IMPROVEMENTS IN THE MANUFACTURE OF GAS RETORTS, AND IN THE MODES OF SETTING GAS RETORTS
Year: 1843

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
MALAM, of Huntingdon, Gas Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Sixteenth day of March, in the sixth year of Her reign,
did, for Herself, Her heirs, and successors, give and grant unto me, the said
James Malam, Her especial licence, full power, sole privilege, and authority,
that I, the said James Malam, my exors, adiñors, and assigns, or such others
as I, the said James Malam, my exors, adñors, or assigns, should at any
time agree with, and no others, from time to time and at all times during the
term of years therein expressed, should and lawfully might make, use,
exercise, and vend, within England, Wales, and the Town of Berwick-
upon-Tweed, my Invention of "IMPROVEMENTS IN THE MANUFACTURE OF GAS
RETORTS, AND IN THE MODES OF SETTING GAS RETORTS;" in which said Letters
Patent is contained a proviso that I, the said James Malam, shall cause a
particular description of the nature of my said Invention, and in what manner
the same is to be performed, to be inrolled in Her said Majesty's High Court of
Chancery within six calendar months next and immediately after the date
of the said in part recited Letters Patent, as in and by the same, reference
being thereunto had, will more fully, and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
James Malam, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are fully described and

page_text: DESCRIPTION OF THE MODE IN WHICH I PROPOSE TO SET CLAY OR IRON
RETORTS, for the Production of Carburetted Hydrogen or Coal Gas
from Pit Coal; Coal Tar, or Water, or from the Vapour of Coal Tar
and Aqueous Vapour; also a Description of my DOUBLE RETORT, and the
Mode of Setting the same.
.
Figure 1 represents a front elevation of three dee clay retorts in a complete
state, set to one furnace and heated by one fire, the breadth of the bed to be
eight feet, the height from the floor line to the strong course or coping to be
eight feet eleven inches. a, a hydraulic screw, ten inches diameter, inside
measurement. c, c, c, pipes four inches diameter. .d, d, d, (Figure 5) the mouth-
pieces, fourteen inches by fourteen inches, and nine inches in depth, and d', d', d,
lids of the retorts t, t, t. See Figures. 3, 4, 5, 6, 7, and 8. The retorts are
shewn with the mouthpieces on, lids and brass bars X, X, X, screwed up.
The mouthpieces and lids are of cast iron; the flanges of the mouthpieces
e, e, e, e, e, e, to be e four inches wide round the dee part of the retort, and two
inches wide on the under side, as shewn at e', e¹, e', the bottom of which to be
flush with the flanges of the clay retorts. The mouthpieces are to be bolted
on the flanges of the clay retorts with proper cement for that purpose, such
as a mixture of iron borings and fire clay. 1, two sight-holes, six inches
by three inches, to look at the top retorts, &c. 2, 2, 2, three sight-holes, five
inches by three inches, to clean out the two top side flues. See Figures 6, 7,
and 8. 3, 3, two bottom side flues, six inches by three and a half inches.
See Figures 2, 6, 7, and 8. f,f,'f, nine-inch arch of fire-brick, semicircular,
and four feet nine inches in diameter. The spring of this arch is four feet
from the floor line; the inside off, f, f, is called the oven, in which the retorts
t, t, are set. g, g, frame for the furnace door, to be one foot eight inches square
and four inches wide. h, the furnace door, to be twelve inches square with
latch and hinges complete, as shewn upon the Plan. i, ash pan, to be eighteen
inches deep, eleven inches wide, and four feet nine inches long at the top,
and three feet long at the bottom. See Figure 3. a, a, piers upon which the
hydraulic main a, a, rests.
1. if t
r
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1,
1
.!
F
Figure 2 shews a plan of the furnace j,,,, and direction of the bottom
flues 3, 3, (see also Figures 1, 6, 7, 8,) as marked upon the Plan by
arrows. 'j, j,j, j, the bottom or plan of the furnace, to be five feet ten inches
long and two feet three inches wide. k, k, k, k, four openings from the furnace,
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.
