IMPROVEMENTS IN ENGINES WHEREIN SUPERHEATED STEAM IS USED. PROVISIONAL SPECIFICATION
Year: 1856

page_text: LETTERS PATENT to Charles William Siemens, of 7, John Street, Adelphi,
in the County of Middlesex, for the Invention of "IMPROVEMENTS IN
ENGINES WHEREIN SUPERHEATED STEAM IS USED.
PROVISIONAL SPECIFICATION left by the said Charles William Siemens
at the Office of the Commissioners of Patents, with his Petition, on the
9th June 1856.
I, CHARLES WILLIAM SIEMENS, of 7, John Street, Adelphi, in the County
of Middlesex, do hereby declare the nature of the Invention for "IMPROVEMENTS
IN ENGINES WHEREIN SUPERHEATED STEAM IS USED," to be as follows:-
My Invention relates to the regenerative steam engine, for which I have
already obtained Letters Patent in England.
The power of these engines depends in a great measure on the increase of
temperature the steam receives in passing through the respirator into the
heating vessel. It is therefore important to raise its temperature in the heating
vessel to the highest practicable point, and to reduce its temperature in the
regenerative cylinder and other parts of the engine as nearly as possible to
the temperature of saturated steam. For this purpose I construct the heat-
ing vessel in such a manner as to obtain a large developement of heating
surface in contact with the fire and with the steam, and dispose the same in
such manner that each portion of it may expand freely by the heat without:

page_text: straining other less heated portions of the same vessel. This is effected by
deeply undulating or corrugating the sides of the heating vessel. I prefer to
make this vessel of cast iron, and to anneal the same by exposure to intenso
heat before it is fitted to the engine.
The process of annealing renders it more durable and less liable to alter its
shape than it otherwise would be. In order to prevent an undue accumula-
tion of heat in any part of the heating vessel, I surround the same by a boiler,
the surface of which is sufficiently removed as to allow of the circulation of tho
fire between it and the heating vessel without intervention of brickwork or
other bad conductor of heat. The excessive heat of the heating vessel is
transmitted by radiation to the boiler surface, and serves to generate steam for
the engine. The part of the heating vessel that is struck first by the fire I
protect by means of a shield of cast iron, coated externally with fire clay, which
is held to it by nails or hooks projecting from the cast iron, having been placed
into the mould before the shield was cast. At about the other extremity of
the respirator, and in the cover of the working cylinder, I provide close cavities,
that are filled with water, and communicate freely with the boiler; they serve
to reduce the steam to the point of saturation or maximum density on passing
from the heating vessel through the respirator into the regenerative cylinder.
For the same purpose I immerse the regenerative cylinder itself in a boiler or
a chamber communicating with the same.
Another portion of my Invention consists in compensating the strains
produed by the unequal pressures upon the piston of the regenerative cylinder
in alternately pressing the steam into the working cylinder, and causing it to
expand again while compressing another volumo of steam into the second
working cylinder. I effect this in attaching considerable weight to the piston
either directly or by means of connecting links and levers, the oscillations of
which effect the desired object, for at the commencement of each stroke the
expanding steam receives a great force upon the piston that is employed to
accelerate the weight. Towards the end of the stroke, however, the expanding
steam has lost its force, but at the opposite side of the piston a considerable
resisting pressure is produced by compression of the steam, which is now
overcome by the inertia or inherent force of the oscillating weight in approach-
ing the point of rest. After the turn of the stroke the reaction of the com-
pressed steam will impart velocity to the weight in the opposite direction,
which velocity is spent in effecting compression of the steam into the first
named working cylinder. The object of compensating the inequalities of
pressure on the piston of the regenerative cylinder can also be accomplished by
means of lateral pressure upon rods attached with one end to the cross head or

