AN IMPROVEMENT IN THE MAKING AND MANUFACTURING OF STEAM ENGINES
Year: 1821

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, AARON
MANBY, of Horsley, near Tipton, in the County of Stafford, Iron Master, send
greeting.
WHEREAS His presents Majesty King George the Fourth, in and by His
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Ninth day of May last, for Himself, His heirs and successors, did
give and grant unto me, the said Aaron Manby, my exors, admors, and
assigns, His special licence, full power, sole priviledge and authority, that I, the
said Aaron Manby, my exors, adññors, and assigns, and every of them, by
myself and themselves, or by my and their deputy and deputies, servants or
agents, or such others as I, the said Aaron Manby, my exors, adññiors, or assigns,
should 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, my
Invention of "AN IMPROVEMENT IN THE MAKING AND MANUFACTURING OF STEAM
ENGINES;" in which said Letters Patent there is contained a proviso obliging
me, the said Aaron Manby, 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 two calendar
months next and immediately after the date of the said recited Letters Patent,
as in and by the same, reference being thereto had, will more fully appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Aaron Manby, do hereby declare that the following is a correct and accurate

page_text: description and Specification of my said improvement in steam engines of the
common construction:
The cylinder is fixed immoveably in a vertical position, and the piston rod
In order to convert this alter-
moves in a direction perpendicular to its axis.
nating into a rotary motion, a continuation of rods, well known by the name of
the parallel motion, is attached to the end of the piston rod, and likewise con-
nected with one end of a lever suspended by its centre of gravity. To the
other end of this beam is attached a crank, which sets in motion the main
shaft of the machinery. This complication of means to produce a rotatory motion
occasions the loss of much power, and adds considerably to the weight and
expence of the engine. In order to overcome these inconveniences many
attempts have been made to produce a direct rotatory motion by the revolution
of the piston in a curvelinear receptacle, but with limited success, in conse-
quence of the increase of friction.
The engine which I have invented produces a rotatory motion by the direct
connexion of the piston rod with a crank attached to the main shaft, without
the intervention of the parallel motion or the beam.. In order to accomplish
this, I employ a cylinder, such as is commonly made use of, and, instead of
fixing it in a vertical position, it is hung on two centres, one on each side of the
cylinder, which allow it to oscillate freely; perpendicular to those points of
suspension a horizontal crank shaft is placed, and to this crank the end of the
piston rod is coupled. By this arrangement the end of the piston rod attached
to the crank revolves about the shaft, and at the same time causes the cylinder
to oscillate on its centres, so that the action of the piston is constantly in the
direction of the axis of the cylinder. In this manner the piston rod and
cylinder describe in their motion the sides of a triangle, the apex of which is
the centre of motion or points of suspension of the cylinder, and the base the
diameter of the circle described by the revolution of the crank. In engines
of the common construction the steam and eduction valves are worked by con-
necting gear, which are generally set in motion by an eccentric from the
fly wheel shaft, or by the rod of the hot-water pump. This method of working
the valves is complicated, increases the friction, and adds considerably to the
expence of the engine.
In the engine which I have invented the whole of this valve gear is
rendered unnecessary, as the oscillation of the cylinder opens and shuts the
slide valves attached to it without any machinery, as will hereafter be more
particularly described in reference to the Drawings hereunto annexed.
.
Another important advantage of this engine is, that by means of a cock the
motion of the engine may at any time be reversed, a property which renders it