3

page_text: nine inches wide, into the bottom two side flues, marked also 3, 3, Figures 1, 6,
7, and 8. 3, 3, the plan of the two bottom side flues, nine inches 'square,
which ascend at each end, at 1, 1, as seen at Figure 4, into the two top side
flues and middle flues, 2, 2, 2, as shewn in Figures 1, 6, 7, and 8. m, m, m, m,
four and a half inch arches, made in three pieces, each of fire clay ashes, &c.
See Figure 26, under which these arches will be found more particularly
described. n, n, m, n, n, openings between the arches m, m, n, m, covered with
fire tiles, the tops of which to be flush with the top of the arches. These tiles
are to be two feet ten inches long, by ten and a half inches broad, and two
and a quarter inches thick. See Figures 29 and 30, under which these fire
tiles will be more particularly explained. Five of these tiles-will-be required
in each set of retorts, three in a bed. 0, 0, 0, 0, 0¹, o¹, plan of fire-brick arch
fff, in which the retorts t, t, t, shown in Figures 1, 3, 4, 5, 6, 7, and 8,
are set, to be seven fect long inside dimensions on the ground plan, as shown in
the Figure now described. p, p, fourteen-inch common brickwork. p¹; nine-
inch, and q, q, four and a half inches common brickwork.
1, 1, r, r, fire bars.
s, s, bearers for fire bars, dimensions as shewn. g, g, and h, furnace.frame
and door. i, ash pan. See Figure 1, longitudinal length of the bed, of which
this Figure is a plan, is eight feet ten inches.
Figure 3 is a plan of the two bottom retorts t, t, as shown in Figures 1, 4,
5, 6, 7, and 8. c, c, plan of pipes. The same letters in this Figure refer to the
same parts as described in Figures 1 and 2, which see. it, t, the two bottom
retorts, and u, u, the flanges of said retorts. See Figure 5. v, v, shew the top
of the two top side flues, and w the top of the middle flue. See Figures 1, 6, 7,
and 8, marked 2, 2, 2. y. y, shew where the heated air or flue ascends from
the bottom flues. 3, 3, (Figures 1, 2, and 4,) into the horizontal top side flues,
and middle flue and w, Figure 3. z, a flue that runs at the bottom of the
two bottom retorts t, t, on the same level with the top: side flues v, v, and
middle flue w,, with each, of which it communicates. x, x, x, three openings
in the flues v; v, and w, six inches square, through which the heated air escapes
from the body of the oven marked 4, 4, Figures 6, 7, and 8; on which the
retorts t, t, t, are set. The letters v, v, and w in this Figure refer to the same
flues as 2, 2, 2, do in Figures 1, 4, 5, 6, 7, and 8.
Figure 4 is a longitudinal section of Figure 2 at I, J; the ash pan i and
fire bars r, r, r, r, are purposely shewn. The Figure particularly shews the
.direction of the flues.. k,.k, the openings from the furnace,.as shown by arrows,
into the bottom side flues 3, 3. 1, shews a vertical section of two square
openings, six inches by six inches, which communicate with the back bottom
flue l', Figure 2, and also with the top back flue 2, Figure 3, through the

page_text: square openings (six inches by six inches) y, y, Figures 3 and 4. y, shews a
vertical section of the square openings (six inches by six inches, which com-
municate with the top side flues 2, 2, 2, Figures 4, 5, 6, 7, and 8. z¹, Figure 3,
shews a square opening (six inches by six inches) which communicates with the
top back fluez and the middle flue w, Figure 3, or the middle flue of 2, 2, 2,
Figures 4, 5, 6, 7, and 8.
