IMPROVEMENTS IN THE MANUFACTURE OF GAS
Year: 1852

page_text: LETTERS PATENT to George Michiels, of 57, Holywell Street,
Westminster, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF GAS."
Sealed the 2nd March 1853, and dated the 24th December 1852.
PROVISIONAL SPECIFICATION left by the said George Michiels at
the Office of the Commissioners of Patents, with his Petition,
on the 24th December 1852.
I, GEORGE MICHIELS, of 57, Holywell Street, Westminster, in the
County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF GAS" to be
as follows:-
The object of this Invention is to encrease the power of the gas
manufacture by a peculiar mode of constructing and working a
retort of large dimensions, which is constructed of fire bricks, and
which are cemented together with a metallic vitreous preparation,

page_text: which, when subjected to the heat necessary for making gas froin
coal, makes a glaze, and renders the bricks impermeable to gas.
The best preparation, I believe, for such purpose is silica, lime,
potass, soda, magnesia, alumina, oxide of iron, oxide of manganese,
and borax. I do not, however, confine myself to these matters.
The retort has a cover at each end, and when a charge has been
completed, I cause, by mechanical means, a piston or surface equal
to the section of the retort to be moved through it, driving before
it the coke, which I receive in an oven capable of being closed, and
when closed I introduce steam, by which I obtain superior coke.
The retort is formed with openings at its upper side with suitable
covers, and trucks on railways supply the requisite charge of coal,
which is ground. The piston which I use for forcing out the coke
is formed with teeth at its lower edge, and by moving it to and fro
in the retort the charge is distributed therein.
SPECIFICATION in pursuance of the conditions of the Letters
Patent, filed by the said George Michiels in the Great Seal
Patent Office on the 24th June 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
GEORGE MICHIELS, of 57, Holywell Street, Westminster, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fourth day of December,
in the year of our Lord One thousand eight hundred and fifty-two,
in the sixteenth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said George Michiels, Her
special licence that I, the said George Michiels, my executors,
administrators, and assigns, or such others as I, the said George
Michiels, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times

page_text: 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 GAS,"
upon the condition (amongst others) that I, the said George
Michiels, by an instrument in writing under my hand and scal,
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 Michiels, do hereby
declare the nature of the said Invention, and in what manner the
saine is to be performed, to be particularly described and ascer-
tained in and by the following statement thereof (that is to say):
The object of this Invention is to increase the power of the gas
manufacturer by a peculiar mode of constructing and working a
retort of large dimensions, which is constructed of fire bricks, and
which are cemented together with a metallic vitreous preparation,
which, when subjected to the heat necessary for making gas from
coal, makes a glaze, and renders the bricks impermeable to gas.
The best preparation, I believe, for such purpose is silica, lime,
potass, soda, magnesia, alumina, oxide of iron, oxide of manganese, and
borax. I do not, however, confine myself to these matters. The
retort has a cover at each end, and when a charge has been com-
pleted I cause, by mechanical means, a piston or surface equal to
the section of the retort to be moved through it, driving before it
the coke, which I receive in an oven capable of being closed, and
when closed I introduce steam, by which I obtain superior coke.
The retort is formed with openings at its upper side, with suitable
covers, and trucks on railways supply the requisite charge of coal,
which is ground. The piston which I use for forcing out the cokc
s formed with teeth at its lower edge, and by moving it to and fro
n the retort the charge is distributed therein.

page_text: It
in the
appears to my mind, that in the present state of progress
different arts which co-operate together in the construction of gas
works, the power of the gas manufacturer may be increased, and
the gas produced more economically than by the present mode,
without employing large numbers of fine strong men to destroy
their health by charging red hot retorts through very narrow
apertures with sinall quantities of coal, and to sweat during twelve
hours in front of an intolerably hot radiating surface. I propose to
substitute for the sinews of these men the action of steain power,
and with this intention I amplify considerably the usual dimensions
of a retort, in order to obtain in one retort as much, if not more
heated surface as is now to be found in a whole bed of 16" retorts
twenty feet long. This I do for the purpose of having the floors of
my huge retorts all upon one and tlie same level, in order that the
same steam apparatus used for charging and drawing one of them
may perform the same operation for the others, by simply moving
such apparatus upon rails in front of the retorts. The dimensions
in the clear which I prefer giving to these huge retorts are thirty
feet in length, two feet in height, and about nine feet in width, the
top being parallel to the floor; so that the transverse section of the
interior of the retort represents an elongated rectangular figure.
I build these retorts with fire bricks; but I observe, that if I only
cemented the bricks together with fire clay, as is usually done, the
working of my retort would depend on the regular action of the
exhauster; that is to say, that should the exhauster cease to work,
the gas
would pass through the joints of the bricks-an occurrence
which would place a gas work in jeopardy. To meet this great
difficulty, I lay the bricks of which the retort is made in a vitreous
cement, which, when subjected to the heat necessary for making gas
from coal, forms a glaze, and renders the retort impermeable to gas.
The best way to prepare this cement is, I believe, to pound and
carefully mix together the elements of a double, treble, or a more
compound fusible silicate, in which silica, lime, potash, soda, magne-
sia, oxide of iron, oxide of manganese, or borax, may be usefully

