air
necessary to support combustion.
One mode of carrying the Invention into effect is as follows:-I attach
just below the burner a cup or shield, made of glass or other suitable
material, which fits at bottom tightly round the gas pipe or bracket, so as

page_text: to exclude the air from below, and forms at top a socket or support on which
the globe rests. On the top of the globe or shade is fitted a disc or cap, made
of wire gauze or perforated metal, or other material formed with orifices;
this disc has a central orifice, through which the chimney of the lamp passes.
Atmospheric air, to supply the burner and render combustion as perfect as
may be, enters through the orifices in the cap or upper part of the globe,
becomes divided into thin streams, and heated in its passage to the burner.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Archibald Brooman in the Great Seal Patent Office
on the 15th January 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of London, Patent
Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of July, 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 Richard
Archibald Brooman, Her special licence that I, the said Richard Archibald
Brooman, my executors, administrators, and assigns, or such others as I, the
said Richard Archibald Brooman, 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
IMPROVED METHOD OF SUPPLYING AIR TO GAS AND OTHER LIGHTS," (communicated
to me by a foreigner residing abroad,") upon the condition (amongst others)
that I, the said Richard Archibald Brooman, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said Iuven-
tion, 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 Richard Archibald Brooman, 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

page_text: statement thereof, reference being had to the Drawings hereunto annexed,
that is to say-
This Invention consists in so arranging gas and other burners that only just
sufficient quantity of air to support combustion may be supplied to the flame,
and that in a heated state, whereby a better light is obtained, and flickering
and cross currents are avoided. These results are obtained by preventing the
direct entrance of the outer air to the flame from beneath, and by supplying
through the upper part or top of the shade or globe of the light the air neces-
sary to support combustion.
The Invention may be carried into effect as follows:-Just below the burner
is attached a cup or shield, made of glass or other suitable material, which
fits at bottom tightly round the gas pipe or bracket, so as to exclude the
air from below, and forms at top a socket seat or support on which the globe
rests. On the top of the globe or shade is fitted a disc or cap, made of wire
gauze or perforated metal, or other suitable material formed with orifices;
this disc has a central orifice, through which the chimney of the lamp passes.
Atmospheric air, to supply the burner and render combustion as perfect as
may be, enters through the orifices in the cap or upper part of the globe,
becomes divided into thin streams, and heated in its passage to the burner.
The Drawing annexed illustrates this arrangement. Figure 1 is a sectional
view of a gas lamp. A is the burner; B, cup or shield, shewn detached in
elevation Figure 2, and horizontal section Figure 3. This cup B is fitted
round the gas pipe, and closed at bottom by a collar D (shewn detached in
Figure 4,) which entirely excludes the air from below. At top the cup B forms
a seat for the globe E to rest on. G is a metallic cap, perforated with a
number of holes a, a. This cap is fitted on the top of the globe, and has a
central orifice, through which the chimney H passes. Figure 5 is a plan, and
Figure 6 a section, of the cap G detached. The cup B may be made either
transparent or opaque. The cap fits as closely as may be round the chimney,
so that hardly any air may pass between, and all the air drawn in to supply
the burner therefore passes through the orifices a, a, in the cap, which is kept
in a heated state by radiated heat.
In cases in which a draught is produced by the rarefaction of hot air in a
chimney, the cold air inlet in front of the flame may be of small dimensions ;
but in the present plan it is necessary to have a small inlet, for when air before
reaching a flame is heated in a space communicating through a wide opening
with the outer air, the results are contrary currents, and flickering, and the
degree and regularity of the temperature are lessened; the heated air is allowed
to escape, and shades often get broken from contact with down draughts; but

page_text: when the perforated cap is employed, access is given to the necessary air, only
it obstructs the entrance of the air drawn in by the chimney, the pressure
within the globe being greater than that without, whereby the escape of hot air
is prevented; but on account of this decrease of pressure the bottom of the
globe must be carefully made air-tight; the flame is thus sheltered from
contrary currents and sudden motions of the air, and burns very steadily.
Air is especially heated when in contact with solid bodies, and if a current
of air passes through an orifice in a surface kept at a regular temperature, the
smaller the opening through which it passes the higher the temperature which
the air attains. Now, the plate to which I have referred being placed within
the radiating influence of the flame, its temperature is considerably raised, and
the air passing through the numerous holes with which it is perforated is
quickly and highly heated; and from this reason, as also from the absence of
contrary currents, the air reaches the burner in a heated state. The cap
fitting closely round the chimney would also prevent it from falling to one
side. The cap may be tinned or silvered on the under surface and serve as a
reflector.
And having now described the nature of the said Invention, and in what
manner the same is to be performed, I declare that I do not confine myself
to the particular mode shewn for carrying the Invention into effect; but that I
claim,―
First, the arranging of gas burners in such manner that only just sufficient
air to support combustion (and that in a heated state) may be supplied to the
flame.
And, second, the particular means for carrying the Invention into effect,
herein-before described with reference to the Drawings annexed, that is to
say, the preventing the direct entrance of outer air to the flame from beneath
by resting the bottom of the shade in a cup made air-tight round the supply
pipe or bracket, and admitting the air necessary to support combustion
through orifices in the upper part or top of the shade or globe, all as before
described.
In witness whereof, I, the said Richard Archibald Brooman, have here-
unto set my hand and seal, this Twenty-ninth day of December, One
thousand eight hundred and fifty-six.
R. A. BROOMAN. (L.s.)