CERTAIN IMPROVEMENTS IN STEAM ENGINES AND BOILERS
Year: 1845

page_text: AL
WHOD THESE PRESENTS SHALL COME, I, OSEPH
FULTON MEADE, of Dublin, 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 Twelfth day of July, in the ninth year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto me, the said Joseph
Fulton Meade, Her especial licence, full power, sole privilege and authority,
that I, the said Joseph Fulton Meade, my exors, adñiors, and assigns, or such
others as I, the said Joseph Fulton Meade, my exors, adññors, 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 Ber-
wick upon Tweed, my Invention of "CERTAIN IMPROVEMENTS IN STEAM ENGINES
AND BOILERS;" in which said Letters Patent is contained a proviso, that I, the
said Joseph Fulton Mead, shall cause a particular description of the nature of
my said Invention, and in what 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 large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Joseph Fulton Meade, hereby declare that the nature of the said Invention, and
in what manner the same is to be performed, are fully described and ascer-

page_text: tained in and by the present Specification thereof, reference being had to the
Drawings hereunto annexed, (that is to say):
My improvements in steam engines have relation to that class of engines
which act by the simple efflux of steam, and have for their object to place the
velocity of the current under control, and to reduce to a low proportion the
amount of misspent or unemployed power.
In an efflux engine of the simplest kind, it is well known that a certain
retro-active effect is produced by the ejection of a fluid at an angle to its former
course. By reversing the current, that is, by its influx, an effect similiar in
kind (and which may be rendered equal in amount) is also produced, but in
the contrary direction. Thus efflux and influx will alike tend to produce
motion of the arm through which they are applied, but in opposite ways.
These two modes of action may readily be made to co-operate by the suces-
sive operation of the same steam with a total amount of effect equal to the sum
of effects respectively producible by their separate employment. An engine on
this construction, (which for the sake of distinction may be termed the duplex
engine,) is represented in Sheet 1, Figures 1 and 2, of the Drawings hereunto
annexed, where A is the steam case, and B the tubular axis, divided inter-
nally, to act first as a conducting pipe from the boiler, and then as a discharge
pipe from the disc, with the efflux and influx passages at the ends of its con-
nected radii.
The steam issuing from the former nearly at a right angle to its previous
course, tends to make the arm revolve in the direction the opposite of that
indicated by the arrow. From the case it passes through the influx port into
the interior of the hollow disc or segment of disc, in which it rapidly expands,
and is discharged through the axis, producing an unbalanced pressure at the
surface of the disc, exterior and opposite to the aperture of influx, which
co-operates in effecting the revolution of the engine. The form of the efflux
and influx passages should be a curve, the radius of which should be regulated
by the velocity of revolution of the arm as compared with that of the expansion
of the steam. Were these velocities equal, the arm itself would describe the
proper curve. Were the velocity of the arm equal to half the velocity of
expansion of the steam, the curve should be one of twice the radius.
As with passages of the same size, the velocity of the steam in its influx
would be greater than that of its efflux, on account of the relatively greater
rarity of the medium into which it passes, and as the rate of revolution of the
arm should as nearly as possible equal the rate of expansion of the steam
which works it, in order to utilize the largest amount of power, it will be
necessary either to give a greater length of arm to the influx port, that its

