IMPROVEMENTS IN STEAM ENGINES AND BOILERS, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO OTHER MOTIVE MACHINERY
Year: 1848

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPII
STENSON, of Northampton, in the County of Northampton, Engineer, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Eighteenth day of July
One thousand eight hundred and forty-eight, in the twelfth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Joseph Stenson, my exors, adñiors, and assigns, Her especial licence, full
power, sole privilege and authority, that I, the said Joseph Stenson, my
exors, admors, and assigns, or such others as I, the said Joseph Stenson,
my exors, adors, or assigns, should at any time agree with, and no others,
from time to time and at all times during the term of years therein ex-
pressed, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick upon Tweed, my Invention of
"IMPROVEMENTS IN STEAM ENGINES AND BOILERS, PARTS OF WHICH IMPROVEMENTS
ARE ALSO APPLICABLE TO OTHER MOTIVE MACHINERY;" in which said Letters Patent
is contained a proviso that I, the said Joseph Stenson, should cause a par-
ticular description of the nature of my said Invention, and in what manner
the same is to be performed, by an instrument in writing under my hand and
seal, to be inrolled in Her Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part

page_text: 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
Joseph Stenson, hereby declare that the nature of the said Invention, and in
what manner the same is to be performed, are fully described and ascer-
tained in and by the present Specification thereof, reference being had to the
Drawings hereunto annexed, that is to say:-
Firstly, my Invention consists in certain improvements in rotary steam
engines.
Figure 1 of the Drawings annexed is a transverse section of a rotary engine,
constructed according to this part of my Invention. Figure 2 is a longitudinal
section of the same. A is a metal cylinder with flanges a, a, on its two ends;
B, B', are two covers, which fit closely upon the flanges a, a; C is a hollow
roller, which is placed inside of the cylinder A, and serves, as afterwards ex-
plained, the office of a piston; it is of the same length as the cylinder between
the end covers B, B', but is about one-third less in diameter. The ends of
this roller are turned and fitted truly to the cylinder A, but one of these ends
is bevilled inwards (see Figure 2), and a metallic ring D, of a triangular section,
is inserted between the said bevilled edge and the straight side of the cylinder,
which serves as a steam-tight packing at that part. M is a working shaft,
with fly wheel attached (not shown in the Drawings), the inner end of which
shaft is cranked, and passed through an opening in the cover B' into the interior
of the roller C. To the cranked end of this shaft there is a pin F, attached by
joint screw pins d' and d", the inner end of which is of the rounded form
shewn in the Drawing, and fits into a hole of a corresponding shape in the
central boss of the roller C, where it is gripped and held in its place by the
brasses b, b, wedges d, d, and screw bolts E, E, (see Figure 2,) so that the
roller may turn freely on the crank pin F, as its axis or bearing. The pin F
is free to vibrate to a small extent on the joint pin d', but is kept at the same
time tight up to the fly shaft M by the other joint pin d", which is fitted with
a spring for that purpose. While on the one hand, therefore, the action of the
screw bolts E, E, upon the wedges d, d, and brasses b, b, serves to keep the
piston roller C central to the crank pin F, so, on the other hand, the action of
the spring screw pin d" has a constant tendency to keep the periphery of the
piston roller C in close contact with the inner surfaces of the cylinder A, and
so to prevent any escape of steam between them. The brasses b, b, and wedges
d, d, are prevented from turning on their centres independently of the crank
pin F by feathers fitting into corresponding grooves, in the manner represented
in the vertical section, Figure 1. G is a sliding diaphragm or plate, which

