CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1837

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, THOMAS
SIMMONS MACKINTOSH, of Coleman Street, in the City of London, Engineer,
and WILLIAM ANGUS ROBERTSON, of Islington, in the County of Middlesex,
Gentleman, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Twenty-eighth day of September, in the first year of Her reign
(One thousand eight hundred and thirty-seven), did, for Herself, Her heirs.
and successors, give and grant unto us, the said Thomas Simmons Mackintosh
and William Angus Robertson, Her especial licence, full power, sole privi-
lege and authority, that we, the said Thomas Simmons Mackintosh and
William Angus Robertson, our exors, admors, and assigns, or such others as
we, the said Thomas Simmons Mackintosh and William Angus Robertson,
our exors, admors, and 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, our Invention of "CERTAIN
IMPROVEMENTS IN STEAM ENGINES;" in which said Letters Patent is contained
a proviso that we, the said Thomas Simmons Mackintosh, and William Angus
Robertson, or one of us, shall cause a particular description of the nature of
our said Invention, and in manner the same is to be performed, to be inrolled.
in Her said Majesty's High Court of Chancery within six calendar months
next and immediately after the date of the said in part recited Letters Patent,
as in and by the same, reference being thereunto had, will more fully and at
lerne annear.

page_text: NOW KNOW YE, that in pursuance of the said proviso, and in compliance
therewith, we, the said Thomas Simmons Mackintosh and William Angus
Robertson, do hereby declare that the nature of our said invented improve-
ments, and the manner in which the same are to be performed, are fully set
forth and described in the following Specification of the same, reference being
had to the several Sheets of Drawings hereunto annexed (that is to say) :-
We declare that our said invented improvements in steam engines consist,
firstly, in so proportioning the cooling surface of the condenser to the heating
surface of the boiler as that a vacuum having been once produced shall be
maintained (as regards the condensation of steam) by the cooling power of
the condenser alone, and in various arrangements, means, and apparatus,
whereby the external atmosphere is wholly excluded from the interior of the
engine, and from the water and steam by which it is worked, (unavoidable
leakage excepted,) so that the use of the air, cold water, and feed pump is
'more or less dispensed with, their size diminished, or the speed at which they
are worked reduced, or only one or two of them used; and in regard to the
air pump, it is only retained to pump out air which may enter by leakage; it
may, therefore, be of very small dimensions. The results of which improve-
ments are, that that portion of the power of the engine which is at present
absorbed in working the said pumps is saved in a more or less degree, and
also by the using of the same water over and over again in continued succes-
sion, (waste by leakage or otherwise only being to be provided for,) the
boiler, engine, and condenser are kept clean, and the pernicious effects of
incrustation and deposits of all kinds obviated; and, secondly, in an improve
ment in the form and mode of construction of the boiler. commonly known
as "Hancock's Boiler," and for which boiler a Patent was granted to Walter
Hancock, bearing date the Fifteenth day of January, One thousand eight hun-
dred and thirty-three; and we declare that, as regards the proportioning the
cooling surface of the condenser to the heating surface of the boiler, the
following general rule will explain the same (that is to say):-Taking water
at the temperature of 60° Fahrenheit as the point of lowest temperature at
which it enters the boiler, and 240° as the highest point of temperature of the
steam, the number of degrees of heat to be forced in and forced out, or drawn
in and drawn out of the fluid, is (240°-60°) = 180°, the absorption of which
forms water into steam, and the abstraction of which forms steam into water.
If, therefore, ten square feet of heating surface at 860° will heat a given
quantity of water 180° in a given time, then, as the water is at 60°, and the
heating surface is at 360°, the said heating surface is six times hotter than
the water which is to be heated; and as the steam is 180° above 60°, the

page_text: temperature of the cooling surface, the said cooling surface is three times.
colder than the steam which is to be cooled, then twenty square feet of cooling.
surface will correspond with ten square feet of heating surface. To render
the above statement the more clear and easily understood, we have not taken
into account the latent heat of steam, but which must be attended to in prae-
tice. It will also be particularly observed, that in this general example of
calculation the parts of the question bear a relative proportion to each other
directly and inversely; (that is to say,) if the hotness of the heating surface be
increased, the extent of that surface should be decreased, and if the hotness-
be decreased, the extent should be increased; also, if the coldness of the.
cooling surface be increased, the extent may be decreased, and if the coldness
be decreased, the extent must be increased, always keeping in view that, in
order to work a condensing steam engine without the aid of an air pump
(except as regards leakage), the heating power and the cooling power must
be so proportioned as to counteract each other; and we further declare that.
the arrangements, means, and apparatus by which the before-mentioned objects
are accomplished are fully set forth in the following descriptions thereof, and
the Drawings thereunto referred, that is to say:-
Drawing marked No. 1; Figure 1, exhibits an engine which will illustrate
the principle of action, the application of which, in our said improvements in
steam engines, we claim as of our Invention. A is the boiler sunk in a shaft-
of a mine or pit dug for that purpose to the depth of thirty-three feet from
the surface of the earth; B is the condenser placed on a level with the earth's
surface; S is the steam pipe communicating with the steam cylinder C, and
working the piston therein, and from thence to the condenser B, which steam
cylinder may be at any particular point of height between the boiler and
condenser; W is the water pipe filled with water, and feeding the boiler A
with the water resulting from the condensation of the steam in the condenser
B. Now heat being applied to the boiler A, and a vacuum produced in the
cylinder pipes and condenser by blowing the steam through by an air pump,
worked by hand or otherwise, in the first instance, and cold water being
allowed to encompass and continually flow over or amongst the chambers of the
condenser B, steam will be generated in the boiler A, ascend through the
team pipe S, give motion to the piston in the steam cylinder C, and (by.
means of alternating valves) thence proceed to the condenser B, where it will
be instantly condensed into water, and entering into the pipe W, return to
and supply the boiler, the pressure of the column of water in the pipe being
ufficient to overcome the pressure of the steam in the boiler, and this action
vill continue as long as heat is supplied to the boiler A, and cold to the