page_text: employed; but should local circumstances not admit of such a com-
pound preparation, the good effect produced by potash, soda, or
better borax in the composition of the cement intended to become
vitrified, must not be lost sight of. It is apparent, per se, that this
cement must be formed into a paste with a small quantity of water,
so as to be casily used by the bricklayer. It will be obvious to
all men practically acquainted with the manufacture of porcelain,
earthenware, or glass, that my idea of setting the bricks of the
retorts in a vitreous cement can be carried out in an infinity of
different ways according to localities, giving in cach place the pre-
ference to the cheapest of the articles here above alluded to. For
instance, in London and in many other towns, recourse can at once
be had to a compound silicate, which is a refuse from the glass
paper manufactories, viz., the glass dust, to which an addition of
2 p' cent. or more of manganese, and 4 p' cent. or more of borax
can be made to facilitate the fusion of the aforesaid glass dust. In
other places it may be cheaper to employ potash or soda as a cement
between the bricks; the silica, and alumina of the fire bricks
when heated, combining with the potash or soda, and forming a
vitreous glazing cement, and so on in a variety of other ways. My
huge retort is furnished at each end with a cast iron mouth piece
plate, contrived for receiving a luted lid, which is firmly secured by
cotters. This retort is provided with two or more openings at the
top, by which the charge of coal is introduced by tilting waggons
running on a proper railways. The coal so introduced in the retort
is then spread equally over the bottom by the aid of a rake, which
forins the head of a rack worked by a steam engine. The charge
of coal which I prefer to work off in such a huge retort is six tons,
forming a layer of less than ten inches deep. When the charge is
worked off, I open the mouth pieces by unfastening and hoisting
the lids, and I push the charge of coke out in one cake, by the
assistance of the steam rack, the head of which, viz. the rake, being
for this purpose turned upside down, so as to act with its head and
not with its teeth. Such coke, if desulphuretted coke is desired,

page_text: may be received in an oven capable of being closed, and there treated
with this Intention by the admission of air and an injection of
steam, leaving one opening at the top for abducting the produces
of them.
One great peculiarity in the construction of my huge retorts is,
that they are well isolated from contact with any of those parts of
the construction which are liable to cool either by radiation or by
contact with the soil. This isolation is obtained by preserving round
the retort a circumambiant empty space, in which the produces of
the combustion in the fire places are caused to decant their heat at
different stages in their perambulation before finally passing under
the immediate foundation of the retort on their way to the main
fluc, which is constructed outside the foundations of the retorts, or
nearly so.
Having given the. leading ideas of my improvements, and the
main features of the construction in which I have embodied them,
I proceed with the technical description of the construction of a
huge retort, and that one to which I give the preference, for reference
to which I refer to the Drawings, Figures 1, 2, & 3; in which A,
is the fire place. The produces of combustion on leaving it divide
into two parts at B, and B'; one follows the course B, C, C, C, till
arriving at the vertical flue D, through which they descend into the
chamber F, which is common to these and to those produces of
the combustion which have followed the course B', C¹, C¹, C¹, D¹.
During such course the produces of combustion decant part of
their heat through the nostrils E, E, E, through which they ascend
round the retort, so that in reality by this phenomenon of decantation
there are formed two inverse currants on the sides of the retort, the
hottest ascending, which, after having parted with a portion of its
heat, will become descending, and the constant repetition of these
effects will have for result the keeping of the sides and top of the
retort at the same temperature as its floor or bottom. The Drawings
shew distinctly how the under floor, the sides, and the top of the
retort, are constructed for allowing this phenomenon of decantation

page_text: I
of heat to produce its full effect everywhere round the retort.
lay a particular stress on this system of construction, which offers
every possible facility to the working out of that law of nature
according to which the hottest part of gaseous products have a
tendency to rise, and the coldest to descend. It is according to the
same principle that the produces of combustion which we have left
in the chamber F, are caused to descend along an inclined plane in
the six flues G, G, G, &c., before they reach the lower chamber H,
which delivers them through one aperture to the horizontal chimney
I. The aperture now spoken of is commanded by the damper K,
which regulates the draught of the fire place. This damper is to
be got at through an inclined fluc, the entrance opening of which is
covered by the tile M, in front of the retort. It is to be observed,
that the flue leading to the damper K, is provided with a stopper L,
the object of which is to prevent the heat of the chimney I, ascending
to M. The six inclined flues leading to the chamber H, are connected
together sideways by the openings J, J.
The under floor of the retort is composed of three parts, differing
one from another in their construction; that is to say, that the floor
of the retort which is formed by bricks on edge is separated from the
fire place by an arch of nine inches thickness, from the subsequent
main flue by an arch of four and a half inches, and from all the
divided flues by flat bricks two and a half inches thick, 18 inches
long, laid in 6 parallel rows, the joints of such rows corresponding
to the centre line of five rows of pillars, as shewn in the Drawings.
In studying the Drawings it will be easy to perceive how these pillars
are constructed for preventing the splitting of the under floor just
spoken of, and that the five rows of pillars supporting the roof of
the inclined flue G are constructed in the same way. It will also
be seen that the sides and top of the retort keep their casing at
equi-distance by projecting bricks symetrically placed in rows every
three and four courses. The casement is distinctly shewn, and
wants no explanation about its construction. The space between
the haunches of the arches forming the top of the casement is