page_text: works through a slot in one side of the cylinder A, on a vertical line with its
axis, and is kept always in close though varying contact with the piston roller
C by means of a weight or spring, or (which I prefer) by means of a lever
movement working by a cam or excentric fixed on the fly shaft M, and acting
on the upper edge of the plate at 0. T, T, is a stufling box to the diaphragm
G. As this diaphragm is kept always in contact with the piston roller C on
one side, and that roller is in constant contact with some other part of the
cylinder A, there is a complete separation effected of the cylinder lengthwise
into two parts or chambers, indicated by the letters II and I. J is an induc-
tion pipe, which conveys the steam from the boiler to the steam chest K,
whence it is admitted by a slide valve into a chamber L, from which it passes
through a number of orifices 1, 1, 1, (the united areas of which are equal to the
area of the induction pipe J,) into the division Fl of the cylinder A...
As there is no way of escape for the steam so admitted either at top or
bottom of the cylinder, being stopped at top by the fixed diaphragın or abut-
ment G, (that is to say, fixed in respect of lateral position,) and at bottom or
some other part of the cylinder by the contact between the piston roller C and
the cylinder, but as the roller is free to revolve within the cylinder, the pres-
sure of the steam against the yielding roller forces it round in the direction
indicated by the arrow c. The roller, as it rotates, drives before it any air or
steam there may be in the chamber I, and compels it to make its exit through
the eduction pipe N, which is connected to the port, and close to the side of
the diaphragin, opposite to that at which the steam is admitted, till on passing
the mouth of the induction pipe, and over the central axial line of the cylinder,
(the diaphragm yielding for the moment to the upward pressure of the roller.)
and also past the mouths (1, 1, 1) of the induction pipe L, the diaphragm G
once more descends, and fresh steam being admitted between it and the piston
causes the latter to continue its rotation as before. It will be obvious, there-
fore, that all that is necessary to keep up a continuous rotation of the piston
roller C with the least expenditure of steam practicable, is to admit (by means
of the slides and the usual appendages to slides) the steam, at proper intervals
and in suitable quantities, which two elements, in the calculation, depend
ointly on the amount of free steam space left in the cylinder, and the degree
of expansion at which it may be deemed advantageous to work the steam.
In the preceding description the engine has been supposed to rotate from
ight to left; but the valve box is so adjusted that the direction of motion may
e changed at pleasure from left to right. All that is necessary for this
urpose is to lower the slide valve D2 by means of the lever E, so that it may
over the lower ports L, and s, instead of the two upper ports and s, when

page_text: hat which was in the first instance the eduction passage becomes the induction
one, and vice versa.
Another modification of this engine is exhibited in Figure 3 (a longitudinal
section), and Figures 4 and 43 (transverse sections). The parts in this case and
their respective forms and offices are the same as in the engine first described,
with the following exceptions:-First, the opening left as aforesaid in the
right hand cylinder cover is closed by a stuffing box, through which the cranked
working shaft is passed. Second, the diaphragmn (G), instead of sliding up
and down, as before described, is a fixture, which projects inwards from the
inner periphery of the cylinder A, and enters at its lower extremity into a
recess in the periphery of the piston roller. And third, the piston roller C is
caused by the eccentric action of the cranked shaft to which it is attached to
describe such a path in respect of the steam cylinder as to open and shut
alternately the steam induction and eduction passages, and thereby to produce
a continuous rotation of the cranked or working shaft. Figure 5 shews a
modification in which the diaphragm is connected by a knuckle joint to the
Or,
piston roller C, and works through a stufling box covered by a hood.
instead of the diaphragm being a fixture attached to the cylinder, it may be a
fixture attached to the piston roller, and work through a slot in the cylinder,
this slot being covered in with a hood or case, as represented in Figure 6.
An improvement in the class of rotatory engines called emission engines is
represented in Figures 7, 8, 9, and 10. It consists in employing two emission
wheels (B and B) instead of one, as usual, of which wheels one (B) is keyed
to the main axis A, and the other (B) rotates freely upon it, being kept steam
tight by means of a stuffing box. The two wheels are of the same diameter,
and revolve parallel to one another. The axis A is hollow, and the arms and
rims of the two wheels are also made hollow, the steam passing through the
axis and arms into the rim. The rim of each wheel has two or more
oblique emission ports; but the ports of the one wheel are placed at opposite
quarters of the circle to those of the other, and those of the one wheel are also
inclined the reverse way to those of the other, so that the two wheels when
put in motion revolve necessarily in opposite directions. The outer face of the
periphery of the wheel B', and the inner face of the periphery of the wheel 13,
that is to say, the opposite faces of the two wheels, are indented after the
manner of the buckets of an overshot water wheel, and, consequently, the
the steam emitted from each wheel is projected against the bucket faced
periphery of the other, causing each wheel to serve as a fulcrum for the steam
of the other to act against. The effective power of both wheels is thus trans-
ferred to the axis, and may be transmitted thence to any working shaft throug

