IMPROVEMENTS IN THE MANUFACTURE OF ILLUMINATING GAB
Year: 1863

page_text: LETTERS PATENT to George Tomlinson Bousfield, of Loughborough Park,
Brixton, in the County of Surrey, for the Invention of "IMPROVEMENTS
IN THE MANUFACTURE OF ILLUMINATING GAB."-A communication from
abroad by Dr. William Elmer, residing at New York, in the United
States of America.
Sealed the 24th November 1863, and dated the. 1st September 1863.
PROVISIONAL SPECIFICATION left by the said George Tomlinson Bousfield
at the Office of the Commissioners of Patents, with his Petition, on the
1st September 1863.
I, GEORGE TOMLINSON BOUSFIELD, of Loughborough Park, Brixton, in the
County of Surrey, do hereby declare the nature of the Invention for "IMPROVE
MENTS IN THE MANUFACTURE OF ILLUMINATING GAS," to be as follows:-
In order that the nature of the Invention may be understood it is expedient
to make a brief statement of the usual process of manufacturing illuminating
gas, and of the results thereof.
Illuminating gas is manufactured on a large scale by subjecting the gas
stock to destructive distillation at a high temperature, whereby the gas stock
is decomposed; a certain portion of it is converted into gas, another portion
into vapours, which pass off with the gas, and can be condensed into a liquid
form, and the remainder into a solid carbonaceous residuum. The process is
generally conducted by charging the gas stock, coal for example, into retorts
in which it is subjected to a red heat, and the mixture of gas and vapours
..
17

page_text: passes from the retort through the "hydraulic main" and the "condenser," in
which the greater part of the vapours are condensed in the form of coal tar
and naptha, while the gas passes from them to the purifiers. The gas is a
mixture of various carbides of hydrogen, the most valuable of which is olefiant
gas, and the process is generally conducted for purposes of economy at the
lowest heat at which this gas is formed. The liquid product is a mixture of
various hydrocarbons and compounds of them, all of which, although containing
a considerable amount of hydrogen, contain an excess of carbon when compared
with olefiant gas, and the total amount of carbon contained in the liquid
products obtained from a given quantity of coal is much greater than the
amount of carbon existing in the illuminating gas obtained from the same
quantity of coal. The liquid product, being useless in the manufacture, is
generally sold by the gas manufacturers, but its marketable value is very
small, so that the large quantities of carbon and the hydrogen remaining in it
are practically lost to the gas manufacturer. These liquid products are given
off in greatest quantities during the commencement of the distillation of the
gas stock, as the operation proceeds their quantity diminishes until the gas
stock becomes exhausted of them. On the other hand, the illuminating gas
given off during the commencement of the distillation contains a larger pro-
portion of olefiant gas than that given off towards the latter part of the
operation; as the operation proceeds the lighter gaseous carbides of hydrogen
increase in relative proportion to the product of olefiant gas until the illumi-
nating power of the gas produced is so low that it is not valuable to the gas
manufacturer. The process is then stopped, and the solid residuum is with-
drawn from the retort, although if the process were continued further a
considerable quantity of these lighter carbides of hydrogen and of hydrogen
could be obtained; hence such of these gaseous products which could be
obtained by continuing the operation, although containing much hydrogen, are
practically lost to the gas manufacturer, while those which are mixed with the
olefiant gas during the latter part of the operation, being of low illuminating
power, deteriorate the product. The solid residuum remaining in the retort
may be divided into two parts, one of which is coke, which is not attached to
the retort, while the other part consists of carbon in a solid form, which is
firmly attached to the retorts, and appears to be formed by the decomposition
of a part of the oily liquid products first given off by the gas stock or of some
of the illuminating gas first formed. This deposited carbon is not only lost to
the gas manufacturer, but is in addition a constant source of trouble, as it
accumulates until it has to be removed from the retorts either mechanically or
by burning it off by permitting air to draw into the empty hot retorts.

