NEW AND IMPROVED METHOD OR METHODS OF DISTILLING OFF THE PRODUCTS OF COAL, AND CARBONIZING COAL, IN THE PROCESS OF MAKING GAS FOR THE PURPOSE OF ILLUMINATION
Year: 1820

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
GRAFTON, of the City of Edinburgh, Civil Engineer, send greeting.
WHEREAS His present most Excellent Majesty King George the Fourth
did, by His Royal Letters Patent under the Great Seal of the United King-
dom of Great Britain and Ireland, bearing date at Westminster, the Eleventh
day of July, in the first year of His reign, give and grant unto me, the said
John Grafton, my executors, administrators, and assigns, His special licence,
full power, sole privilege and authority, that I, the said John Grafton,
my executors, administrators, and assigns, during the term of years therein
expressed, should and lawfully might make, use, exercise, and vend.my" NEW
AND IMPROVED METHOD OR METHODS OF DISTILLING OFF THE PRODUCTS OF COAL,
AND CARBONIZING COAL, IN THE PROCESS OF MAKING GAS FOR THE PURPOSE OF
ILLUMINATION," within England, Wales; and the Town of Berwick-upon-Tweed,
in such manner as to me, the said John Grafton, my executors, administrators,
and assigns, should in our discretion seem meet; in which said Letters Patent
is contained a proviso that if I, the said John Grafton, should not particularly
describe and ascertain the nature of my said Invention, and in what manner
the same is to be performed, by an instrument in writing under my hand and
seal, and cause the same to be inrolled in His Majesty's High Court of
Chancery within two calendar months next and immediately after the date of
the said Letters Patent, that then the said Letters Patent, and all liberties and
advantages whatsoever thereby granted, should utterly cease, determine, and
become void, as in and by the said recited Letters Patent, relation being
thereunto had, may more fully and at large appear.

page_text: "
NOW KNOW YE, that in compliance with the said proviso, 1, the said
John Grafton, have executed this Instrument, by which I do declare that the
nature of my said Invention, and the manner in which the same is to be
performed, are particularly described and ascertainedin mannerfollowing(that
is to say):-
My Invention of a New and Improved Method or Methods of Distilling off
the Products of Coal in the Process of Making Gas for the Purpose of Illu-
mination, consist in a new and improved manner of constructing the vessels
or retorts used for carbonizing coal to produce gas for the purpose of illumi
nation. I construct the vessel or retort of a material known by the name of
the Stourbridge fire-brick clay or any other good description of fire clay which
may be found to resist the action of the fire sufficiently without vitrifying or
cracking, which material has been heretofore tried for retorts but generally
failed in consequence of those retorts having been made in one intire piece,
which caused them to break in pieces very shortly after the fire was applied.
The substance usually employed for making retorts to carbonize pit coal is
cast iron, which substance is quickly destroyed by the combined action of the
external fire in the furnace and the heated coke contained within the retort.
This induced me to try other substances capable of resisting the action of the
fire more completely, and at the same time to construct them in such manner
as not to be easily cracked or broken by the operation of the fire. I cause
the retort to be made of fire clay and composed of several pieces, which may
be put together by any proper cementing substance or mortar, such as the fire
clay made wet, or other material which will not drop out or be destroyed
when exposed to the heat. The means I adopt of forming the joinings where
the pieces connect are various, but some of those which I have found to
answer the intended purpose very well are represented by Figures contained
in the annexed Sheet of Drawings or Plans.
Fig. 1 shews two of the portions of a retort as they would appear in the
direction of the length of the retort, joined together by forming a small square
groove or channel round the end of one piece A, and a corresponding project-
ing rib round the end of the contiguous piece B, which rib is to be inserted
into the channel and rendered air-tight, or nearly so, by any soft cement or
mortar introduced at the time that the two pieces are put together.
Another form of joining is represented by Fig. 2, where the ends of both
portions A and B have a channel formed round them (similar to A, Fig. 1),
and a hoop or ring of metal introduced so as to enter one half of its width
into its channel, and rendered air-tight by cement, in the manner before
mentioned.

page_text: Fig. 3 shews a form of joint which is similar to the fitting of a turned box
lid, where the internal part of the piece A is enlarged for a short distance,
and the external part of B diminished in size, so as to be capable of being
inserted into A, as shewn by the Figure, and rendered tight by cement.
The joining represented by Fig. 4 is very simple and found to be sufficiently
secure. The end of the piece A is formed somewhat concave or hollow round
its edge, whilst the edge of the piece B is rounded or convex, so as to fit the
concave part, and may be pressed together with cement between the joint, and
prevented from separating when fixed by the peculiar arrangement of the parts
of the furnace in which the retort is intended to be placed, and which will
be hereafter explained, although I make no claim to the construction of the
furnace, but confine myself solely to the construction of retorts for gas light
apparatus made in detached or separate portions of fire clay, which are baked
or burned previous to their being joined together for use, since by such method
I can render them very durable in fire clay which could not be effected by any
manner of constructing them in one intire piece, as heretofore attempted.
Fig. 5 on the Drawing shews a cross section of the retort on a large scale,
to explain how the joinings are made in the direction across its length. It is
composed of two side pieces c, c, and a top and bottom piece d and a; the
sides may be fitted into the top and bottom pieces, as shewn by the Fig. 5,
or according to either of the methods described in Figures 1, 2, 3, or 4, or in
other manner which may be found convenient and secure.
any
The various portions which compose my improved retort are to be formed
in molds or otherwise well shaped, so that the parts where the joinings occur
may fit properly together, after which they are to be baked or burnt in the
manner of bricks or pottery before they are put together in the furnace
for use.
Fig. 6 on the Sheet of Drawings represents a longitudinal section of a
furnace, to explain how my new retorts are placed and secured, in order to
prevent the detached portions from separating and allowing the gas to escape
during the operation ofcarbonizing; Fig. Trepresents atransverse section taken
through the retort and furnace; and Fig. 8, a front view of the external part
of the furnace, to shew the iron mouthpiece of the retort, fire door, ash pit,&c.
The same characters or letters of reference denote the same parts on the
Figures 6, 7, and 8. A, the retort, which is composed of fire clay, as before
described, and inclosed in an oven or chamber formed by the walls D, D, D,
which are made with fire bricks or baked clay, similar to the retort. The
walls D, D, D, are surrounded by a considerable thickness of common brick-
work to form the exterior of the furnace, which is coloured red in the Drawing,