page_text: the medium of bevil pignons, driving a wheel, as represented in Figure 7, or
by means of bands and pulleys, as represented in Figure 9, one pulley being
keyed on the main shaft, and the other keyed on the hub of the loose steam
wheel B, and a band from each pulley being carried over two other corre-
sponding pulleys on another shaft, one of which bands is straight and the
other crossed, in order to resolve the contrary motions of rotation into one
revolving movement.
Secondly, iny Invention has relation to oscillating cylinder engines, and
consists in an improved mode of supporting and guiding the piston rod.
Figure 10 is a front elevation, and Figure 11, a side section, of an oscillating
engine (with the cylinder inclined at an angle of about fifteen degrees), eni-
bodying this improvement. A is a rectangular frame, mounted on the top of
the cylinder; D, a cross head, which is attached to the upper end of the
piston, and slides in grooves on the inner faces of the side posts of the frame
A; F is the working shaft, which is supported on standards, and cranked at
the centre, as usual. The arms of the crank are secured by pins to the cross
head D, so that as the piston moves in radial lines corresponding with the
series of arcs described by the cylinder, it carries round the crank and its
shaft along with it; and, whatever may be the length of the stroke of the
piston, the grooves in which the cross bead D slides prevent it from being in
the least warped or strained.
By this arrangement the necessity of making very long stuffing boxes in the
cylinder covers, as is usual, in engines with oscillating cylinders, is completely
obviated, and great facility is afforded for any desired increase of length in the
stroke. The parallelism which the cross head and grooves serve to maintain
does away with the tendency of the piston rod to wear the stuffing box into an
oval form.
Thirdly, my Invention consists of various improvements in steam boilers,
which have for their common object the obtaining of an encreased amount of
fire and flue surfaces, without encreasing proportionably the size of the boiler,
so that I am enabled to generate a greater quantity of steam, and with less
fuel, than can be accomplished by the forms of steam boilers in ordinary use.
Figure 13 is a sectional elevation of an arrangement for this purpose;
Figure 14, a sectional plan taken on the line a, b, of Figure 13; and Figure 15
is a plan of the basement plate N, upon which the boiler is set. B is a hollow
cylindrical fire box with a dome-shaped top. C, C, C, is a water space all
round the fire box, which is connected at top with the external shell or com-
partment of the boiler by the passage D, and at bottom by the pipe E. The
external compartment is also cylindrical and concentric with the fire box. F is

page_text: the feed door which opens into the furnace B, by a water-tight fluc. G is the
opening for the escape of the products of combustion from the fire box, which
then circulate round between the outside of the water space C of the fire box
and the inside of the water space C of the external shell or boiler; after which
it escapes by the opening H, either directly into the chimney, or indirectly,
being first made to circulate in a similar manner round the outside of the water
space C, by means of suitable brickwork. The dotted lines K, K, indicate
the position of doors for cleaning out the flue on the top of the fire box.
These doors are at all other times kept closed. The base plate, represented in
Figure 15, forms the lower bed of the flue, and is supported on two girders
laid across the ash pit. L, L, are openings in it by which the flue M, M, is
cleaned out. N, N, are the fire bars.
Figure 16 is a sectional elevation, and Figure 17 a plan on the line a, b,
of a boiler of a similar construction to that just described, differing from it only
in having an additional water space m, and an additional flue n. A boiler on
another mode of construction is represented in Figure 18, (a front elevation in
section,) and Figure 19 (a plan on the line of the fire door). F is a circular
fire-place. A' A, are concentric cylinders, which are set up in the centre of
the fire-place F, and rest on brick supports, d, d. The furnace bars B, are
fitted into the bottom of the inner cylinder A'. The space between the two
cylinders is appropriated as an auxiliary water space to the boiler, and is com-
pletely closed in, with the exception that it has a side aperture near to the
bottom for the admission of water, and others, e, e¹, near to the top, through
which the steam generated is conveyed into the boiler. From the top of the
inner cylinder A the products of combustion pass over into a down flue f',
between the outer cylinder and the water space of the boiler, whence they
pass into another flue f, carried up between the outside of the boiler and the
external brickwork M, and leading ultimately into the chimney.
passage which is made through the external brickwork M, the water space b
of the boiler, the flue f', and the water space a, for the supply of fuel to the
fire place, and is closed with a fire door as usual. P is the ash-pit.
I is a
A modification of the preceding arrangement is represented in Figure 20,
(an end view) and Figure 21 (a side sectional elevation. A is the boiler,
which is made with flat ends; and Aª, an auxiliary generator, which is formed
of two concentric cylinders, as in the plan last described, and communicates
at C with the main body of water in the boiler. The flame and heated
vapours pass, first, under the bottom of the boiler to the back end, whence
they are returned to the front end through the main flue E, from which they
are returned throug the central flue f, to the farther end of the boiler, and

