AN IMPROVED METHOD OF MAKING CARBURETTED HYDROGEN GAS
Year: 1857

page_text: LETTERS PATENT to John Talbot Pitman, of the American & European
Patent Offices, No. 67, Gracechurch Street, London, for the Invention
of "AN IMPROVED METHOD OF MAKING CARBURETTED HYDROGEN GAS."—
A communication from a Citizen of the United States.
Scaled the 23rd December 1857, and dated the 30th June 1857.
PROVISIONAL SPECIFICATION left-by the said John Talbot Pitman at
the Office of the Commissioners of Patents, with his Petition, on
the 30th June 1857.
J, JOHN TALBOT PITMAN, of the American & European Patent Offices, No.
67, Gracechurch Street, London, do hereby declare the nature of the said
Invention for "AN IMPROVED METHOD OF MAKING CARBURRETTED HYDROGEN GAS,"
a communication from a Citizen of the United States, to be as follows:-
It consists in the use of fused metals in connexion with a suitable retort, so
constructed as to pass distilled carbono-hydrous vapors or substances beneath
or in immediate connexion with the surface of such fused metal or metals,
thereby facilitating the production of carburreted hydrogen gas, by presenting
to the material to be formed into gas a fluid red-hot metallic surface, which
rapidly conducts heat, thereby evolving the gas with a fire of smaller volume
and intensity than is now used for an equal quantity of gaseous products.
The retort is constructed in any of the known convenient forms, so that the
gaseous product is caused to be formed in immediate connexion with the fluid

page_text: metal, which is fusible at a low temperature, and is placed in the bottom of
the retort. Within the retort & over the metal is placed a diaphragm or
other convenient arrangement to contain the coal or other carbono-hydrous
substances. The carbono-hydrous vapors as they are distilled expand and
force their way through or over the fused lead or other metal into the eduction
pipe, and are thus converted into aeriform gas.
I do not confine myself to any particular device for passing gas or hydro-
carbon vapors beneath or in immediate contact with the surface of fused
metals; my Invention being for passing the products of the destructive
distillation of coal and other substances yielding carburetted hydrogen gas
through or over the surfaces of fused metals fusible at a low temperature,
in the manner and for the purpose described.
I also claim the combination of a retort constructed and operated sub-
stantially as described, with fused metal or metals, so as to cause carbono-
hydrous vapors or gas to pass through or over the surface of the fused metal
as described.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Talbot Pitman in the Great Seal Patent Office on
the 30th December 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
TALBOT PITMAN, of the American and European Patent Offices, No. 67, Grace-
church Street, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of June, in the year of our Lord
one thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Talbot Pitman, Her special licence that I, the said John Talbot
Pitman, or my executors, administrators, and assigns, or such others as I, the
said John Talbot Pitman, or my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times there-
after 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 MAKING CARBURETTED HYDROGEN GAS," a communication
from a citizen of the United States, upon the condition (amongst others) that
I, the said John Talbot Pitman, or my executors or administrators, by an

page_text: 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 John Talbot Pitman, 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, reference being had to the Drawings hereto annexed.
Figure 1 represents a perspective view of a vertical retort.
Figure 2
Figure 3
"
Fig. 4
33
a section of same.
the diaphram.
perspective view and section of a large retort.
The same letters in the different Figures indicate similar parts.
The nature of the Invention consists in the use of fused metals in counexion
with a suitable retort, so constructed as to pass carbono-hydrous vapors or
substances beneath or in immediate connexion with the surface of such fused
metal or metals, thereby facilitating the production of carburetted hydrogen
gas by presenting to the material to be formed into gas a fluid red-hot
metallic surface, which rapidly conducts heat, thereby evolving the gas with a
fire of smaller volume and intensity than is now used for an equal quantity of
gascous products.
To enable others skilled in the art to construct and operate the Invention,
it is described as follows:-The retort is constructed in any of the known or
convenient forms, whereby the gaseous product is caused to be formed in
immediate connexion with the fluid metal (m) Fig. 2.
The usual method of effecting this combined object is by constructing a
vertical retort (a) Figs. 1 & 2, fixed in a furnace or stove (6). In the bottom
of the retort (a) a quantity of lead or other metal (m) which fuses at a low
temperature. This lead or its equivalent is caused to fill the retort two inches,
more or less, from the bottom. In connexion with the retort (a) a diaphragm
(c), one inch or less than the retort, is constructed in the form as shown at
Figs. 2 & 3 (c), in the act of making gas; (d) represents the top or cover of
the retort (a), having a flange (e) that fits into the groove (c'), thereby
forming either a fusible alloy or clay luting chamber or joint, the heat of
the retort being sufficient to melt the fusible alloy when such is used. Near
the bottom of the retort and immediately over the lead (m) the diaphragm (c)
Fig. 2, is placed; this may be covered, loaded, or filled with bituminous coal
or other carbono-hydrous substances for the purpose of making gas, by simply