x, x, square openings in the top side flues and
middle flue 2, 2, 2, Figures 4, 5, 6, 7, and-8, and v, w, and v, Figure 3. On
inspecting this Figure the action and direction of the flues will be perceived;
for instance, the flame and heated air from the furnace j,j.j.j, Figure 2,
ascend at the two openings in each side of the furnace, which openings in
Figure 2 are marked k, k, k, k, and in Figure 4 k, k, where only one side of
the furnace is shewn. The heated air and flame then proceed in the direction
of the arrows, shewn in Figures 2 and 4, into the bottom side flues 3, 3, 3, 3,
Figure 2, and 3, 3, Figure 4; from thence through the openings 1, 1, Figure 2,
and 1, Figure 4, into the bottom back flue l', Figure 2, and through the
openings y, y, Figure 4, into the top side flues v, v, Figure 3, and 2, 2,
Figures 4, 5, 6, 7, and 8, as also into the middle flue w, Figure 3, and 2,
Figures 4, 5, 6, 7, and 8, through the opening z¹, Figure 3; and as it will be
perceived, on inspecting this Figure, the heated air from the two top side flues
v, v, and middle flue w, Figure 3 and 2, 2, 2, Figures 4, 5, 6, 7, and 8
'ascends through the square openings x, x, x, as described in Figure 3; from
thence into the body of the oven marked 4, 4, Figures 6, 7, and 8, and from
the oven into the main flue marked 5, Figure 4, as shewn by the arrow, into
the stock or chimney. From this mode of setting retorts it will at once be
perceived that there is as little "dead work," as it is termed, in connection
with the retorts as possible, and consequently the retorts are not robbed of heat
from that cause; whilst on the other hand, though the retorts may be of iron,
they are sufficiently guarded from the action of the flame; but if of clay
the nature of the material of which they are composed will of itself be a
sufficient guard, and guarantee their durability. Both the sides and ends of
each of the bottom retorts are exposed to the action of the heat, and the
bottoms of the same must successively be so, as between the four and a half
inch arches of the furnace there are only two and a quarter inch fire tiles
between the body of the furnace and them. It will be perceived also that the
top retort will be duly exposed to the heat both top and bottom. 7, 7, 7, sand
or common brickwork, to keep in the heat in the oven 4, 4, Figures 6, 7,
and 8, placed over the arch f,f.
Figure 5 shews a longitudinal section of Figure 2 at A, B; the same letters
in this Figure before described. This section is intended to shew a section

page_text: Upon inspecting
this Figure it will be seen that the clay retorts are made and put together in
two separate pieces of equal length with fire clay and iron borings, or any
other proper cement. See Figures 17, 18, 19, and 20. 6, 6, 6, section of three
saddles upon which the top retort is set, made of fire clay. See Figures 6, 7,
and 8, also Figures 31 and 32. These saddles rest upon the tiles which cover
the middle flue w, Figure 3, and marked 2, Figures 4, 5, 6, 7, and 8. The
Fire tiles
length breadth and thickness of these tiles will be given hereafter.
are also placed upon the saddles 6, 6, 6, see Figures 6, 7, and 8, and upon these
the top retort rests. m, m, m, m, shew a longitudinal section through the
arches and key or centre piece. Sce Figures 26, 27, and 28, when these arches
are more particularly described. n, n, n, n, n, openings between the arches
m, m, m, m, m, covered with fire tiles as shewn in the Drawing. See Figures
29 and 30.
through the top retort t, and the mode in which it is set.
Figure 6 is a vertical section of Figure 2 on G, H, through one of the
openings between the arches, having no communication with the flues. In
this section the arches are not seen, though dotted in the Figure, the space
9, 9, shewing the shape of the opening. between the arches which, in this
section, has no communication with the flues, as shewn by the side tiles of the
flues marked 3, 3. a, a, projections, more plainly shewn in Figures 29 and 30
upon the face of the arch m, m, Figure 7, and Figures 26, 27, and 29, to
allow the furnace tiles n', n', Figures 5, 6, 7, and 8, and Figures 29 and 30
to rest upon in lying over the openings n, n, n, n, n, Figures 2 and 5. The
remaining letters refer to parts explained in preceding Figures.