page_text: other portion of the piston rod, and with the other end to weighted levers, or
the piston of a small steam cylinder or cylinders exercising a constant pressure
upon it transversely to the motion of the regenerative piston. At mid-stroke
the rods will be at right angles with its piston rod, and exercise no moving
pressure upon the same, but as the piston approaches either extremity of its
stroke the rod will form an acute angle with the piston rod, and the lateral
pressure upon the same will produce pressure in the direction of the piston
rod, urging the same towards the extremity of the stroke, and compensating
the resisting pressure of the compressed steam upon its piston. In attaching
the outer extremities of the rods on each side of the piston rod to a bell
crank lever, and uniting the second arms with the two bell crank levers
to one common weight or weighted piston guided in the direction of the axis
of the regenerative cylinder, this motion will also accomplish the purpose of
a parallel motion in guiding the cross head of the regenerative piston in a
straight line.
My Invention further consists of certain general arrangements of the
regenerative steam engine, in order to render the same applicable also to
marine purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles William Siemens in the Great Seal Patent Office
on the 9th December 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
WILLIAM SIEMENS, of 7, John Street, Adelphi, in the County of Middlesex,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of June, in the year of our Lord One
thousand eight hundred and fifty-six, in the nineteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Charles William Siemens, Her special licence that I, the said Charles
William Siemens, my executors, administrators, and assigns, or such others
as I, the said Charles William Siemens, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time and
at all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention-for
"IMPROVEMENTS IN ENGINES WHEREIN SUPERHEATED STEAL IS USED," upon the

page_text: condition (amongst others) that I, the said Charles William Siemens, my
executors or administrators, by an instrument in writing under my, or their, or
one of their hands. and seals, should particularly describe, and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, and cause. the same to be filed in tlie Great Seal Patent Oflice within
six calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Charles William Siemens, do hereby
declare the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say:-
My Invention relates to engines wherein the same steam is made to exercise
its clastic force over and over again for an indefinite number of times by being
alternately compressed, heated, expanded, cooled, and compressed again, and of
which the regenerative steam engine (for which I obtained Letters Patent, dated
the 22nd of December 1847, and the 9th of April 1853.) may be considered
to be the type. The power of these engines depends chiefly upon the increase
of temperature the steam acquires during its passage through the respirator
and over the internal surfaces of the heated vessel or cylinder. It is, therefore,
of importance to raise the temperature of the steam to the highest practicable
limit, and to reduce it immediately afterwards as nearly as possible to the
point of saturation, avoiding, however, partial condensation by too great a
reduction of temperature.
I accomplish these objects by the following means:-Firstly, I greatly
increase the available heating surface of the heated vessel by corrugating or
indenting the sides and surfaces of the same, taking care at the same time to
reduce the thickness of the sides or walls of the vessel as much as possible,
consistent with strength, to resist the internal pressure, and to allow each
portion of the vessel to expand freely by heat without straining other and less
heated portions of the same.
Secondly, the heated vessel being usually composed of cast iron, I render the
same more tenaceous and durable than it otherwise would be by subjecting it
to intense heat in a furnace or stove for a sufficient length of time to effect the
partial decarbonization of the cast metal, which same purpose may also be
eflected by treating the fluid metal in a refinery furnace, or by passing currents
of air or steam through the same previous to pouring it into the mould; or,
lastly, by subjecting the metal to any known process of steel-making previous
to founding the same.
Thirdly, I protect the vessel opposite the fire, or where first struck by the

page_text: flame, by means of a shield of cast iron or steel, which in its turn may be.
coated with a thin layer of fire clay or other imperishable material, allowing
only a moderate proportion of heat to penetrate and reach the heated vessel.
Fourthly, in the Specification of my last Patent, dated the 9th April 1853,
I described a certain arrangement of engine wherein the boiler surrounded
the working cylinder, a wall of brickwork intervening between the two, the
object of which arrangement was to economize space and heat. My present
improvement in this direction consists in dispensing with the intervening
brickwork or other non-conducting material between the heating vessel and
the surrounding boiler, and allowing only sufficient space between the two
surfaces for the passage of the flame (either to and fro or only in one direction),
the object being to prevent an undue or dangerous accumulation of heat in any
part of the heating vessel by its direct radiation of heat upon the sides of the
boiler, which radiation encreases rapidly with an increase of temperature of
the heating vessel, and, in point of fact, the pressure of steam in thọ boiler
becomes an approximate indication of the temperature of the heating vessel.
Fifthly, my Invention consists in providing close chambers or cavities about
the extremity of the working cylinder opposite the heating vessel, as well as
around the regenerative cylinder and the passages communicating with the
same, which cavities are to communicate freely with the boiler or boilers, and
are, to contain hot water and saturated steam, the object of such chambers or
cavities being to reduce the temperature within the cylinder as nearly as
possible to the point of saturation, and yet not to cool it down below that point
when condensation would take place.
Sixthly, my Invention consists in certain mechanical arrangements whereby
the working crank of the regenerative cylinder is relieved from the unequal
strains produced by the alternate compression and expansion of the steam. This
is effected either by means of a weight that is attached to the piston of the
regenerative cylinder (either directly or by means of links and a beam), and
which at the commencement of each stroke or oscillation becomes the recipient
of the force produced by the expanding steam, which force it again yields to
the piston towards the end of the same stroke, enabling it to effect the
compression of steam into the second working cylinder; or the same object is
effected by means of an additional steam cylinder, the piston of which is acted
upon by steam from the boiler, and aids the piston of the regenerative cylinder
to overcome its resisting pressure, the peculiarity of which arrangements will
be best understood from the description following.
Seventhly, my Invention consists in certain peculiar arrangements of
regenerative steam engines, chiefly applicable to propelling vessels by means of
.