page_text: pass through d into an outer flue surrounding the boiler, which leads to the
chimney.
A boiler is shewn in Figure 22, (sectional elevation,) and plan, Figure 23,
(plan on the line a, b,) in which the tubular and large space systems are
advantageously combined. The fire-place F is enclosed within the boiler B,
as in Figures 18 and 19, but terminates in a dome, from which the chimney
is carried up directly through the centre of the boiler. C, C, is a circle of up-
right tubes, which are set up within the fire-place, at a little distance from the
sides, and are open at top and bottom to the large water spaces of the boiler.
D. is an auxiliary generator, which is fixed within the fire-place, just below the
dome, and is supplied with water from the body of the boiler, by a pipe c,
while another pipe, d, carries.off the steam generated in it to the boiler. Lis
a feed door.
A small boiler of a very suitable form for portable engines is represented in
Figure 24, (a sectional elevation,) Figure 25 (a transverse section on the
linc c, a,) and Figure 26 (transverse section on the line a, b.). B is the
boiler, which is of a dome shape, and encloses the fire-place F, as before. S is
an iron sheet casing, which is dropped down over the top of the boiler, and
secured to it by wrought iron stays. Round the under end of the outer casing
there is a moveable hoop H, which dips into a ring of metal R, whichi encircles
the body of the boiler, and is partly filled with sand, in order to seal thereby
the space between the boiler and casing. G is an auxiliary generator, which
is placed on the centre of the basement of the fire-place, and communicates by
means of a circle of vertical tubes v, v, v, with the water in the upper part of
the boiler. A section of this generator is given in Figure 24. The fire bars
b; radiate from the generator as from a common centre, and are supported at
their inner ends on a wrought-iron hoop. D', D², are two feed passages, (closed
with doors, as usual,) which are made through the sides of the boiler and fire-
place, and across the intermediate water spaces B', B', into the heart of the
fire-place. I prefer having two of these passages, on account of the greater
convenience which it affords for supplying fuel from either side to the fire bars.
Water is supplied to the body of the boiler by a pipe f, which is connected
with a force pump placed in any convenient situation, and coiled once, twice,
or oftener round the boiler, in the space between it and the sheet iron casing S.
The auxiliary generator obtains its supply of water from the body of the boiler,
through a pipe h. The smoke and unconsumed "gases ascend from the fire-
place, through passages P, P, P, P. into the space. between the top of the
boiler and the outer casing S, and escape thence into the chimney. Sometimes
I bend the tubes v, u, v, over the top, and pass then through the sides of the