page_text: Now the objects of this Invention are to utilize the above-mentioned
practically valueless liquid, gaseous, and solid products of the manufacture of
illuminating gas by transmuting them into illuminating gas (so that the carbon
and hydrogen contained in them are rendered practically valuable to the gas
manufacturer), and also to produce illuminating gas of a higher illuminating
power than is usually obtained.
To this end the first part of this Invention consists in the process of
transmuting into illuminating gas the liquid products obtained in the gas
manufacture by decomposing them by heat in the presence of the light carbides
of hydrogen or hydrogen given off by the gas stock during the latter part of
its distillation.
The second part of the Invention consists in the process of manufacturing
the gaseous carbide of hydrogen called acetyline by decomposing liquid hydro-
carbons at a high temperature in the presence of hot hydrogen produced either
by the decomposition of water in the same vessel in which. the hydrocarbon is
decomposed or produced in a separate vessel, and introduced while highly
heated into the vessel in which the hydrocarbon is decomposed.
The third part of the Invention consists in the process of manufacturing
acetylene by subjecting deposited carbon to a high temperature in the presence
of hot hydrogen produced by the decomposition of water in the same vessel in
which the deposited carbon is contained, or produced in a separate vessel, and
introduced while highly heated into the vessel containing the deposited carbon.
Although each of the above processes may be performed separately, in a
retort specially prepared for the purpose, it is practically advantageous to
perform them all in the retort in which the gas stock from which the products
are obtained is distilled without removing the carbonaceous residuum. The
mode of effecting this when the Invention is applied to the manufacture of
illuminating gas from English cannel coal is as follows:-The ordinary
apparatus is employed, and the following additions are made thereto :-First,
a vat is provided above the level of the retort to contain the liquid products to
be used. Second, a feed pipe is applied to each retort, for the purpose of
supplying the liquid products from the vat thereto, and the feed pipe is
provided with a valve or conical screw rod (such as is well known in the
manufaciure of rosin gas) to regulate the supply. Third, a steam boiler is pro-
vided to generate steam, and a feed pipe fitted with a valve is conducted from
it to each retort, so that steam can be supplied thereto in regulated quantities.
Fourth, a portion of the discharge pipe through which the products of the
destructive distillation pass from the retort is made of glass in the form of a
globe, with nozzles to connect it with the remainder of the pipe, so that the

page_text: presence of the vapour of water (if any escape decomposition) may be made
sensible by the condensation of it upon the surface of the glass. Fifth, a small
gas pipe with a burner and stop-cock is applied to each retort or to the
discharge pipe thereof, so that the quality of the gas can be tested during the
operation by burning it.
As these additions to the ordinary apparatus for making coal gas are so
simple that they can be applied by any gas engineer, it is not deemed necessary
to furnish Drawings shewing the complete apparatus.
The operation is as follows:-The retort being empty and hot is charged
with coal in the usual manner and closed, and the heat is regulated to produce
the largest amount of olefiant gas that can be practically obtained from coal
by the usual course of manufacture, as is well known by gas manufacturers.
The liquid products are carefully collected in a cistern, and are pumped up
into the vat above the retort. As the operation proceeds the quality of the
gas made in the retort is tested from time to time by burning it at the burner,
and as soon as the appearance of the light indicates (by its deficiency in
illuminating power) that the product of olefiant gas is falling off the screw
valve for supplying the liquid product is partially opened, so that it is fed into
the retort, and is therein decomposed in the presence of the light carbides of
hydrogen and hydrogen given off by the gas stock, the result of which is that
these gases combine in whole or in part with the products of the decomposition
of the liquid product to produce a large quantity of olefiant gas. This
operation is continued as long as practicable, and the liquid product is fed to
the retort as fast as it can be transmuted into illuminating gas. The rate at
which it can be fed is determined by the burning of the gas at the test burner.