page_text: velocity may be increased with that of the steam which acts through it, or else
(which seems preferable) to increase the size of the port, so as to diminish the
density and consequently the velocity of the steam which it delivers from the
case. Both these forms are represented in the Drawings annexed.
As the expansion of the steam and its discharge from the interior of the
revolving disc should be as rapid as practicable after its influx action, the bore
of the tubular axis through which it effects its escape should be made of corres-
ponding diameter, and the width of the interior of the disc may also be
advantageously enlarged. A slight inclination of the influx port inwardly, or
towards the centre of revolution, will divert the projectile force of the influent
steam from impinging against the inner circumference of the disc so as to
impede its revolution; or fixed vanes, mounted on a stationary axis passing
through one side of the disc and bearing its revolving axle, as shown in
Figure 3, may be used for the same purpose, care being of course taken that
the vanes as well as the influx port shall lie in a different plane from that of
the arm of efflux. I propose also to work this engine more expansively,
through means of a series of several parallel compartments, each furnished in
a manner similar to that described, the entire apparatus being mounted on a
common tubular axis, divided internally to correspond with the number of
compartments, and to regulate the passage of the steam successively through
them. The size of the apertures of efflux and influx is gradually increased in a
proportion regulated by the velocity with which it is desired to work the engine,
which is dependant on the relative density of the successive media. But this
increase should be confined to their extension laterally, as it is important that
the deflection of the current should be as nearly as possible rectangular.
Another arrangement of the chambers is represented in the Drawing, Fig. 4,
where a series is represented placed in immediate succession and projected
from one radius, being so constructed as to deflect the current of steam nearly
at right angles in each chamber during its discharge. Their lateral extension
is gradually increased so as to admit of a corresponding expansion in the steam,
the velocity of which will be regulated by the rate of this increase, so that
it can be made to flow at any definite rate, and be discharged at any definite
degree of expansion, according to the number and proportions of the chambers
employed. Each chamber will thus absorb a certain amount of power propor-
tionate to the expansion undergone, the sum of which will act upon the arm
which carries the apparatus. The proper number of chambers to develope the
expansive power will depend on the specific elasticity of the steam employed,
the density of the mediuni into which it is ultimately discharged, and the rate
of velocity desired for the engine. It is supposed that an excess of elastic

page_text: force of about two ounces to the square inch in one aeriform fluid over another
with which it communicates, will cause its influx into the latter at a velocity of
sixty miles an hour; and that an excess of half an ounce will induce a velocity
of thirty miles an hour, the necessary excess diminishing nearly as the square
of the velocity required. If then we assume that the steam employed is thirty
pounds pressure above the atmosphere, and that it is to be worked on the non-
condensing method with a velocity of expansion of sixty miles an hour, then, as
each chamber will absorb a portion of expansive force equal to four ounces, its
depth being twice its breadth, the total number required to develope the power
of the steam would be 120 (4 x 120 = 480 = 30 pounds,) the excess of two
ounces to the square inch in the last chamber being in this calculation supposed
to be chiefly produced by the rarefaction of the medium against which it
impinges, caused by the rapid recession of the revolving arm.
With respect
to the increase of the lateral extension of the chambers, as steam of thirty
pounds may expand to three times its own bulk and still be in equilibrum
with the atmosphere, the lateral extension of the ultimate chamber should be
three times that of the first, the intermediate ones respectively being reduced.
in regular gradation as they approach the primary chamber. A velocity of
sixty miles an hour has been mentioned by way of illustrating the mode of
operation; but it is obvious that, on the same principle, any other velocity
is equally attainable. When, however, in this as in the other forms of
engine described, the original velocity of revolution must be reduced to suit
the nature of the work to be done, I propose to employ an endless screw (N)
mounted on the axis, as shewn in Figure 2, to work in a toothed wheel W.
The screw being attached by couplings, may be removed, and one of reverse
action with a corresponding wheel substituted, to change the motion. The
axis is made to bear against a set of conical rollers R, to reduce the friction.
However, in the engine last described, the reverse motion may be effected on
the influx principle, that is, by reversing the current, and making it pass from
the case into the chamber apparatus, and then through the axis into the air or
condenser, the steam passages being suitably altered. But as, owing to the
successive contraction of the chambers as thus used, the full power of the steam
would not be developed, I prefer having a separate arm for the purpose of
reverse action. This is represented in the Drawings.
The passage of the steam is regulated at will by the revolving valve, as
shewn. As the use of this arm is but temporary, full economy of power is
not necessary, and therefore fewer chambers may be used. It may advan
tageously be longer than the forward arm, as, on account of the fewer chambers,
the velocity of the steam will be proportionately greater. I attach a governor to