page_text: fire-place into the main water spaces B', B', as represented by the dotted lines
in Figure 24; and sometimes also I add a central tube a, (see Figure 26,)
which is carried straight up, while the others only are turned over as last de-
scribed. When the inner and outer water spaces are connected in the manner
supposed in the two last mentioned modifications, (Figures 24 and Figure 26,)
I effect the connections in the manner represented in Figure 27. A junction
tube N, of a conical or tapering form, is inserted into the opposite plates of the
two water spaces.
A hoop is then driven up to the small end of the junc-
tion tube, and afterwards a larger hoop h into the large end.
A secure
joining is thus formed, which will resist any pressure to which it is under
ordinary circumstances likely to be exposed. Access is obtained for the pur-
pose of fitting in the junction tubes through a door a in the outer plate of the
boiler, which is afterwards made fast by bolts and nuts.
A modification of the boiler last described is shown in Figure 28 (sectional
elevation). B is a cylindrical boiler, with vertical fire tubes v, 2, which lead
at top into a dome-shaped smoke box, T, enclosed within the steam donie
of the boiler. From the top of the fire box, a pipe b, rises which leads to
the chimney. The steam which collects in the top of the boiler becomes dried
by the heat radiated from the fire box and chimney pipe, and in this consists
one great advantage of this form of boiler. K is a pipe which conveys
a constant supply of water from the side water space B' of the boiler, up
through the centre of the under tube plate P (room being made for it by the
removal of one of the fire tubes). The water and steam diffused by this pipe
preserves the bottom tube plate P from becoming overheated, and thus reduces
greatly the risk of its cracking. The dome of the fire-place is jointed to the
sides and chimney pipe at a and c, so that by undoing these joints both the
pipe and dome, or either of them, may be withdrawn, for the purpose of
cleansing, repairing, or replacing the tubes v, o, or the ferrules by which they
are fastened into the upper tube plate P.
Another mode of constructing a boiler, so as to bring a large portion of the
heat to bear on the steam in the top of the boiler, is shewn in Figure 29.
Here the heated vapours which collect in the smoke box I, at the top of the
fire tubes, are carried by short lateral tubes b, b, into the space a', between the
dome of the boiler and the outer iron casing, which space is sealed at bottom
by a sand lute as before.
Figure 30 is a side elevation in section of a dome-shaped boiler, in which the
half only of the dome is covered with an outside casing, and two vertical
auxiliary generators a', a, are employed. Figure 31 is a plan of the same,
on the line of the feed door; and Figure 32 a plan on the line of the fire

page_text: bars. The flame and heated vapors pass over the first generator a¹, and down
between the two generators, then under the second generator a², and up the
outside of it into the space between the boiler dome and its half cover S,
whence they escape into the chimney. The generators a', a, are fed with
water from the water spaces of the boiler, by the transverse tubes 6, 61, and the
steam generated is conveyed by curved tubes c, c', into the upper portion of the
boiler: The mouths of the tubes e, c', are covered with perforated plates, but
fixed at a little distance from them, which serve to diffuse the issuing steam
through the mass of water in the top of the boiler, and to prevent any undue
agitation in it being produced by the sudden action of the jets of steam.
Instead of the fire bars in the preceding arrangement occupying one-half of
the circular fire box only, they may be successively extended inwards from side
to centre, as represented in Figure 32, so as to describe at their ends a chord
line pushed out into the form of a bow or segment of a circle. In this case
the generator a and a must also have a curve given to them corresponding to
the curve of the chord line.
A boiler, with an auxiliary generator of another form, is represented in
Figure 33, (sectional elevation,) and Figure 34 (plan). This generator a is of
the form of a dome-covered cylinder, but with a segmental portion of it cut
away in front. b and d are short transverse tubes, by which the water spaces
in the generator and boiler are connected. The arrows indicate the course of
the flues, which are protected by two solid check pieces b', b', for the admission
of any fuel into them while the furnace is being fed.
case,
Instead of using a single chambered auxiliary generator, as in the preceding
there may be substituted for it a series of pipes bent to the same curve,
as represented in Figure 35, (sectional elevation), and Figure 36 (plan,) and
communicating with a lateral tube a, at bottom, common to the whole. These
pipes are inserted in the crown of the boiler, as shewn in Figure 35. The pipe a
communicates by a shorter one c, at the back in the water space in the bottom
of the boiler.
A self-acting damper for high pressure boilers of a new construction is re-
presented in Figure 37. To the top of the boiler there is jointed a vertical
cylinder a, of an area equal to one square inch, and on this cylinder is mounted
a conoidal frame d. The cylinder has a piston b, open to the action of the
steam from the boiler, the rod of which passes up through a collar g, in the
top bar of the frame d. The rod is loaded with weights f, which rest on a
collar of the rod at g', equal to twenty-five pounds pressure per square inch, or
such pressure as may be desirable on the boiler. At the top of the weights f
(which are a counterpoise to the damper) there is a ring by which the weighted

