IMPROVEMENTS IN OR CONNECTED WITH APPARATUS FOR THE GENERATION AND APPLICATION OF STEAM FOR IMPELLING PURPOSES
Year: 1856

page_text: LETTERS PATENT to John Wallace Duncan, of Grove End Road, St..
John's Wood, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN OR CONNECTED WITH APPARATUS FOR THE GENERATION
AND APPLICATION OF STEAM FOR IMPELLING PURPOSES."
COMPLETE SPECIFICATION filed by the said John Wallaco Duncan
at the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 9th February 1856, pursuant to the 9th Section of
the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
WALLACE DUNCAN, of Grove End Road, St. John's Wood, in the County of
Middlesex, Gentleman, send greeting.
WHEREAS I, the said John Wallace Duncan, have petitioned Her
Majesty to grant unto me, my executors, administrators, and assigns, Her
Royal Letters Patent for an Invention for IMPROVEMENTS IN
WITH APPARATUS FOR THE GENERATION AND APPLICATION OF STEAM FOR IMPELLING
PURPOSES:
NOW KNOW YE, that I, the said John Wallace Duncan, 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
A

page_text: following statement, reference being had to the five Sheets of Drawings
A, B, C, D, and F, hereunto annexed, and to the letters and figures marked
thereon (that is to say):-
:-
The first part of my Invention relates to the introduction of certain material
between the steam generator and the engine to be driven, in order to prevent
the passage of water with the steam from the generator to the engine. For
this purpose, I place in the steam chest, or in a suitable chamber, a quantity of
waste wire, which may have been coiled up for some other purpose and
crushed together as waste, or it may be, a quantity of. fine metal cuttings, the
result and waste of some previous purpose. Instead of using waste wire,
wire may be placed in successive layers, in the manner of a respirator, or it
may be coiled and crushed up expressly for the purpose. I galvanize a
quantity of this material & place it in, the steam chest of boilers, or in other
situations in which the steam in passing from the boiler to the engine must
pass through the interstices amongst the crushed folds of the wire. The
steam passing through this wire has the effect of separating any water from it
that may be carried up with the steam, and which otherwise would pass over
to the cylinder of the engine. Instead of placing the crushed wire in the
steam chest, it may be enclosed in an enlargement of or chamber in the steam
pipe, but in either case it must have sufficient capacity to afford the proper
area for the free passage of steam. It should be so situated, that while the
steam passes away to the engine the separated water would run back into
the boiler. I further employ a quantity of similar cuttings or wire, which I
place in a chamber between the steam cylinder of an engine and the con-
denser, using the same precautions for the free passage of the steam. By
this means, the grease evaporated in the cylinder and carried off by the steam
will be intercepted and separated from it, which will be found favourable to the
working of condensers condensing by external application, as they will be not
liable to choke or lose the power of conduction by an accumulation or coating
of grease.
Another part of my improvements in steam generators consists in the
introduction of certain mechanical appliances into those vessels which keep up
a constant action during evaporation, the object of their action being to pre-
vent the accumulation of solid matter on the interior surface of the steam
generator or boiler, and also to dislodge any such deposit that may take place.
These mechanical appliances, which I denominate mechanical scavengers, are
represented in Sheet C; they consist generally of metallic or ceramic bodies,
so formed, that ebullition or the rising of vapour through the water will impart
rótary, oblique, or lateral motion to them, and also carry them upwards; or in

page_text: some instances they may be too dense to be carried upwards, while, on the
other hand, some of them may be made to float on the surface.
Figure 14, Sheet C, represents one of these mechanical scavengers; this
consists of a hollow metal vessel A, of the shape shown; the weight being
such and so disposed as to tend to keep it in an upright position when
immersed in water, and of just sufficient specific gravity to sink it. On the
exterior are projecting vanes or blades a, a, a, of a spiral form. When
ebullition takes place in the water of the boiler, the vapour, on rising, catches
these vanes, and induces a rotary motion in the body A, the ascending power
of the vapour also overcomes the gravity of A and it is carried upwards. The
vanes a, a, a, coming in contact with the sides of the boiler keep up a constant
attrition, and thereby remove any matters collected thereon; when the body A
loses its vertical position it will fall to the bottom, and on resting will again
assume its erect position and be carried upwards, as before, thus a continuous
operation is kept up during ebullition. As a further assistance in removing
these matters, a wire brush b is attached to the lower part of A; wire brushes
may also be applied with advantage to other parts of its surface.
proper
Fig. 15 represents in vertical section a modification of the foregoing, in the
form of a double truncated cone B; c is the air space to render it of the
specific gravity. The exterior of this scavenger is studded with projecting
pins d, d, while the coné e forms a passage for the rising vapours. B is
weighted, so as to settle in an erect position, as before, and is furnished with
vanes f, f, on which the rising vapours act during their ascent, and cause it
to rotate, as before described. On losing its equilibrium after being carried
upwards in the water, it will again fall and settle in an upright position, and
will again rise. In this way a constant cycle of operation will be maintained;
the projecting pins d, d, or bruslies coming in contact with the inner surface of
the boiler produce the effect described. In this way the solid matters in the
water will be kept in suspension, and must. be blown out in the usual way, or
removed by mud doors, when it settles at the bottom of the boiler when cold.
I find of advantage to use a small separate chamber in connection with the
main boiler, communicating by a small passage or opening; this chamber is
placed a little below or on the water level, and is not subject to the extreme
heat of the fire, the water therein will consequently be more still. The still-
ness of water in this chamber where the scavengers cannot enter will induce
the solid matters to enter and settle therein, and which may be blown out
therefrom or removed by a mud door for the purpose.
Figure 16, C is an inverted pyramidal form, of specific gravity a little
exceeding that of water, and weighted so as to assume the position shown,

