CERTAIN NEW METHODS OF CONSTRUCTING STEAM ENGINES
Year: 1818

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, Sir WILLIAM
CONGREVE, of Cecil Street, in the City of Westminster, and County of Mid-
dlesex, Baronet, send greeting.
WHEREAS His present Majesty King George the Third, by His Letters
Patent under the Great Seal of Great Britain, bearing date at Westminster,
the Nineteenth day of October now last past, did give and grant unto me, the
said Sir William Congreve, His especial licence that I, the said Sir William
Congreve, my executors, administrators, and assigns, and such others as I
they should agree with, and no others, 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 also in all His
said Majesty's Colonies and Plantations abroad, my Invention of "CERTAIN
NEW METHODS OF CONSTRUCTING STEAM ENGINES;" in which said Letters Patent
there is contained a proviso obliging me, the said Sir William Congreve, by
an instrument in writing under my hand and seal, particularly to describe
and ascertain the nature of my said Invention, and in what manner the same
is to be performed; and to cause the same, to be inrolled in His Majesty's
High Court of Chancery within six calendar months next and .immediately
after the date of the said Letters Patent, as in and by the said Letters Patent,
reference being thereto had, will more fully appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Sir William Congreve, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are described and
ascertained by the Drawings in the margin of these Presents, and the following
description thereof, that is to say:-
my
The principle upon which I apply the elastic force of the steam in New
Methods of Constructing Steam Engines is by collecting that force under the
pressure of any given column of circumambient water or other heavy fluid, so
that its effect to produce motion in any direction will be regulated by the
reacting pressure of the column of such fluid to the expansion of the steam in
a contrary direction; and on this principle I give motion to a variety of
different modifications both of rotatory and reciprocating machines, with much
greater facility and simplicity of construction, and with less friction than in any
other principle of steam engine hitherto invented.
Figure 1 is a section of a rotatory engine on this principle in its simplest
form, wherein A, B, C, D, is a boiler divided into two parts by an internal
horizontal partition a, b, c, d, now in the lower part of the boiler C, D. The
steam is supposed to be generated in the upper part A, B (which is filled also
with water. An overshot water-wheel W, W, made either of wood, iron, or
other suitable material, is suspended on its axis, so as to revolve freely therein,
being completely immersed in the upper water. Under these circumstances,
therefore, the motion is produced the passage of the steam from the lower
compartment of the boiler to the upper one, where it is thrown into the
ascending buckets of the water-wheel W, W, by the following arrange-
ment for increased effect. g, h, i, is a third compartment in the boiler,
formed by the curved partition g, h, the whole breadth of the boiler, and
nearly adapted to the periphery of the water-wheel; this compartment
is, subdivided by another partition k, h, not closed at k, and forms a
steam chamber into which the steam enters from the lower part A, B, through
an opening in the horizontal partition a, b, c, from 6 to c, and passes up to the
outer side of the partition h, k, turns round at k and forces its way down the
other side of k, h, by driving the water before it until it issues with great
force and velocity through the aperture h into the ascending buckets of the
wheel, being compressed in the steam chamber according to the height of the
column of water or other fluid thus forced down from k to h: rushing there-
fore with the force thus acquired through the aperture h, it not only drives
round the wheel by its energy and expansion as it ascends, but produces, by
the actual displacement of all the water or other fluid in the ascending buckets,
a buoyant power on that side of the wheel equal to the actual weight of the

page_text: quantity of water or other fluid thus displaced; the least moving power,
therefore, of such a wheel, independent of the energy and expansion of the
steam, may be reckoned as equal to the power which the same overshot wheel
would exert working in air by the fall of a column of water or other fluid
equal in quantity to the displacement of the steam in this case. The upper part
of the boiler is always kept full by a common ball-cock, and the water in the
upper compartment of the boiler communicating with that in the lower
through the bent pipe e, f, the lower boiler will thus also be regularly fed, and
when the steam is up, the water in the lower boiler, or rather in the bottom
of the steam chamber, will alway's stand on a level with the top of the
aperture ; for then the opposite columns of pressure, condensing the steam
between them will be in equilibrium, and up to this level will the lower com-,
partment of the boiler, while working, be always supplied through the
pipe e, f, though the steam cannot escape through it. These different com-,
partments are, in fact, one vessel or boiler, having not only a free communi-
cation with each other, but having the water in each nearly of the same
temperature. The whole being set in the same furnace and surrounded with
flues, so that in passing from one to the other there is no loss of heat or
expansion in the steam during the whole of the time that it is in action. In
this way a rotatory motion will be produced, not acting by impulses but
revolving with a regular and constant force on the most simple principle, and
by means of machinery within the compass of the most ordinary workman to
execute, at the same time, without loss of power by friction or refrigeration, and
without valves, pistons, or any other of the complex apparatus, involved, I may
say more or less, in every other description of steam engine hitherto produced.
From what has been said as to the calculation of the force of such an engine,
it is evident its power may be increased or diminished in proportion to the
specific gravity of the fluid in which the wheel is made to revolve: thus, if
mercury were made use of instead of water, a vast increase of power would
be obtained; or, in other words, a much smaller wheel would produce equal
powers; a circumstance which, together with the constant action and the
extraordinary simplicity and compactness of its construction, seems to give
this principle of engine peculiar fitness for steamboats, more especially as the
steam wheel may be made to move with the velocity required for the propel-
ling wheels of the boat, so that the latter might be applied at once to the
extremities of the axis of the former, working through stuffing boxes in the
side of the boiler.
".
Figures 2 and 3 are a section and end view of a curious modification of
Figuro 1 whereby increasing the denth of the upper part of the boiler the

