CERTAIN IMPROVEMENTS IN GRATES, FURNACES, AND BOLLERS, AND ALSO IN MANUFACTURING AND WORKING IRON OR OTHER METALS, AND IN MACHINERY CONNECTED THEREWITH
Year: 1843

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
GEORGE BODMER, of Manchester, in the County of Lancaster, 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 West-
minster, the Fifth day of October, in the seventh year of Her reign, and in the
year of our Lord One thousand eight hundred and forty-three, did, for Herself,
Herheirs and successors, give and grant unto me, the said John George Bodmer,
Her especial licence, full power, sole privilege and authority, that I, the said
JohnGeorgeBodmer, myexecutors, administrators, andassigns, and such others
as I, the said John George Bodmer,my executors, administrators, and 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 and Wales,and the Town of Berwick
upon Tweed, my Invention of "CERTAIN IMPROVEMENTS IN GRATES, FURNACES, AND
BOLLERS, AND ALSO IN MANUFACTURING AND WORKING IRON OR OTHER METALS, AND IN
MACHINERY CONNECTED THEREWITH;" in which said Letters Patent is containeda
proviso that I, the said John George Bodmer,shall cause a particular descrip-
tion of the nature of my said Invention, and in whatmanner the same is to be
performed, to be enrolled in Her Majesty High Court of Chancery within six
Price 8d1

page_text: 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
John George Bodmer, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, is particularly described
and ascertained in and by the Drawings hereto annexed, and the following ex-
planation thereof (that is to say):-
My Invention will be clearly understood by reference to the two Sheets of
Drawings attached to these Presents, and to the following description thereof.
Similar letters of reference are marked upon corresponding parts in all the
Figures. In Sheet 1, Fig. 1 is a longitudinal section; Fig 2, a ground plan;
Fig. 3, a front view; and Fig. 4, a transverse section, of my improved beiler
and grate. Upon the bottom plate a the stands bare fixed, which support the
boiler c by means of wrought iron angle pieces or brackets d. To the said
stands are fastened by bolts the bearings e, wherein the cast iron screws f
revolve. The grate bars gare placed between the threads of the screws f,thus
forming an entire grate, and as the ends of them (see Figs. 5, 6, and 7) are
shaped in such a manneras to fit the threads of the screws floosely,it is evident
that in proportion as the screws revolve they (the grate bars g)will travel in
the direction of the arrow towards the bridge h, which is made of fire bricks
placed in a wrought or cast iron angle piece i, which latter is fixed to the side
of the flue . A hopper 1, which contains the coal, is placed above the grate
bars g, and deposits a certain quantity of coal upon them as they pass under-
neath. The grate is put in motion by hand or by power, and in this instance
by means of a strap connected with the shaft and worm m, the worm wheeln,
the shaft o, the bevil wheels p, the pinion q driving the carrier pinion q+,
which works the wheel r fixed to the screw f, and the spur wheel s driving the
spur wheel t fixed to the return screw u. Suppose now the screws fand uto
be set in motion by the train of wheels just described, it is evident that the
coals which are deposited on the grate bars directly under the hopper 7, will
advance along with the grate bars in the direction of the arrow towards the
bridge H, and will cover the grate bars g to such a depth as the aperture
admits of, the size of which aperture may be regulated by an iron plate on
hinges, or by a slide. For the purpose of covering the grate all over with coals,
firstly the worm m is disengaged from the worm wheel n, and the grate thus
far worked by the noss w by hand, the fire being kindled by chips and shavings
introduced through the tube or openingain the hopper 1, which is afterwards
shut by a slide or trap-door. Care should, however, be taken to ignite the coal

page_text: I
rather nearer the bridge, so that that portion may be first consumed. After
this is done the grate is put in motion, and worked at a speed and with a draft
proportionate to the quantity of steam required to be generated. The speed of
the grate may be regulated by a cone pulley, or any similar contrivance, and
the draft regulated by a damper in the chimney. I prefer a narrow and long
grate to one of the ordinary dimensions, because the coal ignites in proportion
as it is deposited by the hopper upon the grate,and the gas generated near the
hopper would be sufficiently supplied with atmospheric air from between the
grate bars and the angles y of the flue k, or through a series of tubes,
answering the same purpose as a series of holes in the brickwork, as shewn in
my former l'atent, dated 26th day of May, 1834, and would thus, in passing
over the whole ignited surface on the grate into the flue A, ignite before reaching
the bridge h. From the flue k the flame turns through the box 1 into the
flues 2, through which it passes into the box 3 and turns into the flues or tubes 4,
and from thence into the chimney 5. Two tubes K* are placed in the flue /,
which are connected with the boiler itself by the tubes lx,there being,as already
explained, no poking required, and therefore little space wanted above the coal.
I give here a description of one mode only of applying my improved grate to
a boiler with flues without any brickwork, but I donot mean to confinemyself to
this identical description of boiler. And although I intend to dispense with
brickwork altogether when my improved grate is applied to my improved
boiler, I nevertheless shew, in Figs. 8 and 9, two ways in which the said
grate may be applied to ordinary boilers set in brickwork.
I have already
mentioned that in proportion as the screws/revolve, the grate barsgare caused
to travel in the direction of the arrow (see Fig. 1). I have now to explain
the manner in which the grate bars receive a gradually increasing rocking
motion, and how the space between them gradually increases as theyadvance
towards the bridge, and how they are brought back to the hopper again. Sup-
pose now the hopper to be supplied with small coals, it is evident that if as
much space were left between the grate bars directly under the hopper as would
be most suitablein that portion of the grate nearest the bridge.and particularly
the rocking motion begun there, the smallest coals would in great part fall
through the grate before they wereignited. For the purpose of remedying this
defect and of obtaining the above-mentioned gradually increasing rocking
motion, I cut the threads of the pattern of the screws f quite regular to a
certain distance, and then cause them to assume a form such as is vulgarly called
"drunken," until they assume (at the end) the shape as developed in Fig. 10.
Fig. 5 is a longitudinal view,and Fig. 6 an end view, and Fig. 7 a ground plan,
of the grate bar, and clearly shews that portion of it marked dx, which fits

