CERTAIN IMPROVEMENTS IN STEAM ENGINES AND BOILERS APPLICABLE BOTH TO FIXED AND LOCOMOTIVE ENGINES
Year: 1834

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
GEORGE BODMER, of Bolton le Moors, in the County of Lancaster, Civil
Engineer, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-fourth day of May, in the fourth year of His reign,
did for Himself, His heirs and successors, give and grant unto me, the said
John George Bodmer, His especial licence, full power, sole privilege and
authority, that I, the said John George Bodmer, my executors, administrators,
and assigns, or such others as I, the said John George Bodmer, my executors,
administrators, or assigns, should at any time agree with, and no others, from
time to time, and at all times hereafter, 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
"CERTAIN IMPROVEMENTS IN STEAM ENGINES AND BOILERS APPLICABLE BOTH TO
FIXED AND LOCOMOTIVE ENGINES;" in which said Letters Patent is contained a
proviso that I, the said John George Bodmer, shall cause a particular descrip-
tion of the nature of my said Invention, and in what manner the same is to
be performed, to be inrolled in His 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.

page_text: 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 in what manner the same is to be performed, are particularly described
and ascertained in and by the following description thereof, reference being
had to the Drawings hereunto annexed, and to the figure and letters marked
thereon, that is to say:-
My Invention of certain improvements in steam engines, and in boilers,
applicable both to stationary and locomotive engines. consist of several novel
features in the construction of such engines and boilers; and first, as regards
the engines in the employment of two pistons in one cylinder, moving in opposite
directions, each piston working a separate crank on the same shaft, by which
arrangement the power applied to the shaft is balanced or equalized, for as one
.piston forces its crank one half of a revolution, the other pistons pulls its crank
the other half, thereby communicating a rotatory motion to the shaft without
strain or stress upon its bearings; and further, that as the expansive force of
the steam acts upon the pistons, and through them upon the cranks alone, it is
evident that there will not be any strain exerted upon any part of the frame-
work or foundation of the engines. By employing two pistons the power is
doubled, and therefore, two cranks, each of four inches radius, would exert
the same power upon the shaft as one crank of eight inches, and the speed of
the engine may be doubled without causing more wear and tear in the piston
and cylinders than in engines of the ordinary construction when working at half
the speed; and owing to the shortness of the stroke and increased size of the
steam ways, great speed can be obtained without diminishing the power of the
engine. The second novel feature of my improvements in steam engines
consists in compensating or balancing the pressure exerted by the elastic force
of the steam upon the slide valves, by which I am enabled to extend the area
of the steam passages, and, consequently, the surfaces of the valves to any
dimensions required, without increasing the friction in the same proportion.
The third improvement consists in adapting segment guides for the bearings
of the crank shaft to move in, by which means the pistons and slide valves are
contined to work within their proper space of action without variation, in what-
ever position the crank shaft may bc. The fourth improvement consists in the
mode of constructing and mounting double bearings for the crank shaft,
between which the running wheels are placed, and also in connecting the carriage
springs with those bearings and the frame of the carriage in such a manner that
the
pressure or stress on the two bearings will be compensated or balanced one
with the other, by which arrangement the weight or pressure of the carriage is
prevented from acting upon the cranks. The fifth improvement consists in an

page_text: improved method of expanding the metallic packings of pistons, and in pre-
venting the wear of the pistons and cylinders when placed in a horizontal
position. The sixth improvement consists in a method of increasing the speed
of a locomotive carriage while it is passing along a horizontal railway, without
increasing the velocity of the crank shaft. The several Figures in Sheets 1
and 2 of the accompanying Drawings, exhibit my improvements in steam
engines, shewing the arrangements of the parts of a locomotive engine with
those improvements applied, and the detail of the same on an enlarged scale.
Fig. 1, Sheet 1, is a vertical section taken longitudinally through the engine.