page_text: piston is linked to a chain which connects it with the damper. A series of
weights w, w, are slid freely upon the piston rod, encreasing progressively in
size from the bottom upwards, but of similar weight, supported each by three
curved stays e, e, projecting from the inside of the frame d, by which they are
kept of about two inches apart from one another, and prevented from pressing
against the piston rod. When the pressure of the steam on the boiler exceeds
twenty-five pounds per inch, the piston ascends, and raises, through the medium
of the collar g', the first weight more or less up towards the second weight,
which is supposed to be equal to five pounds per inch pressure. On the
pressure exceeding thirty-five pounds, the first and second weights are more or
less raised up towards the third, and so on to the top, the damper being lowered
as the weights ascend, and vice versa.
To heat the feed water in the case of condensing engines previous to its
admission into the boiler, I adopt an arrangement shewn in Figure 38. A is
the exhaust or eduction pipe leading from the cylinder, and an enlarged
prolongation of that pipe, which is connected at its under extremity to the
pipe A, which leads to the condenser. The cold water from the feed pump is
forced through a coil of pipes C, placed inside of the enlarged portion b of the
exhaust pipe, and becomes considerably heated by the surrounding steam
before passing out at d towards the boiler.
An arrangement, the converse of the preceding, is shown in Figure 39,
whereby the condensation of the waste steam is accelerated and the quantity of
injection water required for the purpose is considerably reduced. B, B, is an air
chamber, placed in any convenient position, and leading to the ash pit, through
which a strong current of air is constantly flowing inwards from the external
atmosphere. The exhaust pipe A is conducted into this chamber, where it
discharges itself into a receiver a', which is connected by a series of vertical
pipes p, p, with a second receiver a², from which a pipe A2, leads to the con-
denser. The current of cold air which is constantly passing between the pipes
serves to cool and condense the steam within. The ash pit should be closed in
front by a door, with an eye piece of tale in it, and should only be opened for
cleaning the fire bars or removing the ashes.
The air pump ordinarily used in condensing engines, may be entirely dis-
pensed with, or at all events greatly reduced in dimensions, by adopting the
arrangement represented in Figure 40. A is a condenser of the ordinary form,
into which the steam is admitted after leaving the cylinder; b is a close vessel
of similar form, of nearly as large an area as the condenser, from the upper
part of which a pipe rises, to which pipe is fitted a water injection cock m.
The under side of the vessel b is perforated with a number of small holes,' the

page_text: aggregate area of which holes is fully equal to that of the injection cock; c is a
water chest or chamber, which is placed on the same level, or rather somewhat
lower than the bottom of the condenser A, and has an opening in its bottom
plate, which communicates with another chamber d, immediately under it,
which last chamber has also an opening through its bottom plate communi-
cating with an exit pipe e, the lower end of which dips into the hot well f
and below the water-line of the waste pipe g.
The mode in which this condenser operates is as follows:-The steam is
conducted into the condenser by the exhaust pipe, and the injecting water
admitted to it through the vessel b, in a series of small streams. Thence I call
that vessel the water disperser. The water of condensation rests in the chamber c,
upon the valve h, which is made so as to slide over the opening into the
chamber d, which opening may be closed at intervals by means of the rod g'.
On opening the valve h the water falls by its own gravity into the chamber d;
and on that valve being closed, and a small jet of steam admitted into d,
by means of the pipe j, which is connected with the boiler or steam pipe, and
is-furnished with a cock or valve to be opened at intervals (corresponding with
the openings of the valves h and i), the vacuum in d is destroyed, and a
pressure produced in that chamber of not less than that of the atmosphere.
The valve now opened by the rod k, and the water of condensation in the
chamber falls through the pipe into the hot well f, and escapes at the
waste pipe g.
:
The valve rods and are worked by cams or eccentrics, at such times or
intervals as may be found necessary to prevent an accumulation of 'water or
gases in the condenser A. A small air pump (much smaller than is ever used in
condensing engines) may be attached to the chamber d, for the purpose of
extracting any aeriform gases that may collecte in the interior of the apparatus.
The rods and g' are worked through the stuffing boxes, and the valves h and i'
are so fitted that no upward pressure can remove them from the faces of metal
on which they are made to slide.
To obtain, in the case of locomotive engine boilers, as large a fire surface as
may be without any encrease in the quantity of fuel consumed, and to lower at
the same time the centre of gravity, I propose to have two boilers to each
engine, instead of one, as usual. The necessary arrangements for this purpose
are shewn in Figure 41. The axles of the wheels pass between and outside
of the boilers. To cach boiler there is a separate chimney, and to each
chimney a separate blast pipe; but the steain chambers and water spaces of
the two boilers are respectively connected by junction pipes. The door to the
fire-places may be placed at D', D', or perhaps more conveniently at D².

