IMPROVEMENTS IN THE MANUFACTURE OF LIGHTING GAS AND IN APPARATUS EMPLOYED THEREIN.
Year: 1873

page_text: LETTERS PATENT to Louis Bois, fils, of Boulevard de Strasbourg,
No. 23, at Paris, Chemist, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF LIGHTING GAS AND IN APPARATUS EMPLOYED
THEREIN.
"
PROVISIONAL SPECIFICATION left by the said Louis Bois at the
Office of the Commissioners of Patents, with his Petition, on the
6th September 1873.
I, LOUIS BOIS, fils, of Boulevard de Strasbourg, No. 23, at Paris,
Chemist, do hereby declare the nature of the said Invention for “Im-
PROVEMENTS IN THE MANUFACTURE OF LIGHTING GAS AND IN APPARATUS EMPLOYED
THEREIN," to be as follows:-
My method. of manufacturing illuminating gas consists in a new
process and a special apparatus. The process relates to causing steam
to circulate; this steam coming from a gencrator into a set of cast-iron
pipes arranged horizontally and heated to red heat in a furnace; these
pipes contain scrap or waste iron. The steam becomes decomposed and

page_text: the oxygen is carried in part to the iron. The steam on leaving this
first set of pipes passes into a second set of pipes made of fire-clay, and
arranged vertically in the same furnace in order to be heated to red
heat. The second set of pipes contains salts of soda or carbonate of
soda, which takes up the oxygen and isolates completely the hydrogen,
which passes out through a tube, and is conducted into a refrigerator or
cooler arranged as a serpentine or worm, from which it is conducted into
a gasometer.
In order to render this hydrogen gas proper for lighting I place it in
contact with carburetted spirit, which I subject to distillation, and I
obtain thus a gas of great brilliancy, and at the same time of great
steadiness without a flickering of the flame.
The apparatus for carrying out this mode of manufacture is con-
structed in the following manner:-In a furnace is arranged over a
grate or fire-bars a first set of tubes (horizontal) serpentined or coiled in
communication at one end with a steam pipe, the other end abutting or
in proximity with a second set of pipes or tubes arranged vertically, the
upper ends passing through or into a refrigerator. The second set of
tubes, which are vertical, is placed in the same furnace as the first set,
which is horizontal. The furnace is arranged for this purpose with two
flues, one horizontal, the other vertical, and the caloric from the grate
or fire-bars in passing through these two flues (perpendicular at right
angles) heats the two sets of tubes to red heat. The first set of tubes
contains scrap iron or waste iron, and the second set of tubes contains
salts of soda or carbonate of soda. These sets of tubes are provided at
their ends with movable joints in order to empty them, charge them, or
clean them if necessary by means of holes made for the purpose in the
wall of the furnace.
The hydrogen issuing from the second set of tubes (vertical) is
conducted through a tube into a refrigerating serpentine or worm
placed in a reservoir, in which the condensation is effected. The
hydrogen passes under a bell-shaped purifier and thence into a
gasometer.
In order to impart to this hydrogen gas the desirable illuminating
power I mix it in certain proportions with a carburetted gas obtained
by the distillation of mineral essences or oils rich with carbon. I effect
this mixture either directly in a second gasometer in the proportion of
about 80 parts of hydrogen gas with about 20 parts of carburetted gas, or

page_text: indirectly by taking the two gases separately from their respective
gasometers, and uniting them in a third gasometer.
My apparatus performs with advantage the distillation and mixture
of gases in the following manner:-The heavy essences or oils are
contained in a receiver furnished with a stop-cock. A tube causes this
receiver to communicate with a smaller reservoir provided at the inlet
and outlet with a stop-cock. This small reservoir communicates through
a tube with a retort placed in a furnace.
When the small reservoir is
full of the essence I close the cock, which communicates with the large
receiver, and I open the cock, which communicates from the small
receiver, to the retort. By these means there is not any danger of
explosion. The carburetted gas produced in the retort is conveyed
into the gasometer, which contains the hydrogen gas, or else into a
special gasometer, and I operate the mixture of the two gases as already
explained.
The process of manufacture of the gas is very economical, for the
production of the caustic soda which results from it covers the expenses
of the manufactura
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Louis Bois in the Great Seal Patent Office on
the 6th March 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, LOUIS
BOIs, fils, of Boulevard de Strasbourg, No. 23, at Paris, Chemist, send
greeting.
.
•
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of September, in the
year of our Lord One thousand eight hundred and seventy-three, in
the thirty-seventh year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Louis Bois, fils, Her special
licence that I, the said Louis Bois, fils, my executors, administrators,
and assigns, or such others as I, the said Louis Bois, fils, 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
•