page_text: CHARGING AND DRAWING OF RETORTS.
The interior of retort N, receives the charge of coals through the
openings O, O, which are shut by luted caps, P, P, moveable at will.
The coal is brought in trucks so constructed that when tilting their
contents full at once into a moveable funnel placed for the time
being in the openings O. These dispositions are required for
charging the retort quickly, and when well adapted, as indicated in
the accompanying Drawings, the retort can receive its charge of six
tons of coal in less than six minutes, provided that the coal be spread
at the rate it fulls down by proper mechanical power. The apparatus
to which I give the preference for producing this effect is composed
of a cast iron rake Q, which forms the head of a rack sliding in a cast
iron frame, R, R, R. This rack receives its motion from a steam
engine S, fitted to the frame. The motion is transmitted by the
ordinary mechanical contrivances, which can be casily studied in
the Drawings. In order that the same steam apparatus inay be
rendered serviceable for the working of twenty-four retorts or more,
the frame here spoken of rests upon a system of wheels, T, T,
rolling upon rails parallel to the front of the retort. The steam is
adducted by a pipe g, which runs in a casement surrounded by sand
or other non-conductor the full length of the beds of retorts. This
pipe is provided with small outlet branches; and cocks between each
two retorts for the purpose of delivering the steam to the engine of
the steam power rake through a moveable connecting pipe. When
the
gas is worked off, and the charge is ready to be drawn, the lids
of the retorts U are moved, and the coke is pushed out of the retort
in one lump by the action of the steam rack, the head of which, viz'.
the rake, is for that purpose turned upside down by swivelling it
round the collars a, b. By this contrivance the teeth of the rake
are spared, and the head of the rake, which is shaped like a strong
rib, performs the work of clearing the retort. It is well to observe,

page_text: that in order to prevent the teeth or the rib of the rake wearing out
the brickwork, they are kept at half an inch distance from the floor
or bottom of the retort by friction rollers d, c, suitably placed for
bearing the weight of the apparatus. There are also friction rollers
fitted on the sides of the rake for guiding its movement along the
sides of the retort.
I shall now proceed with the description of certain important
features in the construction of the cast iron fittings of the retort.
The bed plates of the lids are kept firmly adherent to the brickwork,
and follow the contraction and expansion of such brickwork by
being kept under the pressure of very strong springs, which borrow
their resistance froin the cast iron binders, each of which has two
holes e, e, for the passage of the springs. The ends of the springs
are provided with appropriate iron buffers, which are screwed tight
against the bed plates. As it is obvious that the lids of these huge
retorts cannot be handled in the ordinary way, they have on both
sides an axle pin, by which they are suspended in a wrought iron
frame, which frame is lifted by two chains passing over two pulleys,
and bearing counterpoises; these pulleys are fitted on the same
shaft, the plummer blocks of which rest on the binders, and in the
centre of the shaft is a small crab for the manoeuvre of lifting the
lid, which lid, when it has arrived at such a height as to clear the
top of the bed, is swivelled in its frame so as to rest horizontally
when slightly lowered partly on a wooden block h, which is to be
seen at the top of the bed, and partly on two iron brackets I, forming
part of the binders; here the lid is cooled by water, cleaned of its
old luting, and fresh pasted before it is lowered and screwed up.
The large dimensions of the lid do not allow of the cotters being
placed horizontally, and the Drawings shew how I have overcome
this difficulty by placing them vertically, and providing suitable
holes in the bed plates for adjusting them.
When the retort is at work the gas goes off through the ascension
pipe V, and enters in the hydraulic main X, through the plunger
Y. This plunger is suspended to a screw, and can be moved up and
down for the purpose of transforming at will the hydraulic main

page_text: into a dry main by suppressing the dip, which contrivance is very
valuable for relieving the retorts from all pressure.
In witness whereof, I, the said George Michiels, have hereunto
set my hand and seal, this Twenty-fourth day of June, in
the year of our Lord One thousand eight hundred and
fifty-three.
Witness,
JNO. COOK,
12, Cursitor Street,
Chancery Lane.
G. MICHIELS. (L.S.)