IMPROVEMENTS IN ENGINES WORKED BY MEANS OF HEATED AIR OR GASES AND STEAM, PART OF WHICH INVENTION IS ALSO APPLICABLE TO COMPRESSING AIR AND AERIPORM FLUIDS
Year: 1864

page_text: LETTERS PATENT to Matthew Piers Watt Boulton, of Tew Park, Oxford-
shire, for the Invention of "IMPROVEMENTS IN ENGINES WORKED BY MEANS
OF HEATED AIR OR GASES AND STEAM, PART OF WHICH INVENTION IS ALSO
APPLICABLE TO COMPRESSING AIR AND AERIPORM FLUIDS."
Sealed the 15th November 1864, and dated the 24th May 1864.
PROVISIONAL SPECIFICATION left by the said Matthew Piers Watt
Boulton at the Office of the Commissioners of Patents, with his
Petition, on the 24th May 1864.
I, MATTHEW PIERS WATT BOULTON, of Tew Park, Oxfordshire, do hereby
declare the nature of the Invention for "IMPROVEMENTS IN ENGINES WORKED
BY MEANS OF HEATED AIR OR GASES AND STEAM, PART OF WHICH INVENTION IS
ALSO APPLICABLE TO COMPRESSING AIR AND AERIFORM FLUIDS," to be as follows:-
This Invention has for its object improvements in engines worked by
means of heated air or gases and steam, part of which Invention is also
applicable to compressing air and aeriform fluids. A combustion chamber is
employed in which inflammable gas, inflammable vapor, or other fuel is burnt
the heat generated by this combustion imparting an expansive force to the
gases or aeriform matter in the chamber, and producing great pressure. A
Price 8d3

page_text: boiler is also employed, in which water is heated and steam generated. The
heated gases and vapours which issue from the combustion chamber unite
with the steam from the boiler in a receiver, or they may do so in the upper
part of the boiler; whence passing onwards they are employed to work an
engine or perform useful work, either by moving a piston in a cylinder or in
any other manner. After the performance of this work they still retain a
considerable degree of heat, and this is utilized by employing them to heat
water in the boiler previously mentioned. A portion of them is also employed
to generate inflammable vapour, such as vapour of petroleum, naphtha, or oils,
when this is made use of as fuel in the combustion chamber. The gas, vapor,
or other fuel and the air needed for combustion may be forced into the com-
bustion chamber at a high pressure; or otherwise inflammable gas or vapor
and air in due proportions may be introduced into the combustion chamber
at a pressure little different from that of the atmosphere, and communication
between this chamber and the atmosphere being then closed and combustion
being caused to take place, the ueriform matter heated and expanded by the
combustion may be forced, in virtue of this expansion, into a vessel at a high
pressure, return from this vessel being prevented by a valve, and several
combustion chambers may be employed.
When air is forced into the combustion chamber by means of a force pump
or forcing apparatus, the engine is started by means of the steam generated
in the boiler which works the force pump or forcing apparatus, and thus
enables combustion to take place in the combustion chamber under pressure.
The inflammable gas or vapor is readily introduced into the combustion
chamber by means of the pressure developed in the vessels in which it is
generated. After entering the combustion chamber, the passage through
which it passes may be so formed that the gas or vapor shall gradually draw
in air through suitable orifices until a nearly explosive mixture is formed.
which mixture on issuing into the air in the chamber is ignited. Other things
remaining the same as above; the aeriform fluids which issue from the com-
bustion chamber may be kept apart from the steam generated in the boiler,
and each may be employed separately to work an engine or perform
mechanical work. In this case, as in thepreceding, the aeriform fluids heated
in the combustion chamber, after performing work in the manner desired, are
employed to heat the water in the boiler, and when inflammable vapour is
used, to generate this, and the steam generated in the boiler plays the same
part in this as in the preceding case in starting the engine. It may also be
employed to generate inflammable vapour where the boiling point of the
liquid whose vapour is used is below that of water. The air needed for com-

