IMPROVEMENTS IN HYDRAU- LIC MACHINERY AND IN STEAM ENGINES
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
THOMSON, of Glasgow, in the County of Lanark, Civil 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 Third day of July,
One thousand eight hundred and fifty, in the fourteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
James Thomson, my exors, adiñors, and assigns, Her especial license, full
power, sole privilege and authority, that I, the said James Thomson, my
exors, adiňors, and assigns, or such others as I, the said James Thomson, my
exors, adiñňors, 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 expressed,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, and in the Islands of Jersey,
Guernsey, Alderney, Sark, and Man, and also in all Her said Majesty's
Colonies and Plantations abroad, my Invention of "IMPROVEMENTS IN HYDRAU-
LIC MACHINERY AND IN STEAM ENGINES;" in which said Letters Patent is con-
tained a proviso, that I, the said James Thomson, shall cause a particular
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 recited
Letters Patent, as in and by the same, reference being thereunto had, will'
more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
James Thomson, do 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 following statement thereof, reference being had to the
Drawings annexed, that is to say :-
•
Firstly, my Invention consists of an apparatus for obtaining motive power
from water, which, as a whole, I call a case wheel. Of this there are two
varieties, in one of which the vanes are straight and in the other curved.
Figures 1, 2, and 3, are respectively a vertical section, a plan, and an elevation
of the apparatus in which the vanes are straight; and Figures 4 and 5 are respec-
tively a vertical section and a plan of that in which they are curved. In several
of the Figures, portions of the apparatus are supposed to be broken away, so
that other parts may be seen.
A is a moveable wheel, which, when it has to
be distinguished from the whole apparatus, may be called the moveable wheel.
It revolves within a fixed case B, the joints F, Figures 1 and 4, between the
case and the wheel being made nearly water-tight by any of the known
methods of making joints, which nearly prevent the escape of water and yet
involve little or no friction. I prefer having the meeting parts made to fit
very truly to one another without touching, so that there may be no rubbing
at all. One method of effecting this is represented in Figure 1, which will
be readily understood from inspection, and another in Figure 4; r, r, in the
latter representing two rings which fit tightly to the case and are capable of
being adjusted (by means of nuts and spiral springs, as shown on the Draw-
ing or in any other convenient way), so as almost to touch the moveable wheel.
The moveable wheel is attached to a vertical shaft C, which turns at its lower
end on a pivot D, Figure 1, and is supported at its upper end by a bearing K
fixed to the cover of the case by a bracket L. The wheel works under the
lower water level W, as represented in Figures 1 and 4, and on this account
at or near the centre of the pivot there is a hole, by means of which and a
pipe connected with it oil may be supplied to the rubbing surface. The
moveable wheel consists principally of a top and bottom plate m, m, Figures 1
and 4, and of a number of vanes or diaphragms inserted in the space between
the top and bottom plates, so as to form many radiating passages. Through
these radiating passages the water (having been introduced into the case B, as
afterwards explained) moves from the circumference to the centre of the
wheel, where it is discharged by orifices in the top and bottom plates. The
parts of the wheel marked s represent a disc and boss, by means of which the
vanes are rigidly connected with the vertical shaft C. When the vanes are
curved (as well as when they are straight), I make the outer extremity of
each to lie in the direction of the radius passing through that extremity,

page_text: although it might be made. to deviate considerably from that direction (but
not so much as to become nearly tangential), without materially altering the
peculiar character of the wheel, or, in other words, without altering in any
material degree the velocities which the wheel and the water should have, and
on which the peculiar character of the wheel mainly depends. Also, when the
vanes are curved, their inner ends should be turned backwards, as shewn in
Figure 5 (and as will be hereafter more fully explained), in such a degree
that when the proper average quantity of water is flowing through the orifices
o, o, thus forme 1, it may be sent backwards from these orifices with nearly
the same velocity as that with which they are moving forwards, so that in
reality the water on leaving the vanes may have little or no velocity of rotation
but only a motion towards the axis of the wheel. It is well to make some
of the vanes, as shown in the Drawings, stop short without approaching so
near to the centre as the rest, especially if they be not made of very thin
metal. The reason for making them thus is to prevent them from occupying
too much space and impeding the flow of the water. The dotted lines in
Figure 1 represent the terminations of two vanes which are shorter than the
one in front of them both. Before reaching the radiating passages between
the vanes, the water coming from the upper reservoir flows into the case by
one or more entrance orifices E, Figure 2, E, E, Figure 5. I do not limit
myself to any particular number of such orifices in either variety of the wheel,
though I consider that one will be enough when the vanes are straight, and
two or four when they are curved. Each of the nozzles Z, Z, terminating
at one end in the entrance orifice and at the other in the supply pipe,
increases gradually in area from the orifice. towards the supply pipe, as shewn
in the Drawings, its form being made such as may be supposed would allow
the water to attain its velocity with the least possible resistance. After
flowing into the case the water passes along the inside of its circumference,
which is made of a spiral or spiral-like form, so that the water as it revolves
may be uniformly impelled towards the centre; the water is thus made to
enter the radiating passages in the wheel, and, because it has very nearly
the same motion both in regard to direction and velocity as the circum-
ference of the wheel, there is little or no loss of mechanical effect from impact
between the water and the wheel. The centrifugal force tends to prevent
the water in the wheel from moving towards the centre, but the water is
constantly urged in that direction in relation to the wheel by the new supplies
of water which are continually entering at the circumference of the case.