When the liquid product is fed in too slowly the gas is deficient in illuminating
power; when it is fed in too rapidly the gas smokes in burning, so that a
little practice on the part of the attendant will enable him to regulate the
supply of liquid with facility, and to stop the supply when the gas stock ceases
to give off any practical amount of the light carbides of hydrogen and hydrogen,
because the greater part of the liquid then fed to the retort is vaporized, and
produces a dense smoke at the test burner.
At this stage of the operation the process which constitutes the first part of
the Invention is practically completed, but as the gases given off by the
gas stock do not contain sufficient hydrogen to supply the carbon of all the
liquid product with the quantity required to transmute it into olefiant gas
a considerable quantity of the liquid is left in the vat.
The object of the ensuing stages of the operation is to utilize this residue
and the solid deposited carbon in the retort by transmuting them into

page_text: acetylene, which is a gaseous compound of hydrogen and carbon containing a
larger proportion of carbon than olefiant gas, and burning with an intense
white light, exceeding that of olefiant gas in brilliancy.
To this end the
retort is opened, and a quantity of metallic zinc, or of an equivalent material
for decomposing water at a high temperature, is charged into the retort upon
the carbonaceous residuum remaining therein. The quantity of zinc so charged
should (for economy) be proportioned to the quantity of hydrogen required to
convert the carbon of the remaining liquid and of the deposited carbon into
acetylene; if zinc be used about one and a half pounds of metallic zinc are
required for each fluid gallon of liquid remaining; if wrought-iron turnings
be used about two pounds of them are required for each gallon of liquid for
this purpose; after the zinc or its equivalent is introduced the retort is closed,
and the heat is raised to whiteness; steam is then permitted to flow into the
retort by opening the valve or cock in the steam pipe, and the feeding of the
remaining liquid is recommenced. The liquid entering the retort is thereupon
decomposed in the presence of the nascent highly heated hydrogen produced
by the decomposition of the steam by the zinc or its equivalent, and the
heated hydrogen combining with the products of the decomposition of the
liquid and with the deposited carbon in the retort produces acetylene, which
passes from the retort in a gaseous state. The state of the operation is known
by the products given off; if the steam be admitted too rapidly a portion of it
passes from the retort without being decomposed, and its presence is made
apparent by the condensation of it upon the inner surface of the glass portion
of the discharge pipe, and if the liquid product be admitted too rapidly the gas
produced smokes. When all the liquid is exhausted and the gas produced
ceases to be practically illuminating, the operation is stopped and the retort
is opened, when it will be found (if the operation has been carefully conducted
that all the deposited carbon has been utilized. The residuum remaining in
the retort is then withdrawn, a new charge of coal is inserted, and the operation
proceeds as before.
In the foregoing description the liquid product used has been supposed to be
that produced from the same charge, which remains in the retort until the
liquid so produced is utilized, but it is clear that the liquid product of each
charge of gas stock may be fed to a succeeding charge, and it is believed the
operation can be most conveniently conducted by allowing a small stock of the
liquid products to accumulate, and then feeding to each retort at each charge
a certain number of gallons of liquid about equal to the quantity produced by
one charge of gas stock, varying the quantity so fed as the stock of liquid on
hand increases or diminishes. The operation is facilitated by superheating the

page_text: steam previous to its introduction into the retort, by causing it to traverse a
heated pipe. The gas produced passes from the discharge pipe of the retort
to the "hydraulic main" and condenser" of the gasworks, and thence to the
purifiers, from which it passes to the gas holders. If, therefore, any portion
of the liquid escapes transmutation and passes off with the gas in the form of
vapour, it is recondensed, and no loss ensues. If any bisulphide of carbon
exists in the gas it should be passed through lime heated to 400° Fahrenheit
before being introduced into the gas holders. As the gaseous products of the
whole operation are mechanically mixed in the gas holder, and as acetylene
has a higher illuminating power than olefiant gas, the average illuminating
power of the mixture obtained by the above-described mode of operation is
considerably higher than that of ordinary coal gas.