page_text: Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF LIGHTING GAS AND IN APPARATUS
EMPLOYED THEREIN,"
"
upon the condition (amongst others) that I,
the said Louis Bois, fils, 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
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 I, the said Louis Bois, fils, do hereby declare
the nature of my 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, reference being had to the Drawings here-
unto annexed, that is to say :-
My method of manufacturing illuminating gas consists in a new
process and a special apparatus. The process consists in causing tho
steam of water to circulate through a series of cast-iron tubes heated to
redness, and containing little pieces of scrap or waste iron in order to
commence the decomposition of the steam, the oxygen from which
unites partly with the iron, and in then immediately leading the steam
into a second series of tubes made of fire-clay also heated to redness, and
containing salts of soda or carbonate of soda, which unite with the
remaining oxygen and thus completely isolate the hydrogen which is
now set free. The hydrogen is then led into a refrigerator or cooler,
serpentine or worm-shaped, from which it passes into a gasometer, but
to render this gas suitable for lighting purposes I place it in contact
with carburetted spirit, when I obtain thus a gas of great brilliancy,
steadiness, and power.
The apparatus for carrying out this mode of manufacture is con-
structed in the following manner :—
In the accompanying Drawings, Figure 1 is a longitudinal section of
the whole of the apparatus, and Figure 2, a horizontal section of the
steam decomposing furnace.
The apparatus consists first of a series of cast-iron tubes a, a, arranged å
parallelly in the same horizontal plane, and united in couples by joints
so as to form a sort of continuous worm. These pipes are filled with

page_text: little pieces or scraps of iron, and steam is introduced into them through
a tube 6 leading from any convenient generator of steam. The other end
of the worm communicates by means of a pipe c with another series of
tubes also arranged in a worm,, which are placed vertically to the other
5 set. This second serpentine is formed of large tubes of fire-clay, and
contain salts of soda or carbonate of soda, and the end is provided with
an escape pipe, which is itself terminated by the refrigerating coil S
contained in a receiver R arranged for the purpose. The horizontal
worm and the vertical worm are both placed in the same furnace A,
comprising two flues B, C, which are perpendicular to one another, and
which receive heat from the same fire-place F. Peep holes m, m, are
made at convenient places in the wall of the furnace A in order to
provide every facility for the cleaning, filling, and emptying of the
horizontal and vertical tubes; and the latter are provided for that
purpose with moveable stays or digesters at each end.
The scrap iron in the tubes a, and the salt of soda in the tubes d, are
also heated to redness as before mentioned. On arriving in contact with
the scrap of red hot iron the steam commences to decompose, and a
portion of its oxygen unites with the iron, the steam is then immediately
caught by the soda salts, which absorbs all the oxygen and becomes
transformed into caustic soda, whilst the hydrogen disengaged is collected
into the pipe f. This pipe leads the hydrogen into the refrigerating
worm S, wherein the purifying condensation is operated. The products
of this condensation are collected into a bell-shaped receiver g, the
purging of which is effected by a pipe / leading to a little reservoir i.
The purified hydrogen proceeds from the receiver g by the upper receiver
by the pipe j, which leads into a gasometer G.
In order to give the necessary lighting power to this hydrogen, and
to hinder the vacillation of the flame, I mix it with the vapour pro-
ceeding from the distillation of mineral essences rich in carbon. I effect
this mixture either directly in a second gasometer G³ in the proportion
of about 20 per cent. of rich gases to 80 per cent. of pure hydrogen,
either indirectly or by drawing the gases separately from two gasometers
respectively into a third. For this distillation the essences or heavy oils
are held in a receiver 7 provided with a cock n, from which a pipe o leads
into a little intermediate reservoir p on each side with an obturating
cock q, q. From this reservoir p a pipe r leads to a retort k arranged
into an ordinary furnace. The rich gas produced in this retort is led

page_text: through the pipes to the generator G³ in order to there become mingled
with the hydrogen, as I have explained above. The retort k is provided
with a peep hole t to allow the operation to be overlooked. The essences
coming from the receiver arrive into the reservoir p, which is then
shut off from the first one by closing cock 9. The cock q¹ is then
opened and the work is effected into the retort; thus there is nothing to
fear from the explosion, since the essence receiver is never in direct
communication with the retort.
The above described process for the manufacture of gas effects a great
economy, for the production of the caustic soda which results from it:
more than covers the expences of the generation of the steam.
And having now described the nature of my said Invention, and in
what manner the same is to be performed, I declare that I claim,—
First. The process of manufacturing gas by decomposing air by
passing it first through iron tubes lieated to redness containing scrap
iron, and then through tubes of fire-clay, also heated to redness, con-
taining salts or carbonates of soda, and by mixing the hydrogen thus
disengaged with the gases proceeding from the distillation of mineral
essences, as herein-before described.
And, Secondly. The apparatus and the arrangement thereof for
carrying out my process for the manufacture of gas, as herein-before
described and as shown in the accompanying Drawings, or any mere
modification thereof.
In witness whereof, I, the said Louis Bois, fils, have hereunto set my
hand and seal, this Twenty-fourth day of December One thousand
eight hundred and seventy-three.
Witness,
ALBERT CAHEN,
Civil Engineer,
of Boulevard Magenta, 32,
at Paris.
L. BOIS, FILS. (L.S.)