page_text: raising the flange or cover (c) by means of the screws (k), as constructed and
shewn at Fig. 2.
The carbono-hydrous vapors are distilled from the coal in the retort (a), and
expand and force their way through or over the fused lead (m) in which the
bottom of the diaphragm (e) is immersed, by means of the eduction pipe being
connected to the diaphraghm & through the body of the retort in such a
manner that the gas must pass under the diaphram and over the surface of
the lead, as shown in the Drawing by the arrows, thus passing beneath and
through the bath of red-hot fluid metal; by this means the great desideratum
of a clean red-hot metallic surface is at all times presented to the first
products of gaseous distillation eliminated from the material, or from the coal
loading the diaphram in the retort, thus causing its perfect conversion into
aeriform gas.
All carbonaceous deposits which gather upon the interior surfaces of
ordinary retorts are obviated by using fused metals in the manner above
described, as the deposits in this case merely float upon the surface of such
fused metal, leaving the track of the gascous vapors through the body or over
the metal constantly clean and in the most favorable condition for making
gas.
Another form of retort is shown at Fig. 4, for large gas works, in which the
bottom of the retort (a) is fitted with a depressed flue (Q), which opens in the
retort near the mouth thereof by a trap (s), and extends under the retort to
the eduction pipe. This depressed flue is filled with lead in such manner that
the carbono-hydrous vapors eliminated from the coal being distilled in the
retort, shall have no vent except by depressing the lead in the flue, thus at all
times ensuring a clean metallic surface by passing over the face thereof.
When vertical retorts of a large size are used they may be removed and
operated, as shown at Fig. 2, by means of a screw, for the purpose of holding
the retort securely in its place when in the act of making gas. The screw (k)
confines the upper section of the retort to the lower section thereof by means
of the frame or bail (n).
The gas is purified by being passed from the retort through the pipe (o)
into the cleanser (p), from which it is transferred to the gasometer through
the pipe (Q) and finally from thence to the burners; Fig. 3 represents the
diaphram, which is also seen in section in Fig. 2.
Having now described the Invention, and the mode of operating the same,
as communicated to me by the Inventor, I would first state that, I am
aware that vertical retorts with interior cylinders have been heretofore
used for the ostensible purpose of reheating the gas; such a contrivance

page_text: presenting merely a solid metallic face, is, however, only equivalent to passing
the gas or distilled hydro-carbonaceous vapor over heated bricks or anthracite
coal, which has equally been long in common use and equally liable to be
clogged with fixed carbon. I do not confine myself to the above described or
any other mechanical device for passing gas or hydro-carbon vapors beneath
or in immediate contact with the surface of fused metals. An endless variety
of methods for effecting this purpose will be readily suggested to the me-
chanical mind, and therefore I desire to be free to adopt that which for the
time and place may be considered the most convenient. A variety of metals
and their alloys may also be used for this purpose, such as lead, zinc, tin,
antimony, bismuth, &c., &c.; of these metals lead, zinc, I consider preferable
to others, as they fuse at a low temperature, and are sufficiently cheap and
available for common usc.
What I claim under the herein-before in part recited Letters Patent as my
Invention, is, passing the products of the destructive distillation of coal and other
substances yielding carburetted hydrogen gas through or over the surfaces of
fused metals, fusible at a low temperature, in the manner and for the purpose
substantially as described.
I also claim the combination of a suitable retort with fused metal or metals,
so constructed as to cause carbono-hydrous vapors or gas to pass through tho
fused metal or over the surface thereof, substantially as described and shown
in the Drawings.
In witness whereof, I, the said John Talbot Pitman, have hereunto set
my hand and seal, on this Twenty-eighth day of December, Anno
Domini One thousand eight hundred and fifty-seven.
JOHN TALDOT PITMAN. (L.S.)