In consequence of the combined motion of the wheel and water each particle of
water moves in relation to the case along a certain continuous spiral course from

page_text: the entrance to the exit orifice. The spaces within the case above and below the
wheel contain water which has a considerable rotatory motion, but no motion
towards the centre except what is necessary to supply water for the slight leakage
which takes place at the joints F, F, between the case and the wheel. The centri-
fugal force of the water in these spaces has the good effect of making the pressure
inside of the case at the joints less than it would otherwise be, and of thus
diminishing the leakage. The principal conditions to be fulfilled as nearly as may
be in practice in the action of this mechanism are, that the water should enter
the wheel without impact, should pass through it without resistance, and
should leave it without velocity. Hence, the entrance orifices are made of
such magnitude that when all the water which is intended to supply the wheel
is flowing through them its velocity may be very nearly that due to half the
head (or height of fall). Then since, as was before stated, the circumference
of the wheel moves at very nearly the same rate as the water, it can be
demonstrated that in the case of straight vanes the centrifugal force of the
water in the wheel must maintain a pressure at the circumference which
very nearly balances the other half of the head, and that, in the case of curved
vanes, the same pressure at the circumference will be maintained by the
centrifugal force, and the contraction of the inner ends of the passages in the
wheel produced by the curvature of the vanes. When the vanes are straight
I make the diameter of the wheel several times (usually about three and a
half times) as large as that of the central orifices or eduction passages; then
as each portion of the water moves towards the centre of the wheel it comes
successively in contact with parts of the vanes, each of which has less velocity
than the part immediately preceding. Thus the rotatory velocity of the water
is gradually diminished, till, by the time the water reaches the central orifices,
the mechanical effect belonging to its rotatory velocity is almost nothing.
When the vanes are curved I do not usually make the diameter of the wheel
more than double that of the central orifices: In this case the water is
deprived of its, rotatory velocity partly in the same way as in the other case,
and partly by its being sent backwards from the inner extremities of the vanes.