page_text: condenser B, the one being so proportioned as to counteract the other. A
vacuum being formed in the first instance, if every part of the engine were
perfectly air-tight, that vacuum would remain, as in the common barometer,
and the engine be worked without the use of either air or feed pump. And
we further declare, that as it would in most cases be impracticablo to place
the boiler thirty-three feet beneath the level of the condenser, and, further, as
even with that height, the steam in the boiler must be kept at a pressure
under 15 lbs. on the square inch, or one atmosphere, as, on its exceeding that
amount, it would force the water up the pipe W into the condenser, to
obviate that inconvenience we use the apparatus which we call a "water
returner," and which is shewn separately in Figure 2 of Drawing No. 1, and
which is immediately hereafter particularly described. By means of this water
returner being interposed between the condenser B and boiler A, the said
boiler need not be more than two or three feet lower than the condenser, and
at the same time the steam may be raised to any desired pressure without its
being able to enter the condenser or force the water up the pipe W. In
Figure 2, Drawing No. 1, a, a, a, a, is a cylindrical air-tight vessel into which
three pipes W', W2, and P enter by corresponding apertures. In the pipes
W and W are placed self-acting clacks or valves in the positions shewn in
the Drawing Y, Ya, both allowing a free passage to the water downwards
towards the water returner through Y', and from the water returner to the
boiler through Y', but preventing the water from flowing upwards towards
the condenser B, by the pressure of the steam at certain times closing the
said clacks or valves. In the steam pipe P, at X, is placed a sliding valve E
attached to the rod F, working through a stuffing box at w, which is connected
with the float M, the said sliding valve being opened and shut by the said
float, as herein-after described. The said float M is one half the specific
gravity of water. Suppose, for instance, it displaces 20 lbs. of water, and
that it weighs in steam 10 lbs., then it will rise in water by a buoyant force
of 10 lbs., and fall in steam with an equal force of 10 lbs. Now, the vessel
a, a, a, a, being empty, and the float M consequently at the bottom of the
said vessel, and the sliding valve E shut, the water from the condenser B
begins to enter the vessel through the clack Y, which, while there is no
pressure on the under side, remains open (as shown in the Figure), and as the
water rises in the said vessel a, a, a, a, the float commences and continues to
press upwards; but in order that the said float M may not rise slowly and by
degrees, but remain stationary until the whole or nearly the whole of its
buoyant force is collected, a stud O is fixed upon the rod F, which, pressing
against the lever b¹ on the under side, and near its point, and which point i

page_text: kept pressed upon the stud O by one end of another lever b³, loaded at its
other end with the weight r³, both levers, & and b, turning on axes at a, x,
the weighted end of the lever is prevented from descending by the catch or
rests. It will thus be seen that the float cannot rise until, by the admission
of a certain quantity of water through the valve Y', in the pipe W, it has
received sufficient buoyancy to overcome the weight r². As soon, therefore,
as the float M has attained this buoyancy, the stud O presses up the one end
of the lever b', which depressing with its other end the one end of the lever b³,
whose contrary end is loaded with the weight r³, until the stud O raises and
passes the lever b'; the whole buoyant power of the float M is then exerted
on the sliding valve E, which is pressed up promptly and at once; the steam.
from the boiler then enters by the pipe P, P, and presses tipon the surface of
the water in the vessel a, a, a, a, which pressure closes the clack valve Y' and
opens the clack valve Y', through which the water descends into the boiler.
The vessel a, a, a, a, being now filled with steam instead of water, the float M
will fall with a force equal to a weight of ten pounds; and this drawing down
the sliding valve E, closes the communication with the boiler; but the valve E
must be kept perfectly open until the whole or nearly the whole of the water
in the vessel a, a, a, a, has descended into the boiler, and the valve prevented
from closing gradually as the buoyant power of the water is withdrawn from
the float M. The stud O, on the rod F, having in its ascent passed the lever
C, which is divided at d by a rule joint, allowing the end to turn freely
upwards, but preventing it from turning downwards, on the float M attaining
a'tendency to descend, the said stud O is caught by the said lever C, and is
held up thereby until the water, having issued from the vessel a, a, a, a, the
full weight of the float M is exerted, which being greater than the obstruction
offered by the weight, the stud passes the lever C, and the rod descending
draws down the sliding valve E, and shuts the communication with the boiler.
The stud O, on the rod F, in its descent with the float M, easily passes the
one end of lever b', it only having to overcome a slight preponderance of the
opposite end. The clack valve Y' being now closed by the force of the steam
in the boiler, and the slide valve E being shut, the water from the condenser
begins to flow through the pipe W' (the clack valve Y', on the pressure of
steam being removed by the shutting of the slide valve E, opening by its own
gravity,) into the vessel a, a, a, a, until it is filled, and the float again raised in
the manner already described, and so on in succession.
We do not confine ourselves to the precise arrangement of levers and
weights described, but claim any variation in which the float is prevented from
acting until all or nearly all its buoyant power and weight is collected by