Fig. 2, is a partial transverse section, also taken vertically. Fig. 3, is a plan
or horizontal view of the same, complete. Fig. 4, Sheet 2, is a plan view of
both the cylinders upon a larger scale. Fig. 5, is a longitudinal section of the
same, taken through the piston, cylinder, and side valve. Fig. 6, is a trans-
verse section and end view of the same; A, A, are the cylinders, cach cylinder
having two pistons, B, and C, working within it, with their rods D, and E,
passing through stuffing boxes in the covers F, G. H is the slide valve,
working in the box or steam chamber I, to which is connected the steam
pipe K, leading from the boiler. a, b, and c, are the steam ways of the
cylinder, and are alternately induction and eduction passages, according to the
position of the slide valve, which is hollow, and forms the exit way of the
steam discharged to the exhauster or chimney, through the passages or
ways d, c. Supposing the pistons and valves to be in the position shewn in
Fig. 5, that is, with the passages b, and c, open to the interior of the slide, by
which the steam makes its exit, the passage a, would be open for the admis-
sion of the steam into the cylinder, when the steam would first insinuate itself
between the pistons B, and C, and there exerting its expansive power, would
force the pistons apart, or in the direction of the arrows, toward the ends.
When the pistons have arrived at the ends of their strokes, the slide valve will
have moved in the direction of the arrow, opening the aperture d, to the steam
way a, which will now become an exit passage, and at the same time the
ways b and c, towards the ends of the cylinders, will have become open for the
admission of steam into the interior, the clastic force of which will now move
the pistons back again into the middle of the cylinder, as shewn in the Figure.
By this time the valve will have been again changed, and the passages or ways
situate as before. It will be seen that the exit way d, is sufficiently large to
be always open to the discharge passage e. The manner or method of com-
pensating or balancing the pressure of the steam upon the slide valve is best
shewn in Figures 5 and 6, and is effected by the following means. To the
valves H, are connected, by means of the rods or links L, L, the two steam-

page_text: tight pistons M, M, which are constructed so that the expansive force of the
steam presses their sides outward in close contact with the small cylinders N, N,
the sides of the piston M being made elastic by the thinness of the metal, which
has three or more slits or saw gates cut in it to about two-thirds of its depth,
but any other description of steam-tight pistons will do equally well. The
pistons M, M, work in the two small cylinders N, N, fixed on to the valve box
or steam chamber I, over the opening f, f, formed in it. The outer end of
these cylinders N, N, are open to the atmosphere. The steam admitted into
the chamber I, exerts its expansive force upon the surface of the slide valve II,
and also (through the opening ff) upon the pistons M, M. It is therefore
evident that the force of the steam exerted upon the pistons M, M. will,
through the links L, L, have a tendency to draw the sliding surface of the
valve II, from contact with the surface of the cylinder, and therefore relieve
that surface from the pressure of the steam, by compensating it with the force
exerted upon the pistons. And as the area of the pistons M, M. are some-
what less than that of the surface of the valve 11, in contact with the cylinder,
the valve will always be kept in contact with it, and at a pressure dependent
upon the area of the pistons M. M. It will be evident by thus relieving the
slide valve from the pressure of the steam, the induction and eduction passages
of the cylinders may be enlarged to any desirable extent, without regarding the
friction caused by the pressure of the steam upon the consequently enlarged
surfaces of contact, as that can be compensated by the area of the pistons M, M,
and therefore the engine may be worked at a very great speed without being
cramped or confined by the want of a full supply of steam, as is the case with
engines of the ordinary construction. In further explanation of the working
of the slide valve, it is necessary for me to state that when the slide valve is
moving to change the induction and eduction passages a, b, and c, at the
precise moment the solid parts of the valve cover those apertures, the steam in
the cylinder will exert its power, in conjunction with that upon the pistons M,
to force away the valve from contact with the cylinder, but this removal is
prevented by the following means: The pistons M. M, are directed in their
action by the cylindrical parts g, g, working in the guides h, h, and the pins i, i,
which work in hollowing adjusting screws k, k passed through female screws
in the top part of the cylinders N, N. These screws k, k, are furnished with
tightening nuts, and are so adjusted that at the precise moment the solid parts
of the slide valve cover the steam ways a, b, c, the shoulders 1, 1, of the pistons
come in contact with the end of the screws; the action of the pistons M, M, is
therefore stopped; consequently, at this moment, the whole force of the steam in
the box 1, is exerted upon the valve, the abutting of the pistons against the

page_text: power
adjusting screws preventing the compensating or balancing of its for
that moment. I would further remark, that if it should be found necessary to
stop the engine or reverse its motion suddenly, and this should happen at the
very moment that the solid parts of the slide valve cover the steam ways a, b, c,
then the velocity of the running wheels of a locomotive carriage, or the fly
wheel of a stationary engine, would cause the pistons to compress the steam
within the cylinder, it being prevented from escaping out of it. The resistance
would then be so great, that if the steam were not allowed to escape, some parts.