In practising the process it is expedient to manufacture the illuminating gas
under the lowest possible' pressure in the retort, as thereby a less quantity of
deposited carbon is formed in the retort to be subsequently transmuted into
acytelene, and consequently the gas first given off by the gas stock is richer in
olefant gas.
The Invention is not confined to the manufacture of illuminating gas from
coal as the gas stock, but is applicable also to the manufacture of illuminating
gas from other materials, such, for example, as bitumen, petroleum, naptha,
asphaltum, resin, and wood; the liquid producis obtained from these materials
although less in quantity than that obtained from coal, being valuable sources
of carbon and hydrogen, and being capable of transmutation into illuminating
gas by decomposition in the presence of highly heated hydrogen or the nascent
light carbides of hydrogen. Neither is the Invention confined to the decompo-
sition of the water in the illuminating gas retort in which the hydrocarbon is
decomposed or the deposited carbon contained, as hydrogen formed in a
separate vessel and introduced while hot from that vessel immediately into the
illuminating gas retort will answer the purpose, and this plan of generating
the hydrogen separately is advantageous whenever it is desirable to keep the
solid product resulting from the decomposition of the water by a heated metal
separate from the residuum in the illuminating gas retort.
The second part of the Invention is not confined to the manufacture of
acetylene from the liquid products obtained in the manufacture of illuminating
gas, as other liquid hydrocarbons, whether liquid at ordinary temperatures or
rendered so by heat or solution, can be transmuted into acetylene by con-
ducting the process in an apparatus suited to the purpose by the same mode
of operation.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Tomlinson Bousfield in the Great Seal Patent Office
on the 1st March 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
TOMLINSON BOUSFIELD, of Loughborough Park, Brixton, in the County of
Surrey, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of September, in the year of our Lord One
thousand eight hundred and sixty-three, in the twenty-seventh year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said George Tomlinson Bousfield, Her special licence that I, the said George
Tomlinson Bousfield, my executors, administrators, and assigns, or such others
as I, the said George Tomlinson Bousfield, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time and 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 THE MANUFACTURE OF ILLUMINATING Gas," a communication
to me from abroad by Dr. William Elmer, a person resident at New York,
in the United States of America, upon the condition (amongst others) that I,
the said George Tomlinson Bousfield, 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 George Tomlinson Bousfield, 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 statement thereof, that is to say:-
In order that the nature of the Invention may be understood it is expedient
to make a brief statement of the usual process of manufacturing illuminating
gas, and of the results thereof.
Illuminating gas is manufactured on a large scale by subjecting the gas
stock to destructive distillation at a high temperature, whereby the gas stock
is decomposed; a certain portion of it is converted into gas, another portion
into vapours, which pass off with the gas, and can be condensed into a liquid
form, and the remainder into a solid carbonaceous residuum. The process is

page_text: generally conducted by charging the gas stock, coal for example, into retorts
in which it is subjected to a red heat, and the mixture of gas and vapours
passes from the retort through the "hydraulic main" and the "condenser," in
which the greater part of the vapours are condensed in the form of coal tar
and naptha, while the gas passes from them to the purifiers. The gas is a
mixture of various carbides of hydrogen, the most valuable of which is olefiant
gas, and the process is generally conducted for purposes of economy at the
lowest heat at which this gas is formed. The liquid product is a mixture of
various hydrocarbons and compounds of them, all of which, although containing
a considerable amount of hydrogen, contain an excess of carbon when compared
with olefiant gas, and the total amount of carbon contained in the liquid
products obtained from a given quantity of coal is much greater than the
amount of carbon existing in the illuminating gas obtained from the same
quantity of coal. The liquid product being useless in the manufacture, is
generally sold by the gas manufacturers, but its marketable value is very
small, so that the large quantities of carbon and the hydrogen remaining in it
are practically lost to the gas manufacturer. These liquid products are given
off in greatest quantities during the commencement of the distillation of the
gas stock, as the operation proceeds their quantity diminishes until the gas
stock becomes exhausted of them. On the other hand, the illuminating gas
given off during the commencement of the distillation contains a larger pro-
portion of olefiant gas than that given off towards the latter part of the
operation; as the operation proceeds the lighter gaseous carbides of hydrogen
increase in relative proportion to the product of olefiant gas, until the
illuminating power of the gas produced is so low that it is not valuable to the
gas manufacturer.