page_text: means of levers and weights, or levers and springs instead of weights.
Instead of causing the water to pass through the clack valve Y', in the pipe
W", another slide valve, similar to that at the top of the vessel a, a, a, a, by
which the steam enters, may be placed at the bottom of the said vessel, as
shewn at Q, and worked by a rod attached to the under side of the float M.
This slide valve Q opens and shuts at the same instant with the slide valve E.
The slide or shutter of the valves E and Q should be somewhat longer than
the apertures they have to cover, in order that they may not uncover them
until the stud O on the rod E has passed the lever.
Although by the arrangements and means hereafter to be described the
admission of external air will be almost entirely precluded, yet, as in practice
it is found impossible to prevent some leakage, we provide and attach a small
air-pump (an air-pump strictly speaking, and drawing only air, intermingled
perhaps, with a small portion of steam,) fixed to any convenient part of the
engine, and connected by a pipe to the upper part of the condenser, or any
part of the condenser above the level of the water of condensation therein, at
the end opposite to or farthest from the part where the eduction pipe
discharges its steam into the condenser.
Drawing II. exhibits an arrangement for a mine engine with our
water returner. A is the boiler; B, the condenser; G is the induction
steam pipe; C, the cylinder; H, the eduction steam pipe; W, the pipe
conveying the water of condensation into water returner E; W', the pipe
conveying the water of condensation to the boiler; P, the pipe conveying the
steam to the top of the water returner; I, the small air-pump worked by
the beam of the engine; T is the pipe leading from the condenser to both
ends of the air-pump; K, K, are the mouths or pipes by which the air is
discharged from the pump; clack valves are used to the air-pump, those
attached to the pipes T opening inwards, and those attached to K, K, opening
outwards. The plunger or piston of the air-pump is solid, and the action of
the pump is double, drawing and discharging air with both up and down stroke.
Lis the mine pump which delivers the water into the tank or receptacle M,
in which tank or receptacle (in cases where it is convenient to lower the boiler
to a sufficient depth below such receptacle to allow of the water returner
acting) we recommend that the condenser should be placed. But in cases
where such lowering of the boiler is not convenient, and in order that no
additional duty may be imposed on the engine by raising the water pumped
from the mine to a higher level than would otherwise be necessary, we place
the condenser in an air-tight tank B. The pipe N has one end open in the
water in the tank M, and the other fixed air-tight into the condenser tank B,

page_text: .
and the pipe D, E, leads from the top, or near the top, of the condenser
tank B, and has its mouth at some point lower than the mouth of N. The
pipe N, the condenser tank B, and the pipe D, E, being all air-tight, form
together a syphon whose longest leg is D, E. The syphon having been brought
into action, the cold water from the tank M will ascend continually through N,
flow amongst the chambers of the condenser, and descending through D, be
delivered at E. The condenser, with the syphon, may be placed at any height
less than about thirty feet from the surface of the water in the tank M, above
which height, the syphon, being dependent on atmospheric pressure, will not
act. S is the safety valve, the discharge pipe of which communicates with
the eduction pipe of the engine, or it may be made to communicate directly to
the condenser, where the escape steam is condensed into water and returned
to the boiler by the water retainer, and this whether the engine is at work or
at rest. O is a cock to stop the flow of water through the condenser when the
engine is at rest. In some cases we do not use the water returner herein-
before described, but so arrange or construct two pumps to be worked by one
rod herein-after more particularly described in the arrangement recommended
for a marine engine.
Drawing No. III. exhibits a plan for a land engine for a factory or other
work, in which the condenser is supplied with a constant current of cold water
from any pond, lake, river, canal, or stream, or any natural or artificial
reservoir within a convenient distance from the engine. A, the boiler;
B, condenser; C, cylinder; D, water returner; E, a chamber formed in or
near the side of the pond or other reservoir, and communicating freely there-
with; F, F, is the cold water pipe by which water flows into the condenser
tank B, in which tank water will stand at the same level as in the pond or
other source of supply, as shewn by the line Z, Z, so long as the water in the
tank B is cold. But on steam from the engine being discharged into the
condenser enclosed in the tank B, the water will become heated, by which
it will be expanded, and rising to a higher level in the tank, shewn by the
line X, will overflow and enter the pipe G, G, and return to the pond or
other source of supply, and by this circulation the steam will be condensed
without the necessity of a cold water pump attached to the engine. The
water in the pond may be kept from rising too high by means of waste pipes,
sluices, or other ordinary and well-known contrivances; and to keep the pond
up to its proper level, and compensate for that which passes off by evaporation
from the surface, a small supply pipe may be introduced, where such supply
cannot be obtained from quick springs, streams, or other natural sources. The
general arrangements, herein-before described, are those which we propose