Figure 7 represents a vertical section of Figure 2 on E, F, through one of
the arches m, Figure 2, and m, m, Figure 7. n, fire tiles set upon the
saddles 6, to be the saddles in three lengths, each twenty-two inches by twenty
inches, and two and a quarter inches thick. The same letters in this Figure
refer to some parts as described in preceding Figures.
Figure 8 represents a vertical section of Figure 2 on C, D, through one of
sor flues 12, 12, 12, 12,
the openings n between the arches, on which the openings
Figure 2, are situated, and through which the flame and heated air ascend
from the furnace f, f, into the bottom side flues marked 3, 3. These flues or
openings are marked k, k, Figure 8, and 12, 12, Figure 4, which see; and for
remaining letters see preceding Figures.
Figures 9 and 10 represent a mode of producing carburretted hydrogen gas
from the mechanical mixture of aqueous vapour and vapour of coal tar.
Figure 9 represents a plan of the two bottom retorts, which are set upon
exactly the same principle as the retorts described in the preceding Figures, to
which the same letters refer: A, A, are two cast-iron pipes, three feet six

page_text: inches long from the end of the retorts t, t, to the opposite end, and project
_two fect from the brick work. These pipes are inserted in a slanting direction
into the ends of the retorts.t, t, near the tops, as shewn in Figure 10, and
communicate with the inside of the retorts. B, small lids and cross bars;
these lids are fitted tight by.luting to the ends of the pipes A, A, which are
round and four inches in diameter at this part. These lids are intended to be taken
off every four or six hours to clean out any obstruction which may accumulate
during that time in the production of gas from the aqueous vapour and vapour
of coal tar. The lids of the retorts d', d', are taken off only as occasion
may require to clean out the retorts t, t, or any obstructions in the H pipe.
C, C, C, C; fire brick or tiles which rest upon the covering of the top back flue L,
Figure 3, to protect the pipes A, A, from the action of the heat. E, E, section
of one such wrought-iron screw pipes which convey the vapour of tar into the
pipes A, A, and from thence into the retorts t, t. D, D, section of one of
such wrought-iron pipes which convey the aqueous vapours into the pipe A,
and from thence into the retorts t, t. It will be seen, on looking at this
Figure, that the ends of the pipes A, A, which are inserted into the end of the
retorts t, t, are of an oval shape, the conjoined diameter being four inches, and
the traverse seven inches, which is done to prevent the speedy stoppage of
these pipes.
A, B, Figure 2,
Figure 10 is a longitudinal section of Figure 1 at
with the cast-iron pipes A, A, added. G, is a small boiler, ten inches
diameter, and seven, feet long, partly filled with coal tar, and heated with
being placed in connection with the main flue (marked 5), to be placed
behind the boiler marked H. It is placed in its proper position in this Figure,
so as to be seen. H, a small boiler of the same dimensions as G, partly filled
with water, and heated the same as G. These boilers are intended to be
supplied with coal tar and water from cisterns conveniently placed in the
retort house. E, pipe conveying the vapour of tar into the upper pipe A.
D', the pipe conveying the vapour of tar into the upper pipe A. D, the pipe
conveying the aqueous vapour into the lower pipe A. E and D, communicating
with the bottom retorts, are shewn disconnected with G and H, but are
intended to have communication with the pipes from G and H above the
taps F of the pipes D' and E'. The taps F, F, F, F,. are to regulate the.
supply of the vapour of tar and the aqueous vapour into the retorts. The s
mode of fixing the pipes A, A, into the retorts is shewn in the section of the
top retort t. The pipes A, A, near the end, which are inserted. inside of the
retorts, have a flange cast upon them projecting three inches on the under side,
and only one inch and a half on the upper side.