page_text: the screw propeller, which enables me to obtain a continuity of driving power
by means of one engine having two heating cylinders, and to place the cylinders
and furnaces in a line with the working shaft, that is to say, lengthways with
the vessel.
But in order that the different parts of my Invention may be more fully
understood and readily carried into effect, I will now proceed to describe the
best mode I am acquainted with for performing the same.
Sheet I. represents an elevation, partly in section, of my improved engine;
Sheet II. is a cross section through the middle of the same; and Sheet III.;
Figure 1, represents a plan, partly in section, through the line A, A, of Sheet I:
The engine consists of two working cylinders B and B', and a central or
regenerative cylinder C, which communicates at its upper extremity with the
working cylinder B, and at the lower extremity with the working cylinder B¹
through passages V and V. Each working cylinder consists of the middle or
breast piece (a), which is screwed down upon the framing of the engine, and is
cast hollow, forming a circular chamber, the heating vessel or cylinder (b), the
internal cylinder or open tube c, and the top cylinder d, which has also a
circular chamber or jacket, surrounding it. The heating vessel (b) is of a
corrugated or undulated form (except at its upper extremity), as will be best
seen from the section in Sheet III., Figure 1. In each of the internal ridges
or undulations a strip of cast metal e is placed to augment the surface of heated
material in contact with the steam passing to and fro. The strips é are shown
only in some of the internal recesses of the heated vessel. Tho undulated
portion of the heating vessel is made slightly conical, diminishing towards the
bottom, and a plain tube of cast iron f (being also slightly conical inside) is
made to slip over it, and to touch the crown of each undulation in order to
releave the sides of the heating vessel from internal pressure of steam. g is a
shield of cast iron or steel, coated with clay or other incombustible material,
held to the shield by a number of nails or pins projecting from the cast metal.
This shield is attached to the heating vessel by means of a bolt in the centre,
as will be seen from the Drawing. The annular space between the internal
cylinder e and the upper end of the vessel b, as well as the breast piece a, is
filled with masses of wire guaze, copper turnings, or other metallic substances,
(the respirator) presenting large aggregate surfaces, and allowing of the
passage of steam through them. I prefer for this purpose the use of rolls of
wire guaze inclosing in the interior annealed turnings of copper, which rolls
are piled one upon the other into the annular space, as will be seen on Sheet I.
The upper cylinder d is bored inside, and contains a working trunk D, which
is attached to a crank in the fly-wheel E by means of the connecting rod F.