page_text: to be adopted in land engines. In all cases where the water returned is
used, the boiler must be lower than the condenser, but in land engines where
the air and feeding pumps, to be hereafter described in connection with
marine engines, are used, this relative position of boiler and condenser is not
necessary. And we declare that the general arrangements of parts of our
improvements in steam engines, which we propose as applicable to marine
purposes, is described as follows, that is to say :-
Drawing No. IV. is a side view of a marine engine. A, the boiler; B, the
condenser; C, the cylinder; D, the air, and E the feed pump. The water
of condensation falls to the bottom of the condenser B, and through the
pipe a, a, into the force pump E through the valve f, which opens inwards
towards the pump; by the working of the piston in the said pump, the water
is forced into the boiler through the pipe b and valve 9. which opens outwards
from the said force pumps. As there is no pressure of atmosphere on the
surface of the water in the condenser, the said force pump must always be
below the level of the bottom of the condenser, in order that water may
flow into the pump by its own gravity, to be from thence forced into the boiler,
which may be in any convenient position. The pipe c, c, c, leads from the
upper part of the condenser or any part above the level of the water of con-
densation, at the furthest or contrary end to that at which the eduction pipe
delivers its steam, to the small air-pump D, which has clack or spindle valves
opening inwards at h, h, and others opening outwards at d, d, by the former
of which the air is drawn into the pump, and by the latter is ejected into the
external atmosphere. Both the pistons of the air-pump D, and of the water
E, are worked by one rod, which passes through the bottom of the air-pump D,
as shewn in the Drawing. We should recommend the size of the air-pump
to be about from one twelfth to one twentieth the capacity of the steam
cylinder, although in well constructed engines this size will be more than is
necessary, but this can only be determined of from experience. S is the
safety valve, the discharge pipe e of which conducts the escape steam into
the eduction pipe of the cylinder, or directly into the condenser at e. The
boiler A may be either the ordinary boiler or our improved boiler herein-
after described, and placed in the part of the vessel in which the boilers are
usually placed. The condensers are placed in two water-tight tanks of wood
iron, or other suitable material, within the vessel, one on each side, and before
the paddle shaft. A continual current of cold river or sea water is made to
flow through the chambers of the condenser in the said tanks by the following
means, that is to say:-We make one, two, or more apertures in the bottom
of the vessel (similar to those made for the injection water of coinmon

page_text: engines), through which a pipe or pipes is inserted leading to the lower part
of the tank in the end nearest the bow or stem of the vessel. These aper-
tures may have projecting lips or edges on the outside of the vessel, the
better to catch the water as the vessel proceeds, one of the apertures in the
condenser tank communicating with the apertures in the vessel, as shown at Y,
or entrance may be given to the water by apertures in the front or stem of the
vessel, and pipes or channels convey it to the condenser; for the exit of the water
other. apertures are made from the upper part of the condenser tank through the
sides of the vessel, as near as may be in front of the paddle wheels, one of
which apertures is shewn at Z; thus, while the vessel is advancing through rivers,
canals, or other smooth or calm water, a trough or hollow is made in the water
in front of the paddle wheel by the continual rotation thereof, and the water
in the tank being forced to a higher level than that of the external water by
the passage of the vessel through the water which forces water into the
apertures or holes Y, and assisted by the trough or hollow in the hinder
part of the condenser tank produced by the paddle, as also by the levity of
the water as it becomes hot by contact with the surface of the steam chambers
of the condenser, a continual current of cold water is produced through the
said condenser tanks among the chambers of the condenser, and whereby
the steam is condensed. In rough water, where full advantage cannot be
taken of the hollow produced by the action of the paddles, a sufficient
current of cold water through the condenser will be produced by the passage
of the vessel through the water, assisted by the rotation of the paddles, which
will tend to draw or suck the water out of the condenser, and assisted
by the continually forming levity of the water in the condenser tanks by
absorption of the heat from the steam. Or, instead of the methods just
described, we insert two iron gratings into apertures in the side of the vessel,
one or more at or near the bottom, and the other or others at or upon
a level with the top of the condenser, and thus a free communication is
established between the external sea or river water and the interior of the
tank. By these various means the surfaces of the condenser are kept cool by
the continual ingress of cold and egress of heated water, without the aid of
pumps or other mechanical means connected with and substracting power from
the engine. Care must be taken to make the internal sides of the tanks
sufficiently strong and water-tight to guard against the entrance of water into
the interior of the vessel. Where, however, a pump or pumps are preferred
for supplying the condenser with cold water, they may be used.
And we further declare that, having now described the general arrange-
ments which we would recommend in applying our improvements in steam