shape, as the pipe is at this end. The sides of the
The flange is of an oval
retort at the ends project. 4

page_text: one inch and a quarter over the ends. An oval hole is made through the end
of the retorts near the tops; the small pieces of pipe which project beyond the
flange is inserted into the hole, and the flanges fit tight against.the ends of the
A thin coat of fire clay and iron facings is put over the flanges and
the ends of the retorts, and then one and a quarter inch tiles made to fit into
the D-shaped cavities formed by the retorts, and the sides projecting over the
ends one inch and a quarter. In this way the flanges of the pipes A, A, are
made fast and tight between the ends of the retorts and the D-shaped picces
of tiles before mentioned. See this Figure, in which this is shown. The other
letters refer to the same parts as the preceding Figures. These retorts being
set three to one furnace, and in the same way as those described in former
Figures, it will be noticed that the aqueous vapour and vapour of coal tar
from the boilers G and H partly combine in the pipes A, A, and from thence
enter into the retorts t, t, and are then resolved through the calcine given out
by the retorts into carburretted hydrogen gas, and passed into the hydraulic
WAY

page_text: the retort d, Figure 13, and made gas-tight in the usual way with luting.
K, K, K, K, K, K, lids, six inches by four inches, which communicate through
a square hole in the front of the double retort I, I, I, I, with the space L, L, L,
Figure 12, between the outer and inner retorts of the double retorts, the former
marked N and the latter t. These lids are made tight by luting and small
brass bars, &c., in the usual way, and are intended to be taken off only as
. occasion may require to clean out any carbonaceous deposit, which will more
or less accumulate within the space L, L, L, between the other retort N and
the inner retort t. The lids of the mouthpieces J, J, J, are also intended for
the same purpose, and that of cleaning out any stoppage that may occur in
the pipes marked c, c, c.
Figure 12 shews a vertical section of the double retorts through the flues;
the section is of the same nature as Figure 8 is at C, D, Figure 2, and the
same letters refer to the same parts in the three Figures. L, L, L, the space
between the inner and outer retorts, which is six inches.
t, t, t, the inner
retorts, and N, N, N, the outer retorts of the double retort. 0, 0, 0, ribs or
ridges of fireclay, which run the whole length of the double retorts, except
over the hole marked M, Figure 13. These ribs or ridges are six inches deep
and two inches thick, one end of which fits tight up to the cast-iron front
I, I, I, I, of the double retort, and the other end to the bottoms of the outer
retorts N, N, N. It will perceived, upon inspecting the Figure, that these
ribs are placed in the centre of the D part of the spaces L, L, L, between the
inner and outer retorts t, t, t, and N, N, N. This is to keep the inner
retorts t, t, t, which are made without bottoms and ends, firm in their places.
The ends and bottoms of the inner retorts t, t, t, are made perfectly gas-tight
to the bottoms and ends of the outer retorts N, N, N, and the end of the inner
retorts may have a flange on to fit the better to the end of the outer retorts
N, N, N, which flange is not, however, shewn in these Drawings.
P, P, P, may be set in proper cement the more firmly to unite and make
gas-tight the inner retorts t, t, t; these tiles should run the whole length of the
double retort. The large retorts N, N, N, are twenty inches diameter, and
twenty-one inches and a half high, inside measurement, and seven feet
long (in the equal separate pieces) out and out, and two inches thick, the
flanges four inches thick from the inside of the retort, and four inches deep.
The inner retorts t, t, t, are also to be made in two equal separate pieces, the
whole length of which to be six feet ten inches without bottoms and without
ends, and one inch and a quarter thick. The cast-iron fronts of the double
rails I, I, I, I, to be made to fit gas-tight with proper cement and bolts to the
flanges of the outer retorts N, N, N, and the inner retorts t, t, t, (which may.