page_text: these several forms of engine, which may act, either by controlling the admis-
sion of the steam into the arm, or its exit from the case. In that last
described, the exhausted steam is discharged from the bottom of the case
through a tube, in which, as in the induction pipe, the throttle valve may be
placed. As all the working apparatus is here enclosed in a case, there need
not be the same provision against radiation as in the other forms specified, in
which the case should be felted, or otherwise protected from loss of heat. The
chambers, as represented in Figure 4, may conveniently be constructed of
grooved surfaces placed so as that the partition between the grooves in one
surface may divide into equal parts the groove opposite.
The breadth of each groove is as much less than twice its depth as each
partition projects into the opposite groove, (which projection should be equal to
the thickness of the partition,) the object being to preserve the steam from
being irregularly contracted and dilated.
The grooves may be constructed of several forms, but I prefer the rectangular
one represented in Drawing, Figure 4. The depth may vary in proportion to the
velocity of the current, but one-sixth of an inch will probably be found suitable
for a velocity of sixty miles an hour. Several parallel sets of this expansion
chamber apparatus may be mounted on the same axis, and being all placed in con-
nection with a common steam box, they may be worked separately or conjunc-
tively, according to the power required, a slide valve closing or opening the
communication with the steam box at will. The chambers may be constructed
in several analogous forms, but the one described I consider the simplest and
most compact.
I also apply the engine to direct horizontal propulsion, (which the reduction
of the velocity of the current enables me profitably to do,) so that its parts are
fixed in place of revolving. The chambers are here composed of flat grooved
surfaces, as shewn in Drawings, Fig. 5, 6, 7, 8. Several tiers or ranges are
placed one over the other, till the required acting surface is obtained. Each
range may be put in communication with a steam reservoir T, by the action of
the slide valve N, exhibited in Drawing Fig. 5 & 6, and may be thus rendered
active or inoperative, so as to adjust the power to the load. As in engines of
this description, the higher the ratio of the power to the load the more economy
is there in its application, a proportionate approximation to its complete
absorption may be made; but, in accordance with the principles heretofore laid
down, this object should be sought, not by increasing the velocity of the
steam, which would require a corresponding increase in that of the load, but
by bringing a larger surface, that is, a greater number of ranges, into operation.
Retrograde action may be effected, as in the revolving engine, either by influx,

page_text: that is, reversing the current in the apparatus, or more conveniently and
effectively, for the reason already assigned, by a separate apparatus mounted in
the reverse direction. Finally, I propose to use the different sorts of engines
before described, not only separately, each by itself, but in conjunction with
and supplementally to other engines of the ordinary piston description. When
they are worked by the unexhausted steam in its passage to the condenser or
open air, provision should be made for the escape of the steam from the
primary engine in such time as to retard but slightly the succeeding stroke of
the piston. If the supplementary engine is of the revolving kind, it may be
made to co-operate with the main shaft of the primary engine, or to work the
engine pumps, or, still more conveniently, to restore to the boiler some portion
of the steam after its expansion in the cylinder or other vessel. The fixed or
rectilinear engine described would, as applicable only to horizontal propulsion,
be adopted where such motion was required.
My "Improvements in Steam Boilers" have for their object the diminution
of that internal expenditure of power caused by the self-diffusion of the steam
during its ascent thro' the superincumbent mass of water. This process of
expansion, by which its elasticity is constantly being reduced as it recedes
from the point of generation, I propose to limit by an internal arrangement,
which will preserve for operation in the engine a certain portion of the power
now previously expended. The nature of this improvement may be the more
readily understood from a consideration of what would seem to constitute the
superior utility of steam of a higher degree of elasticity, as generated by a
specific quantity of fuel, namely, the reduced amount of expansion in the boiler
as the elasticity increases, and the consequent retention of the power thus
saved for profitable application in the engine. The mode of construction
which, in accordance with this view, I adopt, is such as to subject the steam to
a portion of that weight of water which bears upon the lower parts of the
boiler, so that, without augmenting the internal pressure against the latter, such
an amount of the original elasticity of the steam is preserved for engine use as
is equivalent to the weight of water thus counterbalanced. The boiler, which
from its method of action may be called the hydrostatic, is represented in
Sheet N° 2, of the Drawings hereunto annexed; Figure 1 being a longitudinal
sectional elevation, and Figure 2 a cross section. A, A, is the external case;
B, a receiver, submerged in an inverted position, for the purpose of inter-
cepting and collecting the steam in its ascent.
It is placed within a few inches of the bottom of the boiler, so as to leave
beneath it only such a depth of water as is sufficient for the ready absorption
and transmission of the heat. A lateral interval of two or three inches is