page_text: engines to the usual motive purposes, we now proceed to describe the various
portions of the same, and the manner of making or constructing certain parts
thereof; and first, as regards the condenser.
Drawing No. V., Figures 1, 2, 3, and 4, represent our improved condenser or
refrigerator comprised of a series of separate are-tight chambers communicating
with each other throughout, to contain the steam to be condensed, and with
spaces between the said chambers, which spaces also communicate with each
other, allowing the condensing water to flow freely therein. All these Figures
are drawn to the same scale, and like letters refer to like parts. Figure 1, a
vertical section showing the outside of a chamber, excepting at two opposite
corners, where it is broken away to give a view of the connections and interior
of the chamber. Figure 2 is an end elevation broken away at two corners to
shew the interior, and also a partial section of the chambers and connection.
C, C, C, are the chambers which are each made of a sheet of thin metal with
semispherical embossments turned up, rounding at bottom, and pinched
together at the edges of the top and both ends. The embossments or semi-
spherical projections are alternately convex and concave, that is, project from
the plate of metal alternately from one side and from the other, and by which
they support each other throughout the series, and prevent either distending or
collapsing; frames R, R, R, each of the clear width between the metal of two
chambers at the pinched edges, surround the top and both ends; H, H, are
pipes connected with the cylinder eduction pipe, bringing in the steam at cach
end of the top connections; M, M, are similar pipes which collect and carry
off the water of condensation from all the chambers to the water returner or
to the force pump, or otherwise to return it to the boiler. A free commu-
nication between the insides of all the chambers, the one with the other, along
the top as well as along the bottom, for the admission of steam to be condensed
throughout the whole condenser, is formed as herein-after described, and to
elucidate which the horizontal section Figure 3, and the vertical section
Figure 4, are given; that is to say, in each plate forming a side of a chamber
at opposite corners, as at C, C, Figure 1), are cut circular holes of the same
diameter as the interior of the rings a, a; the edges of these circular holes are
embossed or projected, so that when two chambers are placed together the
edges of the circular holes will meet. In the interior of each chamber, and
coincident with these circular holes, are placed the perforated rings or collars
a, a, a, a, throughout the whole succession of chambers, and when the whole
condenser is screwed up, uninterrupted pipes or passages are formed from side
to side. P, P, P, P, are the side plates through which pass the bolts B, B,
which screw up the whole into one body with nuts outside. Most of theso

page_text: Figure 6. is a section of two
bolts are shown broken off to give a better view of the end of the condenser.
X, X, X, X, are bolts passing through the bottom parts of the pipes H, H, and
M, M, through the whole range of perforated rings a, a, a, a, a, through the
side plates P, and screwing up the whole together by means of screws and
nuts on the outside.. Figure 5 is a separate view of one of the connection
rings a.. The cold water used for condensation of the steam has a free passage
between all the. chambers, not only at the bottom, but also at the top and
ends, by the holes c, in the division frames R.
chambers, showing a method of forming chambers by which any length or
any height may be readily obtained. The plates or sheets forming the sides of
a chamber are returned round at each end, and rivetted together in the middle,
as shewn at 6; and should not two sheets give sufficient length or breadth to
the chamber, any number of sheets may be rivetted in between the two extreme
In a chamber thus formed it would only be necessary to pinch together
two edges out of the four, and, therefore, instead of frames R, before described,
two bars only would be required, one along each of the pinched edges. The
chambers marked S, Figures 2 and 6, are shewn pinched together, and
rivetted and soldered at the edges.
ones.
A modification of this condenser. or refrigerator, in which a part of the heat
given out by the steam in the course of its condensation is used to heat the
water to feed the boiler, and also. to heat a blast or current of air to promote
the combustion of fuel in the furnace, is shewn in Drawing No. VI.; Figures
7, 8, 9, and 10. This condenser is formed of a series of chambers and spaces
between them, as before described with respect .to Figures 1.and 6. These
Figures also are drawn to the same scale, and the same letters of reference
denote similar parts. Figure 7 is a vertical. section taken down the centre of
the middle chamber. Figure 8 is an end view partly shown. in section.
Figure 9 is a plan taken at the top; part of this is also shewn in. section.
C, C, C, C, are the chambers into which the steam or vapour passes to be
condeused; between each chamber, is a perforated frame or rim F, F, F, and
which has two cross bars p and q. extending from side to side. These frames
form the edges of the steam chambers between the embossed sheets of metal m.
In Figure 7 this frame F is shewn in one casting with the pipes H and M
(representing the section of the middle chamber). Figure 10 is a vertical
section of one of the frames R; R, R, which are placed between the exteriors
of the chambers; and Figure 11 an end view of the same. These frames
are of the same external dimensions as the frames F, F, F, and of such
thickness as to keep the chambers a proper distance apart for the purposes.
hereafter named. All the frames F and R, the side plates P, and sheets m,