The quantity of water admitted to the wheel may be regulated. in various
ways, so that it may be just sufficient to do the work required at any particular
time.. If the amount of power required be not subject to much. variation, and
if a moderate variation in the speed of the wheel be allowable, it may be
unnecessary to have any peculiar regulator, since the wheel is capable of regu-
lating the supply in a considerable degree for itself. Thus, if the work to be
performed be diminished while the wheel is in action, the speed of the wheel
increases slightly, and therefore the centrifugal force of the water in the

page_text: wheel increases, and produces an increased pressure inside or the case at the
circumference, which diminishes the quantity of water admitted by the entrance
orifice or orifices. On the other hand, if the work required be increased the
speed of the wheel, and consequently the centrifugal force, diminishes, and the
quantity of water increases. Again, if the water be not very valuable, the
supply of the water and the speed of the wheel may be regulated by a simple
sluice, or by a throttle valve. This method, however, is not good in cases
in which it is of importance that the water should be economised to the
utmost. In such cases I prefer the employment of mechanism, such as is
represented in Figures 4, 5, 6, 7, and 8, or such as in Figures 9 and 10. In
Figures 4, 5, 6, 7, and 8, the case is supposed to have two entrance orifices
E, E. Should there be only one, or should there be more than two, a
mechanism of exactly a similar character, but adapted to the number of
orifices, would be used. The principal part of this regulator consists of two
sluices a, a, adapted one to each orifice. One only of these is represented
in Figures 6, 7, and 8, the other being supposed to be removed. They
occupy art of the space within the case outside the circumference of the
wheel, and are capable of being lowered to the bottom of the recesses b, b,
Figure 6, or raised almost entirely out thereof. The sluices should be made
to fit pretty closely to the vertical sides of the recesses at all parts, but more
especially at the parts outside of the entrance orifices, as any opening there
through which water could leak would be injurious. To prevent water from
passing below the sluices through the entrance orifices a vertical plate c is
attached to each sluice. These plates pass through slits in the bottoms of
the recesses b, b, and they should fit as well as may be to the vertical sides
of the recesses and to the slits. By means of these plates, and of spindles
d, d, the sluices are connected to a ring e, which can be raised or lowered
in any convenient way, as, for instance, by three vertical rods attached to it
at the ears f, and hanging by means of screws at their upper ends, which
screws, being connected by toothed wheels, revolve all at the same rate,
so that all parts of the ring may be equally raised or lowered at pleasure.
It may be advantageous to have packing boxes attached to the bottom of
the case, as shewn in Figure 4, to prevent leakage round the vertical plates
and spindles just mentioned. In Figures 9 and 10 there are supposed to
be four entrance orifices marked E, the areas of which can be altered at
pleasure by moving the pieces marked 6 round vertical axes determined
by pivots or hinges marked a. These moveable pieces are the lateral
boundaries of the nozzles marked Z in this Figure, as in the preceding

page_text: ones; and the inside of each of them facing the wheel forms the spiral
which guides the water uniformly towards the centre. The water ascends
through four openings P before entering the nozzles. The apparatus marked d
is for giving the requisite motion to the pieces marked b. The explanations and
principles already given in reference to the case wheel will render the meaning
of Figures 9 and 10 sufficiently clear when it is observed that the arrows
on these Figures indicate the principal motions of the water.
According to the best calculations I have been able to make as to the
principal dimensions of the wheel and case, and the velocity of the wheel, these
should be as follows:-
Let Q be the quantity of water in cubic feet per minute, and H the height
of fall in feet. Then, total area of entrance orifice or orifices=00329square
feet; diameter of each central orifice of the moveable wheel- 0915 Vfeet;
diameter of the wheel if the vanes be straight=3.5 times the diameter of
each central orifice of the wheel; diameter of the wheel if the vanes be
curved twice the diameter of cach central orifice of the wheel; revolutions
per minute if the vanes be straight=316 V; revolutions per minute if the
vanes be curved=558 VV.
Again to determine the angle which the inner end of each vane should
make with the radius passing through it, let c=circumference of each central
orifice in feet; d=distance in feet between the top and the bottom plate of the
wheel, minus the thickness of the plate for attaching the vanes to the shaft;
t-thickness of each vane in feet (or fractions of a foot); n=number of vanes
which terminate at the circumference of the central orifice; v-velocity of the
inner end of each vane in feet per minute.
Also, let C, Figure 11, be the centre of the wheel; DSG, part of its outer
circumference; NFB, part of the circumference of one of its central orifices;
and let F be the termination of one vane, and K that of the next, which
reaches to the circumference of the central orifices. Make TH perpendicular
to FC, and such that FT: TH::: v. Then FH would be the direction of
the inner end of the vane passing through F, if the vanes were infinitely thin.
To correct for the thickness, make FT: FO:::
and parallel to TH. FP is the true direction of the end of the vane. Again;
draw FL perpendicular to FP, and a little longer than FC. It may be about
1.2 FC. From L, as centre, describe an arc of a circle FR terminating
at R, in the continuation of C.K. FR is the inner portion of the vane;
and in forming the remaining portion all that need be attended to is to give
; draw OP equal

page_text: it a gentle curvature, and to make a short portion of it at S be in the direction
of a radius passing through S.