page_text: whereby the ascending vapours act on the vanes g, g, and cause it to rotate
and be carried up, as before described, the angles continuing the action of
attrition when in contact with the boiler sides. If C be made considerably
heavier than water, the act of its falling will tend to chip off solid matters
from the bottom.
Fig. 17 is a cylindrical form, furnished with vanes and weighted to maintain
its erect position when resting. The action of this is the same as described
with reference to the foregoing, and need not be repeated.
Fig. 18 is a side view, and Fig. 19 a transverse vertical section, of a
scavenger, which is weighted so as to maintain a horizontal position in the
water, and whose specific gravity is but little more than that of water. h, h, h,
are projecting hoods, which affords space for the vapours disengaged from the
water to collect on one side, thereby causing the body to turn round. The
extreme points of the hoods h, h, come in contact with the boiler sides and
perform the office required..
Fig. 20 is an external view, and Fig. 21 a section, of a scavenger of denser
formation, being intended to work on the bottom of boilers. It is circular in
plan, and concave on the under side, and the weight so disposed that it remains
with the concave side downwards. The vapours collecting in the concave
bottom overcome the preponderance of the metallic body F, and lift in on one
side, and thereby escape. The constant recurrence of this lifting and escape of
vapour keeps up an oscillating motion of the metallic body F, the lower angle
at the same time striking the bottom of the boiler and removing matters
collected thereon. This, as also the next two modifications to be described,
are only adapted for use in boilers where the heat is applied at the lowest
parts of the boiler.
Fig. 22, of which Fig. 23 is a section, represents a cube of solid metal or
other suitable material, having cavities formed in all its side alike, so that a
collection of vapour in the under side will cause the cube to roll over; thus
a constant turning over or rolling of the cube will take place, the contact of
whose angles effect the dislodgement of solid matters at the bottom.
Figs. 24 and 25 represent different views of a solid polyhedron, whose
sides have each a cavity for the collection of vapours to contribute to the
turning or rolling motion, in the manner and with the purpose mentioned in
reference to the Figures last herein described.
.Fig. 25 represents another form of scavenger; it is in form like the half of
a cylinder twisted, so that the flat side forms a screw surface, against which
the rising vapours act and cause it to rotate, as before described. It is
weighted so as to retain the vertical position, as in Fig. 17, and is little more

page_text: than the specific gravity of water. It may or may not have projecting pins
to act on the boiler surface, but otherwise the angles at extremes of the flat
side will effect the act of attrition.
Fig. 25, B represents a mechanical boiler scavenger in the form of a cone,
having a hemispherical end, in order that it may always fall over on its
inclined side. The conical surface has coarse spiral serrations cut or formed
around it. This body is also of metal or other suitable substance, and of a
density considerably more than that of water. The spiral serrations on one
side of the cone have the effect of catching the steam in rising through the
water by reason of their inclined position, while on the other side these
serrations are nearly vertical, and therefore it passes up freely. The lifting
pressure on one side causes the cone to roll round and to act on the bottom of
the boiler, whereby the sharp projecting angles of the serrated cone produce
the effect desired. If this body is made of but little greater specific gravity
than water, it will be partially lifted and suffered again to fall, as described
with reference to some of the other Figures, the apex of the cone dislodging,
and its other motions preventing the accumulations of deposit.
Figure 25, C represents another form of scavenger, in which the one end is
of less and the other end of much greater specific gravity than water, while
the whole body but little exceeds the specific gravity of that fluid. As a
consequence, it retains a vertical position when immersed, but it is so weighted
on one side that it always leans over. This leaning over being opposed to the
rising of the steam, that vapour in passing upwards gives it an oscillating.
motion, causing the upper end to beat against the sides or other vertical.
portions of the boiler; it may be further furnished with projecting pins to.
assist in dislodging any deposit, and also furnished with spiral vanes or pro-
jections to induce rotatory motion therein, as described with reference to soniė
of the other bodies. The action of all these bodies amongst the water in
steam boilers will also facilitate the evolution of steam..
The second part of my Invention refers to improvements in multitubular
boilers, and consists in the introduction of spiral diaphragms or dividing plates
within the tubes, in order to enhance the action of the heated gases in passing.
through them.
Fig. 26, Sheet C, represents a front view of a portion of the tubes, plate,.
and tubes of a boiler; and Fig. 27, a longitudinal section of the same. a, a,
is the spiral plate inserted, which may be either a casting or a piece of stout
hoop iron twisted. It is placed loosely in the tube, and may be inserted or-
withdrawn at pleasure, as indeed will be requisite for cleaning tlie tubes.
The object of this spiral plate is to produce a spiral circulation of the heated

