IMPROVED APPARATUS TO BE USED IN THE PROVISIONAL SPECIFICATION COAL AND OTHER BITUMINOUS OR RESINOUS SUBSTANCES
Year: 1854

page_text: LETTERS PATENT to George Frederick Evans, of Hanover Lodge, Kew
Bridge, in the County of Middlesex, Gas Engineer, and Frederick John
Evans, of the Gas Works, Horseferry Road, in the same County, Gas
Engineer, for the Invention of "IMPROVED APPARATUS TO BE USED IN THE
PROVISIONAL SPECIFICATION left by the said George Frederick Evans
and Frederick John Evans at the Office of the Commissioners of Patents,
with their Petition, on the 14th September 1854.
We, GEORGE FREDERICK EVANS, of Hanover Lodge, Kew Bridge, in the
County of Middlesex, Gas Engineer, and FREDERICK JOHN EVANS, of the Gas
Works, Horseferry Road, in the same County, Gas Engineer, do hereby declare
the nature of the said Invention for "IMPROVED APPARATUS TO BE USED IN THE
DISTILLATION OF COAL AND OTHER BITUMINOUS OR RESINOUS SUBSTANCES" to be as
follows:-
Our Invention of Improved Apparatus to be used in the Distillation of Coal
and other Bituminous or Resinous Substances relates more particularly to the
retorts or vessels in which the distilling process is carried on for the purpose
of obtaining gas for illumination, but is also applicable to retorts for distilling
turpentine and other hydro-carbons.

page_text: Hitherto coal and other bituminous or resinous matters, from which gas
for illumination is usually obtained, have been submitted to the distilling
process, either in cast-iron retorts, which are liable to injury from the great
heat to which they are usually subjected, or in earthen retorts, which are to
a certain extent porous, and will consequently allow the gas to escape; or their
inner surfaces, being rough and porous, will allow the carbon to condense
thereon, and in time choke up the retort, and cause other inconveniences.
Earthen retorts do, however, possess certain advantages over iron retorts, and
they have therefore been very generally used for some purposes in place of the
iron ones.
The principal object of the present Invention is to obviate and remedy the
objections to which these earthen retorts are open, and this is effected by
coating the retorts internally with an enamel or glaze, which will prevent the
gas from escaping through the pores of the material of which the retort is
composed, and will also, by presenting a smooth surface, prevent the carbon
from adhering thereto and forming a crust thereon.
Any of the processes which are well known and in use, or that may
hereafter be invented, for glazing or enamelling surfaces, may be employed
for the purpose of our Invention, as we do not confine ourselves to any
particular process, as any plan whereby the glaze or enamel may be made
to adhere firmly to the body of the retort will answer the purpose.
In order to prevent carbon from depositing and crusting on the internal
surface of iron retorts, we also propose to enamel the surfaces of iron retorts
by any of the processes for enamelling hollow iron vessels.
We would also observe, that, if required, the external as well as the
internal surface of earthen or iron retorts may be also glazed or enamelled.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Frederick Evans and Frederick John Evans in the
Great Seal Patent Office on the 12th March 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, GEORGE
FREDERICK EVANS, of Hanover Lodge, Kew Bridge, in the County of Middle-
sex, Gas Engineer, and FREDERICK JOHN EVANS, of the Gas Works, Horseferry
Road, in the same County, Gas Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of September, in the year of our Lord 3

page_text: 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 us, the
said George Frederick Evans and Frederick John Evans, Her special license
that we, the said George Frederick Evans and Frederick John Evans, our
executors, administrators, and assigns, or such others as we, the said George
Frederick Evans and Frederick John Evans, our 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
"IMPROVED APPARATUS TO BE USED IN THE DISTILLATION OF COAL AND OTHER
BITUMINOUS OR RESINOUS SUBSTANCES," upon the condition (amongst others) that
we, the said George Frederick Evans and Frederick John Evans, by an
instrument in writing under our hands and seals, or under the hand and seal
of one of us, 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 Offico within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that we, the said George Frederick Evans and Frederick
John Evans, do hereby declare the nature of our said Invention, and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement (that is to say):-
Our Invention of Improved Apparatus to be used in the Distillation of
Coal and other Bituminous or Resinous Substances relates more particularly
to the retorts or vessels in which the distilling process is carried on for the
purpose of obtaining gas for illumination, but is also applicable to retorts for
distilling bituminous or resinous substances for other purposes. Hitherto
coal and other bituminous or resinous matters, from which gas for illumination
is usually obtained, have been submitted to the distilling process, either in cast-
iron retorts, which are liable to injury from the great heat to which they are
usually subjected during the process of distillation, or in earthen retorts, which
are to a certain extent porous, and will consequently allow the gas to escape;
or their inner surfaces, being rough and porous, will allow the carbon to
condense thereon, and in time choke up the retort, and cause other incon-
veniences. Earthen retorts do, however, possess certain advantages over iron
retorts, and they have therefore been very generally used for some purposes in
place of the iron ones.
The principal object of the present Invention is to obviate and remedy the
objections to which these earthen retorts are open, and this is effected by

page_text: coating the retorts internally with an enamel or glaze, which will prevent the
gas from escaping through the pores of the material of which the retort is
composed, and will also, by presenting a smooth surface, prevent the carbon
from adhering thereto and forming a crust thereon.
Any of the processes which are well known and in use, or that may here-
after be invented, for glazing or enamelling surfaces, may be employed for the
purpose of our Invention, as we do not confine ourselves to any particular
process, as any plan whereby the glaze or enamel may be made to adhere
firmly to the body of the retort will answer the purpose, the object of the
present improvement being to stop the pores of the material, and present a
smooth internal surface.
In order to prevent carbon from depositing and crusting on the internal
surface of iron retorts, we also propose to enamel these surfaces of iron
retorts by any of the processes for enamelling hollow iron vessels.
We would also observe, that, if required, the external as well as the
internal surface of earthen or iron retorts may be also glazed or enamelled.
Having described the nature and object of our Invention, we would
observe that we have not thought it necessary to describe the process of
glazing or enamelling the surfaces of earthen or metal retorts, as the mode of
carrying on these operations is well known; neither do we intend to limit
ourselves to any particular process; but we claim, as the Invention secured to
us under the above in part recited Letters Patent, the glazing or enamelling
of the inner and outer surfaces of earthen or metal retorts for the purposes
above set forth; and the application of retorts with a glazed or enamelled
surface to the manufacture of gas for illumination, or the distillation of coal or
other bituminous or resinous substances.
In witness whereof, we, the said George Frederick Evans and Frederick
John Evans, have hereunto set our hands and seals, this Ninth day
of March, in the year of our Lord One thousand eight hundred and
fifty-five
Witness,
J. W. MOFFATT,
66, Chancery Lane.
G. F. EVANS. (L.S.)
F. J. EVANS. (L.S.)