page_text: between the threads of the screws. The circular dotted line a* shews the shape
of that port ioof the grate bar which is beyond the reach of the fire; and the
dotted line by shews the shape of that portion which slides upon the bars or
rails cx, which are marked in Figs, 1, 2, 3, and 4. The ends d* take between
the threads of the screw, as already explained, and the flat parts ex work against
the guide levers 13 and 17, when the bars descend and ascend. * shews those
portions of theboiler between which the coals are confined. I have given thefore-
going explanations of the grate bars in order to facilitate the description of the
operation of the grate. Suppose now the wholegrate to be covered with ignited
coal, and the screws f& u in motion at their required velocity, it is evident that
as the grate bars fit between the threads of the screws, in the manner already
explained, they will travel upon the rails 6 towards the bridge, each of them
successively as it advances alternately assuming a gradually increasing inclina-
tion and returning again into the vertical position, at every half revolution of
the screws, to relative positions of the grate bars from one end of the grate to
the other, is clearly shewn in section, in Figure 1. By means of this gradually
increasing rocking motion, the coal is kept in a constant slow undulating move-
ment whilst it advances, whichisnecessary for obtaining the most advantageous
consumption, inasmuch as it does not only clear the bars from clinkers, but also
changes the points of contact of the burning coal, and clears it from the ashes,
which are an impediment to the combustion, whilst by means of the increasing
pitch of the screws, room is made for larger clinkers to fall through the grate
and a larger supply of air to be admitted to the fire. As each grate bar arrives
at the end of the screw f it is stripped of its coal and clinkers by the scraper
plate 7,and afterwards depressed by the cams 8 (see Figure 4), which are cast
to the screws f, being held in its vertical position on its descent by the sliding
bushes 9, seen in detached Figure 2*, the levers 10, and the weight 11, and
the shaft 12, to which the levers 10 are fixed. The elbow levers 13 are fixed
to the shaft 14, and pressed also by the weight 11 with their upper end towards
the descending grate bar, which is thus pushed by them between the rails 6and
15; and when it is taken up by the lower and regular return screws u, it is evident
that as these screws revolve in the opposite direction to the upper screw, and
as they are making five revolutions for one of the screws f, four spaces or threads
are left unoccupied by the returning grate bars, and ample space is give to the
falling ashes and clinkers and to the ascending air. As the returning grate
bars arrive at the feeding end of the grate, they are received by a recess 18 of
the lever 17, and pressed against the its upper part 19, whereby they are
guided in their ascending motion to the upper screw, into the thread of which
they are forced by the said levers and the weight 20. Those clinkers which