page_text: whilst the fire bricks or clay is coloured yellow. B, the body of the furnace
where the fire is made. It is supplied with air from the ash pit C, through
the grating bars b, Fig. 6 and 7. The bottom a of the retort is supported
upon piers of fire clay or brick, E, E, E, which are situated in a row on each
side, extending the whole length of the retort, as shewn by Fig. 6, having
spaces left between them for the flame and smoke to pass through from the
furnace B. The piers E, E, E, are placed immediately under the joinings
in the retort, which renders the joinings very secure from injury. The
upright sides of the retort C, C, are inserted a short distance into channels
formed in the bottom a, and the uppermost edges of the sides are also
inserted into channels in the top piece d, which prevents the sides from going
asunder. The top piece d is kept down and rendered firm by the insertion of
small piers of fire clay F, F, F, placed upright between the top piece d of the
retort and the roof of the chamber D. These piers have spaces left between
them for the flame to pass through, similar to those under the bottom of the
retort, and the piers are situated immediately over the joinings in the same.
One end of the retort at G is closed by fire clay, of the same description as the
sides and bottom, and secured by a pier of the same material, extending to the
back wall at I, Fig. 6. The mouth piece H,of the retort, is of cast iron or other
fitmetal formed like a squareframe, of such dimensions as to embracethe end of
the clay retort, and also enter into it for a short distance, as seen by the longitu-
dinal section at H. It has a projecting flanch, through which screw bolts n, n,
are passed, to unite it firmly to the front plate K, of the furnace, which is also
of cast iron, and of the form seen at K, K, in Fig. 8. A similar plate to K, K,
or otherwise bars of metal, are placed at the back of the furnace wall, as
shewn at L, L, Fig. 6. These two plates are united by long wrought iron
bolts, passing intirely through the brickwork of the furnace (at such distances
from the inside as not to be materially injured by the action of the fire) and
secured by nuts screwed on their ends or otherwise, as seen at e, e, e, e,
Figures 6, 7, and 8. By this arrangement the whole of the furnace is firmly
bound together, so as to avoid the danger of breaking the joinings in the
retort by the expansion or contraction of thebrickwork composing thefurnace.
The front plate K has the fire door M, Fig. 8, attached to it, as also the
ash, pit door N, which serves to regulate the draught of air through the
furnace, or to damp the fire when the operation of carbonizing is completed.
The coal or other substance from which gas is to be produced are introduced
through the mouth piece H, which has an iron door or cover O fitted to it, and
secured by a cross bar h, h, which bar may be removed when the coal is
introduced or the coke withdrawn from the retort. The cover is pressed

page_text: close up to the mouth piece by means of a screw i, having a cross handle to
turn it by. P, the pipe which conveys the gas off from the retort as fast as it
is generated. The fire is made in the body of the furnace at B, and the flame
ascends against the bottom of the retort, which is guarded immediately over
the fire by a piece of burnt fire clay or other fit material, shewn at r, r, to
prevent an excess of heat at that part so as to injure the retort. The flame
passes through the openings between the piers E, E, rises up on each side of
the retort, then through the spaces between the piers F, F, over the retort,
and escapes through an opening or openings at the back of the furnace, as
seen at Q, Q, Fig. 6 and 7, into a flue R, formed above the roof of the
chamber D, along which it passes in its way to the chimney or vent, as shewn
by the direction of the small darts or arrows in the Figures.
The common
brickwork is continued some height above the flue R, to keep the top of the
chamber D and retort firm by its incumbent weight.
I have described a furnace containing only one retort, but two or more may
be placed in the same furnace, provided that the piers of fire clay, before
described, are introduced between them, so as to support and keep the portions
of the retort together. The dimensions and proportions of the parts may be
varied according to the discretion of the workmen.
In witness whereof, I, the said John Grafton, have hereunto set my hand
and seal, this Thirty-first day of August, in the year of our Lord One
thousand eight hundred and twenty
AND BE IT REMEMBERED, that on the Thirty-first day of August, in
the first year of the reign of His Majesty King George the Fourth, the said
John Grafton came before our said Lord the King in His Chancery, and
acknowledged the Instrument aforesaid, and all and every thing therein con-
tained and specified, in form above written. And also the Instrument aforesaid
was stamped according to the tenor of the Statute made in the fifty-fifth year
of the reign of His late Majesty King George the Third.
Inrolled the Thirty-first day of August, in the year of our Lord One