page_text: very applicable to the propelling of vessels, the working of mines, and to all
operations of an alternate description. I construct engines of this description,
which I call the oscillating steam engine," of any given power, with only
one cylinder; but in most cases I prefer the use of two cylinders, working with
quarter cranks, in order to equalise the rotatory motion of the shaft, and render.
a fly wheel of large dimensions unnecessary. In cases where the required
power is very great, I employ three or more cylinders, all attached to the same
crank shaft, by which means the weight of the engine is reduced; and when
the power required is variable, any number of the cylinders may be uncoupled.
without interfering with the working of the rest. By this means you may
have a large or a small engine in action at will.
The second part of my Invention consists in a method of generating the
steam, by which a considerable saving of fuel is effected, and steam at a high
pressure may be used without the possibility of danger. In situations where
water and fuel are scarce, various modifications of the steam engine, known
under the name of high-pressure engines, have been employed, but in conse-
quence of the numerous accidents arising from the explosion of their boilers
their use has of late been gradually on the decline. The danger of vessels of
this description is. entirely owing to their being exposed to the direct action
of the fire, and to the large quantity of water which they contain. It is well
known that vessels of a moderate capacity may be so constructed as to bear
with safety a much greater degree of compression than is ever required for the
working of a steam engine, and that it is only by being subjected to the long-
continued action of the fire, and of the impurities contained in the coal, that
they are at last so weakened as to become highly dangerous. It has been
attempted to remedy this by reducing the size of the boiler, so that, in case of
explosion, the small quantity of water it contains is incapable of. doing great
injury; but, in reducing the size of the boiler, the surface exposed to the
action of the fire is at the same time diminished, which occasions a great waste
of fuel.
My Invention consists of a method by which the quantity of water in the.
steam boiler may be reduced to any extent, and at the same time the heated
surface from which the steam is generated be increased, without exposing the
steam boiler to the action of the fire, so that it is subject to no wear, or conse-
quent danger of explosion. This I accomplish by applying the heat to an
intermediate substance, and employing it as the means of generating the steam.
It is well known, as a property of fixed oils and fatty matters, that they are
capable, of being raised to a temperature far exceeding that of boiling. water

page_text: without undergoing decomposition, but it has never been taken advantage of in
the construction of steam engines.
The apparatus which I employ for generating steam on this principle con-
sists of an oblong vessel of wrought iron, similar to the boiler of a steam
engine, set in brickwork, with a fire under it of a moderate size. The dimen-
sions of this vessel depend on the quantity of steam to be produced, but the
greater the surface exposed to the action of the fire the greater will be the
economy of fuel. In this vessel I put about twelve inches in depth of oil, and
raise it to the temperature of about three hundred degrees of Fahrenheit.
The steam boiler consists of a cylinder of wrought iron, nearly filled with cast-
iron tubes, through which the oil, heated as described, is made to circulate by
the action of a pump, and these tubes being surrounded by the water
in the cylinder the heat is absorbed from the oil in its passage through
them, and the water, is rapidly converted into steam.
In this manner, by
regulating the heat at which the oil is worked, the degree of pressure in the
steam vessel is completely under controul, and it is obvious that by enlarging
the surface of the tube in the steam cylinder any degree of rapidity may be
given to the generation of the steam. By this Invention it is impossible that
any danger can arise from the explosion of high-pressure boilers. They are
subject to no wear; and as the surface of the oil vessel exposed to the action
of the fire is not limited, a considerable saving of fuel is effected, and this appa-
ratus is equally applicable to the generation of steam for engines working at a
low pressure, and for every other purpose.
This is a general description of my Invention; but, in order that it may be
more fully understood, it is more particularly explained in the Drawings here-
unto annexed, and references thereto.
Figure I. is a longitudinal section of the oscillating engine constructed as a
condensing engine, with two cylinders; but the same may be employed
as a high-pressure engine, by removing the condenser and air pump. A, A, are
the cylinders; B, B, B, B, are the pivots by which the cylinders are suspended,
and upon which they oscillate; C, C, are the pistons; D, D, are the piston rods;
E, E, the cranks to which the piston rods are coupled, and by the revolution of
which the rotatory motion is produced; F, F, are the steam passages connected
with the boiler; G, G, are two quarter or four-way cocks, by turning which
the steam passage is converted into the condensing, and the condensing into
the steamway, by which means the motion of the engine is reversed; H, H,
are the passages from the cylinders into the air pump; I, is the air pump;
K, the air pump shears and rod, and L, the air pump crank; M, M, M, the

