IMPROVEMENTS IN THE PRODUCTION OF LIGHT
Year: 1843

page_text: TO ALL TO
THESE PRESENT SHALL COME, 1, TERKE
PELLETAN, of Fitzroy Square, in the County of Middlesex, Esquire, but at
present residing at the Hotel Royale, Brussels, in the Kingdom of Belgium,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of the United Kingdom of Great Britain and
Ireland, bearing date at Westminster, the Sixth day of September, in the
seventh year of Her reign, did, for Ierself, Her heirs and successors, give
and grant unto me, the said Pierre Pelletan, Her especial licence that I,
the said Pierre Pelletan, my executors, administrators, and assigns, or such
others as I, the said Pierre Pelletan, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and at all
times during the term of years therein expressed, should and lawfully might
make, use, exercise, and vend, within England, Wales, and the Town of
Berwick-upon-Tweed, my Invention of "IMPROVEMENTS IN THE PRODUCTION OF
LIGHT;" in which said Letters Patent there is contained a proviso, obliging
me, the said Pierre Pelletan, by an instrument in writing under my hand
and seal, particularly to describe and ascertain the nature of my said Invention,
and in what manner the same is to be performed, and to cause the same
to be enrolled in Her Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said recited Letters Patent,
as in and by the same, reference being thereunto had, will more fully and at
large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Pierre Pelletan, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are fully described and
ascertained in and by the following statement thereof, reference being had to
the Drawings hereunto annexed, and to the figures and letters marked thereon,
that is to say-
Whereas in the Specification or instrument in writing under my hand and
seal, dated the First day of May last, and duly enrolled in Her Majesty's High
Court of Chancery on the Second day of May, pursuant to the proviso con-
tained in certain Letters Patent dated the Second day of November, in the
sixth year of Her reign, and which said Letters Patent were granted to me by
Her said Majesty for the using, exercising, and vending a certain other Inven-
tion of improvements in the production of light, within England and Wales,
and the Town of Berwick-upon-Tweed, I explained sufficiently the method I
adopt to produce and distribute light from volatile combustible matter,
employed either separately or mixed with water, or other volatile substance or
matter. Now, my said Invention, for which the said first-recited Letters
Patent of the Sixth day of September last were given and granted, applies to
the manner of employing the liquid used, the nature of the liquids, and the
method of burning the vapour produced therefrom. The liquid I employ is
spirit of turpentine, but any other combustible liquid less volatile than water
will answer the purpose. I mix together in the generator water and spirit of
turpentine; the proportion may be ten of water to one of turpentine, and it
may vary from that to four parts of water to one of turpentine, without thereby
materially affecting the nature of the flame; the above proportion applies to
measure and not to weight. The temperature at which spirit of turpentine
boils is at least 272°, whereas water boils at 212°, and under atmospheric
pressure the temperature in the generator in which they are both mixed will
not exceed 212°; at this temperature steam is generated from the water, and
in passing off carries with it a certain portion of the spirit of turpentine
through which it is forced to pass, so that the vapour that escapes from the
burner is a mixture of water and spirit of turpentine of about equal weight;
but as the spirit of turpentine is converted into steam, the proportionate
measure of each is very different, for vapour of water only weighs ten-
sixteenths of the weight of atmospheric air, whereas the vapour of turpen-
tine weighs about four and a half times the weight of atmospheric air
consequently, for equal weights of water and turpentine, the relative volume
of the vapour of water consumed will be that of the vapour of turpentine as
seven and a half to one, the specific gravity of vapour of water being 0.625,
;