page_text: To expand and dry the steam, in the case of locomotive boilers, before its
admission to the working cylinders, I propose to insert within the chimney,
immediately above the smoke box (see Figure 40), a longitudinal steam case,
through which the steam is passed on its way to the cylinders. I is a pipe,
which conveys the steam into this case; and K, another pipe, by which it is
transmitted in its dried and expanded state to the working cylinders.
To compensate in some measure for the sudden fluctuations of the water level
to which locomotive boilers are subject, from inequalities in the rails and rapid
ebullition, and the consequent uncertainty in the indications afforded by guage
cocks, I propose to attach to the inner ends of the guage cocks two concentric
cylinders of this sheet copper, placed about a quarter of an inch apart. The
sides of both cylinders are perforated all over with small apertures (the top and
bottom remaining entire). Those of the inner cylinder are about one-eighth of
an inch, and those of the outer about one-sixteenth of an inch in diameter;
and the aggregate area of both sets of apertures is a little more than the area
of any one of the guage cocks. In consequence of the equalizing effect of these
apertures, the height of water exhibited by the gunge cocks will be always very
nearly the mean height of the water in the boiler.
In order to lessen the risk of accidents from the rupture of the steam pipes
employed in steam boilers and engines, I propose to strengthen them by means
of tension bolts, in the manner represented in Figure 42. a, b, c, are three
steam pipes; a being an intermediate one, which is fitted with its ends into
two stufling boxes in the usual manner, as a provision for the expansion of the
pipes. The steam exerting a force at a, a, which has a tendency to burst the
pipes b and c, I fix a tension bolt ce inside these pipes, as shewn, and secured at
the ends by nuts. The ends pass through two packed collars or glands, to
prevent leakage or I sometimes place the tension bolt outside the pipes, and
secure the ends through snugs, as shown by the rod d, and its connections with
the pipes.
A boiler, on a plan very suitable for cooking apparatuses, is represented in
Figures 43 and 44. C, C, are the fire bars; B, the boiler; D, D, a number
of fire tubes, which pass horizontally through the water, and open into a flat
iron case which rises behind the back of the boiler up to the height of from
four to six feet, so as to ensure an active draught through the tubes; E is
a damper, by which the current through the tubes may be stopped or allowed
to go on at pleasure; F is a steam pipe, which rises from the top of the boiler,
and is provided at its upper termination with a safety valve. Into the side of
this pipe a branch pipe G, with steam cock attached, is inserted. An emission
steam wheel. H is fitted to this branch pipe, and turns a spindle e, which