page_text: bustion may be forced into the combustion chamber by a force pump, but it
may otherwise be forced into it by the action of liquid set in motion by a
blast of steam or aeriform matter, the liquid thus set in motion acting on the
principle of the Montgolfier ram; in this case the ram requires to be modified
so as to become an instrument for forcing air instead of forcing water.
In the Montgolfier ram, as at present constructed, some air is forced into
the air vessel at each stroke, this air being admitted into the tube between
the air vessel and the main pipe, when the flow of water through the main
pipe takes place by means of a valve opening inwards called the "snifting
valve." If this valve be increased in size more air will be admitted by it, and
more air and less water will be forced by the ram at each stroke into the
further vessel, and by properly adjusting the size of the parts, air alone will
be forced by the ram at each stroke into the further vessel. A float may be
employed, which when the water sinks to a certain point in the tube or
chamber by which air is admitted, closes the communication between that
chamber and the main pipe. As it may be difficult so to adjust the parts as
to prevent the entrance of some water into the further vessel the adjustment
may be so made that the ram at each stroke shall force into the further vessel
a considerable quantity of air and a small quantity of water, and a ball or float
floating on the water in this vessel may regulate its level in the usual way, so
that when its level reaches a certain point, a valve is opened and further rise
of water prevented. A ram constructed in this manner for the purpose of
forcing air or aeriform fluids may be worked by a current of water or liquid,
however that current be set in motion.
In all engines worked by heated air or aeriform fluids it is desirable that
the temperature of the aeriform matter employed should be very high, the
heat in this case acting to greater advantage. On the other hand there is
difficulty in working a piston in a cylinder by means of highly heated gases,
the tallow, oil, or other matters employed for the purpose of lubrication being
speedily dissipated by the heat. To obviate this difficulty, I propose that
between the central portion of the piston and a disc or plate attached to the
piston rod above a considerable quantity of oil or other liquid should be
carried. The vapour generated when this liquid comes in contact with the
heated sides of the cylinder passes through a tube in the piston rod or in
some other rod connected with the piston, and may be utilized either by being
condensed or by being carried to the combustion chamber and burnt, or
otherwise this vapor may pass away as waste into the upper portion of the
cylinder. This liquid is supplied through a tube in the piston rod, or in some
rod connected with the piston.

page_text: Below the central portion of the piston rod there may be a similar chamber,
into which liquid is introduced and from which the vapour is conducted in a
similar manner; thus in whichever direction the piston moves it will move
over a lubricated surface.
In the external portions of the piston, between the heated gases and the
liquid, substances which impede the passage of heat may be employed. The
valves employed in contact with the heated gases may be constructed in a similar
manner; such valves may either slide or revolve.
In order that heated air may be advantageously employed as a motive
power, great heat and pressure must be developed in the combustion chamber
and the vessels communicating with it, and it is necessary, therefore, that these
should be so constructed as to be capable of resisting this. For this purpose
they may be made inside of fire-brick or any other material suited to obstruct
the passage and resist the action of heat, and on the outside of strong metal,
and they may consist of many chambers.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Matthew Piers Watt Boulton in the Great Seal Patent
Office on the 23rd November 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MATTHEW
PIERS WATT BOULTON, of Tew Park, Oxfordshire, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of May, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-seventh year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Matthew Piers Watt Boulton, Her special licence that I,
the said Matthew Piers Watt Boulton, my executors, administrators, and
assigns, or such others as I, the said Matthew Piers Watt Boulton, my
executors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN ENGINES WORKED
BY MEANS OF HEATED AIR OR GASES AND STEAM, PART OF WHICH INVENTION IS
ALSO APPLICABLE TO COMPRESSING AIR AND AERIFORK FLUIDS," upon the condition
(amongst others) that I, the said Matthew Piers Watt Boulton, my execu-
tors or administrators, by an instrument in writing under my, or their,