page_text: are too large to drop through between the grate bars are received upon the
scraping plate 7, wheretheyaccumulateagainstthe bridgeh, and from which they
aredischarged by drawing the said plate inthedirectionof the arrow by means of
the hand rod 21, the lever 22 and the rod 23. The scraping plate is supported
by the pillar 24, to the top of which the rails 25 are fixed. As the making of the
pattern of the screw fis attended with difficulty, I shall hereafter describe the
tool which I have invented for that purpose. Having already claimed in my
former Patent,dated the Twenty-sixth day of May, 1834, the system of deposit-
ing the coal upon empty grate bars which are moving onwards, and igniting the
fuel by degrees as it makes its appearance under the boiler, Iconfine my claims
inthisinstance totheimprovedarrangement and construction of themechanism,
as shewn in Figures 1 to 10, in Sheet 1, and above particularly described,
claiming, however, particularly a gradually increasing, oscillating, or rocking
motion, and a gradually increasing distance of the grate bars commencing from
the hopper. As I intend to work the boilers above described with steam at a
very high pressure, I construct the stuffing box of the ram of the force pumps
as seen in Figure 11. a is the barrel of the force pump,into which the ram of
brass or iron may be made to fit or work loosely; c,a brass ring, into which
the ram fits, and upon which another ring d, of brass or other suitable metal,
is placed, which fits loosely the inside of the stuffing box, and which is cut in
two places, as shewn in Figure 12,or cut only in one place. Into the ring d
a ringe is placed, fitting into its conical part, and which is also cut in two places
or in one only. The ringe is cast of soft metal, which may be pure tin or a
mixture of other suitable metals, and which may be cast in moulds made for
the purpose at once, to the right size, or cast in sand and bored and turned in
and outside. A number of these rings are placed upon one another, as shewn
in Figure 11, and care must be taken that the joints of them do not meet,
and also that in the lowermost brass and tin rings a blade of brass or other
suitable metal be inserted across the joint, as shewn at Figures 11 and 13. The
shape of the brass ringd and tin ring eis clearly shewn in section in Figure 13.
fis a gland, by means of which and a pair of bolts or screws, made in the
ordinary manner, the series of rings already described is compressed, whereby
(because of their conical shape) the rings of brass or other suitable metal d are
forced against the inner circumference of the stuffing box, and the rings of
soft metal against the circumference of the plunger,and thusformasteam-tight
fit. By the use of this packing, which is not liable to be destroyed at high
temperatures like hemp, I not only avoid much friction, but I also preserve the
plungers from being grooved or cutas with common hemp or metallic packing,
besides effecting an important saving both in repairs and lubrication, and also

page_text: ensuring the central position of the plunger. I claim this arrangement of
packing not only for plungers of high pressure force pumps, but also for
plungers in coal pits and for the packings of piston rods of any description for
water,steam,and air-tight stuffing boxes, for revolving shafts,and for naves or
bushes of wheels,pullies, et cetera, as shewn in Figure 14, or even for cocks or
taps,particularly of larger descriptions (see Figures 15 and 16). I consider
these cocks particularly adapted for boilers of high pressure, whether for the
purpose of letting out the water from the boiler, or on a large scale, instead of
steam valves, because I do not consider them liable to get leaky or fast by
expansion and contraction, particularly when an elastic body is applied between
the washer and the tightening nut (Figs. 19 and 20 are parts of a cylindrical
tap,the socket of which is made tight by the screw a). This may be seen at A,
(see Figure 1,) which is the cylinder (of about four inches diameter, more or
less) of a safety valve,in which the piston B,of a similar construction as the
stuffing box, is working; by the use of this safety valve not only the steam
is allowed to escape from the boiler when at a certain pressure, but the pressure
of the steam in the boiler is indicated from five pounds, or even less, up to
ninety pounds, or even more, by means of the rod C and the lever D, which is
connected with a spring balance E, made in the ordinary manner. Suppose
now the steam acting against the piston Bwith a pressure equal to five pounds,
the index on the spring balance E will indicate that figure, and as the pressure
of the steam increases, the piston B will rise and indicate a higher figure, until
the hand of the spring balance indicates, for instance, 90°, when the lower part
of the piston B will have arrived at a series of slots F, which are cut in the
cylinder A,and through which the steam will escape the moment the piston B
has risen beyond the lower part of said openings; and in proportion as the
pressure of the steam continues to increase, the piston B will rise and allow
more steam to escape, and the piston will descend again in proportion as the
pressure of the steam diminishes. It is evident that a solid piston could not be
made steam-tight, or, if so, that it would soon become fast in consequence of
the irregular expansion of the metal. To avoid this I construct the piston as
shewn in sectionat Figure 17, a being the lower portion of the piston, in which
the piston rod b is fixed, which passes through a boss in the upper part or lid c
of the piston; four round eyes d fit into the four recesses c of the lower part of
the piston,and thus the lid is kept steady; there are four corresponding
cylindrical holes fcast in the lower part of the pistons, in which strong spiral
springs g are lodged; into these springs long nuts h are placed, which have a
shoulder below on which the springs g rest; the cylindrical holes f are closed
by means of brass nuts i, and thus the nuts h and springs g are held in their