of the machinery must give way and probably be destroyed. To obviate this
evil, I allow the slide valve to give way a little as soon as the compressed steam
in the cylinder has power to overcome the force of that in the chamber I.
This is effected by forming the connection between the links L, L, and the
slide valves I, II, by a short slot, through which the connecting pin is placed,
as shewn at m, m, in Figure 5. This slot allows the steam compressed in the
cylinder to force up the slide valve and make its escape, thereby preventing
the breaking of any part of the engine or machinery. Having now described
the action of my first and second improvements, I shall proceed to show how I
apply the power exerted by the working pistons upon the cranks to propel a
locomotive carriage, or actuate machinery. The ends of the piston rods D, D,
work between V-shaped guides 0, 0, and are connected to the rods P, P,
in the usual manner; the other ends of these rods are connected to the
cranks Q, Q, on the shaft R, which shaft is shewn detached in plan and end
views at Figure 7, Sheet 1. The piston rods E, E, also work between
guides S, S, and their extremities form the plungers of the hot water
pumps T, T; upon these piston rods are also formed the cross heads U, U, to
the ends of which are connected the rods V, V, these are connected to the
arms or cranks W, W, on the shaft X, mounted on bearings in the framework.
To the cranks or arms W, W, are connected the rods Y, Y, leading to the
cranks Z, Z, upon the shaft R, by which means the power exerted by the
pistons will be communicated to the crank shaft in the manner already men-
tioned. My third improvement on locomotive steam engine, videlicet the
segment guides to the bearings of the crank shaft, is shewn in Figures 1 and 2,
in Sheet I., and in detached views at Figures 8 and 9; n, n, are the segment
guides firmly fixed to the framework of the carriage; these guides have
grooves formed in their inner sides, in which the ribs o, o, on the bearing
pieces p. p, slide; (see the detached Figure 10.) The pieces p, p, support the
weight of the carriage upon the bearings of the crank shaft R. It will be
perceived that as the carriage descends, by any extraordinary weight or sudden
jerk, the guides n, 1, and also the cylinders and pistons, will descend

page_text: with it; and that from the peculiar shape of the segment guides, the same
distance will at all times be preserved between the ends of the piston
rods D, D, and the centre of the crank shaft, and also between it
and the pins of the crank arms W. W; the segment form of the guides
being part of a circle, the centre of which is the connecting pins of the
crank arms and piston rods. By these means the piston and slide valves
are obliged to work within their proper sphere of action, as before stated. My
fourth improvement, viz. the mode of connecting and mounting the double
bearings of the crank shaft, is shown in Figs. 1, 2, and 3 in Sheet 1., and also
in detached views at Fig. 10. The weight of the carriage and engine is sup-
ported by the roils 9, 7, the lower ends of which are placed in sockets r, r,
formed on the sides of the pieces p, p, which rest upon the bearings of the
crank shaft these rods are passed through guides on the springs, and their
upper ends are furnished with adjusting screws and connected to the lever s.