Tiles

page_text: have a flange, not however seen in the Drawings) both of which are to be set
flush with each other. At the ends of the inner retorts t, t, t, and three inches
from the ends of the outer retorts, N, N, N, is a hole eight inches in diameter,
as shewn in Figure 13, marked M. This hole is to allow the escape of gas
from the inner retorts t, t, t, made in the process of carbonization of pit coal,
into the spaces L, L, L, L, &c., and meeting with an additional quantity of
caloric from the heated surfaces of the outer retorts N, N, N, and the inner
retorts t, t, t, the vapours of coal tar and ammonia usually deposited in the
hydraulic main, and from thence conveyed into the tar well or tank in the
common distillation of pit coal for the purpose of producing coal gas, will,
through the additional dose of caloric, be resolved into carburetted hydrogen or
coal gas, in addition to the quantity of coal gas procured in the usual way;
and as it has been satisfactorily proved that coal tar contains a greater amount,
in proportion of "olefiant gas" (to which coal gas owes its principal lighting
quality) then pit coal. The coal gas thus produced must necessarily be of
superior quality, and in greater quantity than that ordinarily produced,
providing that the quality of it be not deteriorated by allowing the outer
retorts N, N, N, of the double retorts to approach to a higher heat than a
bright cherry red, visible by daylight, or about 27° Wedgewood, the heat at
which copper melts, otherwise the hydro-carburets will be resolved into carbon
and hydrogen gas.
Figure 13 shews a longitudinal section of Figure 1-1, the same as Figure 5 is of
Figure 2 at A, B. The same letters refer to the same parts as former Figures.
This section more particularly points out the mode in which the cast-iron
fronts of the double retorts I, I, I, I, Figures 11 and 25 are bolted on t, t, the
retorts. M, the hole through which the gas finds its way into the spaces L, L, L.
J, the mouthpiece, which communicates with the regenerating part of the
double retort, marked L, L, L; this mouthpiece is shewn with the lid on, but
without cross bars, handles, &c. c, the ascension pipe, which communicates
with the mouthpiece J, and conducts the gas to the hydraulic main. The
side of this mouthpiece towards L, L, L, is bolted on with proper cement
to the cast-iron front of the double retorts I, I, I, I, &c., see Figures 11 and 25,
the mouthpiece d of the inner retorts t, t, being cast on the front of the double
retorts I, I, I, I.
Figure 14, shews a front elevation of a double retort, set singly to one
furnace heated by one fire. The breadth of the bed is seven feet six inches,
and the height of the bedroom from the floor line to the string course seven
feet six inches. The spring of the arch f, f, f, to be three feet two inches

page_text: from the floor line, and the diameter of the arch f. f, f, to be four feet four
inchés semicircular. The furnace j, j, Figure 15, to be two feet wide, and
two feet high. The only difference of setting the double retort single is the
above dimensions, and the absence of the middle flue 2, and marked win
Figure 3, otherwise this double retort is set exactly the same as those before
described.
Figure 15 shew's a vertical section of Figure 14, the same as Figure 7 does
of Figure 2 at. E, F, supposed to be a section through the arch m. 2,2, the
two top side flues. 3, 3, the two bottom side flues. j,j, the furnace. m, m, arch.
See Figure 26.
..
Figure 16, a longitudinal section of Figure 14, the same as Figure 5 is of
Figure 2 at A, B. The same letters refer to the same parts as in Figures 14,
15, and 16, &c., and needs no further description.
Figure 21,shews a longitudinal section of the double retort on the half-inch
.scale. u, u, flange on the outer retort. N, N, N, N, the outer retort. t, the
inner retort. M, the eight-inch hole through which the gas escapes into the
-spaces L, L, L, Figure 22. This hole to be three inches from the bottom of
the outer retort N, N. O, O, a section through the rib or ridge. See
Figure 22.