page_text: passes down through the top of the oven, and turns, through the medium of a
pinion f, a wheel g, to the axis of which there is attached a frame of iron
carrying one, two, or more shelves on which the articles to be baked are placed,
and which are preserved by the revolution of the shelves (along with the
wheel g) from being injured by the fire. The wheel and pinion, instead of
outside of the oven, as shown at
being placed on the inside, may be fixed
hand in Figure 43. The emission steam wheel I may also be made use of
to turn the spit, by connecting it by a band and pulleys to the spit handle,
whereby the jacks in ordinary use would be entirely superseded.
Thirdly, my Invention consists in obviating the objection commonly made
by Fire Insurance Companies and others, to the introduction of steam engines
into barns, stack-yards, and other places where corn, hay, and other com-
bustible matters are stored, for the purpose of working threshing machines or
agricultural machines of any other sort. I station the engine (which should
be. portable) at any distance that may be thought consistent with perfect
safety, and connected by means of a long flexible lose with the hollow shaft of
an emission wheel (constructed either on the single or double wheel plan before
described) placed along side of the machine to be worked. The steam engine
is employed to condense and force air into the hose, and the air transmitted
through the hose is made to give the motion to the emission wheel or wheels,
and the machine or machines in connection with them.
And, lastly, my Invention consists in adapting a steam emission wheel of
either of the varieties before described (or any other sort of engine which may
be substituted for it to the eliciting of electric light from steam for purposes
of illumination and signalizing. I present a rod of copper, or other metal,
having a number of small pointed rods or spikes projecting radially from it, to
the current of steam issuing from the wheel. The rod and spikes become
this highly charged with electricity, which I propose to convey along copper
wires, and through electrodes of charcoal, or a preparation of charcoal, to the
framing or some other part of the engine in contact with the earth, in order to
complete the electric circuit. The light is developed as usual by the breaking
.of.contact between the electrodes. Should the quantityof steam escaping from
the wheel not supply a sufficiency of electricity, I propose to blow off' as much
as may be necessary directly from the boiler by a valve or cock placed so as to
project the steam passing through it against the collecting rod.
A sketch, explanatory of these arrangements, is given in Figure 45. The
wheels a, b, c, d, are placed in an iron frame (insulated), and a slow motion is
communicated to the electrode a' by means of a band driven by the engine on
the V pulley a". By using small engines of this sort, the galvanic batteries,

page_text: hitherto supposed to be necessary for lighting by electricity, and which are
attended with many inconveniences, would be entirely dispensed with; and if
the same system were applied to locomotive engines they might be enabled to
furnish their own lights at a very small cost.
And having now described the nature of my said Invention, in the several
parts of which it is composed, and in what manner the same is to be per-
formed, I declare that the improvements which I claim as constituting my said
Invention are as follows:-
First, I claim the rotary engine first herein-before described, in the peculiar
arrangement and combination of parts of which the same consists (but without
claiming any of the same individually and separately), and also the three
several modifications thereof before described.
Second, claim the improved rotary emission engine before described, in so
far as regards the employment therein of two steam wheels, one attached to
and revolving with the axis, and the other turning freely upon it, and in so
far also as regards the indenting of the inner faces of the edges of the wheels.
Third, I claim the improved oscillating engine, before described, in so far as
regards the cross-head D, and the frame in which it slides.
Fourth, I claim the several improved methods of constructing boilers repre-
sented in the Drawings from Figure 13 to Figure 36, both inclusive, and
before described, in so far as regards the encreased amount of fire and flue
surfaces obtained in each case, and the peculiar arrangements by which such
encrease is effected.
Fifth, I claim the self-acting damper, as before described.
Sixth, I claim the arrangement for heating the feed water of condensing
engine boilers, as before described.
Seventh, I claim the arrangement for facilitating the condensation of the
exhaust steam in condensing engines, as before described.
Eighth, claim the employment in locomotive engines of two boilers, placed
and connected as before described.
Ninth, I claim the arrangement whereby the steam issuing from the boilers
of locomotive engines is caused to pass through a case placed within the smoke
box, before passing to the working cylinders, as before described.
Tenth, I claim the improvement in guage cocks, before described.
Eleventh, I claim the mode of strengthening steam pipes by tension rods, as
before described.
Twelfth, I claim the improved cooking apparatus, before described, in so
far as regards the boiler and the parts immediately connected therewith and
dependent thereon.

page_text: Thirteenth, I claim the employment of steam engines to work from a
distance threshing and other agricultural machines through the medium
of condensed air and emission wheels (or other equivalent machinery), as
before described.
Fourteenth, I claim the adaptation of emission and other steam engines
the obtaining of electric light from steam, in manner before described.
And, Fifteenth, I claim the arrangement whereby the air pump may be dis-
pensed with in condensing engines, or at least used of much smaller dimensions
than usual, as before described.
In witness whereof, I, the said Joseph Stenson, have hereunto set my
hand and seal, this Eighteenth day of January, in the year of our Lord
One thousand eight hundred and forty-nine.