page_text: are perforated alike for the bolts B to pass through, by which the whole is
screwed up together; all the frames and sheets m are also perforated alike, to
form the passages A throughout the whole series, for the transmission of steam.
The middle chamber shewn in Figures 8 and 9, is of greater thickness than
the others, as it receives the steam or vapour from the pipe H at top, and
distributes right and left to all the other chambers, and at bottom passes off
the condensation from all of them to the pipe or channel M. The operation
of this condenser is as follows:-The steam first passes from the eduction pipe
of the engine into the top compartment I of the chambers C, from the pipe H,
and here the greatest portion of the heat of the steam is given off, and it is
partially condensed; it then passes through the apertures n, into the second
compartment K, where it is further condensed, and from thence, by tho
passages O, into the lower compartment L, where the condensation is com-
pleted, and the water of condensation descends into the pipe or channel M.
It will be seen at Figure 10, that all vertical communication between the
three compartments is prevented by the bars p and q not having any vertical
perforations in the spaces between the exteriors of the chambers, as thoso
within the chambers have. The condenser is separated into compartments
(between the exteriors of the chambers) for the following purposes :-Into the
top or hottest compartment D is injected a jet or stream of the cold water of
condensation, or other water, by the pipe f; this rapidly absorbing the heat
from the steam in the chambers on each side, becomes hot to supply tho
boiler by the pipe 9; as the water has to be raised from the bottom to the
top of the condenser, this arrangement can only be adopted where a force
pump is used to feed the boiler. A current of air is made to pass through
the middle division E, whereby it is heated by the caloric given off by the
steam as it is condensed, and proceeds into the furnace through the holes
h, h, h, h, to promote the combustion of the fuel. Cold water flows through the
exterior of the chambers of the lower division, as in the first described condenser.
Our improved method of joining a series of chambers together to form one
condenser, is herein-after described in connection with the method of putting
together the parts of our improved boiler.
And we further declare that, as by means of our said invented improvements,
the same water is constantly used over and over again (waste by leakage only
having to be provided for), the pernicious effects of encrustations and deposits
of carthy and saline matters are avoided, and consequently boilers consisting of
a series of small chambers may be used without being liable to be choked by
such deposits or encrustations, whereby great additional safety, as regards
explosion, and great saving in fuel and in the space occupied, will be effected.
any

page_text: We shall therefore now proceed to describe our improvements' in the form
and mode of construction of the steam boiler or generator invented by Walter
Hancock, and for which Letters Patent, bearing date the Fifteenth day of
January, One thousand eight hundred and thirty-three, were granted to him,
that is to say:
:
Drawing No. VII., Figures 12, 18, 14, 15, and 16, are descriptive of a
boiler or generator of steam, or évaporator of fluids, composed of a number
of distinct thin chambers or compartments' united by passages as hereafter
described. These five Figures are drawn to the same scale, and the same
letters of reference apply to similar parts. Figure 12 is a vertical section
taken in the centre of one of the flues or spaces S. Figure 18' is an end
view, a part of which is given in section. Figure 14 is a plan taken at top,
part of which is also shewn in section. C, C, C, C, are the chambers' con-
taining water and steam, each of which is composed of two sheets of thin metal
placed opposite each other (with the embossments or semispheres projecting
outwards), with a rim or frame of metal F all round each of them next
adjoining the extreme edges, and which frames keep the before-named sheets
of metal composing the sides of each chamber at the proper distance apart,
and form the thickness or distance between the sides in the interior of the
chamber. A central vertical section of one of these frames is 'shewn 'nt
Figure 15. Other rims or frames of metal R, of like dimensions with F,
are placed between the exterior sides of each chamber at the edges, and
keeping the chambers at a sufficient distance apart from the flue or space S, S';
a central vertical section of one of these frames is shewn at Figure 12. The
frames F and R are all perforated alike as regards holes for the bolts B, B, B,
which pass through them, as well as the two side plates P, P, and all the
metal plates m, m, m, forming the sides of the chambers C, C, C, C, by
which the whole are securely held together with nuts and screws. All these
frames are also perforated, as well as the metal plates m, m, m, to make con-
tiuned passages A, A, A, A, for both water and steam throughout the whole
boiler. The frames F, F, F, are also perforated into the chambers to com-
municate with the before-named' passages, as shewn at u, v, v, Figure-15,
but the frames R; R, "have no such perforations, otherwise the steam-or
water would escape into the flues; but these frames R, R, are perfo-
rated through for the transmission of heat, as shewn by a, a, a, x; and' 'in
order that both the frames R, R, and the plates of the chambers may
be reversed to equalize wear, these perforations are also shewn all round,
but with a sheet of iron y, y, y, y, against the two sides to stop the
radiation or loss of heat in that direction. It might be found convenient

page_text: to take the heat in at one or both sides, in which case the sheets y, y, y, y,
should be placed at top and bottom. For the generation of high-pressure
steam, it will be necessary to strengthen the boiler by external stays, shewn
at Z, Z, Z, Z. W shews the injection pipe, or pipe by which water
enters the boiler, entering one of the chambers near the bottom, but which
may be in any convenient position; the steam or exit pipe may be inserted
at any convenient part of the top of a chamber, or one common trunk or pipe
may be used communicating with all the chambers, similar to Figure 7,
Drawing No. VI., herein-before described. V is the safety valve fixed on the
top of one of the chambers. The method of putting the parts of this boiler
together, which is also applicable to the putting together the parts of the con-
densers herein-before described, with a few variations hereafter mentioned, is as
follows: On the edges of the frames I and R, copper wires are tied on
with light string or fine wire on each side of the passages on both sides of each
frame, as shown at k, k, k, Figure 16, which shews only one side of a frame
in part. The bolts B, being placed upright, a side plate P, P, is placed over
them through the holes for the reception of the said bolts, which suid plate P
will then rest on the bolt heads; a frame F is then passed over the bolts, and
next a plate m, forming a side of a chamber; then a frame R followed by
another plato m, when one chamber will be complete, and thus the operation
is continued till the number of chambers and spaces of which it is desired to
form the boiler are placed together; the other side plate P, P, is then placed
above all, and the whole (excepting bolts) subjected to great pressure by an
hydraulic or other press, by which the copper wires between the frames and
plates are flattened down and accommodated to the inequalities of the metal,
and every joint rendered steam-tight. The bolts are now to be screwed up
by their nuts, a ring of wire or zone of soft sheet copper having been pre-
viously placed under each bolt head, to make a steam-tight joint against the
plate P, P, and a zone of sheet copper having also been put between the nut
and the opposite plate P, P, for the same purpose, as shewn at d, d, Figure 13.
Removed from the press, and the injection and steam pipes and safety valve
inserted, the boiler is complete. Steam-tight joints may be made by using
wire of other metal, or by surfacing, cementing, or any other applicable
means. In placing together the parts of the condenser, the same general
directions are to be followed, excepting, that instead of the wire used between
the frames and chamber plates of the boilers to form steam-tight joints, cards.
or strips of solid caoutchouc or india-rubber are used to form air-tight joints
in the condenser, and rings of the same substances on each side of the per-
forated rings a, a, a, Drawing No. V., and also between all surfaces, which