page_text: the same, steam may be made to do its work twice over or more.. Thus the
upper part of the boiler, is here furnished with two wheels and two steam
chambers, &c., exactly as in Figure 1, so that the steam issuing from the.
lower boiler enters into the first steam chamber, from whence, it issues and
drives the first wheel Number 1 (Figures 2 and 3), at the top of which it is
liberated; from thence it enters the second chamber, and, issuing as before,
turns the second wheel Number 2, and so on, without loss of buoyancy or
power so long as the temperature of the, water in which this series of wheels
is immersed remains but little diminished...
Figures 4 and 5 are the side and end view of another modification of this
principle; where, under the same arrangement as to the steam chamber,.
&c., as in Figure 1, the buckets instead of being placed in the periphery of
an overshot water-wheel, are attached to an endless chain working on two.
centers. In this manner therefore equal power may be obtained on a smaller
base by increased height.
from
Figure 6 is another variety, where, instead of the boiler A, B, C, D, being,
an open vessel, as hitherto supposed, it is an inclosed one, and is sur-
mounted with a common engine with piston, condenser, &c. In this case the
steam is collected in the steam chamber, and drives the wheel in its passage to
the surface of the water, as in the other cases; after which it is again col-
lected and compressed between the top of the boiler and the surface of the
water, and from thence passes through the usual pipes and valves to perform
its operations with undiminished force in the common steam engine, after
having previously exerted all the powers above calculated in its passage
the bottom to the top of the boiler: nor does the boiler in this case, being a
close vessel, make any assignable difference in the calculation of these powers;
for though the column of pressure against the ascent of the steam is thus
increased, still the reacting pressure which forces it up is equally increased, so
that the only difference is in the volume of the steam generated under the
different pressures, which is compensated by the increased retention of heat in
the close boiler. Hence, therefore, in all the foregoing cases, it seems a.
matter of little consequence whether the boiler be a close or an open vessel.,
An open vessel is of course least expensive, is safer, as it wants no safety
valve or other provision for the escape of the steam; it is also easier fed, and
the power, as in Figure 1, may be applied to any machinery without stuffing
boxes, and therefore with less friction. Here I have also to observe, that the
steam may, if desired, instead of entering into the buckets of the wheel, on
the common principle of the water-wheel, as hitherto explained, from the cir-
cumference, be carried into those buckets from the centre through a hollow

page_text: axis and radii, allowing it only to enter into the ascending buckets. These:
buckets also may be either open buckets or close ones with valves;: so also they
may either work as in Figures 1, 2, and 3; wholly immersed in water or other.
fluid, or the fluid may be only partially so employed, and the steam may.be:
allowed to escape as hitherto described, or it may be got rid of by condensation.
All which varieties,, though they may modify the action and force, of this.
engine, would not probably be found to induce advantages equivalent to the
increased expence and machinery involved when compared to the 'extreme
facility and simplicity of the construction of the machinery as delineated in the:
foregoing Figures, and therefore need not be further detailed. I shall now
therefore only further particularize one other construction, which is the appli-
cation of this principle of reaction to a reciprocating. steam engine...
Figure 7 is such an engine, having an open cylinder A, B, C, D, attached
to the upper part of the boiler F, into which cylinder the boiling water rises
as high as a,, b. In this cylinder, in lieu of a common piston, is placed another
cylinder of equal length, having a small space. between the two, so that the
interior one may rise and fall freely within the outer. one without friction.
This internal cylinder or plunger is divided into two parts by the horizontal.
partition c, d, which comes nearly down to the surface of the water a, b, when
the top of the plunger is flush with that of the exterior cylinder at A, B. In
this situation suppose the steam to rise; its first effort is to drive a column of
water from that portion of the fluid in the lower part of the cylinder up into
the space between the cylinder and plunger, where it will rise till it over-
flows at A, B. A, a, therefore, which may be of any desired height, is in this
case the regulating column of compression to the steam accumulating under
the plunger, and the steam so compressed will exert a force equal to the
cubical measure of water arising from multiplying the area of the base of the
plunger by A, a, while the length of the stroke is regulated by the position of
the horizontal partition c, d. The steam may be got rid of to allow of the
returning stroke of the plunger either by simple discharge thro' a valve
opened by any common contrivance at the top of the up stroke, and shut at
the bottom of the down stroke, or by condensing it. And this action may be
carried on either by one or by two cylinders on the boiler or attached thereto,
in which latter case a constant power of expansion and condensation may be
produced at the opposite ends of a beam. This reciprocating application of
the principle is equally capable of cheapness and simplicity of construction,
and of facility of movement by the absence of friction, as the rotatory engine
above described; in its simplest form, but in all reciprocating actions there
is a certain loss of power by the perpetual change of direction, which loss is

page_text: avoided in the immediate production of rotatory motion, and which is therefore
a principal reason why a simple rotative engine is so great a desideratum.
Hitherto, however, the rotative engine has appeared to require more difficult
and complex machinery than the reciprocating engine. To dispense with this
therefore has been the great object of the present Invention; and it should
seem that the object cannot possibly be more completely realized than as here
effected by the total absence of all valves, pistons, air pumps, condensers,
stuffing boxes, packing, and the contact of parts, as above described, to which
must be added the great facility of execution.
In witness whereof, I, the said Sir William Congreve, have hereunto
set my hand and seal, this Nineteenth day of April, One thousand
eight hundred and nineteen.
Inrolled the same Nineteenth day of April, in the year above written.