To this lever are suspended by a pin two other levers t. t, to the ends of which
are connected the rods, . These rods embrace and support the springs
and to the ends of the springs are attached the links w, w, which are connected
to the frame of the carringe, and by these means the carriage and engine are
suspended. By this mode of suspending the carriage and springs, there cannot
be any more weight or strain exerted upon the bearing on one side of the wheel
than the other, as the weight is compensated or balanced between the two; and,
further, to prevent any unequal strain or stress upon the hearings caused by
the carriage or the segment and guides being out of a perpendicular line with
the centre of the crank shaft, 1 form the upper parts of the collars or pieces, a,
in which the shaft revolves. partly of a convex spherical shape, as shown in the
detached Fig. 10, the upper parts of these pieces fitting into corresponding
concave sockets or recesses on the under side of the bearing pieces p, p; by
these means the pieces a, a, will adjust themselves in the manner of a ball and
socket joint, so as always to have a proper and equal bearing upon the crank
shaft. The bearings may be supplied with oil or other lubricating material by
means of a small reservoir and roller, running in contact with the shaft, as shewn
in the detached Figures. My fifth improvement is shewn in the detached
views. Figures 11 and 12. Fig. 11 is a sectional plan view of my improved
piston; Fig. 12 is a transverse section taken through the same. The solid
parts of the piston are composed of two halves a, a, fitted upon the end of the
piston rod by a double cone, and secured by screw bolts. which fasten the two
halves together. c, c, are metallic rings, one of which is shewn detached at
Fig. 18 (Sheet 2). These rings turn loosely upon a cylindrical part of the
piston, their outer surfaces being convolute curves. On their inner surfaces are

page_text: formed the segment of teeth d, d, which take into a pinion e, placed in a socket
or recess formed in the solid parts of the piston. The outsides of these con-
volute rings are embraced by what may be called circular wedges f, f, one of
which is shewn detached in Fig. 14 (Sheet 2). These pieces constitute the
packing, and their ends are connected to the solid parts of the piston d by pins
at g, to prevent their being turned round; when it is required to tighten the
packing, which is done by passing a key through the opening h in the piston
into the square hole in the pinion, and on turning it in the direction of the
arrow, the convolute rings will be made to move in that direction, and expand
the circular wedges f. It will be understood that the joints of the circular
wedges should not be placed in a line with each other, but should overlap, to
prevent the steam from escaping through the packing of the piston; by this
construction I combine the advantages of a solid piston with those constructed
with elastic packing. In order to prevent the unequal wear of the pistons and
cylinders when placed in a horizontal position, I form a groove i, see Fig. 11,
extending the whole length of the under side of the cylinder, part of which is
only shown in section in this figure; into this groove is accurately fitted a rod
of hardened steel k, and furnished with adjusting screws 1. Another groove, of
a dovetailed shape, is formed in the piston or its packing, into which is fitted
another piece of steel m, which bears upon the former and supports the piston.
Should these surfaces wear by the friction, the rod can be readily brought up
by the adjusting screws. I would here remark that as this groove is formed
by a planing machine, I prefer planing the whole of the interior of the
cylinders instead of boring, as I consider a much truer cylindrical surface can
be obtained by planing than by boring. My sixth improvement, viz., the im-
proved method of changing the speed of the carriage when running upon hori-
zontal railways, is represented in vertical and longitudinal sections, Figures 23
and 24 (Sheet 3); a is the crank shaft turning in bearings compensated in
the manner herein-before described; is one of the running wheels, which
turns loosely on the crank shaft, as its axle; c is a toothed wheel fixed upon the
boss of the running wheel; d is a disc, with an inside toothed rim e, formed
upon it; f is another disc, or what may be called a double crank, fixed upon
the crank shaft; this disc f carries two crank pins g, g, upon which revolve
two pinions h, h, which gear into the toothed rim e, and also with the toothed
wheel c; i is a collar or bush, sliding upon the end of the crank shaft; upon
this bush is formed the disc k, k, into which are fixed two pins 1, 1; by means
of these pins the running wheel b and the disc d, with its inside wheel e, are
connected, as shewn in Fig. 1, viz., so that the whole of the parts revolve with
the running wheel at the speed of the crank. When it is desired to increase

page_text: the speed as before stated, the pins 1, 1, are to be drawn out of the disc d by
sliding the collar i upon the crank shaft, by means of a lever or otherwise; at
the same time the inner tooth wheel e is prevented from revolving by means of
a break or friction band m, m, embracing the outer surface of the wheel c, and
which is brought into contact with it by the rods n, n, and excentrics placed on
the shaft o, o, and the shaft is suspended by the rod or link p from the frame-
work of the carriage. By these means the toothed rim e is gradually stopped
by the friction of the break, and as the crank shaft continues to revolve, the
pinions h, h, on the disc f begin to turn upon their axes, from being in gear
with the teeth of the now stationary wheel e; and as they revolve, will turn the
toothed wheel c, and with it the running wheel b, at the increased speed of three
revolutions to one of the crank shaft. On again releasing the friction break,
which is suspended from the rod q, and sliding the pins 1, 1, into connection with
the disc d, the running wheels will again take the speed of the crank shaft as
before.