Secondly, my Invention consists of another apparatus for obtaining motive
power from water, which, as a whole, I call a suction wheel. Figure 12 is a
vertical section, and Figure 13 a plan, of this apparatus. A is the moveable
wheel, and B, B, are fixed nozzles (represented as four in number on the
Drawings, though this number is not essential), which receive water from
a supply pipe C, and spout it into the upper part of the moveable wheel, as
indicated by the arrows on the Plan. This upper part is a sort of shallow
cylindrical tub, and the water in it flies out by centrifugal force so as to
form a whirlpool, the average surface of which is shewn by the lines n, i, n, i,
Figure 12. The part marked j is a rim, which projects inwards at the top
of this tub to prevent the water from flying over the top, except in small
quantities. The part which may be regarded as the bottom of the tub is
double, and in the space between the two bottoms are placed radiating vanes
e, e, which are analogous in their nature and office to those already described
in the case wheel with straight vanes. The moveable wheel terminates at
bottom in an upright suction pipe k, and the weight of the column of water
in this removes part of the atmospheric pressure from the inner ends of the
vanes, and thus allows the atmospheric pressure in the tub to urge the water
from the tub through the annular space l, and between the vanes towards the
centre against the centrifugal force. The wheel turns on a pivot p, like that
of the case wheel already described, and the upright shaft E of the wheel
passes through the centre of the descending knee F of the supply pipe, and
works in a bearing D. The water is prevented from escaping round the
upright shaft by a tube o. Each nozzle is made so that it will spout the
water as nearly as may be perpendicularly to the plane passing through its
mouth and the axis of the wheel. The mouth of each is made long and
narrow, and its outer lip is placed almost in contact with the surface of the
whirlpool before mentioned, so that the water may have to fly outwards, and
fall as little as may be in passing from the mouth to the surface of the
whirlpool. As horizontal lines along the plate which forms the inner lip are
not perpendicular to the plane passing through the mouth of the nozzle and
the axis, the outer lip is made to project a little beyond the inner, as shewn
in Figure 13, so as to give the proper direction to the water. The orifices
are placed midway between the upper and lower levels, and thus (as in the
case wheel) one half of the fall is expended in producing the velocity with
which the water enters the wheel, and the other half acts in combination with
the motion of the wheel in staying that velocity again.

page_text: The following are the best directions which I am able to give for deter-
mining the dimensions and forms of the different parts of this apparatus.
Fix on the diameter of the suction pipe, making it not larger than what is
considered necessary to permit the passage of the water with sufficient freedom.
I would recommend that a head of from two to four per cent. of the entire
head should be expended in producing the velocity and overcoming the
friction of the water in this pipe; then Y, H, being the lower level of the
.water, and K, L, the axis of the wheel, make K, M, equal to this portion of
the entire head. At any convenient distance from the axis (usually not less
than two or two and a half times the diameter of the suction pipe), and midway
between the upper and lower levels, fix on P, as the middle point of the outer
lip of a nozzle. Draw n, i, a tangent to a parabola passing through P and
M, and having its axis coinciding with the axis of the wheel. Make the
outer lip of the nozzle to lie along n, i, and the inner to lie as near it as other
circumstances (such as the depth which may be thought allowable for the
tub) will permit. The narrower the mouth is made the greater must be
its length, so that it may permit the passage of the requisite quantity of
water, but at the same time the narrower it is, within any moderate limits,
the better will the new water be laid on the wheel. Make the ends of the
vanes be at the same distance from the axis of the wheel as the point P.
The speed of the wheel will be determined by making the ends of the vanes
move with the velocity due to the fall from P to M. The chief deviation
which I think might perhaps be advantageously made from the foregoing
directions would be to fix on the point P a little lower than the position
assigned to it, as I would prefer that the velocity of the water at the outer
extremities of the vanes should be greater than the velocity of these extremities,
rather than that it should be less. It may be well to have a little space,
as shewn in Figure 12, between the bottom of the nozzles and the plate m,
which covers the vanes so as to allow any bubbles to escape which may be
introduced into the whirlpool. As an additional security against any of these
or at least any large ones passing through the annular space l, the plate m may
made to project a little beyond the ends of the vanes, as shewn in the Drawing.