page_text: gases in their passage through the tubes, and at the same time a change in
the contact with the tube, by which means the more ready and complete
transmission of heat to the water will be effected.
of
The third part of this my present Invontion relates to further improvements
an engine formerly invented by me, and described in a former Specification
under my hand and seal, and enrolled in Her Majesty's High Court of
Chancery. It consists of two cones, which receive the pressure of the steam
and oscillate from a centre, and roll round on either side of a stationary
diaphragm or partition, within two concave hemispheres enclosing the cones, as
shewn in the Drawings of former Specification before referred to, and also in
the Drawings hereunto annexed, which partition I distinguish by the term
.equator.
My present improvements refer to the arrangements for the admission and
escape of the steam to and from the steam chambers, and to the means of
regulating and controlling the same, and also to other details of the engine.
Fig. 1, Sheet A, of the annexed Sheet of Drawings, represents a side eleva-
tion of the improved engine, and Fig. 2 a longitudinal vertical section; Fig. 3
_a transverse vertical section through the line 1, 2, Fig. 1, but with the centre
portion removed, which is separately represented at Fig. 5; and Fig. 4 a
transverse section, shewing one of the hemisphere ends removed. As before
mentioned, this engine consists of two cones, which receive the pressure of the
steam and revolve or roll round on either side of the stationary equator D,
and within the two hemispherical ends W, W, seen in Fig. 1. A, A, is the
bed or framework, on which the separating equator D, D, is fixed by the
bracket B, B, B, it is further bolted to two side frames E, E, at a, a. This
separating equator D is cast in one piece, and, by preference, has its sides
b, b, b, b, inclined to each other in lines radiating from the common centre.
C, C, are the two cones, which revolve each in its orbit on either side of the
equator D; they are rigidly connected to each other by means of the central
shaft F, fixing at the same time the hollow central ball or spherically formed
pieco G, to which the smaller ends of the cones C, C, are accurately fitted.
The ball G has a separation on one side for the reception of a diaphragm H,
passing between and connecting the two cones at the lower part, as best scen
in Fig, 5, which is a section through the ball and diaphragm H, on the line
3, 4, Fig. 6, which is a separate view of that diaphragm, and its connection
with the cones C, C. The separation in the side of the ball G, with the
elasticity of the metal, permits a sufficient contraction to get it within the
centre of equator D, and at the same time to expand and fit accurately
therein;
the diaphragm H is then slid into its place through the opening c

page_text: (Fig. 3); mortises d, d, are formed in the cones, see Fig. 7, which is a view
of small end of one cone.
Tenons on ends of H take into these mortises,
and the whole securely held by the central shaft F, binding the whole firmly
together, as seen in Fig. 6; in Fig. 2 the diaphragm H is removed in order
to show the other parts of the engine. In the lower part of equator Da
conical plug or cock is fitted, and receives a partial rotary motion during the
working of the engine, through which cock the passage c is formed to pass
the diaphragm H, which forms the abutment for the steam to act against, the
steam being admitted between such abutment and the points of contact of
the cones C, C, with the equator D. The expansion of the steam within the
chamber thereby prescribed forces the cones round in their orbit with a
rolling kind of motion, causing them to describe circles within their respective
hemispheres, and inducing the rotary action of the engine; the ball on end
of shaft F is at the same time caused to describe the red circle represented in
Fig. 4, and this ball, taking into the crank T on the main shaft U, imparts
rotary motion thereto. Fig. 8 shows the equator D and diaphragm H, with
the cones C, C, as seen from below. The dotted cross lines show the extent
to which the diaphragm H oscillates during one revolution of the engine. e is
the induction steam passage, formed on one side of the cone plug I, a similar
passage for the exhaust being formed in the other half of the plug; these
passages have openings g, g, to the space c, but this space being fitted by the
diaphragm H, induction and eduction is regulated
passages h, h, and i, i,
formed in that diaphragm, h, h, being the induction formed on one side of H,
and i, i,. the eduction on the other side; as seen in the section, Fig. 5, and side
view, Fig. 6. When the diaphragm H is wholly on one side of the equator D,
as is the case in the position shown in Fig. 2, the steam is cut off on the
right-hand side, by reason of the solid part of the diaphragm H, at the end of
passages h, h, being then within the space c, and the shorter these passages
are made the sooner will the steam be cut off in each revolution. At this
time the steam will be full on in the left-hand chamber, Fig. 2; further
revolution will bring the diaphragm H back into the right-hand chamber,
and immediately the passages h, h, emerge from the plug I on that side, the
steam will be admitted thereto, and coming between the diaphragm H and
the point of contact of cone C and equator D, impels the cone onwards in
its revolution at all parts, except when either of the cones are in the lowest
position (seen in Fig. 2). Steam is admitted by passages h, h, at the same
time to the steam. chambers on either side of D, while, on the other hand, the
exhaust passages i, i, are at similar times open to f. In order to render
the cut off of the steam passage steam-tight, packing strips, k, k, are intro-