Having described particularly the arrangement and construction of my
several improvements in steam engines, I shall proceed to explain briefly the
other parts of the locomotive engine, shewn in the Drawings, to which my
improvements are connected, and then describe some variations of the same as
applied to stationary or marine engines. The cylinders A, A, are supported
on the cross bars of the framework of the carriage 1, 1, 1; upon these cross
bars the boiler is also supported. The slide valves I, II, are worked by the
eccentric 2, 2, on the crank shaft R, R; 3, 3, are rods leading from the eccen-
tric to the levers 4, 4, working on the shaft X, as their fulcrums; the other
ends of these levers are connected to the rods 5, 5, which are again connected
to the hand gear levers 6, 6, from the end of which extends the rods 7, 7, to
other rods 8, 8, (see also Figures 4 and 6). connected thereto by adjustable
screw joints. The rods 8, 8, pass through cylindrical guides 9, 9. formed on
the steam chamber I, with stulling boxes at their ends. From the rods 8, 8.
the arms 10, 10, (see also Fig. 5) project into the steam chamber, through the
opening or slot 11 (shewn by dots in Figuro 4), and between projecting
ribs 12, 12, formed on the tops of the slides I, H. By these means the slides
are worked at the required periods, and by the hand gear the engineer stationed
at the platform 13, 18, Figure 1., can reverse, the motion or stop the engine
when required. The discharge pipes 14, 14, for the exit of the steam, are
connected with others leading to the chimney, herein-after described. Figures
15 and 16 are plan and sectional views of one method of packing the piston
rods steam-tight in the covers of the cylinders, and in which the elastic force
of the steam is used as an auxiliary to prevent its escape. D is the piston

page_text: rod; F, the cover. The metallic packing consist of two parts 15, 15, placed
round the piston rod, the joints on their upper flange being covered by pieces
16, 16; the whole is secured by the cap piece 17, fastened by screw bolts to
the cover F; steam is admitted through an opening into the recess of the
metallic packing, and by its expansive force presses the packing into close
contact with the piston rod, and thereby prevents its escape. Figures 17
and 18 are plan and horizontal views of another mode of packing the piston
rods. D is the rod; F, the cover; 18, 18, semicircular pieces of hard-
ened steel, embracing the piston rods with common hempen packing, placed
behind them in the recesses 19, 19, and the whole is secured by the cap piece 20.
Figures 19 and 20 are plan and sectional views of another construction of
pistons, in which the expansive power of the steam is made to force outward
the sigments of metallic packing in contact with the cylinder; B is the piston;
D the rod; 21, 21, the segments of packing, secured steam-tight between the
two halves of the piston; but there is a small space left between the sides of
the solid parts of the piston and the packing, where the steam is admitted, to
force the packing outward. If it should be desirable to communicate the
power of both pistons through one end of the cylinder only, it may be done by
making the rod of one piston hollow, and allowing the rod of the other to work
through, its end being furnished with a proper stuffing box. Figures 21 and 22
are representations of this method of communicating the power of the engine;
B and C are portions of the piston connected to the ends of their rods D, E.