The process is then stopped, and the solid residuum is
withdrawn from the retort, although if the process were continued further a
considerable quantity of these lighter carbides of hydrogen and of hydrogen
could be obtained; hence such of these gaseous products which could be
obtained by continuing the operation, although containing much hydrogen, are
practically lost to the gas manufacturer, while those which are mixed with the
olcfiant gas during the latter part of the operation, being of low illuminating
power, deteriorate the product. The solid residuum remaining in the retort
may be divided into two parts, one of which is coke, which is not attached to
the retort, while the other part consists of carbon in a solid form, which is
firmly attached to the retorts, and appears to be formed by the decomposition
of a part of the oily liquid products first given off by the gas stock or of some
of the illuminating gas first formed. This deposited carbon is not only lost to
the gas manufacturer, but is in addition a constant source of trouble, as it

page_text: accumulates until it has to be removed from the retorts either mechanically or
by burning it off by permitting air to draw into the empty hot retorts.
Now the objects of this Invention are io utilize the above-mentioned
practically valueless liquid, gaseous, and solid products of the manufacture of
illuminating gas by transmuting them into illuminating gas (so that the
carbon and hydrogen contained in them are rendered practically valuable to
the gas manufacturer) and also to produce illuminating gas of a higher illumi-
nating power than is usually obtained.
i
To this end the first part of this Invention consists in the process of
transmuting into illuminating gas the liquid products obtained in the gas
manufacture by decomposing them by heat in the presence of the light carbides
of hydrogen or hydrogen given off by the gas stock during the latter part of
its distillation.
The second part of the Invention consists in the process of manufacturing
the gaseous carbide of hydrogen, called acctyline, by decomposing liquid
hydrocarbons at a high temperature in the presence of hot hydrogen pro-
duced either by the decomposition of water in the same vessel in which
the hydrocarbon is decomposed, or produced in a separate vessel and
introduced while highly heated into the vessel in which the hydrocarbon is
decomposed.
The third part of the Invention consists in the process of manufacturing
acetylene by subjecting deposited carbon to a high temperature in the
presence of hot hydrogen produced by the decomposition of water in the
same vessel in which the deposited carbon is contained or produced in a
separate vessel and introduced while highly heated into the vessel containing
the deposited carbon.
Although each of the above processes may be performed separately
in a retort specially prepared for the purpose, it is practically advantageous
to perform them all in the retort in which the gas stock from which
the products are obtained is distilled without removing the carbonaceous
residuum.
The mode of effecting this when the Invention is applied to the manufacture
of illuminating gas from English cannel coal is as follows:-The ordinary
apparatus is employed, and the following additions are made thereto : 1st, a
vat is provided above the level of the retort to contain the liquid products to be
used; 2nd, a feed pipe is applied to each retort for the purpose of supplying
the liquid products from the vat thereto, and the feed pipe is provided with a
valve or conical screw rod (such as is well known in the manufacture of rosin
gas) to regulate the supply; 3rd, a steam boiler is provided to generate steam,
1

page_text: and a feed pipe fitted with a valve is conducted from it to each retort, so
that steam can be supplied thereto in regulated quantities; 4th, a portion of
the discharge pipe through which the products of the destructive distillation
pass from the retort is made of glass in the form of a globe with nozzles
to connect it with the remainder of the pipe, so that the presence of the
vapor of water (if any escape decomposition) may be made sensible by the
condensation of it upon the surface of the glass; 5th, a small gas pipe
with a burner and stop-cock is applied to each retort or to the dis-
charge pipe thereof, so that the quality of the gas can be tested during
the operation by burning it.