page_text: 2
duced in open space c, on either side of the diaphragm h. The parallel part
or neck of plug I is fitted in a cylindrical bore at 1, 1, and rendered steam-
tight by a packing m and gland n. The cylinder K forms a continuation of
the plug I, which part K is fixed; it is kept central therewith by a central
pin p. The junction of the parts K and I are kept tight by means of a
second packing and gland r; the dotted lines show the steam passages in
Fig. 2, which are distinctly seen in Fig. 3 and Fig. 9 and 10, which are
transverse sections through plug I, showing the amount of movement of the
one part on the other with the position of the passages, which are at all times
free. The part K is held up by stud bolts s, 8, 8, 5, which also serve to sus-
tain the glands n and p, and to compress the packings m and q, by suitable
nuts on such stud bolts. Steam admitted by the passage e sets the engine in
motion without the intervention of any other valves for regulating the admis-
sion (other than the governor throttle valve) and escape of steam to the steam
chambers than that provided by the working of the diaphragm H, as before
described. In order to reverse the action of the engine, I employ a slide
valve L, fitted so as to work on the lower part of K, in which are five ports;
t is connected with the steam pipe, which, in the position of the valve shown
in Fig. 3, is open to e. The ports u, u', are both connected with the exhaust
steain pipe, best seen in the plan, Fig 11. The passage f being now open to
u', when the slide valve L is moved to the right, the present exhaust passage f
will be open to t, and will become the induction, while at the same time e will
be opened to port u, and will become the eduction; the motion of the engine
being thereby reversed, motion is given to the valve L by the winch handle M,
which is held stationary by a gudgeon in the frame, and when turned round
propels the screwed valve's rod N according to the direction it is turned. When
the position of the slide is changed, the steam will be admitted to the opposite
side of diaphragm H, the passages i, i, becoming the induction and the pas-
sages h, h, the exhaust. It will be observed that the diaphragm II oscillates
alternately to the positions shewn by the dotted lines in Fig. 8, while at the
same time it is being projected to and fro through the equator D, and that
the steam is being admitted the whole time into both steam chanibers X, X,
on the one side of the diaphragm II, except when either of the cones C, C, are
at the dead point, as represented on the right-hand side in Fig. 2, and until
it moves in its orbit past the conical oscillatory plug I, on to the face b, b,
of D, that is, until the point of contact of cone C passes the line b', b', sec
Fig. 4; at the same time the steam is admitted at each succeeding revolu-
tion, the escape or eduction of the previous revolution is established. The
steam chambers X, X, are enclosed by hemispherical ends W, W, bolted