page_text: The trunk D contains packing rings h, h, h, such as are known by the name of
Ramsbottom's packing rings, which prevent the escape of steam from the
interior of the working cylinder B. In placing the trunk D in its highest
position and raising the cap i, the packing rings h, h, h, may bo got out and
renewed, as will be understood by inspection of the Drawing, Sheet I.
The large hollow piston or plunger G is bolted to the working trunk D, and
is entirely filled with charcoal powder, or other non-conducting material. Each
heating vessel is surrounded by a boiler H, the construction of which is
sufficiently explained by the Drawings. The upper internal surface of the
boiler is protected against the fire by means of a conical ring I, resting upon a
projection attached to the boiler, the space between the ring I and the side
of the boiler being filled with clay or other material. The fire-places K and K'
are intended to contain moveable furnaces, that being mounted upon wheels
may be withdrawn at pleasure in order to gain access to the flues for the
purpose of cleaning, &c. These furnaces are not shown in the Drawing
because their construction presents no feature of novelty; it is only necessary
to remark, that the upper surface of the furnace is bevelled towards the back,
so as to adapt itself against the bevilled lower edge of the conical piece L.
The flame proceeding from the furnace is guided by the piece L upward
through the channels formed by the undulations of the heating vessel b and
the surrounding tube f; it afterwards descends between the tube f and the
internal boiler surface; it next passes the bottom surface of the boiler, and
after ascending again on its circumference, passes into the flue M, and thence
into the chimney. The two working cylinders B and B', together with their
surrounding boiler and furnaces, are alike in every respect. The working trunk
of the cylinder B' is attached to a crank on the wheel E', standing opposite or
under an angle of 180° to the crank on the wheel E; rectangularly or nearly
so with the two outer cranks stands the central crank of the main shaft N, to
which the piston P of the regenerative cylinder C is connected, by means of a
piston rod and connecting rod F".
The central cylinder C is surrounded by a casing O, which casing extends
downwards in the form of a cylinder, which is bored, and contains a working
piston or ram Q. The cylinder Ohas an extension O' with two longitudinal
slots, through which two arms Q', Q', project, forming part of the ram Q.
The extremities of the arms Q', Q', are attached by means of rods and ¹ to
bell-crank levers 1 and P, that turn upon fixed centres m and m³, and are also
connected by means of links n'and ' to the cross head o of the piston P. It.
will be perceived that when the piston P makes its ascending stroke the rods
or links n and n¹ will gradually rise to a horizontal position, causing the piston

page_text: Qto ascend. During the second half of the ascending stroke of the piston P
the rods n and n' will form an acute angle upwards, causing the piston Q to
descend again; the piston Q will consequently make two strokes for one
stroke of the piston P, and being perfectly guided by the cylinders O and O',
will oblige the cross head O to move in the same perpendicular direction. In
admitting, however, the steam from the boilers into the jacket of the cylinder O
a constant pressure will be exercised upon the piston Q, which pressure will
liave no effect upon the cross head o when the rods n and n¹ are in a hori
zontal position, but in proportion as the rods n and n deviate from the
horizontal position, the transverse force exercised upon them by the piston Q
will produce a resulting pressure perpendicularly, which reaches its maximum
when the piston P has reached the end of its stroke, tending to balance the
direct pressure of the compressed steam upon the piston P. In proportion as
the piston P moves towards the middle of its stroke, the direct pressure of the
expanding steam upon it has to overcome the relative and diminishing pressure
derived from the piston Q. When the piston P is at half-stroke, there will
be an equality, or nearly so, of the opposing direct pressure upon the same,
and the relative effective pressure derived from the piston Q will also be zero.
During the second half of the ascending or descending stroke of the piston P
it has to overcome an excessive resisting pressure in compressing the steam
into the ono or other working cylinder, which resisting pressure increases and
reaches its maximum at the turn of stroke; the relative increasing pressure
derived from the piston Q in its descent will balance, to a great extent, the
increasing direct resistance to the piston P, and relieve the crank shaft N from
the same. Instead of the constant steam pressure upon the piston Q, it may
be made solid, in order to act by its own weight only; the bell-crank levers
and I, and connecting rods k, k', and n and n', may also be dispensed with, and
the weight Q be attached directly, or by means of links and levers, to the
piston P, in which case it will perform the office of relieving the main shaft of
the engine of the inequalities of pressure upon the piston P by its mere inertion,
as has been before described. The piston Q may also be connected directly
to the piston P, and the steam pressure upon the same be so regulated by
means of valves as to produce, at least partially, the desired effect of relieving
the main shaft from excessive pressure, which arrangement will be described
hereafter. R is the feed pump which delivers the water into the annular
chambers of the cylinders d and d'; the water thence descends through pipes
2 and p respectively into the cavities a and a¹, and thence into the boilers II
and H' through the pipes q and q'. R is a spare pump, to be worked by
hand when occasion requires it. The pump R is worked by an excentric S,