page_text: and that of the vapour of spirit of turpentine about 47, or as 1.7. The
difficulty of burning the vapour of turpentine without producing smoke arises
from the great density of this vapour, and from its containing too much carbon.
By mixing the vapour of water with that of turpentine the mean density is
diminished, as is also the quantity of carbon relative to the total quantity of
the mixture; and although it might be supposed that the pressure of the
water would be detrimental to combustion, such is not the case; the water in
the form of vapour serves as an incombustible gas, and its temperature of 212°
renders the combustion of the inflammable vapour more perfect. The above
mixture burns with a bright white flame, without producing smoke, in a
common burner having a great number of very small holes, but the flame is
short, and when you attempt to increase its length by opening the cock, smoke
is immediately produced, thereby proving that the mixture of the two vapours
above described is still rather too rich in carbon. To remove this objection,
I employ a burner of a peculiar construction, which I will describe. The
pipe 1 conveys the steam which escapes by the orifice 2, the quantity being
regulated by the size of the orifice 2, as well as by the hydrostatic cock
already described. A is a hollow tube that screws on to the pipe 1; this tube
A is enlarged at its upper end to receive the piece B, which is closed at the
bottom by a plate S, having openings round the outer rim, as shewn in
Figure 2, for the passage of the steam; this piece B is open at the top,
and is surrounded by teeth b, b, the extremities of which fit into the cylin-
drical head of the tube A, the spaces between the teeth being intended for
the passage of the steam towards the orifice of the burner; these teeth b, b,
are seen in Figure 2. Inside the piece B there is another piece C, the
upper end of which forms, with the upper edge of the tube A, the annular
space through which the steam escapes to produce the light; the bottom of
this piece is perforated by a hole, the size of which is regulated to admit a
sufficient quantity of atmospheric air through the centre of the flame.
above pieces A and B being put together, four holes are made a, a, to admit
air, and four pieces of pipe d are fitted therein, to prevent any escape of steam
from the annular space between A and B. The lower end of the tube A is
also enlarged, and is perforated by four holes 3, 3, surrounded by a ring 4, 4,
in which are four corresponding holes, serving as a register valve to regulate
the admission of common air into the tube A to mix with the steam coming
from the generator previous to its escape from the annular orifice of the burner.
This burner acts in the following manner:-Steam is discharged from the
orifice 2, the whole of the burner gets heated thereby, and the steam rises
towards the orifice of the burner mixed with a certain proportion of common
The

page_text: air that has been admitted through the holes 3, 3, and this mixture escapes
without pressure through the annular orifice of the burner, the quantity of
common air admitted being regulated by means of the ring above described,
and in this manner a flame may be obtained as white and as voluminous as
may be required. When too much air is admitted, the flame gives very little
light, but by gradually diminishing its quantity, the light may be made very
intense; the regulating ring 4, 4, admits more or less, according as it is allowed
to interrupt to a greater or lesser extent the passage of the air through the
holes 3, 3. This flame requiring a very weak current of air through the
chimney, it is advisable to cover the bottom of the gallery with a fine gauze
wire, in order to obtain a steady flame. I do not confine myself to the con-
struction of the burner, as above described; any other form or mode of
construction that will fulfil the above condition may be adopted, but I must
positively claim as my Invention, firstly, the means of burning the steam of
spirit of turpentine (or any other combustible matter less volatile than water),
mixed with the vapour of water in such proportion as is naturally determined
by the ebullition of the liquid; and, secondly, the idea of mixing common air
with the steam in any suitable space previous to its being ignited, and the
mode of regulating it with the proportion of the mixture.
In witness whereof, I, the said Pierre Pellets have hereunto set my
hand and seal, the Third day of February, in the year of our Lord
One thousand eight hundred and forty-four

page_text: Secretary of State for Foreign Affairs, maketh oath and saith, that he knows
and is well acquainted with the handwriting of Godschall Johnson, Esquire,
Her Majesty's Consul at Antwerp, in the Kingdom of Belgium, and that the
names or signatures "Godschall Johnson" respectively set and subscribed to
the Specification of Pierre Pelletan, Esquire, and Drawing thereto hereunto
annexed, are respectively the proper handwriting of the said Godschall Johnson,
as this deponent verily believes, and that the seals of office of the said Goodschall
Johnson affixed thereto are the respective proper seals of the British Consul
at Antwerp aforesaid, as this deponent also verily believes.
JAMES HERTSLET.
Sworn at the Public Office, Southampton Buildings,
Chancery Lane, this 6th day of March 1844,
before me,
S. DUCKWORTH.
Inrolled the Sixth day of March, in the year above written.