It may also be found advantageous to add a vent pipe a, by means of which
a small quantity of air may be conveyed to the suction pipe before a great
rush of air can pass downwards through the annular space l. For regulating
the supply of water, the width of the mouth of each nozzle is made variable.
The plater, forming the inner lip, is attached to the fixed portion of the
nozzle by a water-tight hinge, which may be made of leather, or of strong
waterproof cloth; and the top and bottom of the nozzle adjacent to this plate

page_text: are also made of one of the same or of some other suitable material or materials.
The interual diameter of the rim j, which projects inwards at the top of the
wheel, may perhaps be made as large as the distance from the outside of one
nozzle to the outside of the opposite onc. Should it however be made
smaller, notches n should be made to admit of the nozzles being let down
into their places. The depth of these notches, or the internal diameter of
the rim must be adjusted so as to keep the surface of the whirlpool up to
'the place assigned to it, but to allow a little of the water to fly out when the
surface. reaches that position, and of course more to fly out when the surface
approaches nearer to the centre. Round the top of the wheel is placed a
circular stationary trough G, adapted to catch the drops of water which fly
over the top, and to collect them and let them fall into a bucket 6 having a
hole in its bottom. This bucket is connected by means of cords, pulleys, and
levers, or in any other suitable way, with the hinged plates which form the
inner lips, in such a manner that when the bucket becomes heavier, in con-
sequence of the supply of water from the trough to it being more than the
expenditure by the hole in its bottom, it may descend and partially close the
mouths of the nozzles, and that when the bucket becomes lighter from the
opposite cause it may ascend and allow the mouths to open wider. Thus
the water will always remain almost exactly at the same height or distance
from the centre, and the wheel will revolve almost exactly at the same rate,
even though the work which it is required to perform should happen to vary
considerably. The system of pulleys, levers, &c., represented in the Figures,
will be easily understood. The bucket hangs from the side J of the pulley J.
A cords passes from the opposite side of the roller V, on which the pulley is
fixed to one end of a lever z. The other end works the hinged plater by
means of the connecting rod y. A similar lever z I is worked in the same
way by another cord hanging from the roller V, and other two similar levers
z 2, z 3, are worked by cords w, w, passing from the top of the roller and over
the pulleys N, N, to the ends of those levers. To prevent the bucket 6 from
sinking too low when the water contained in it becomes sufficient in quantity to
weigh it down, and from rising too high when the water in it becomes small
enough in quantity to allow it to ascend; or, in other words, to make the bucket
always assume its proper position, and remain there steadily as long as the
quantity of water required by the wheel remains unaltered; a spring (not
shewn in the Drawing) should be so connected to the pulley J, or to some other
part of the regulating apparatus, as to serve as a counterpoise to the weight of the
bucket. The quantity of water which must accumulate in the bucket to
depress it from the top of its range to the bottom, depends on the elasticity

page_text: of the spring adopted. This elasticity may vary within very wide limits. The
least stiffness which the spring should have is that which is just sufficient to
prevent the bucket from starting up and down in the manner before de-
scribed, but no evil effect would be produced by the springs having greater
stiffness, provided that this were not so great as to require an inconveniently
large bucket, which might operate too slowly unless an otherwise unnecessarily
large quantity of water were kept flowing through it. Instead of a spring a
weight hanging from a pulley with a varying radius like the fusee wheel of
a watch may be employed. If the surface of the whirlpool in the wheel be
at exactly the best height, that is, if it be as near the nozzles as possible
without touching them; more water will fly over the edge of the wheel into
the trough G in a given time when the mouths of the nozzles are wide open
than when they are nearly shut. Hence it is desirable, though not necessary,
that the water should be allowed to flow through the orifice in the bottom
of the bucket at a greater rate when the bucket is at the top of its range
than when it is at the bottom; that is to say, the water should be discharged
from-the bucket most rapidly while it contains its least load, and least rapidly
while it contains its greatest load. To fulfil these conditions, all that is
necessary is to hang within the orifice of the bucket a tapered plug f, Figure 12,
with its small end uppermost, by means of a rigid rod g, and to suspend the
bucket by means of a spiral spring h, so that as the load of water increases
the bucket may descend in reference to the plug, and the area for the exit
of the water may thus be diminished. The proper diameter of the plug at
each part of its length may be readily determined by experiment when the
wheel is in action.