page_text: being closed, are to form a joint in the condenser. The square perforations
in Figure 16 are to. diminish the weight of the frames F and R, but they
may be round or of any other convenient form. The advantages of a boiler
made on this plan are, that the use of a great number of rivets which are
usually required is avoided; it may also be easily taken apart for cleaning, for
removing and replacing a defective or worn part, for diminishing or encreasing
the extent or surface by adding or taking awaychambers, and for many other
purposes. The mode of joining together and forming a series of flat chambers
into a condenser or boiler, as herein-before described, may be adopted, either
with plates forming the sides of the chambers, with hemispherical emboss-
ments as herein described, or with corrugations or projections of any shape,
or altogether flat. It will be observed generally, both as regards the con-
densers and boiler herein-before described, that although represented square
and oblong, they may be made of any other suitable form; any number of
chambers or compartments may be used consistent with strength, and accord-
ing to the particular circumstances of each case. The sides of the chambers
are represented as of copper, the bolts, stays, and side plates of wrought iron,
and the frames and perforated rings of cast iron, but they or any or either of
them may be made of other metals, or alloys of metals.
:
We shall now proceed to describe those parts of our improvements which
have for their object the more perfect exclusion of the external atmosphere
from the interior of the engine.
the
:
Drawing No. VIII., Figures 17 to 25, shew a new method of packing
pistons and stuffing-boxes.by, the use of flexible cloth. The same letters refer
to the same parts. Figure 17 is;a: section of part of a steam cylinder, the
piston of which is composed of two plates of metal N, N, between which are
secured, by screws running through them, or otherwise, the metal springs Y, Y,
and flexible cloth Q, Q, Q, Q. The object of the springs Y, Y, is to press
flexible cloth against the interior circumference of the cylinder, and thus make a
steam-tight packing. The springs are each composed of a ring or zone of copper
or other plate, cut or slit at the edges in radial lines, as far in as it is intended
to be turned up to form the. spring, as shewn by the right-hand semi-
circle of Figure 18, the left-hand semicircle of which Figure shews the
folding in and turning up of the above-named cut or divided edges. Figure 19
represents in part an edge view of this metallic spring, when folded up in the
position in which it works; and both Figures 18 and 19 are laid down to the
size proper for the cylinder shewn at Figure 17. The two layers of flexible
cloth QQ, and which are put between the springs Y, Y, and the piston
plates N, N, are each composed of several thicknesses united in the manner

page_text: hereafter described. These layers or packings do not require to be slit at the
edges, as the springs are shewn to be. Each successive ring or zone of cloth
diminishes in diameter towards the centre, as shewn at plan Figure 20, and
section Figure 21. When united into one thickness and pushed into the
cylinder, from being the thinnest at the exterior circumference they will turn
up to the shape of the metal spring, and fill out the space of tho interior of
the cylinder. Should steam of high pressure be used, a metal ring fitting the
interior diameter (or nearly so) of the cylinder may be interposed between
the layers of flexible cloth, as shewn at w, Figure 24, to prevent the cloth
from collapsing, and thus diminishing its effect as a packing. A stuffing box
is shewn at the top of the cylinder, Figure 17, for the piston rod to work
through; the manner of making and firing which is the same as that just
described for the piston, excepting that the successive rings or zones of cloth
forming the packing are the reverse of those forming the layers for the piston,
diminishing in diameter from the centre, as will be seen by plan Figure 22,
and section Figure 23. Figure 25 shews a spring similar to Y, already
described, excepting that as it is employed against a convex surface, the radial
slits are made to open towards the centre. The flexible cloth or packing may
be made in the following manner :-Rings or zones of cloth or canvas, of
hemp, cotton, or other suitable material, as before explained in describing
Figures 20, 21, 22, and 23, (which are shewn composed of four thicknesses),
each ring is separately covered or coated on both sides with a solution of
caoutchouc or india-rubber; they are then hung up for seven or eight hours
to dry, and then again coated with more solution of caoutchouc or india-rubber
and dried, and so on three or four times; when the last coating has been
laid on about three hours, the several rings composing a packing may be
placed over each other, and subjected to considerable pressure for a short
time; they will then be fit for use.
In Drawing No. 1, Figures 3 and 4 shew a substitute for packing, or a
method to be used in addition to packing, for more effectually preventing air
from entering the cylinder by the stuffing box, through which the piston rod
works on a vacuum being produced above the piston. We enclose the piston
rod a, a, in a flexible sheath of india-rubber or caoutchouc cloth, or other air-
tight fabric b, b, the one end of which is attached to a collar round the cylinder
stuffing box at c, c, and the other end attached to the top of the piston rod at d, d.
Where india-rubber or caoutchouc cloth is used, collets or collars of cork,
wood, or other non-conducting substance should be placed between it and the
metal of the collars of the cylinder and piston rod, as the heat of the metal
would be liable to partially decompose the india-rubber or caouthouc by its