As these additions to the ordinary apparatus for making coal gas are so
simple that they can be applied by any gas engineer, it is not deemed
necessary to furnish drawings showing the complete apparatus.
The operation is as follows:-The retort being empty and hot is charged
with coal in the usual manner and closed, and the heat is regulated to produce
the largest amount of olefiant. gas that can be practically obtained from coal
by the usual course of manufacture, as is well known by gas manufacturers.
The liquid products are carefully collected in a cistern and are pumped up into
the vat above the retort. As the operation proceeds the quality of the gas
made in the retort is tested from time to time by burning it at the burner, and
as soon as the appearance of the light indicates (by its deficiency in illuminating
power) that the product of olefiant gas is falling off the screw valve for
supplying the liquid product is partially opened, so that it is fed into the rotort
and is therein decomposed in the presence of the light carbides of hydrogen
and hydrogen given off by the gas stock, the result of which is that these gases
combine in whole or in part with the products of the decomposition of the
liquid product to produce a large. qantity of olefiant gas. This operation is
continued as long as practicable, and the liquid product is fed to the retort as
fast as it can be transmuted into illuminating gas. The rate at which it can
be fed is determined by the burning of the gas at the test burner; when
the liquid product is fed in too slowly the gas is deficient in illuminating
power; when it is fed in too rapidly the gas smokes in burning, so that a little
practice on the part of the attendant will enable him to regulate the supply of
liquid with facility, and to stop the supply when the gas stock ceases to give off
any practical amount of the light carbides of hydrogen and hydrogen, because
the greater part of the liquid then fed to the retort is vaporized and produces a
dense smoke at the test burner.
:
At this stage of the operation the process which constitutes the first
part of the Invention is practically completed, but as the gases given

page_text: off by the gas stock do not contain sufficient hydrogen to supply the
carbon of all the liquid product with the quantity required to trans-
mute it into olefiant gas, a considerable quantity of the liquid is left in
the vat.
The object of the ensuing stages of the operation is to utilize this residue
and the solid deposited carbon in the retort, by transmuting them into acety-
lene, which is a gaseous compound of hydrogen and carbon containing a larger
proportion of carbon than olefiant gas, and burning with an intense white light
exceeding that of olefiant gas in brilliancy. To this end the retort is opened,
and a quantity of metallic zinc, or of an equivalent material for decomposing
water at a high temperature, is charged into the retort upon the carbonaceous
residuum remaining therein. The quantity of zinc so charged should (for
economy) be proportioned to the quantity of hydrogen required to convert
the carbon of the remaining liquid, and of the deposited carbon into acety-
lene. If zinc be used about one and a half pounds of metallic zinc are
required for each fluid gallon of liquid remaining; if wrought-iron turnings
be used, about two pounds of them are required for each gallon of liquid
for this purpose; after the zinc or its equivalent is introduced the retort
is closed, and the heat is raised to whiteness; steam is then permitted to flow
into the retort by opening the valve or cock in the steam pipe and the feeding
of the remaining liquid is re-commenced. The liquid entering the retort is
thereupon decomposed in the presence of the nascent highly heated hydrogen
produced by the decomposition of the steam by the zinc or its equivalent, and
the heated hydrogen combining with the products of the decomposition of
the liquid and with the deposited carbon in the retort produces acetylene,
which passes from the retort in a gascous state. The state of the operation is
known by the products given off; if the steam be admitted too rapidly a
portion of it passes from the retort without being decomposed, and its presence
is made apparent by the condensation of it upon the inner surface of the glasз
portion of the discharge pipe, and if the liquid product be admitted too rapidly
the gas produced smokes. When all the liquid is exhausted, and the gas
produced ceases to be practically illuminating, the operation is stopped and
the retort is opened, when it will be found (if the operation has been carefully
conducted) that all the deposited carbon has been utilized. The residuum
remaining in the retort is then withdrawn, a new charge of coal is inserted, and
the operation proceeds as before.