Thirdly, my Invention consists of a centrifugal pump regulator for con-
troling the speed of machinery driven by water wheels, especially those
commonly called bucket or overshot wheels. Figure 14 is a sectional
elevation of a regulator of this kind, and Figure 15 is a plan. A is an
upright revolving tube through which the water ascends to the revolving arms
B, B. The tube and the arms are the chief parts of the pump. The pump
turns on a pivot shewn at E, and it is made to revolve by being connected
through the means of a tubular upright shaft M, surmounted by a solid one D,
with the machinery whose speed is to be regulated. A valve F prevents the
water from descending, but allows it to ascend freely. The upper extremities
of the arms or the discharge orifices are better to be made oblong, as shewn at
C, Figure 15, than circular. K, K, are tie rods for strengthening the arms.
G is a circular wall which serves as a support for the upper bearing of the
pump, and also to confine the water thrown up by the pump so as to make it

page_text: fall back into the well H. The connection between the pump and the
machinery to be regulated should be so arranged, that when the machinery is
going at its proper speed the centrifugal force may balance, or nearly so, the
gravity of the water in the pump, which it will do when the upper discharge
orifices C, C, move with the velocity which a heavy body would attain in
falling from C to the water level L, L, Figure 14. The pump should be
kept usually raising a moderate quantity of water, and then, when the
machinery goes a little too quickly the pump will raise a much greater
quantity of water, and will thus occasion an increased resistance to the motion
of the driving water-wheel and vice versa. The speed of the machinery may
be altered at pleasure, by altering the water level L, L. If a man be
employed to take charge of the driving wheel he should diminish the supply of
water to it whenever the centrifugal pump is raising too much water, and he
should increase the supply whenever the pump is raising too little. If,
however, the supply of water for the driving wheel be scanty so that it must
be economised, even at the cost of allowing the machinery to go occasionally
too slow for a short time, he should keep the pump usually raising no water,
but just on the point of raising it. The apparatus will thus be ready to check
any excess of speed which may tend to occur. Instead of the man a self-
acting apparatus such as that already described for the suction wheel may be
employed. For this purpose the bucket with the hole in its bottom would be
supplied with water thrown up by the pump, and would be made to act on a
sluice or some equivalent contrivance for adjusting the supply of water to the
driving wheel. The pump may have various forms. Thus the moveable
wheel of my suction water-wheel, with a valve added to prevent the water
from descending, would be a good form.
.
Fourthly, my Invention consists of an improvement in steam engines.
whereby the steam is freed from any water which may be carried along with
it. The mode in which the water is separated from the steam is as follows:--
The steam is made to blow into a circular vessel tangentially, at or near the
circumference, and to pass away from the vessel at the centre. The steam and
water in the vessel are thus subjected to a rapid whirling motion, and the
water flies outwards by the centrifugal force and passes away from the vessel
by an aperture or apertures at the circumference. The water on leaving the
vessel may be disposed of in various ways, as will be more particularly
explained hereafter. The apparatus may be applied to the engine in varions
situations, according to convenience or to the purpose to be served; thus it'
may be applied to the steam pipe either without or within the boiler, and it
may be applied at the top or at any other part of the waste steam" pipe.

page_text: Figures 16, 17, and 18 represent it as it would be applied to a vertical pipe
through which the steam ascends. Figure 16 is a vertical section, and
Figure 17 is a plan in section along the line a, b, in Figure 16; and Figure 18
is a section of one of the orifices o, in the diaphragm c. Through the expla-
nation already given, and by reference to the arrows on the Figures, it will be
seen that the steam is injected into the circular vessel B, tangentially through
the orifices o, that therefore it must exist in the vessel B in a whirling state,
and that it passes away by the pipe D from the centre of the whirl. The
water leaves the vessel B by the orifices s at its circumference, and is conveyed
by a pipe t to any required place. If, for instance, A and D be parts of the
steam pipe leading from the boiler to the cylinder, and the vessel B be placed
sufficiently high above the level of the water in the boiler, the water may be
allowed to descend into the boiler by its own gravity through the pipe t, which
would then be made to terminate in the boiler near its bottom. When this
arrangement is adopted, a valve opening towards the boiler may be found
requisite in the pipe t to prevent regurgitation of the water. Again, the pipe t
may lead the water to a close cistern, having in its bottom a valve, which is
opened by a float whenever the water accumulates in the cistern to a certain
amount. The water can be returned to the boiler by the feed pump. If the
apparatus be placed on the waste steam pipe of a steamboat engine, the pipe t
may convey the water into the paddle box, and the escape of a little steam
along with the water will not be detrimental. In locomotive engines for
railways the apparatus should be placed within the steam chest, the pipe A
and the plate m are in that case omitted; 'and instead of the steam pipe D, a
similar pipe leads downwards from the centre of the diaphragm c towards the
cylinder.