Figure 22, a vertical section through Figure 21. L, L, L, the spaces, to be
six inches between the outer and inner retorts N, N, and t. N, N, the outer
retort. t, the inner retort. O, the ridge or rib that runs the whole length of
the retort in the centre of the dee part of the double retort, as shewn in the
Figure. This rib does not, however, run across the hole M, as shewn in
Figure 21. P, P, fire tiles, six inches broad, which run the whole length of
the retorts, to secure these firmly, the inner retort t, to the bottom of the outer
retort N, N, and also to prevent communication between the two retorts,
except at, M. The outer: retort to be seven feet long, out and out, to be two
feet five inches broad, and twenty-one inches and a half high, inside measure-
ment. The inner retort to be fourteen inches high, and fourteen inches
broad, and six feet ten inches long, and one inch and a half thick. The outer
retorts N, N, to be. put together in the same way as the inner retorts t, and to
be two inches thick.
Figure 23 shews a plan of Figure 21. u, u, the flange.
retort, put together in two equal pieces.
N, the outer
Figure 25 shews a front view of the cast-iron front of the double retort on
the one-inch scale. I, I, I, I, the front of the retort which, is butted on with
proper cement to the flange u, u, Figure 21. This front also fits tight up

page_text: against the rib 0, 0, and the retort t, which can have a flange on at this end,
if necessary, the better to insure the soundness of the inner retort. K, K, (six
inches by four inches) lids which fit on the front I, I, I, I, with cross bars and
handles. These are to be taken off as occasion may require, to clean out the
space L, L, L, Figure 22. J, lid of the mouthpiece d, Figure 13, which is
to be taken off only as occasion may require to clean out the space L, L,
Figure 22.
11
I.
Figure 25, d', the lid of the mouthpiece d, Figure 13. c, the ascension
pipe. The dimensions have been given.
Figure 26, a front view of the arch m, m,, Figure 7, on the one-inch scale,
to be two feet three inches wide, and two feet high, and six inches thick, and
four and a half broad. This arch is made in three pieces. 8, the key piece.
m, m, one side of the arch. a, a, pieces upon the face of the arch m, m, which
project two inches, and six inches long for the furnace tiles, Figures 29 and 30,
to rest upon. c, c, recesses, two inches by one inch and a half, for the bottom
side flue tiles to rest upon.
...
Figure 27, the end view of the Figure 26. c shews the recess for the
bottom side of the tiles to rest upon. a, a, the projections for the furnace ties
to rest upon m, m. The thickness of the arch to be six inches.
Figure 28, plan of the arch, Figures 26 and 27. c, c, recesses. m, m, arch.
8, the key piece.
Figure 29, plan of the furnace tiles n', n', n', n', Figure 5, on the one-inch
scale. e, e, recesses to fit on projections a, a, Figure 27, to be thirty-four
inches by nine inches, and two inches and a quarter thick.
Figure 30 shews a section of Figure 29. e, e, the recesses.
Figure 31, front view of the saddles, marked 6, Figure 6. The breadth
from m to m seventeen inches, the depth from m to n four inches and a
quarter thick; the whole length from e to n fourteen inches, four inches
thick. Three of these required for each top retort. The saddles for the
double retorts to be the same shape, but the breadth to be twenty-seven inches
and a half, and the length twenty-two inches, and four inches thick.
Figure 32, side view of Figure 31, m, m, four inches.
Having thus described the nature of my Invention, I would have it under-
stood, that what I claim is,-
of
First, the mode of arranging the flues in setting retorts for the manufacture
gas, as herein described.
Secondly, I claim the mode of manufacturing carburetted hydrogen gas by
conducting the vapours from water and tar into retorts, in the manner
herein described; and,

page_text: Thirdly, I claim the mode of manufacturing carburetted hydrogen gas by
means of double retorts, as herein described.
In witness whereof, I, the said James Malam, have hereunto set my
hand and seal, this Sixteenth day of September, in the year of our
Lord One thousand eight hundred and forty-three.