page_text: main shaft, from which the power of the engine may be taken in the usual
manner; N, N, N, N, are the pillars which support the engine..
Figure II. is a ground plan of the engine. A, A, are the cylinders; B, B,
the pivots which support the cylinders; G, G, the quarter cocks; C, C, C, the
steam passages; D, D, D, the openings into the condensers, which are alter-
nately the steam ways and condensing passages, by the turning of the quarter
cock G; P is the condenser; 0, 0, 0, 0, are the frames which join tlie
pillars N, N, N.
Figure III. is a cross section of the engine, in order to shew the nature of
the valves. A is the cylinder; B, the centre on which it oscillates; F, F, F, F,
is a flat plate of brass, ground plane, upon which another brass plane moves, so
that, by the oscillation of the cylinder, the passages C, C, are alternately opened
and shut, in order to admit the steam. This motion is performed without any
hand gear or connecting rods, simply by the oscillation of .the cylinder, so that
the power lost by the friction of these parts is entirely saved.
D is the cap
which connects the piston rod with the crank. The dotted line E, E, repre-
sents the motion of the crank round the shaft M, by which the rotatory motion
is produced. N, N, are the pillars which support the engine. O is the cross
frame which supports the whole.
Figure IV. is the reverse of the plate F, F, Laving two openings for steam
and two openings for condensing.
Figure V. is a slide valve, which may be used instead of the cocks G, G, of
which F is the steam pipe; H, the exhausting pipe; D, C, are alternately
steam and condensing pipes, according as the valve Q is moved.
Figure VI. is the transverse section of the same.
Figure VII. is the plan of the same.
Figure VIII. is a longitudinal section of the apparatus for generating steam
by the circulation of beated oil. A, A, A, is the vessel in which the oil is
heated. The dotted line B, B, represents the level of the oil. The fire
is applied under it in the usual manner. C is a pump constructed so as to be
worked by hand, or by the power of the steam engine; D is the suction pipe
of the pump which dips under the surface of oil to within two inches of the
bottom; E, F, E, is the steam boiler; F, F, F, the pipes contained in it,
through which the oil circulates by the motion of the pump, and returns back
to the oil vessel by the pipe G; H is the steam pipe; I, the pipe by which
the boiler is fed with water in the usual manner; K, a safety valve; L. L, are
columns for supporting the boiler E; they are connected to a frame which rests
on the brickwork of the oil vessel A; M, the manhole of the oil vessel; N, A,
small tube for allowing any aquacous vapour to escape from the oil. This tube

page_text: is carried through the roof into the open air. O is a thermometer for ascer-
taining the heat of the oil. It is obvious from this description that if the oil in
A be heated to a temperature of three hundred degrees Fahrenheit, and the
pump C be worked, that this heated oil will be raised by the suction pipe D,
and forced through the pipes F, and return to the other end of the oil vessel by
the exit pipe G; the pipe F being surrounded by the water in the steam
boiler E, it will be heated with a greater or less degree of rapidity according to
the length of pipe and quantity of oil circulated through it. This Figure
represents the boiler E with only one series of pipe, but the number may be
increased to as great an extent as the boiler will contain, when a very rapid
production of steam is necessary; the formation of steam depending entirely on
the circulation of oil, it is necessary that the pump should be worked before the
steam can be raised. For this reason the pump is fitted up with hand gear,
by which it is worked until the engine. is set in motion, after which it is kept at
work by the power of the latter.
In witness whereof, I have hereunto set my hand and seal, this Fifth day
of July, in the year of our Lord One thousand eight hundred and
twenty-one.

page_text: AND BE IT REMEMBERED, that on the Fifth day of July, in the year
of our Lord 1821, the aforesaid Aaron Manby came before our said Lord
the King in His Chancery, and acknowledged the Specification aforesaid, and
all and every thing therein contained and specified, in form above written.
AND ALSO BE IT REMEMBERED, that on the Seventh day of July, in
the year of our Lord 1821, the aforesaid Aaron Manby came before our said
Lord the King in His Chancery, and acknowledged the Specification aforesaid,
and all and every thing therein contained and specified, in form above written
(the word " degrees" having first been inserted between the forty-third and
forty-fourth lines from the top, and between the sixth and seventh lines from
the bottom). And also the Specification aforesaid was stampt according to the
tenor of the Statute made for that purpose.
Inrolled the Ninth day of July, in the year of our Lord One thousand
eight hundred and twenty-one.