And having now described the nature of my said Invention in the several
parts thereof, and in what manner the same is to be performed, I declare that
what I claim is as follows:-
In respect of the case wheel, I claim the same in the peculiar combination
and arrangement of the parts or methods of which it consists, or of any two
or more of them which may in practice be combined together to the exclusion
of the others; that is to say, the several parts or methods following, namely,
First, the employment of a stationary outer case, with entrance orifice or
orifices of such capacity, that when all the water is flowing through, its velocity
may be that which is due to half the fall, or nearly so, together with the
arranging of the connexion between the moveable wheel and the machinery to
be driven by it, in such a way as that when the machinery is going at its proper
speed, the moveable wheel may have such a velocity as that the centrifugal

page_text: force or the water contained in it, when straight vanes are employed, or the
centrifugal force and the force necessary to send the water back through the
orifices between the vanes at the centre when curved vanes are employed, may
balance the other half of the fall, or nearly so.
-
Second, the giving of a spiral or spiral-like form to the inside of the case
facing the circumference of the moveable wheel, for the purpose of causing the
water to move as nearly as may be uniformly towards the centre, while it
revolves with the wheel in the case.
Third, the forming of the moveable wheel with the top and bottom plate,
having between them radiating passages leading into the centre of the wheel,
and bounded laterally by straight or curved diaphragms, with a disc, boss, or
other equivalent contrivance to connect the diaphragms with the shaft and
with two central orifices for discharge, one in the top and one in the bottom.
plate.
Fourth, the forming of the curved vanes (when used) according to the
principles and rules herein-before given.
Fifth, the adaptation of a cover or lid to the case.
Sixth, making the various parts of dimensions depending on the height of
fall and quantity of water, as set forth in the calculations and rules herein-
before contained.
And seventh, the arrangements for regulating the supply of water to the
wheel represented in Figures 6, 7, and 8, as also the arrangements for the
same purpose represented in Figures 9 and 10.
In respect to the suction wheel, I claim the same in the general combination
and arrangement of the parts or methods of which it consists, or of any two or
more of them which may in practice be combined together to the exclusion of
the others; that is to say, the several parts or methods following, namely,-
First, the combination in one of the moveable wheel and suction pipe.
Second, the use of nozzles having orifices long, narrow, and adapted to the
slope of the surface of the whirlpool.
Third, the making of the outer lip of the moveable wheel project beyond the
inner one, for the purpose of securing a tangential motion to the water.
Fourth, the use of a vent pipe for admitting air on certain occasions to the
suction pipe.
And fifth, the regulating apparatus depending on the principle of employing
small quantity of water which is allowed to fly off from the circumference of
he wheel.
In respect of the centrifugal pump regulator represented in Figures 14
nd 15, I claim the adaptation of a centrifugal pump to the controuling of

page_text: machinery driven by water wheels, or by any other motive power, in the
manner therein exemplified and herein-before described, as also the combination
of the pump with the self-acting apparatus, having a bucket with a hole in its
bottom for working the sluice of the water wheel.
And in respect of my improvements in steam engines, I claim-
First, the freeing the steam from water by drawing the steam off from the
centre of a whirl, while the water passes away at or near the circumference, by
the apparatus represented in Figures 16, 17, and 18, and before described, or
any suitable modification thereof.
Second, the arrangements for permitting the water to return to the boiler by
its own gravity.
And third, the close cistern, with a valve worked by a float for permitting
the water to escape after the steam in each case has been removed by having
been drawn off from the centre of a whirl.
In witness whereof, I, the said James Thomson, have hereunto set my
hand and seal, this Fourteenth day of December, in the year of our
Lord One thousand.eight hundred and fifty.