The rod D is formed as a hollow tube, with the cross head U, U, on its end,
to which cross head rods are connected leading to the crank shaft; the rod E
works through the stuffing box formed in the cross head, and its end is also
connected by a rod to a crank on the same shaft, as before described.
Having explained my several improvements as applied more particularly to
locomotive engines, I must remark that it will be evident the explanation of
the first and second heads of my present Invention are equally applicable to
stationary and marine engines; and I shall, therefore, state briefly the mode
of applying the power of a stationary engine constructed in this improved
manner. Suppose the crank shaft of my locomotive engine to form part of a
main shaft in any factory (say a cotton mill), and that this main shaft is
required to make from two hundred to two hundred and fifty revolutions per
minute, which speed is given to them in common by multiplication of wheels
and pinions, for moving this main shaft by my engine no gearing would be
required. A fly wheel of about four feet diameter is put on the main shaft
(that is the crank shaft), and one or two cylinders, according to the power
required, fixed to the wall of the building or elsewhere, the pistons of which

page_text: cylinders (either by means of a hollow piston rod or a communicating shaft
and rods, as already described) are connected by crank rods with the main shaft,
without the necessity of any toothed wheels, because the engine can be worked
at a speed of two hundred and fifty or more strokes per minute, without impeding
the exercise of the full power of the steam upon the pistons. Another feature
of importance is the facility and ease with which the power may be increased,
when it is wanted, merely by applying another cylinder to the main shaft, and
(in cases where a loss of steam by condensation is not objectionable) a similar
cylinder might even be applied to detached machinery, at any distance to which
n steam pipe might conduct steam from the boiler. The value and utility of
this improved steam engine is greatly enhanced by its requiring but very simple
and slight foundations or framework to support it, since (as has been fully
stated) no stress or straining is exerted by the engine upon the foundation or
framework on which it is mounted. My improvements in boilers applicable
to fixed and locomotive engines are exhibited in the several Figures in Sheets 4
and 5 of the accompanying Drawings, and consist, first, in a new and improved
construction or arrangement of safety valves to be applied to steam boilers.
Secondly, in the general arrangement and construction of a boiler for a loco-
motive engine, with its fire-place or furnace, feeding channel, ash-pits, and
chimney, and also its apparatus for regulating the draft caused by the exit
steam. Thirdly, in improvements in the arrangement or construction of boilers
for stationary or marine engines. My first improvement in the boilers is shown
in Figures 25 and 26. Sheet 4. Figure 25 is a vertical section, taken through part
of the boiler and safety valve. Figure 26 is a sectional plan or horizontal view of
the same. A, A, is a part of the boiler. B is the steam pipe leading from the
boiler to the cylinder C of the valve D. This cylinder is mounted upon the
cross plate E, supported by two other cylinders F and G, fixed on to sockets or
flanges fastened to the boiler. Each of these cylinders have other valves 1
and placed in them, and are open at their lower ends to admit steam from the
boiler. The piston safety valve D fits accurately in the upper part of the cylin
der C, and is connected by the rod a to a second piston K, placed below the
opening of the steam pipe B, and working steam-tight in the lower part of the
cylinder; it is of a little larger area than the piston D. The steam contained
in the cylinder C, between the valve D and the piston K, exerts its elastic force
against each of them, and from the larger area of the piston K, depresses it, and by
means of the connecting rod a, draws down the valve Dupon the shoulders b, b,
as shown in Figure 1, and thereby closes the cylinder steam-tight. The piston 1
is connected to the rod c, which passes through the plate E. and its end serves
as an index to the steam guage d. This piston is kept down by a helical spring e

page_text: capable of contracting under a pressure of from five pounds to above fifty pounds,
upon the square inch without breaking. The ball valve H is depressed or kept
in its seat by the rod f. passed through the plate E, which has a lifting screw 9
on its end. This valve is kept down upon its seat by a helical spring h, h,
calculated not to give way to a pressure under fifty-one pounds upon the square