page_text: contact therewith. The elastic sheath is kept distended, or prevented from cling-
ing to the sides of the piston and so impeding its action, by a series of rings, or a
helix of wire, cane, or whalebone, e, a, e, e, e, e; the latter substances are preferred,
being non-conductors of heat, and therefore not liable to injure the india-rubber
or caoutchouc fabric, should such be used. The piston rod is shewn at the
top of its stroke in Figure 8, with the sheath b, b, distended; and nearly at the
bottom of its stroke by Figure 4, and the sheath collapsed or folded; thus
the possibility of the entrance of air through the stuffing box is avoided, as
there is no sliding joint through which the particles thereof can pass. The
said sheath may be used either in conjunction with, or as a substitute for, the
ordinary, or our improved, or any other kind of stuffing boxes, and either in
connection with our other improvements or applied to engines of the ordinary
construction.
Now, having fully described our said invented improvements in steam
engines, and the manner in which the same are performed, we declare, that
we do not claim as new, or of our Invention, any of the parts or portions of
ordinary steam engines herein-before described, as in themselves new, but
only in as far as the same are newly combined and arranged for the purpose
of carrying into effect the principle or principles of our said Invention; but we
declare, that we-claim as new and of our Invention,―.
Firstly, the proportioning the cooling surface of the condenser to the heating
surface of the boiler, so as that the condensing power of the one shall coun-
teract the evaporating power of the other on the opposite sides of the piston
in a steam cylinder; also the combination and arrangement of parts herein-
before described, by which there is effected a continual circulation of fluid in
the engine, both in the shapes of water and steam, without its at any time
coming in contact with the external atmosphere, whereby a vacuum having
been produced, may be maintained without the assistance of an air pump,
or with only the assistance of a small air pump to obviate the effects of
leakage.
Secondly, we claim the condenser; of the form and constructed in the
manner herein-before described, by which an air-tight vessel composed of a
number of chambers; giving a great extent of cooling surface in a small
space, as well as great strength, simplicity, and economy of construction are
obtained. We also claim the use of the said condenser, not only in con-
nection with steam engines, but as a condenser or refrigerator for various
other purposes.
Thirdly, we claim the improvements in form and mode of construction

page_text: upon the boiler commonly known by the name of "Hancock's Boiler," herein-
before described.
Fourthly, we claim the apparatus herein before described and designated
a "water returner," in so far as the same is worked or made to operate by
the water of condensation passing into the same in connection with a float
and weight, and also as regards the means whereby the valve or valves is or
are made to act promptly and efficiently.
Fifthly, we claim the method of causing a constant current of cold water
to flow through a condenser, placed at any height less than about thirty-two
feet from the surface of the source of supply of such cold water, by the form-
ing of a syphon by one pipe or conduit from the water to the condenser tank,
and another from the condenser tank downwards, the mouth of which shall
be lower than the mouth of the first pipe, the pipes or conduits and condenser
tank all being air tight.
Sixthly, we claim the method of continually supplying the condenser with
cold water herein-before described, by the circulation caused by the levity and
expansion of the water, resulting from its being heated in the condenser,
whereby it overflows at the top, and cold supplies its place at the bottom of
the said condenser, the cold water being supplied from any neighbouring
natural or artificial pond, canal, lake, river, stream, or other rescrvoir.
Seventhly, we claim the method of causing a constant current of cold water
to flow through the condensers of marine engines, through holes or apertures
in the vessel, as before described, by the force or impetus of the vessel in its
progression through the water.
Eighthly, we claim the method of packing the piston and piston rod herein-
before described.
Ninthly, we claim the method of excluding the air from the cylinders and
valve boxes of steam engines, by meams of a flexible air-tight sheath, one end
of which is connected with the top of the piston rod, and the other to the edge
of the aperture in the top of the cylinder.
In witness whereof, we, the said Thomas Simmons Mackintosh and
William Angus Robertson, have hereunto set our hands and seals,
this Twenty-eighth of March, One thousand eight hundred and thirty-
L

page_text: AND BE IT REMEMBERED, that on the Twenty-eighth day of March,
in the year of our Lord 1838, the aforesaid Thomas Simmons Mackintosh
and William Angus Robertson came before our said Lady the Queen in Her
Chancery, and acknowledged the Specification aforesaid, and all and every
thing therein contained and specified, in form above written. And also the
Specification aforesaid was stamped according to the tenor of the Statute
made for that purpose.
Inrolled the Twenty-eighth day of March, in the year of our Lord One
thousand eight hundred and thirty-eight.