page_text: places; the lid c is connected with the nuts h by means of the screws k, and as
the said screws are tightened up the lid c will be depressed by means of the
springs g, and thus cause the rings 1, which are cut in one place, to be pressed
against the cylinder in the way already explained with reference to Figure 11,
and form a steam-tight fit. It is evident that the expansion and contraction
of this piston will be completely compensated by the elastic conical rings and
the springs h. Suppose now a similar piston to be applied to an engine
cylinder, for which I consider this construction very useful and particularly easy
of repair, it is evident that when the pressure of the steam acts upon the top
of the piston c, the rings l, et cetera, will be compressed and form a tight fit even
if the springs g were not strong enough by themselves to do so. And when
the steam is acting against the bottom of the piston the friction of the rings
against the cylinder will, in addition to the springs g, act as a resistance, and
thus effect a tight fit again. I claim this construction of pistous not only as
applied to the safety valves, as shewn in Figure 1, but also for pistons of steam
cylinders, air and water pumps, et cetera. I shew here one way only of con-
structing a piston with such packing; the same purpose may, however, be
effected in various ways; for instance, instead of having the four holes in which
the springs g are placed, the springs g and nuts h may be placed from within
the piston, as shewn in Figure 18, under a flange or rim acting as a nut, and
the lid c may fit upon the part of the piston, also in form of a rim, instead of
fitting four cylindrical holes, or one strong spring may be placed in the centre
of the piston. Sheet II., Figure 1, is an elevation; Figure 2, a ground plan;
and Figure 3 an end elevation of my lathe for cutting my oscillating grate
screws, or the patterns for them. a, an ordinary lathe bed, with the head-
stock b, and the following headstock and slide, et cetera, as usual, an:l which I
do not therefore think it necessary to explain. The back shaft cin this instance,
however, instead of driving by means of the pinion d the wheel e, which is
fixed to the spindlef, has the pinion g fixed upon its projecting end which gears
into the wheel h, which is of the same pitch and diameter as the wheel e; the
wheel works upon a bush i, which is tightly screwed upon the spindlef, and
prevents with its shoulder the wheel / from moving sideways; a disk / fits
the shoulder of the bush i, as well as the rim or bend of the wheel h, and is
fixed to the wheel h by two bolts m. For the purpose of cutting double or
manifold screws upon the cylinder p under operation, one thread having been
cut, in order to cut the next, the bolts m are withdrawn from the wheel, and
the disk & turned to the next required division, where it is again fixed by the
boltsm, and thus the division produced without altering the division wheel; or
even a worm wheel may be cut into the disk and a worm applied to the
wheel to produce any required division; see Figure 4. It is well known

page_text: that screws of a very quick pitch, say from three to ten inches, or even more,
are extremely difficult to cut upon a lathe of ordinary construction, because the
guide screw n has to perform so many revolutions whilst the spindlef makes
only one; by the use of any dividing chuck, however, which is driven by the
pinion g, and by connecting the speed pulley o directly with the wheel e, cause
the spindle to perform about twelve revolutions more or less, while the
dividing chuck performs only one revolution, and thus, by a very easy train
of wheels, I cause the guide screw n to perform many revolutions whilst the
screw p under operation performs only one revolution. For my oscillating or
rocking grate screw pattern, not only a coarse pitch is required, but also the
slide of the lathe moves only for a very short distance at a uniform speed, after
which it not only begins gradually to increase, but for each revolution of the
screw the slide travels twice at a reduced and twice at an increased speed,
these differences increasing until at last it comes to periodical stops and starts
when a screw is produced, as developed at Sheet 1, Figure 10. The mechan-
ism by which this shape of a screw is obtained consists of the pinion q fixed to
the spindle fin the usual manner, the pinion r on the radial arm f, the pinion t
on the radial arm u, cast to the same bush with the radial arm f; this radial
arm, with the two pinions r and t, is simply for the purpose of reversing the
guide screw or of disengaging the same from the lathe; the pinion v gears
into the pinion r, and is fixed to one end of the shaft w, which works in the
bush; to the other end of the shaft w the wheel y is fixed, which gears into
the wheel; the shaft 1 of the wheel z has the pinion 2 fixed to it, which
gears into the wheel 3, on to the boss of which the worm 4 is cut, which is
connected with the screw n by a steel feather and a groove 5 in such a manner
that it can slide upon the screw, but not revolve without it; a worm wheel 4*,
which is fixed to the end of the screw 6, and which works between the two
projections 7 of the bracket S, (see Figure 3), gears into the worm 4, and thus
the slide 9, which works in a V groove 12 of the bracket 8, is caused to move
in the direction of the arrow (see Figure 3) until the roller 10, which works
against the shaping disk 11, arrives at the periphery of the latter. I have
already described the shape of my grate screw, and developed a portion thereof
in Sheet I., Figure 10, and after having explained that the face of the disk 11
is quite even at*, where the roller 10 begins its motion in the direction of the
arrow, and then becomes gradually more and more undulating towards its
periphery, where the roller 10 terminates its motion. I have to describe the
effect produced by this mechanism upon the screwing slide. Suppose the pitch
of the screw pattern p under operation required to be one and a half inches,
the pitch of the guide screw n is to be three quarters of an inch, because it has
to peform two revolutions whilst the screw pperforms one only. It is therefore