page_text: up to the equator D, the larger ends of the cones fitting and moving in
contact with the interior of the hemispheres W, W, throughout the entire
revolution, and kept steam-tight by spring packing rings P, P, as seen in
section Fig. 2, and end view, Fig. 12. In order to facilitate the removal of the
hemispherical ends W,W, they are furnished with lugs or brackets R, R, which
rest on the ridges of side frames E, E, and slide to and fro thereon, when the bolts
w, w, are disengaged and the bearings S of main shaft removed. T is a crank
fitted to main shaft u, into which crank the ball end of the central shaft F is
fitted in a bearing a, a, adjusted by wedges y, y, drawn up by nuts z, z, so that
a constant force may be exerted to keep the cones hard up to the faces b, b, of
D, D. Instead of removing the hemisphere ends for the purpose of adjusting
the bearing a, plug openings may be made in the hemispheres opposite to the
ends of the wedges, and means provided to force them up from the outer end,
which may be actuated by a key or wrench inserted through such plug
openings, when the plugs are removed therefrom.
In Figs. 1 and 2 one shaft only is shown; two such shafts may, however, be
actuated, one from each end of the engine, as represented in dotted lines; in
either case I form the shaft F the same at both ends, in order that the weight
of the parts may counterbalance each other.
In order to render contact with the ball G and equator D steam-tight, á
spring packing ring v, which contracts upon G, and has sliding end pieces,
which are forced up to contact with the oscillatory cone plug I. Instead of
admitting the steam up through passages e, e in K, this piece K may be
dispensed with altogether, and a single gland n used to force up the cone plug
I and keep it steam-tight. The lower part of I is made solid, and the steam
allowed entrance and escape through the back or circumference of the cone
plug I, as will be understood by reference to Fig. 13, Sheet C, which represents
a horizontal section through cone plug I taken on the line 1, 2, Fig. 3.
Fig. 13* is a vertical section of the same. In this case, suppose the steam
to enter at w¹ by steam pipe, it is admitted to a cavity a¹ in the equator D,
at the back of the cone I; this cavity has constant communication with the
interior of cone plug I by the slit y', whereby the steam has ingress through
e and h, h, as before; a like arrangement on the opposite side of the cone plug
affords egress for the steam at ¹ from passages e¹ and f¹. In order to render
the engine reversable in its motion, the passages w₁ and z' must be placed in
connection with a four-way tap, or contrivance similar to slide L, whereby the
passage can be converted into the induction. Instead of regulating the
entrance and escape of steam to the steam chambers X by the diaphragm H, this
2¹

page_text: piece may be solid, and simply pass through the space c in conical plug 1
steam-tight, the steam to be regulated and admitted by means of slides
actuated in the ordinary manner. The slides are best placed in a position
between the plates of equator D, close up to the solid metal, in which the conical
plug I is fitted; the steam from these valves entering by the ports, as seen in
dotted lines in Fig, 4, between b', 6', and the plug I, which are the inclined
faces, seen dotted in Fig. 8. Instead of making the diaphragm H a parallel
piece, it may have its sides inclined to each other, as represented by dotted
lines in Fig. 5, with this advantage, that, in case of any wear from the side
pressure of the steam, it will be more equal than when this diaphragm is
parallél, as represented in the Drawings. The extreme diameter of His
rendered steam-tight by means of a metal packing having a radial expanding
force. It will be observed, although an opening through the equator exists
throughout the inclined surface b, b, which is filled up by cone plug I, that the
extreme flanges of D, D, are entire. Instead of making the equator D in one
piece it may be formed with a lateral division, and the two parts bolted
together by bolts through the two flanges of the circumference, or lugs cast
thereon for the purpose. In order to balance the diaphragm H, the cones
C, C, may be made thicker on the opposite side to that on which the diaphragm
is attached to these cones. The cutting off of the steam, to regulate the
expansion by the diaphragm, may be varied, by inserting pieces of lengths
suitable to the degree of expansion required into the steam slots h, h, in the
diaphragm, whereby these slots are proportionably shortened, and therefore
are open during a greater or less portion of each revolution. In order to
permit the escape of condensed water from the steam chambers at all
times, I fit valves to those chambers at the lowest and most suitable points;
these valves open outwards, and are constantly held up by the pressure of
springs, which give way when any pressure, exceeding that of the steam in the
boiler, is exerted against them, and thus suffers pent up.condensed water to
escape during the action of the engine. H and stop-cocks may also be applied
for that purpose, as usual..
Fig. 40, sheet D, represents a side view of an instrument or machine for
boring or cutting out the concave side of the hemispheres; and Fig. 41,
another view of the same, taken at right angles to Fig. 40; it. consists of a
shaft a, a, which carries two circular plates b, b, of a. diameter nearly equal to
the internal diameter of the hemispheres; these are fixed rigidly to the shaft a;
between the plates 6, 6, a disc c is fitted. so as to revolve on a pin d, but
embraced sufficiently close as to be held firm at. all points of its revolution:

page_text: This disc carries the cutting tool e, which is held by a tool carrier f, fixed to
disc c; the disc has a half thread or worm cut in its periphery, into which an
endless screw g takes; this is fitted in bearings on the fixed plates b, b, and
driven at a slow rate of motion; the shaft a is fitted to the shaft hole of the
hemisphere to be bored, which hemisphere is mounted on a horizontal chuck,
to which motion is given; the motion of the chuck causes the tool to take
a cut round the interior of the hemisphere near the shaft or centre, the screw
wheel c at the same time receiving a very slow motion to advance the tool in
a circular direction, by which it approaches gradually the larger diameter of
the hemisphere, and is thus turned or bored throughout. Instead of the
hemisphere receiving the rotary motion, it may be fixed, and the shaft a, a,
caused to revolve. In order to communicate the slow rotary motion to disc c,
in this case it must be driven by level wheels, shown in dotted lines, the upper
one being on a tube shaft embracing a, a, and connected with gearing to reduce
the motion to the required extent.
i
The fourth part of my improvements consists of an improved governor for
controlling the revolutions of an engine by its action on the throttle valve.
Fig. 28, Sheet D, represents a side view of my improved governor, with
some of the parts in section; and Fig. 29, a transverse section of the same.
a, a, is the governor shaft, supported in bearings b, b, and in communication by
means of bevel wheels c, c, with the main shaft U of the engine. d is a collar
fixed on shaft a, having a series of joints e, e, e, around it ; ff, are a series of
strong steel springs, which are jointed at one end to joints e, e, e, of a, and
similarly jointed at the opposite end to the joints 9, 9, of a similar jointed
collar h; this collar / slides freely on the shaft a, and it is also free to oscillate
on a ball centre, as seen in the sections Figs. 30 and 31. is a socket which
revolves with the shaft a, but slides freely thereon; it is constantly pressed
against the collar h by a spring i; is a forked lever fitted into the groove of
sliding collar k, through which the throttle valve m of the engine is acted on.
The springs fff, have an inherent tendency to remain in the position shown
in Fig. 28, and to control the other parts accordingly. When rapid rotary
motion is given to the shaft, the centrifugal force, thereby generated, tends to
throw the springs further from the shaft, & to a position shown dotted, and
so draws up and contracts the space between the collars d and h, and closes the
throttle valve m. In order to get a greater extent of action, I place on and around
the springs fff, a heavy metal ring n, n, which, when the shaft a revolves
slowly, bears its whole weight on the then upper spring f, pressing it close down
on the shaft a, as seen in the section, of Fig. 31, and still further extends the

page_text: distance between the collars & and h, with a further proportionate action of
opening on the throttle valve m, the canting or oscillating of collar h on its
ball centre permitting the upper spring to extend without the lower ones.
When a medium velocity is attained, the centrifugal force of the ring n,n,
counteracts its gravity in a great degree, it being carried round the
revolution of the shaft a and springs f, f; and as the velocity is increased,
the centrifugal force of the springs comes into more active operation, till they
reach the position represented by the dotted lines, which is the extreme limit,
further expansion being prevented by the internal diameter of the ring n,
which embraces the whole number of springs f,f,f; the throttle valve at this
linit is closed. In order to keep the ring n, n, in its place on the springs f,f,f,
two horns or projections p, p, are fixed on each, which retain it always in
proper position, and which at the same time do not interfere with the free
action of the ring. Instead of the long springs being placed on the outside of
a shaft, they may be all enclosed within a cylinder with a stud form, cach
projecting through, each stud having a crutch or saddle in which the metal
ring rests, in a similar manner to that in which it now rests on the springs.
The studs or saddles must have sufficient traverse to and from the centre to
permit the action of the springs, before described. The ring will also require
to be of larger internal diameter for this arrangement, as it cannot fall lower
than the diameter of the enclosing tube or cylinder,
Figs. 38 and 39 represent a modification of the governor, having the weight
or gravitating body in the form of a ring, which revolves on a horizontal axis;
Fig. 38 is a section taken transversely through the ring and in line with the
rotating shaft; and Fig. 39, a lateral vertical section through the ring, and
transversely to the shaft. In this case the springs á, a, a, a, which carry the
rings, are fixed on the end of the shaft b, b; this shaft is overhung on the
bearing c, and driven by suitable connection with the main shaft of the engine
to be controlled or governed. The inner end of the springs a, a, a, are bolted
to the shaft b, as represented, while the ring d rests on the extreme ends of the
springs a, a, which have an inherent tendency to extend themselves from the
shaft b, but are of insufficient strength to lift the ring d, and which, when in a
state of rest, comes down on the shaft d, as represented in dotted lines in
Fig. 38.
When the shaft b is driven rapidly, the centrifugal force throws the
springs from the centre or shaft, assisted by the strength of the spring, and lifts
the ring to a higher elevation, as represented, the lift being dependant on the
rate of velocity maintained. The highest rise can never much exceed that
represented in the Figures, as, on the ring attaining a position nearly con-