page_text: provided between it and the sides of the boiler for the circulation of the water.
It is upheld in its place by the screw bolts S, S, which are made adjustable to
different heights, and admit of its removal on occasion. As both its surfaces
are subject to nearly equal hydrostatic pressures, its structure may be propor-
tionably light. It should be rendered non-conducting by being covered with
wood or other suitable material, or made of double plates with a layer between
them. C is a pipe, which conveys the steam from the crown or steam dome
to the engine, and D, a float valve, attached to it for the purpose of regulating
its admission. As the steam, arrested in its ascent by the collector E,
accumulates in the dome, it depresses the surface of the water beneath, till,
when it reaches the bounding line a, b, a sufficient supply of dry steam being
then provided, the valve is opened by the float f, and steam admitted. And
when, conversely, the water rises above the line a, b, through a deficiency of
steam, the rise of the float closes the valve and cuts off communication with
the pipe. Any excess of steam above the consumption of the engine will, by
depressing the water below the verge of or lips of the collector E, escape into
the cooler body of water above. When a not very high degree of elasticity is
required, the pressure upon the steam in the collector may be conveniently
regulated by means of the re-curved pipe G, which will also serve the office of
a safety valve without liability to derangement, and permit the discharge of the
steam if the level of the water should by accident be allowed to sink below
that of its curvature. The height at which the water is made to stand in it
will of course regulate the elasticity of the steam in the collector. That part
which is within the boiler is coated with some non-conducting material; its
re-curved form, by reason of the slow descent of heat, will retard the escape of
vapour, and the telescope joint at g, g, admit of its height being adjusted
according to the pressure desired. A waste pipe may be attached, to carry off
any occasional overflow. Where this arrangement is inconvenient, the ordi-
nary valve apparatus is retained, the pressure under which the feed is
introduced having the same effect as the simple hydrostatic action of the
column of water in the tube. In the Drawing, a boiler of the ordinary
proportions is represented, but in practice I would prefer a lesser depth, as
thus its strength could be increased without additional cost, and an equally
abundant supply of steam maintained. On account of the large proportion
which the fire surface in this boiler bears to the bulk of water into which the
heat is discharged, its effect will, it is considered, be found equivalent to that of
a tubular one, without involving its complexity of structure, while it retains at
the same time the benefit derived from the application of the incumbent water
contained as preventive of internal expansion.

page_text: And having now described the nature of my said Invention and in what
manner the same is to be performed, I declare that though the different forms
of construction I have before described will probably be found the most con-
venient and useful, yet I do not restrict myself to the same, inasmuch as they
may each and all be variously modified without departing essentially from the
principles of my Invention. But that what I claim is:-First, the twofold
employment of steam by efflux and influx, whether thus acting but once and
in one compartment, or more expansively several times and in several com-
partments, as heretofore exemplified and described. Second, the application
of steam expansively through the medium of a series of consecutive and
inter-communicating chambers borne by and forming part of a working arm
or arms, and whether such arm or arms are moveable or fixed, as also before
exemplified and described. Third, the application in manner before explained
of any of the engines comprehended under the preceding claims, as auxiliary
And
to the ordinary piston engines, and wrought by their discharged steam.
fourth, the application, through means of a collector partially or entirely sub-
merged as described, of a portion of the weight of water contained in the
boiler, to limit the internal expansion of the steam and proportionally to
augment its useful effect.
In witness whereof, I, the said Joseph Fulton Meade, have hereunto
set my hand and seal, this Twelfth day of January, in the year of
our Lord One thousand eight hundred and forty-six