page_text: which samé excentric works a slide valve T, which is shewn separately in
section on Sheet II., Figure 2. The steam from the boilers passes first into
the jacket O of the centre cylinder, and thence into the valve casing T through
a piper, containing a stop valve and throttle valves, that is acted upon by the
governor U in the usual manner. The two pipes t and communicate
respectively between the two extreme ports at the slide valvo T and the
passages V and V, connecting the centre and working cylinders, whereas the
intermediate pipe ut discharges the waste steam into the atmosphere. The
pipe u traverses a large tube or cylinder W, through which the feed water
passes on its way to the boilers, and becomes heated by contact with the
exhaust steam pipe.
Before starting the engine a fire is kindled below the two heating vessels b
and , and must be continued till steam of from 40 to 80 lbs. pressure is'
raised in the boilers. The engine being in the position as represented, the
steam, on being admitted through the valve s into the valve chamber T, passes
through the pipe t' and the passage V₁ into the working cylinder B', and
below the piston P; the working trunk of the cylinder B will be urged
upwards, while the working trunk D will descend to the bottom; the piston
P will next ascend, causing the steam in cylinder B to expand. Arrived at
nearly its highest position, the slide valve T will admit steam into the working
cylinder B through the passages t and V, causing the working trunk D to
ascend. The action of the respirator and the regenerative cylinder, in alternately
heating and cooling, as well compressing and expanding the steam, has been
sufficiently described in my former Patents. It is only necessary to add, in
regard to the cavities d and a, that before starting the engine they should be
filled with steam or water of the same temperature as within the boilers,
which is effected by simply opening a discharge cock x, discharging the cold
water contained in the cavity, and drawing the hot steam and water contained
in the boiler into them. Instead of the cylinders d' and d', ordinary stuffing
boxes may be used for the trunks D and D' to work through. The engine
should be provided with all the usual appliances of pressure guages, blow-off
cocks, water levels, &c. The framework Z may be arranged and varied as
circumstances may direct, and according to the position of the engine, which
may be placed either in a perpendicular, horizontal, or a slanting position.
In cases where no fly-wheel is used (such as marine engines) I arrange
two engines, such as I have just described, in an angle of 90°, or thereabouts,
to each other, and connect the same to one crank shaft, the middle crank
being connected to the pistons of the two regenerative cylinders, and each of
the outer cranks to the trunks of two working cylinders.

page_text: An arrangement, essentially differing from the above, and which is more
particularly applicable for imparting motion to the screw propeller of vessels,
is represented by Figures 2, 3, and 4 of Sheet III., Figure 2 being a sec-
tional clevation of the same, Figure 4 a cross section; and Figure 3, a sectional
clevation through the line Z', Z', of Figure 4. It consists of two working
cylinders Band B', and the regenerative cylinder C, the working trunks and
piston whereof are connected to the circumference of disc E by means of
connecting rods and universal joints. The disc E itself turns upon a universal
joint in its centre, whereby it is attached to a strong framing Z. A dome is
raised upon the surface of the disc, culminating in a boss, where a crank pin F
is fixed, which works into a crank N upon the main or screw shaft. It will
be readily understood that a rotatory motion of the crank N would produce
a reciprocating motion of the piston or trunks connected to the circumference
of the disc; and, vice versa, that the alternate reciprocating action of the
working trunks and piston will cause rotation of the crank N. Jn order
to prevent rotation of the disc itself, it must be guided at one point of the
circumference, which is accomplished conveniently by a guide or radius rod 7.
It is hardly necessary to remark that the trunks of the two working cylinders
B and B should be connected to opposite points of the circumference of the
disc, whereas the piston of the regenerative cylinder is connected to a point
at right angles, or nearly so, to the former, the three cylinders being con-
nected by means of passages, as before described with reference to Sheets I.
and II. One common boiler H surrounds the two working cylinders, whereas
the regenerative cylinder C and the equalizing cylinder O are immersed in
the same. K and K₁ are moveable furnaces sliding upon rails r, r. The
fire passes in the direction indicated by arrows, first over the undulated
surfaces of the beating vessels into the fire chamber L, and hence through
numerous tubes f. f, f, traversing the boiler into the smoke box M, and
thence away through the chimney Y. The working cylinders of this engine
vary materially from the working cylinders before described, inasmuch as a
the working trunks D and D₁ are of the same diameter as the displacing
plungers Gand G. The effect produced by this change of proportion will be
that a smaller regenerative cylinder suffices to produce the same degree of
compression as before; and, further, that the action and reaction of the steam
upon the piston P will no longer be equal but that there will be a surplus s
of reaction that has to be overcome by the power of the engine. The
excessive reaction or load upon the piston P is in a great measure, if not
wholly, compensated by the peculiar arrangement of the equalizing cylinder o,
the piston of which is fixed to the same piston rod with the piston P'.