inch (the extent of pressure required in the boiler). Supposing the pressure of
steam in the boiler to be only five pounds upon the square inch, the piston I,
will not be affected; but as the pressure of the steam increases, the piston I, will
rise in the same proportion, the spring e giving way; and when the pressure
exceeds fifty pounds per inch (say fifty-one pounds), the piston I, will have risen
in the cylinder G, until the opening i has arrived at the groove or steam way k, k,
which leads from the cylinder to the under side of the piston ; the steam will
therefore immediately escape from the cylinder G along the passage k, k, and
fill that part of the cylinder C which is below the piston K, and immediately lift
it and force up the valve D, when the overplus steam will immediately escape
through the openings 1, 1, and up the exit pipe m to the atmosphere. As soon
as the pressure of the steam falls below fifty pounds upon the square inch, then
the spring e forces down the piston I and closes the aperture k, when the pressure
of the steam will again exert its force upon the upper surface of the piston K,
draw down the piston valve D, and prevent the further escape of the steam;
and the small portion of steam contained in the cylinder below the piston K,
may be allowed to condense or escape through a very small aperture to the
atmosphere. Supposing the valve I at any time to get out of order or not act
properly, the other valve I will act as a second safety valve, its spring & giving
way under a pressure exceeding fifty-one pounds upon the square inch, when
the valve will rise and allow the steam to escape up the passage n to the under
side of the piston K, and it will be raised as before described. When the
engineer wishes to open the safety valve D, he has only to turn the lifting
screw g, which will release the valve H, and allow the steam to act upon the
piston K, as before stated. Figure 27, Sheet 4, is a vertical section, taken
longitudinally through my improved boiler for a locomotive engine, with its feed-
ing channel. fire-place or furnace, tubular flues, ash-pit, and chimney, also the
throttle valve and pipe for conducting the exit steam to the chimney. Figure 28
is a plan or horizontal view of the same complete. Figure 29 is a front end
elevation; and Figure 30 is a similar view of the back end.
A is the feeding
channel, which may be formed with a door at its upper end.
or furnace. C, C, are the fire bars. D, D, are casings or water chambers
surrounding the feeding channel and furnace. E is another chamber or part
of the boiler, which is formed separate and placed over the furnace, its bottom
Bis the fire-place

page_text: forming the arch of the fire-place. This part is connected to the main boiler F, F,
by bolts, and has water and steam communications by means of the pipes a and b.
The chambers I, D, at the side of the fire-place, are connected by tubes G, G,
in the manner shewn in the detached view, Figure 31, and are braced or secured
with rods and serew plates and nuts c. c. c. These chambers D), have also a
water communication by the pipe a*. HI, H, I, are tubular flues, passing
through the boiler in the ordinary manner into the ash-box I, upon which is
fixed the chimney K. The sides of this ash-box are also furnished with water
chambers dande, having two series of water pipes and g placed across it.
connecting the chambers in the way shewn in the detached section, Fig. 32.
The water forced by one pump of the engine enters the lower chamber d by
the pipes h, and after passing along the set of pipes across the ash-pit, enters
the chamber at the opposite end and proceeds by a pipe i to the boiler. The
water passing from the other forcing pump, enters the chamber by the pipek,
and after proceeding through the tubes, enters the boiler from the opposite
end by the pipe 7; by these means the water becomes heated in the tubes before
it passes into the boiler. Lis the throttle valve, of the ordinary construction.
M, M. are the steam pipes, branching off in two directions and embracing the
boiler, and leading to the steam boxes of the slide valves of the engines. as
before stated. N is the exit pipe of the steam leading from the engine. This
pipe also embraces the boiler and then passes up the chimney. In order to
regulate the draught caused by the exit steam in the chimney, the end of this
pipe N is formed as represented in the sectional Figures 38 and 34. K is the
chimney, which is contracted near its upper end. N is the exit pipe, upon the
end of which is placed another pipe 0, of a peculiar shape, as shown in the
Figures. This pipe is formed with a rack m on its side, the teeth of which
take into a pinion 72 on an axle, mouted in bearings, fastened to the chimney.