In the foregoing description the liquid product used has been supposed to
be that produced from the same charge which remains in the retort until the

page_text: liquid so produced is utilized, but it is clear that the liquid product of
each charge of gas stock may be fed to a succeeding charge, and it is
believed the operation can be most conveniently conducted by allowing a small
stock of the liquid products to accumulate, and then feeding to each retort
at each charge a certain number of gallons of liquid about equal to the
quantity produced by one charge of gas stock, varying the quantity so fed
as the stock of liquid on hand increases or diminishes. The operation is
facilitated by superheating the steam previous to its introduction into the retort
by causing it to traverse a heated pipe. The gas produced passes from
the discharge pipe of the retort to the "hydraulic main" and "condenser"
of the gas works and thence to the purifiers, from which it passes to the
gas holders. If therefore any portion of the liquid escapes transmutation
and passes off with the gas in the form of vapor it is recondensed, and
no loss ensues. If any bisulphide of carbon exists in the gas it should
be passed through lime heated to 400° Fahrenheit before being introduced
into the gas holders. As the gaseous products of the whole operation are
mechanically mixed in the gas holder, and acetylene has a higher illu-
minating power than olefiant gas, the average illuminating power of the
mixture obtained by the above-described mode of operation is considerably
higher than that of ordinary coal gas.
In practising the process it is expedient to manufacture the illumi-
nating gas under the lowest possible pressure in the retort, as thereby a
less quantity of deposited carbon is formed in the retort to be subsequently
transmuted into acetylene, and consequently the gas first given off by the gas
stock is richer in olcfiant gas.
The Invention is not confined to the manufacture of illuminating gas
from coal as the gas stock, but is applicable also to the manufacture
of illuminating gas from other materials, such for example as bitumen,
petroleum, naptha, asphaltum, resin, and wood, the liquid products ob-
tained from these materials, although less in quantity than that obtained
from coal, being valuable sources of carbon and hydrogen, and being capable
of transmutation into illuminating gas by decomposition in the presence of
Neither
highly heated hydrogen, or the nascent light carbides of hydrogen.
is the Invention confined to the decomposition of the water in the illumi-
nating gas retort, in which the hydrocarbon is decomposed or the deposited
carbon contained, as hydrogen formed in a separate vessel and introduced
while hot from that vessel immediately into the illuminating gas retort
will answer the purpose, and this plan of generating the hydrogen separately

page_text: is advantageous whenever it is desirable to keep the solid product resulting
from the decomposition of the water by a heated metal separate from the
residuum in the illuminating gas retort.
The second part of the Invention is not confined to the manufacture of
acetylene from the liquid products obtained in the manufacture of illuminating
gas, as other liquid hydrocarbons, whether liquid at ordinary temperatures
or rendered so by heat or solution, can be transmuted into acetylene by con-
ducting the process in an apparatus suited to the purpose by the same mode of
operation.
The Invention and the best mode of practising it with which the Inventor is
acquainted being described as above, what is claimed as the Invention to be
secured by Letters Patent, is,-
First, the process of transmuting into illuminating gas the liquid products
obtained in the gas manufacture by decomposing them by heat in the presence
of the light carbides of hydrogen or hydrogen given off by the gas stock during
the latter part of its distillation, the said process being conducted substantially
as above set forth.
Second, the process of transmuting liquid hydrocarbons into acetylene by
decomposing them at a high temperature in the presence of heated hydrogen
produced by the decomposition of water, the process being conducted substan-
tially as above set forth.
Third, the process of transmuting deposited carbon into acetylene, by sub-
jecting it to a high temperature in the presence of heated hydrogen produced
by the decomposition of water, the process being conducted substantially as
above set forth.
In witness whereof, I, the said George Tomlinson Bousfield, have hereunto
set my hand and seal, this Twenty-ninth day of February, in the year
of our Lord One thousand eight hundred and sixty-four.
ATO M POLISFIELD (ra)
GEO. DOUSFIELD (ro)