page_text: The extremities of the cylinder O communicate with the extreme ports of a
a slide valve T, which have two exhaust ports and u, that communicate
respectively with the forward and backward extremity of the cylinder C.
The steam being admitted through the valve s from the boiler to the valve
easing, is admitted alternately to the one and the other extremity of the
cylinder O, and expands afterwards below the piston P into the cylinder C,
in a manner of Woolfs engine. The steam is finally exhausted through a
slide upon the back of the principal slide, which is moved to and fro by
a lever, the motion of which is so regulated that the exhaust takes place
at the proper moment when the piston P has nearly accomplished its stroke.
The two slides receive their motion by two excentrics w and w³, the latter
of which has to be set at an angle at from 30 to 60°, following the motion of
the former. The two excentrics are mounted upon a shaft x, carrying at
its other extremity a crank y, which receives rotatory motion from an inward
projection of the crank pin E. The motion of the excentrics w and w¹ may,
however, be obtained in various other ways. When it is desired to reverse
the motion of the engine, the lever m is detached from the slotted rod of the
excentric w by withdrawing the connecting pin . A communication is.
moreover, established between the ports and t and u and t by means of
suitable cocks or valves, that are not shewn on the Drawing, to avoid com-
plication. On reversing the position of the principal slide by means of the
hand lever n, steam from the boiler is made to enter into the passage t¹ below.
the piston p, and through the communication valve and the passage u below
the piston P, entering also one of the working cylinders B. Motion will
consequently take place in the opposite direction to what it usually is; but
the sheaves of the excentrics w and w' are allowed to remain stationary for
nearly half a revolution, and before resuming motion in the opposite direction
the pin has again been put into its former position, connecting the excentric
rod with the lever n. It is necessary to remark, however, that in going back-
wards in this manner the steam does not act by its regeneration, but only by
its simple effect, and discharges, as in ordinary expansive engine. The steam
is discharged through the pipe g into the atmosphere or a condenser, the
waste steam being made in both cases serviceable for heating the feed water.
The feed pump is not shown on the Drawing, but the water on its way to the
boiler is made to pass through the cavities a, a, a, in the cylinder covers.
Another mode of reversing the motion of these engines was described in
my Patent of April 1853, which mode may be applied also in the present
instance.
Ilaving now described the nature of my Invention, and the best means I

page_text: am acquainted with of performing the same, I wish it to be distinctly under-
stood that I do not confine myself to the details or proportions herein set
forth. The relative position and arrangement of the regenerative cylinder in
particular may be varied in many different ways. In one of these arrange-
ments the cylinders d and d, Sheet I., may be used as the regenerativo
cylinders by enlarging the diameter of the same, and allowing the trunk D to
work through the piston thereof by means of stuffing boxes, the piston and
trunk being attached to separate cranks, or to points of the circumference of
a disc from 30 to 90° apart. The proportion between the diameters of the
working trunk D and the plunger G may also be varied between the limits
of being equal (as shewn in Sheet III., Figures 2, 3, and 4), or of the trunk
being reduced to the dimensions of a mere rod, in which case the power of
the engine will be derived from the regenerative cylinder. The regenerative
cylinder may be entirely suppressed and a succession of chambers bo sub-
stituted, as were described in my Patent, dated the 22nd December 1847.
What I claim is the arrangements herein set forth and described as applied
to engines wherein superheated steam is used.
In witness whereof, I, the said Charles William Siemens, have hereunto
set my hand and seal, this Ninth day of December, in the year of our
Lord One thousand eight hundred and fifty-six.
Witness,
JAMES GRAFTON JONES.
CHARLES WILLIAM SIEMENS. (L.S.)