page_text: evident that while the roller 10 on the slide is working at where it is drawn
in black, and where the surface of the disk is plane, as already stated, the
tool slide of the lathe, impelled by the guide screw . nust advance regu
larly, and begin by forming a regular screw upon the cylinder p, but in pro-
portion as the worm wheel causes the slide 9 to move in the direction
of the arrow. by means of the screw 6, and thus the roller It to move
on the undulated portion of the disk 11. it is evident that the screw slide
not only must advance three quarters of an inch for every revolution of the
screw, but in addition to that, so much more as the rising portion of the
disk working against the roller 10 will cause the screw to move in the
direction of the arrow; and it is also clear that when the descending portion
of the disk arrives upon the roller 10 the screw will be allowed to recede in
the contrary direction to that of the arrow accordingly, and thus form upon
the cylinder, a portion of a thread, so much less rising as the other por-
tion of the disk 11 has before added to the steepness of the thread, and thus
the threads of the screw towards the end, which is shewn in the Drawing,
will be cut on its periphery partly at a right angle with their axis and partly
at double their regular inclination. The number of threads in the screw 6,
the number of teeth in the worm wheel 4*, and the diameter of the disc 11,
are of course so proportioned that while the tool slide moves the whole length
of the screw under operation, the roller 10 moves from the place marked *
on the surface of the worm 4 to that in which it is shewn in red lines at 10,
Fig. 3. The effect of the undulating disc here described will be twice repeated
upon the screw 1' in consequence of the screw performing one revolution for
two of the disc 11, as above stated.
The above description clearly shews how the "drunken" screw is produced.
I have now further to explain the mechanism whereby the gradual increasing
pitch of the screw p is obtained. A wheel 18, with strong arms and a long
boss, works loose on the end of the screw n, being held in its place by a washer
nut 18, and gears into the pinion 14, which is fixed upon the shaft 1.
upon which also the pinion 2 is fixed. A cylindrical inclined plane or shaper 15
is cast to the wheel 13, against which the roller 16 works, which is connected
with the disk of the wheel 3 by means of the bracket 17 and bolts. I have
already stated that the wheel 3 turns the screw by means of a groove and
feather, but is at liberty to slide on the screw longitudinally; it is therefore
clear, that by the resistance of the tool slide, the screw n is drawn in the con-
trary direction to that of the arrow, and thus causes the shaper 15 on the
wheel 18 to bear against the roller 16, which latter being connected with the
wheel presses the shaper disk 11 towards the roller 10, and therefore in-
13

page_text: parts any longitudinal motion produced by the shape of the surface of the
disk 11, and the shaper 16 to the screw n, and consequently to the tool slide.
Suppose now the relative numbers of teeth of the wheels,pinion 2,pinion 14,and
wheel 18 to be such that while the tool slide travels the whole length of the
screw under operation, or while the wheel 3 performs 22 revolutions, the
wheel 13 performs 23, then the height of the shaper 15 will be added to the
regular pitch of the screw in such proportions as pointed out at Fig. 6, the
various ratios of increase to each thread being marked 1 to 22, the distance from
0 to 1 forming that regular portion of the screw p, or that upon which the coal
is first deposited. Fig. 5 shews the shape of the surface of the disc 11 at its
outermost periphery, which from a straight line nearest the worm 4 it gra
dually assumes; Fig. 7 shews the application of my improved grate to a fur-
nace of cementation" (in the manufacture of steel) of the ordinary construc-
tion; but as the grate is already shewn in Sheet 1, I merely shew, in this
instance, the mode in which the brick work is supported by cast iron plates a
with strong ribs bat their tops, and how the bearings of the screws c which
propel the grate bars are fixed, and how they are protected against the heat
from the furnace. The bearings of the screws, see Sheet 1., Fig. 4, are either
fixed to the plates & above or to the brackets 7. which are placed in the wall
behind them. It is well known that it is of the greatest importance in the pro-
gress of converting iron into steel to keep up a very regular fire, which in the
commencement, say perhaps for the first day, must produce a moderate heat,
then regularly increase in density, and when the process is nearly accomplished,
again be reduced to a certain extent before it is entirely stopped. By the
application of my improved grate this effect is produced in the most perfect
manner by regulating the charge of coal upon the grate bars, the speed of the
screws c, and the draft of air accordingly. It is well understood that by con-
verting iron into steel the process is influenced to a great extent, not only
perhaps by a slight difference in the quality of the charcoal iron, which is
generally used for this purpose, but much more so by the bars being exposed
to various degrees of heat in the boxes, particularly when the latter are of
large dimensions. In consequence of the regularity of the heat produced by
my grate, and in consequence also of the almost perfect combustion of the
coal gas, this defect is rectified to a great extent. It being considered to be a
matter of great importance that the iron exposed to the process of converting
should be in perfect and equal contact with the charcoal or cement, andasit is
almost impossible that bars of large dimensions could be packed in such a
manner as to be all over in equal contact with the cement, and moreover
remain so during the process, whilst the cement is to a certain extent dimin-