page_text: centric with the shaft, the ring will still preponderate in some degree, and bear
down the springs. The springs a, a, are fitted and fixed within a recess e,
formed in the body of ring d, as seen in the cross section; and in order to
prevent any oscillation of the ring d, a disc or plate f is fixed on the shaft
b, against which the ring bears. The ring d has a centre or boss g, carried by
arms or a solid centre, as at g¹, g¹; a cylindrical central hole h receives a ball i
on the end of a bell crank lever k, and by which any rising or falling movement
of the ring d, is communicated to the bell crank lever k, the ring being free
to revolve at the same time. The vertical arm of k, k, is placed in connection
with the throttle valve of the engine by means of the connecting rod 7 and rod
m, by which any movement of the bell crank is transmitted to the throttle
valve, so as open or close that valve in the ordinary manner. When tho
ring drises, the throttle valve will close, and when it falls that valve will open,
and the bell crank assume the position shewn in the dotted lines. The ball
on the vertical arm k is merely to counterbalance the ball i when the ring dis
at its highest and most sensitive position. Instead of forming these governors
on a separate shaft, driven from the main shaft of the engine by wheels or
other gear, they may be applied to the main shaft direct, in which case the
weight rings will require to be of much larger diameter, to permit their
necessary amount of motion on such increased diameter of shafts.
The fifth part of my Invention relates to the application of steam power
to propelling purposes; and, consists in certain particular arrangements and
construction of screw propellers, which are represented in Figs. 32, 33, 34, 35,.
36, and 37..
Fig. 32 represents a vessel with two propellers fitted and arranged according
to my Invention.
Fig. 33 shows the opening in the dead wood with my propeller fitted thereto,
on an enlarged scale; and Fig. 34, an end view of the same.
This propeller,
although placed at an angle, has its shaft somewhat in line with the keel of
the vessel, as seen in Fig. 32. The propeller blades a, a, may be of the
ordinary form, but I prefer them of the form represented in Fig, 34; they are
secured to a ring b, b, the plane of whose motion is controlled by two fixed
rings c, c, bolted to the dead wood, which form a bearing all round for the ring
b, b, to work in. The ring b, b, is made in two parts, bolted together; and
in the junction of the parts the propeller blades are fitted and fixed. The ring
b, b, is fitted to trunnions or bearings 1, 1, on a second ring d, d, also made in
two parts, as best seen in Fig. 35, which is a section taken laterally through
this ring d, and transversely to ring b, with part of the shaft e; while Fig. 36 is

page_text: a section taken transversely to ring d, and through the junction of d. f is a bal
or solid piece of metal, separately represented in section in Fig. 37, which forms
the centre or boss, two arms 9, 9, forged on the end of the screw shaft e, are
fitted into openings h, h, in this centre f, into which they are fixed and held by
washer plate i and bolts k, k, inserted from the opposite ends of openings h, h
the centre piece f has a groove turned in and around it for the reception of
ring d, which is free to move round therein, while the ring b, b, being mounted
on the trunnionis l, l,. is free to oscillate, the whole forming a kind of gimble;
thus, although the propeller is carried round by the revolution of the shaft, the
plane of its motion is free to be controlled, which control is exercised by the
plane of the guide rings c, c, which keep the plane of the propeller at all points
of its revolution at an incline to the shaft e, as represented. The dotted lines
in Fig. 34 represent the thickness of the dead wood, which, being less than the
diameter of the rings c, c, taper thickness pieces m, m, are applied to carry
the water clear of the rings of propeller boss, as seen in Fig. 32. By thus
placing the propeller at an incline to the line of the keel, the act of propulsion
at the bow of the vessel will tend to displace the water immediately in the
course of the vessel, and cause her to make easier way through it; besides
which, throwing the water in a downward direction has the effect of offering
a more solid resistance to the action of the propeller. The stern propeller is
represented in Fig. 32 in a position inclined, so that the water will be drawn
from below and thrown upward, which will assist in preventing the tendency
to void or vacuum under the vessel's counter during her progress through the
water. I also propose to place the stern propeller at an incline.in the opposite
direction, as represented in dotted lines in Fig. 32, which when so acting will
enable the propeller to obtain a more dense hold of the water, and will assist
in keeping her stern up, and so tend to reduce her draught of water at
the keel.
Fig. 42 represents a modification of the propeller, before described, showing
a portion of the dead wood of the ship in section. In this case the parts
a, b, d, e, f, g, h, and l, are the same, as before described; but instead of the fixed
rings c, c, which control the position of the propeller, these rings c¹, c², are in
this modification so fitted as to move round in either direction, and so allow
to be varied, or vary the position of the propeller, and this not only with regard
to the inclination, to the horizon but also to the line of the keel.
Fig. 43 represents a detached view of ring c¹, viewed from above; and
Fig. 44, a front view of the same. The rings c', c, are precisely similar, except
the segment 1 of c', which has an opening 2 formed through it for the passago

