IMPROVEMENTS IN GLASS CHIMNEYS FOR GAS BURNERS OR LAMPS
Year: 1854

page_text: Sealed the 27th March 1855, and dated the 30th September 1854.
PROVISIONAL SPECIFICATION left by the said Gémis Filhon at the
Office of the Commissioners of Patents, with his Petition, on the
30th September 1854.
I, GÉMIS FILHON, of Paris, Gentleman, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN GLASS CHIMNEYS FOR GAS BURNERS OR
LAMPS to be as follows:-
These improvements in glass chimneys for gas burners or lamps consist in
giving them the form either of a cylinder or of an inverted truncated cone,
and presenting one or more contracted parts near their upper end, forming a
sort of open cap at the upper part of the chimney, the periphery of which
contracted part or parts may be closed, or have one or more apertures.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Gémis Filhon in the Great Seal Patent Office on the
30th March 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GÉMIS
FILHON, of Paris, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of September, in the year of our Lord
One thousand eight hundred and fifty-four, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto him,
the said Gémis Filhon, Her special licence that he, the said Gémis Filhon, his
executors, administrators, and assigns, or such others as he, the said Gémis
Filhon, his 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 "IMPROVEMENTS IN GLASS CHIMNEYS
FOR GAS BURNERS OR LAMPS," upon the condition (amongst others) that he, the
said Gémis Filhon, by an instrument in writing under his 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 he, the said Gémis Filhon, do hereby declare the
nature of his said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement—
These improvements relate to glass chimneys for circular gas burners, or
lamps with round wicks, but which are more particularly suitable for circular
gas burners. They consist in a particular form of glass chimney, by which a
more perfect combustion, and consequently an economy in the consumption, is
obtained. The form of my improved glass chimneys may be readily under-
stood by referring to the annexed Drawing, in which Fig. 1 shows an elevation
view of one form of chimney; Fig. 1*, the same fitted to a gas burner;
whereas Fig. 2 shows another form. In the three Figures the same letters refer
to corresponding parts. The same consists of an inverted truncated cone A, B,
at the upper part B of which commences a contraction C, which afterwards
expands into a bell-mouthed part D. In Fig. 2 a second contraction E is
situated at some height above the first C, whereby a sort of reservoir C, D, E,

page_text: is obtained; whereas the part F is again in the form of a bell-mouth, but in
this form the glass might be cut flush at E. The principle of my Invention
consists in having the contraction C corresponding with the upper end of the
flame, or a little above this end, forming the contraction gradually and imme-
diately afterwards, making the chimney again expand gradually in such a way
that the contracted part C (or C and E of Fig. 2) forms only a circular line
round the chimney, and not, as. has already been done, a cylindrical con-
tracted part of a certain height. Glass chimneys offering a contraction
similar to mine have already been employed, but the contraction in those
chimneys was situated near the under part of the flame, whereas mine is
at the upper end of the flame, or a little above this end, by which quite a
different result in respect to economy of gas is obtained. If required, small
perforations may be made in my chimneys in order to increase the supply
of air into the same,, though I rather prefer not having these perforations,
as the glasses are then more liable to break.
Having now described the nature of my Invention, and the manner in
which the same is carried into practical effect, I declare that what I claim as
my Invention consists in the above described forms of glass chimneys for
circular lights, either gas burners or lamps.
In witness whereof, I, the said Gémis Filhon, have hereunto set my
hand and seal, this Twenty-ninth day of March, in the year of our
Lord One thousand eight hundred and fifty-five.
GEMIS FILHON. (L.S.)