page_text: ishing in bulk, and perhaps settling between the bars, whereby an irregular
cementation must take place; instead of breaking the bars after they have
undergone the process of cementation into small pieces for the purpose of
examining their quality and assorting them, cut the iron bars, which may be
half an inch in thickness by three inches broad, more or less, by means of a
revolving or reciprocating tool made for the purpose.crossways into pieces equal
in breadth to their thickness, see Fig. 8 and 9. or into small cubes, see Figs 10
and 11, and instead of packing the bars into the cementing boxes, as usually
done, I put a layer of these small pieces of iron into a layer of cement, and
thus continue until the boxesare full, when they are closed in the usual manner.
It is evident that by this process the iron is brought into more perfect contact
with the charcoal, and if a regular heat throughout the boxes can be obtained, a
more equal and regular cementation must take place, and this steel must be ina
fitter state for the crucible or forge. Should an examination of the parts of steel
produced even by this process still be necessary, the iron may be cut into pieces.
as shewn at Fig. 8, and these may be afterwards broken and examined as
usual. Forthe purpose of avoiding the difficulty of giving an equal degree of
cementation of the whole of the iron contained in the boxes (Fig. 7). and for
the purpose of saving a great deal of fuel and time, I adopt another construc-
tion of furnace, which is represented in a vertical section at Fig. 12, and in a
horizontal section at Fig. 18. A slightly conical shafta is built of fire-bricks,
which may be from twelve to twenty-four inches, more or less, in diameter at
the bottom, and from ten to twenty inches, more or less, at the top; or for the
greater convenience of filling the furnace in the beginning, a wider shaft, large
enough to admitat least a boy to deposit the cement and iron, would be prefer-
able. The furnace may be built square, as shewn in section at Fig. 14, and
oval or flat, as shewn in Fig. 15. This shaft is surrounded by a spiral flue b,
which is made of the same fire-bricks as the shaft itself, and the whole is sur-
rounded by a shaft c of common bricks, which is secured at the outside by
cast or wrought iron plates or bars and hoops. A strong cast iron plate / is
laid upon the brick foundation, which supports by means of the ribs e the cast
iron plate f, which has a hole in its centre of the same diameter as the shafta
below, and thus a space y is left of about four inches, more or less, between
the bottom of the shaft a aud the foundation plate d; at the height of about
seven or eight feet, more or less, from this foundation plate the flue h of my grate
is joined to the flues b, and as the shaft above the flue / can be built to any
convenient height, it is evident that the heat will be most intense round the
shaft a in that place nearest the grate, aud diminish in proportion to the height
of the furnace, and the flue & will be led into a chimney at that height of the

page_text: shaft at which the heat evolved from the grate has lost its effect; shews the
shape of the furnace above the grate; the necessary atmospheric air is intro-
duced through the holes in a similar manner as explained with reference to
my grate and boiler; and the ground plan, Fig. 13, clearly shews the connec
tion of the furnace with the flucb; the furnace is first filled with common sand
up to the fine, at which place the common sand is covered with a layer of
few inches of refractory sand; upon this a layer of charcoal is deposited, and
upon this a layer of those small pieces or cubes of iron described with reference
to Figs. 8, 9, 10, and 11; another layer of charcoal then follows, and so on in
succession, up to the mouth of the shafte. The manorlad who performs this
operation in the shaft receives the iron and cement from above in a tub or bag
handed down by means of a rope, or through a tube, and he proceeds with
his operation until he arrives at the top of the shaft, which may be from three
to four feet, more or less, above the flue which goes into the chimney. Sup-
pose now the furnace to be filled, the grate is covered with coal, and fire
having been set to it and the whole surface fairly ignited, the grate is started
ata slow speed, to which the depth of the coal and the admission of atmospheric
air is proportioned; after a certain time the heat is increased, and the firing
continued for as long a time as will be required to convert that portion of iron
into steel which is directly opposite the fine, and which is, therefore, exposed
tothegreatest heat: one of the number of bars/, which reach through the brick-
work of the flue right into the shaft is then withdrawn, and the state of the
cementation ascertained; this bar is of the same thickness as the pieces of iron
represented at Fig. 8; and it is to be supposed that it will indicate the state
of cementation of the iron in the furnace; as soon as the state of cementation
is found to be sufficient, a quantity of the sand underneath the flue / is
removed from between the plates and f, and the whole miss which the shaft
contains will descend, and thus bring that portion of the iron (which is suffi-
ciently converted) below the flue , and out of contact with the direct heat
from the grate, a new portion of the iron (not yet sufficiently cemented) taking
its place; by the number of test bars/, which have all been withdrawn before
the mass of iron and cement has been put in motion, and by which the state
of the steel has been ascertained, thetime required for the cementation of the
iron nearest the flue has been ascertained with sufficient accuracy as to deter-
nine at what periods and to what extent the sand below the flue /, and after-
wards the cement and the steel which is held up by the plate is to be
removed; the level of the material at the top of the furnace will sufficiently
indicate how the material at the bottom is to be removed; as the cement
and steel are removed below, fresh layers are introduced at the top of the