page_text: of the propeller shaft e, which at the same time permits sufficient amount of.
movement in c¹ for the purposes required. The bands or segments 3, 3, are
formed in the solid with the rings c¹, c; these segments are described from the
centre of propeller boss as a centre, and are portions of a sphere; they are
accurately fitted to cavities formed in the dead wood 4, 4, of the ship, or suitable;
metal bearings fitted therein. The segments 3, 3, have a very limited extent
of motion up or down in the dead wood, being simply to permit a little.
variation of the incline of the propeller to the horizon. The segments 1, 2,.
which are described from the same common centre, are jointed or gimbled at
5,5, to the main rings c¹, c³, which permits these rings to move round horizon-:
tally to a considerable extent on joints 5, 5. The segments 1, 2, are also fitted.
to the dead wood so as to move in a vertical plane on their common centre..
Each of the segments 1, 1, are furnished with a few rack teeth 6, 6, into which
pinions 7, 7, (recessed into the dead wood) gear; these pinions are actuated
simultaneously by suitable shafting carried up on deck, by which the incline of
the propeller to the horizon can be varied by inclining, the rings c, c, more or,
less, by the means described. The bands or segments 3, 3, afford a con-
siderable extent of movement in the horizontal direction, this movement.
being for the purpose of steering the vessel, and are furnished with a sufficient.
number of rack teeth 8, 8; accordingly pinions 9, 9, gear into these racks,
whose shafts 10, 10, are actuated simultaneously by suitable communication,
with the deck or other convenient part of the ship. During this latter move-
ment, the segments 1, 2, remain stationary, while rings c¹, c, move round on
their gimbles 5, 5. By so moving the propeller while in motion as to incline.
it on either side to its shaft, an impulse will be given to the shaft to cause the
vessel to turn round in the manner of steering without the assistance of a
rudder. The power of altering the vertical incline enables the best incline to.
be established for the purposes of propulsion.
The sixth and last part of my Invention relates to the application of motive:
power, for the purpose of impelling a raft or vessel through the water, and.
also at the same time render it capable of. travelling over land or ice.
Fig. 45 represents a side elevation of a ship constructed according to my.
Invention; Fig. 46, an end view, with part in section; and Fig. 47, a partial-
plan of the same. a, a, a, a, are iron or other suitable cylinders, shown partially
in section in Fig. 45; these cylinders produce the buoyancy or floating power
of the raft, and constitute the support of deck b, b, which is mounted on suitable
framework and bearings c, c, c, in which the cylinders a, a, are free to turn.
round on their axes; motion is communicated to the axis of each from the

page_text: engine d by shafts e, e, and bevel (or other) gearing ff, and in such
order that the cylinders both revolve towards or from each other. The
cylinders a, a, are furnished with spiral blades or screws 9, 9, 9, which impel
the vessel through the water when immersed therein. In travelling on ice
the edges of the (suitable) 'screws 9, 9, 9, will support the vessel, and will when
set in motion propel the vessel over that surface in the same manner as
through the water, with this difference, that the flat side of the screws will
take a bearing on the water, while the extreme edge only will take hold of the
ice for propulsion. If necessary plain transverse cylinders, herein-after described,
may be adapted to take a bearing on the ice & carry the weight of the raft,
allowing at the same time the screws g, g, to take sufficient hold of the ice for
the purpose of propulsion, so that by keeping up the motion of the screw.
cylinders the vessel will be propelled on the surface of the ice, as described..
The conical ends of the cylinders which enables the raft to make way
through the water, also enables the raft to ascend inclines, or rise on
the ice, or to mount over any obstacles thereon. In travelling on land,.
the raft should be fitted with two or three plain cylinders, placed trans-
versely to the screw cylinders. The lower part of these plain cylinders.
should be on a level a little below that of the body of the screw cylinders,
in order to receive the weight of the raft on such transverse cylinders, and at
the same time permit the screw blades to enter the ground partially. By this.
means the transverse cylinders will carry the raft when it is propelled over the
ground, by screws g,g, taking hold of earth during the rotary motion of these
cylinders. The plain transverse cylinders should be fitted in bearings, so that
they may be elevated and depressed, according to circumstances, and when in
the water to be lifted almost out of that element. Instead of propelling the.
raft, while on land, by means of the screws, the transverse plain cylinders may.
be lowered below the level of the spirals g, g, and the power of the engine
applied direct to the transverse cylinders, the rotation of which will carry the
whole over the ground, as well known in the propulsion of vehicles by steam.
Instead of making the screw cylinders inflexible in their length, they may con-
sist of short lengths, fitted in their bearings so that they may accommodate
themselves more or less to inequalities of the ground; or that the fore parts-
may be more or less inclined, in order to mount over any obstacle or ascend an
abrupt ascent. The screw and transverse cylinders may be fitted with water-
tight hatch holes, and the interior fitted up for the stowage of goods in greater
or less quantity, either for land or water transit.
Another improvement under this. head of my Invention consists in con-

page_text: structing a machine on the principle of the raft last herein-before described,
having cylinders with spirals or screws thereon; in the application of steam to
cultivation, for the purpose of carrying or dragging implements or other things
necessary over or through the land.
In witness whereof, I, the said John Wallace Duncan, have hereunto
set my hand and seal, this Eighth day of February, in the year of our
Lord One thousand eight hundred and fifty-six.
JOHN WALLACE DUNCAN. (L.S.)
Witness.
WILLIAM CLARK,
Patent Agent,
53, Chancery Lane, London.