The end of this axle projects, so that a key or winch handle can be placed on it,
by which it can be turned for the purpose of raising or depressing the pipe 0);
and as the end of this pipe is placed nearer to or further from the contracted
part of the chimney, so will the draught be regulated; and it may be completely
stopped if required, as shown in Fig. 34, without impeding the passage of the
exit steam. When it is desired to cause a draught in the chimney before the
engines are at work, and no exit steam is escaping, the valve I', which is kept
down upon its seat by the lever o and spring box p, is opened by pulling the
rod
7. which will raise the valve and allow the steam to escape directly from the
boiler to the chimney. This valve p is placed in a box connected with the exit
pipe N, and is also used as a safety valve. My improvements in beilers for sta-
tionary or marine steam engines are exhibited in the several Figures in Sheet 5

page_text: of the accompanying Drawings, and consists in the improved arrangement and
construction of the same, to be applied to my novel construction of fire grates, pro-
pelled under furnaces which are described in the Specification of a Patent
granted to me by His present Majesty King William the Fourth, and dated the
Twenty-fourth day of May, One thousand eight hundred and thirty-four, the
Specification of which is duly inrolled in the office of the Rolls Chapel, in His
said Majesty's High Court of Chancery. Fig. 35 is a vertical section, taken
longitudinally through one of my improved boilers. Fig. 36 is a transverse
vertical section of the same. A, A, is the boiler; B, B, the fire-place; C, C,
the situation of the fire bars and ignited fuel. D is a portion of the boiler,
projecting downwards at the front end, and under which the travelling grates or
frames of fire bars described in the above named Specification, enter the fire-
place. E, E, are bridges or parts of the boiler projecting into the fire-place.
The sides of the boiler are connected by a series of water pipes F, F, properly
secured in the boiler. G is the man-hole. H, the entrance to the flue. Fig. 37
is a longitudinal section of another of these improved construction of boilers.
Fig. 38 is a transverse section of the same. A is the boiler; B, the fire-place;
C, the situation of the fire-bars; D, the front part of the boiler; E, E, the
bridges; F, F, sets of tubular flues placed in them; G, the man-hole; II, the
entrance to the fluc. Fig. 39 is another longitudinal section; and Fig. 40
is a vertical section taken through a boiler, composed of three cylindrical
tubes A, B, C. The two lower ones, B, and C, are connected together by a
range of water tubes D, D, placed across the fire-place, and are each connected
with the upper one A by the openings at E, E, and pipes F. The ends of these
boilers are formed of cast iron pieces G, with the man-holes in them. H are
the covers, which have four ears 1, I, I, I, cast on them, and are placed in this
situation by passing them edgeways through two notches formed in the man-
hole and then brought up to close it from the inside; two of the ears I, covering
the notches in the man-hole, as shewn by dots in Fig. 40, the other two serving
to keep the covers in their proper places. The covers are merely held by a rod
passed through the handle or by clamps; until the boiler is filled, when the
pressure of the water and steam will keep the joints tight. K is the situation
of the fire bars and ignited fuel; L, the entrance to the flue.
In witness whereof, I, the said John George Bodmer, have hereunto set my
hand and seal, this Twenty-fourth day of November, in the year of our
Lord One thousand eight hundred and thirty-four.
JOHN GEORGE (L.s.) BODMER.

page_text: AND BE IT REMEMBERED, that on the Twenty-fourth day of November.
in the Fifth year of the reign of His Majesty King William the Fourth, the
said John George Bodmer came before our said Lord the King in His Chancery,
and acknowledged the instrument aforesaid, and all and every thing therein
contained and specified, in form above written. And also the instrument afore-
said 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.
papuna andra person and N TO AND a partner
and thirty-four.