page_text: furnace, where, as already stated, no heat or at least very little can be
filt, and where, after the furnace has been filled again, the opening
may be closed by an air-tight lid It is evident that this description of
furnace will afford the means of a much more perfect cementation than
the common furnace; and if the materials of which the shaft and flues are
made be such as to withstand the effects of the heat, the operation of the
furnace may continue for months and even for years without interruption,
like that of a blast furnace, and by removing the steel and cement less or more
frequently below, a softer or harder steel may be produced accordingly. The
description of this furnace sufficiently explains the principle on which I intend
to operate for the conversion of iron into steel; but the same may be accom-
plished by various constructions of the furnace and the removal of the material
below may be performed regularly by the application of any suitable mechanisın.
I claim firstly the application of my improved grate to the ordinary furnaces
used for the manufacture of steel, see Fig. 7; and, secondly, the particular
construction and arrangement of the furnace for the purposes of continuous
cementation in the manufacture of sreel, and also the application of my
improved grate thereto, see Figs. 12 and 13. Fig. 16 is a vertical, and
Fig. 17 a horizontal section of a furnace for smelting iron upon a foundation
of bricks or stones, or upon an iron plate a, resting upon a bed of bricks b:
the round brickwork is erected in wings or partitions in such a manner asto
support by means of the cast irou plates d, the flues e, which are built of fire-
bricks, or the flues may be supported by brickwork without iron plates. Upon
the partitions of the flues e the basin is built of the best fire-bricks, and
over this basin the arch or domey is erected. which supports the shaft h, which
is also made of fire-bricks; the whole structure is surrounded with a brick walli,
which is held together by means of iron plates, which latier are fixed in the
foundation below, and connected at the top by the plates 7, which form the
cover of the lower portion of the furnace; the space m between the wall &
the fire-bricks of the furnace isfilled with refractory sand or ashes and cinders;
the shaft h is surrounded by a brick wall, which is held together by iron plates
and hoops, and a bed of refractory saud, as generally used for such purposes, is
placed into the brickwork for its protection. To begin the process of smelting
the furnace is filled with coke up to a certain height in the shaft h, fire is set
to it, and the fan n, which stands at a distance from the furnace and discharges
the air into the chimney o, is then set in motion; and as the flue p is in con-
nection with the fan n, the air is withdrawn from the flues under the basin f
and new atmospheric air rushes in at the top of the shaft and supplies the
combustion from above; the flue may be in connection with a very powerful

page_text: I consider that
chimney, and the fan may be dispensed with, but the effect of the fan will at
all times be greater than that of the chimney. As soon as the coke is in a
state of combustion, a charge of iron with limestone as usually practised may
be put upon the coke, then another charge of coke may follow, and so on. It
is evident that the iron thus melted will fall into the basinf, and will not only
be kept hot there from above, but as the flues are completely surrounding the
basin, the flames of the coke in going in the direction of the arrows into the
chimney will heat the brickwork of the basiny from below, aud keep the iron
in fusion. For the purpose of increasing the combustion of the coke as wellas
for the purpose of burning the sulphur contained in it as soon as possible, air
is admitted through the apertures q, which may be opened and closed at dis-
cretion; by this arrangement a large quantity of iron can be melted in a very
short time, and with comparatively little fuel, and, moreover, the iron can be
leprived of its carbon if required to a very great extent by allowing the coke
to burn down in the shaft and the atmospheric air to come in contact with the
iron in the basin. is an opening through which the iron is tapped, and s a
door which will be necessary for the repairs of the furnace.
this furnace may be used not only for the smelting of pig iron for the purpose
of casting but also for brass and other metals, and, with some modifications,
even for the refining and puddling process of iron. I claim the particular mode
of smelting iron and other metals, as shown at Figs. 16 and 17, whereby the
heat is caused to descend. Fig. 18 is a ground plan, Fig. 19 a longitudiual
section, Fig. 20 a top view of my improved pudding furnace, to which my
improved grate is applied. The hearth a does not deviate much from the
ordinary construction; that portion, however, through which the flame from the
grate passes into the furnace will be much narrower than the furnace itself,
because I intend to use a long and narrow grate, covered with an arch b (see
Fig. 19) for the purpose of having the gas completely heated and ignited
before the flame reaches the hearth. By the application of my moveable grate
with the self-acting feeder, I keep up a regular combustion of the fuel and
as I admit the air for the combustion of the coal through a large number of
orifices between the bars, the draft will not be required so powerful as to carry
small particles of coals away from the grate bars unconsumed; and by the
increasing rocking of the grate bars, by which the burning coal is kept in
constant motion, I cause the greater portion of those small clinkers and ashes
to fall through the grate bar, which otherwise might be carried upon the iron
under operation, similar to what I described with reference to Fig. 13. I
admit a certain quantity of air through orifices c on the side of the grate,
besides which, in this instance, I also place a small fan d in the brickwork

