IMPROVEMENTS IN APPARATUS FOR MAKING ILLUMINATING GA§
Year: 1871

page_text: C
PROVISIONAL SPECIFICATION left by the said James Moffat at the
Office of the Commissioners of Patents, with his Petition, on the
11th December 1
1871 to sourating
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I, JAMES MOFFAT, of the Firm of J. FeAllan, and; Company, of
Glasgow, in the County of Lanark, North Britain, Gas Engineers, do
hereby declare the nature of the said Invention for IMPROVEMENTS IN
APPARATUS FOR MAKING ILLUMINATING GA§ to be as follows:
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This Invention relates to apparatus of the kind described in the
Specification of Letters Patent granted to John Fleming Allan, and
dated 16 January 1871 (No.113); and consists of an improved con-
struction or arrangement of the retort and furnace and other parts in
immediate connection therewith. i „hih aming mail to
1
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page_text: In carrying out the present Invention the retort is made of a cylin-
drical form, and is placed centrally in a vertical cylindrical furnace,
which last is an iron shell having within it a fire-brick fire-box with a
space for the passage upwards of the flames from a grate at the lower
part between the fire-brick and the retort. The retort is formed with an
outlet branch pipe for the gas at the side close to the top; and the
retort cover is fitted to the top, the cover and retort mouth being both
engine turned to make a close joint without luting. The cover is fitted
down by eccentrics, and when being opened slides on horizontal guides
cast on the retort.
The smoke and gases from the furnace pass up a vertical funnel
directly over the top of the retort, and a hood arranged to slide tele-
scopically in the upper fixed part of the funnel is suspended by chains
passing over pulleys to counterweights, which admits of its being lowered
down over the furnace and retort when working, and of its being raised
for charging the retort. Metal cages fitting inside the retort are pro-
vided for the coal; and when a charge is exhausted the cage which has
been in use is lifted out with the coke in it, and another cage is inserted
with fresh coal.
The outer shell and the fire-brick fire-box are of such sizes as to leave
a space
between them to which air has access at the bottom; and this
air passing up keeps the outer shell cool, and may at the top be led into
the funnel, or if preferred the heated air may be allowed to escape into
the chamber through apertures in the shell.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Moffat in the Great Seal Patent Office
on the 10th June 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
MOFFAT, of the Firm of J. F. Allan and Company, of Glasgow, in the
County of Lanark, North Britain, Gas Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eleventh day of December, in the
year of our Lord One thousand eight hundred and seventy-one, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,

page_text: give and grant unto me, the said James Moffat, Her special licence
that I, the said James Moffat, my executors, administrators, and
assigns, or such others as I, the said James Moffat, my 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 "IMPROVEMENTS IN
APPARATUS FOR MAKING ILLUMINATING GAS," upon the condition (amongst
others) that I, the said James Moffat, 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 James Moffat, 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 in writing, reference being had to the accompanying
Drawings, that is to say :-
My said Invention relates to apparatus of the kind described in
the Specification of Letters Patent granted to John Fleming Allan, and
dated 16 January 1871 (No. 113), and consists of an improved con-
struction or arrangement of the retort and furnace and other parts in
immediate connection therewith.
And in order that my said Invention and the manner of performing
the same may be properly understood I hereunto append a Sheet of
explanatory Drawings to be herein-after referred to, and representing a
comparatively small size of gas making apparatus as constructed with
my improvements. In these Drawings the same reference numerals
are used to mark the same or like parts wherever they are repeated.
Figure 1 is a plan of the apparatus with its covering hood removed,
and Figure 2 is a vertical section. The retort 1, which is of cast iron,
is made of a cylindrical form, and is placed centrally in a vertical
cylindrical furnace, which last is an iron shell 2, having within it a fire-
brick fire-box 3 and fire-brick shell 4, with a space 5 surrounding the

page_text: retort 1, such space being for the passage upwards of the flames from a
grate 6 at the lower part. The structure rests on a cast-iron base 7,
which serves as an ash pan, whilst the outer shell 2 is of sheet iron, and
a doorway 8 is formed at the side for introducing fuel into the grate 6.
The retort 1 is formed with an outlet branch pipe 9 for the gas at the
side close to the top, and the retort cover 10 is fitted to the top, the
cover and retort mouth being both engine turned to make a close joint
without luting (but which may be used if preferred). The cover 10 is
fixed down by eccentrics 11 on a horizontal spindle 12, the end of which
spindle is squared to receive a handle; and when the cover 10 is being
opened it slides along horizontal guides 13 cast on the retort 1, the eyes
or staples which hold down the eccentric spindle 12 moving in slots in
the guides 13. A cast-iron plate 14 is placed on the top of the fire-brick
shell 4, and the retort 1 rests on it by three lugs cast on for the purpose.
The bottom of the retort is protected from the too intense direct heat of
the fire by a fire-brick piece 15 formed with lugs by which it rests on
the top edge of the fire-box 3.
The smoke and gases from the fire pass up the space 5, and through
openings in the plate 14; they then proceed up a vertical funnel 16
directly over the top of the retort. A hood 17, arranged to slide tele-
scopically in the upper fixed part of the funnel 16, is suspended by
chains 18 passing over pulleys 19 to a counterweight ring 20, which
admits of its being lowered down over the furnace and retort when
working, and of its being raised for charging the retort. Metal cages of
the kind shown in plan in Figure 3, and in side elevation in Figure 4,
are provided to contain the coal; and when a charge is exhausted the
cage which has been in use is lifted out with the residuary coke in it,
and another cage containing fresh coal is inserted into the retort. The
cage is by preference made with a tube 21 at its centre, such tube
having perforated sides, and thus providing free egress for the gas from
the middle parts of the coal.
The outer iron shell 2 of the furnace and the inner fire-brick lining 4
are of such sizes as to leave a space 22 between them to which air has
access at the bottom, and this air passing up keeps the outer shell 2
cool, and may at the top be led into the funnel 16; or if preferred the
heated air may be allowed to escape into the chamber through apertures
in the upper part of the shell 2.
The modification of my improved apparatus, shown in the Drawings

page_text: and hercin-before described, is suitable for a small house; but it may
easily be made of larger size or capacity, it being preferable in such
cases to combine two, three, or more retorts (1) in one furnace, placing.
them vertically and near together.
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· In some cases it may be more convenient to lead off the smoke from
the furnace by a pipe at the side, as indicated by dotted lines at 23 in
Figure 2; and when this is done the hood 17 may be retained, or any
other convenient cover may be substituted for it.
Having thus particularly described my said Invention, and the
manner of performing the same, I have to state that I do not restrict
myself to the precise details herein described or delineated; but that
what I believe to be novel and original, and claim as the Invention
secured to me by the herein-before in part recited Letters Patent,
is,―
1. The arranging or combining together of the parts of apparatus for
making illuminating gas substantially in the improved manner herein
described and delineated.
2. The disposing of the retort or retorts vertically, and the applying
of the cover (10) in the manner herein described and delineated.
3. The application of the movable hood (17) as herein described and
delineated.
In witness whereof, I, the said James Moffat, have hereunto set.
my
hand and seal, this Eighth day of June, in the year of our
Lord One thousand eight hundred and seventy-two.
Witness,
EDMUND HUNT,
'
Patent Agent,
Glasgow.
JAMES MOFFAT. (L.S.)