page_text: directly under the broad bridge e, which may be started and stopped at
pleasure, for the purpose of supplying such a quantity of atmospheric air as
may be required at certain stages of the process. /represents the tap or floss
hole behind the hearth of the furnace for drawing off the slag, &c. Over the
hearth a I erect another hearth g, with a chimney h, completely disenected
with chimney, which belongs to the pud lling hearth at the top of these
chimneys place dampers as usual. The flue is in direct connection with
the flue of the fire grate, and directly over the bridge e, and thus when the
chimney is shut and the chimney/open.it is evident that the flames coming
from the grate will pass through the flue over the hearthy, instead of over
the hearth, and will operate upon the pig iron which has been introduced
through the opening 4, and fuse it. The fan will then he set in full action,
and during the time the iron in the hearth below is worked and formed into
balls, the greatest portion of the air produced by the fan will go np the fine /
into the hearth g, in which the iron under operation will undergo a kind of
refining process. By this time the balls below will have been removed from
the hearth, and a new supply of iron will be let down from the hearth ginto
the hearth a through a slot in the bridge m, by means of an iron bar intro-
duced through the opening a. The two chimnies and having, as already
stated, separate dampers. the heat in the hearths a and g can be regulated
according to the nature of the operation, and the grate kept in a constantand
regular motion. I claim the application of my improved grate to puddling
furnaces, and also the particular construction of the furnace as shown at
Fig. 19. Fig. 21 is a longitudinal, and Fig. 22 a transverse section of a
furnace for heating the air for blast furnaces, and to which my improved grate
is applied.
The cold air enters into the pipe a, passes through a series of pipes b into
the pipe c, and from thence through a series of bent pipes into the pipe e
afterwards through the pipes into the pipe g. from which it is taken hot to
the furnace in the ordinary manner. The coal is deposited upon the grate in
the same manner as already explained; it travels in an ignited state between
the two ranges of fire-bricks, which rest upon cast iron plates, and which
support the pipes a and g. A fire-brick arch is formed between the two
pipes a and g, which, as well as the pipes just mentioned, is heated by the fire
of the grate. At the end of the said pipes and arch the flame returns in the
direction of the arrow through the flues i, heats there the pipes band f, and
those c and e, which are again supported by the seating bricks and the arch/
between them, under which the flame and heat returns and enters into the
flue m, where it heats the pipe d, and then passes into the chimney o. It is

page_text: evident that by this arrangement the heat of the air can be kept extremely
regular, and increased and diminished with great facility by altering the charge
of coal through the hopper, the speed of the grate, and the draft. I claim the
application of my improved grate to the heating apparatus of blast furnaces as
shewn at Figs. 21 and 22 Fig. 23 is a side elevation, and Fig. 21 a ground
plan of a pair of rollers in a rolling mill, similar to those described in my
Patent for rolling tyres and hoops, dated December the Eighth, One thousand
eight hundred and forty-two, but on a smaller scale. intended for rolling what
may be called endless saw blades. A bar of steel of the width of which the
saw blade is intended to be, and perhaps a quarteror half an inch in thickness.
is welded like a hoop; it is then reduced into an oblong shape, so as to be
adapted for being placed in a heating furnace. in which it is heated to such an
extent as not to injure the steel; after that it is brought over the roller a, and
the pulley b, when the mill is started and the roller c screwed up against the
blade until it has attained its necessary thickness and length. The pulley b
works in a slide, and during the time the rollers a and c are revolving at a
very great speed, the slide is drawn in the direction of the arrow by means of
a screw, either by hand or mechanism, at such a speed as will keep the saw
blade tight during the operation of rolling. This saw blade, which may be
rolled to the length of from four to twenty feetor more, would then be ground
while running over two large pullies on its flat parts and on its edges, and
toothed, and it may be applied as a continually acting saw by running over
two pullies proportionate in diameter to the length of the saw blade and to
the work it is intended to perform; and the blade may be guided by an
appropriateguide on its working side and between the periphery of the pullies
and the piece of timber it has to cut. As machinery for sawing timber is per-
fectly understood, I have only to mention that in this case the fixing of the
timber to the carriage would have to be somewhat altered, and that the
carriage, instead of being worked by ratchet wheels, would be advanced by a
regular screw or rack motion. It is quite clear that a saw of this construc-
tion would be much superior as to speed and accuracy to common saws for
sawing boards, and that it may even be applied for the purpose of sawing very
thin boards, or perhaps veneers. 1 claim this mode of rolling or manufac-
turing endless saw blades, or bands of steel, or other metal.
In witness whereof, I, the said John George Bodmer, have hereunto set
my hand and seal, this Third day of April, in the year of our Lord
One thousand eight hundred and forty-four.
JOHN GEORGE (L.s.) BODMER.

page_text: AND BE IT REMEMBERED, that on the Third day of April. in the seventh
year of the reign of Her Majesty Queen Victoria, the said John George
Bodmer came before our said Lady the Queen in Her Chancery, and acknow-
ledged the instrument aforesaid, and all and every thing therein contained 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 Fourth day of April, One thousand eight hundred and