page_text: or one of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Matthew Piers Watt Boulton, do
hereby declare the nature of the said Invention, and in what manner the
same is to be performed to be particularly described and ascertained in and
by the following statement thereof, that is to say):--
This Invention has for its object improvements in engines worked by means
of heated air or gases and steam, part of which Invention is also applicable to
compressing air and aeriform fluids. A combustion chamber is employed in
which inflammable gas, inflammable vapour, or other fuel is burnt, the heat
generated by this combustion imparting an expansive force to the gases or
aeriform matter in the chamber, and producing great pressure. A boiler is
also employed in which water is heated and steam generated. The heated
gases and vapours which issue from the combustion chamber unite with the
steam from the boiler in a receiver, or they may do so in the upper part of
the boiler, whence passing onwards they are employed to work an engine or
perform useful work either by moving a piston in a cylinder or in any other
manner. After the performance of this work they still retain a considerable
degree of heat, and this is utilized by employing them to heat water in the
boiler previously mentioned. A portion of them is also employed to generate
inflammable vapour, such as vapour of petroleum, naphtha, or oils, when this
is made use of as fuel in the combustion chamber.
The air is forced into the combustion chamber by means of a force pump
or forcing apparatus, and the engine is started by means of the steam
generated in the boiler, which works the force pump or forcing apparatus,
and thus enables combustion to take place in the combustion chamber under
pressure. The inflammable gas or vapour is readily introduced into the
combustion chamber by means of the pressure developed in the vessels in
which it is generated. After entering the combustion chamber the passage
through which it passes may be so formed that the gas or vapour shall
gradually draw in air through suitable orifices untila nearly explosive mixture
is formed, which mixture ou becoming mixed with a further portion of air is
ignited. Or the air may enter through such a passage and become mixed in
a similar manner with the inflammable gas or vapour.
In Figure 1, B represents a boiler, in which petroleum or any other liquid
whose vapour is inflammable is evaporated. The inflammable vapour passes

page_text: along the pipe 6 into the chamber A, where it is mixed with a suitable quan-
tity of air and burnt. Air is forced into this chamber through the pipe E by
meaus of a force pump worked by the engine, or by some other fercing appa-
ratus. C is a boiler in which water is heated and steam generated. The
steam issuing from this boiler unites with the licated products of combustion
issuing from the chamber A, and both pass onward through the pipe D.
Passing through this they are employed to work a piston in a cylinder, just as
steam does in an ordinary steam engine, or they may be employed to perform
work in any other manner, as by working a turbine or wheel. After they
have performed this work they, as before mentioned, still retain a considerable
degree of heat, and this is utilized by employing them to heat the water in
the boiler C; F represents the pipe or flue through which they pass for this
purpose; a portion of them may also be employed to heat the liquid in the
boiler B. Other heat besides that of the mixed steam and gases may be
employed to heat the water in the boiler C, especially for the purpose of
starting the engine.
In the Drawing I have represented the boiler C as distinct from the com-
bustion chamber A, but the chamber A. or a portion of it, may be placed
inside the boiler C, so as to communicate heat through its sides to the water
contained in that boiler. The heat of the gases in the interior of the com-
bustion chamber may be reduced to any desired degree by the injection of
steam from the boiler. Instead of inflammable vapour, such as vapour of
petroleum, inflammable, gas, such as coal gas, may be employed, in the manner
described. Figure 2 represents the mode of mixing the inflammable vapour
or gas with air.
A is the combustion chamber supplied with air through the passages E, E.
The inflammable vapour or gas enters through the pipe B, and passing
onwards through C draws in air through the orifices D, D, so as to make a
nearly inflammable mixture, as in a Bunsen's gas burner. This mixture on
issuing from the pipe C is ignited at F. Other things remaining the same as
above, the aeriform fluids which issue from the combustion chamber may be
kept apart from the steam generated in the boiler, and each may be employed
separately to work a piston in a cylinder, or otherwise perform mechanical
work. In this case, as in the preceding, the aeriform fluids heated in the
combustion chamber after performing work in the manner desired are em-
ployed to heat the water in the boiler, and when inflammable vapour is used
to generate this vapour. And the steam generated in the boiler plays the
same part in this case as in the preceding case in starting the engine. It
may also be employed to generate inflammable vapour where the boiling point

page_text: of the liquid whose vapour is used is below that of water. It is to be
observed that by raising sufficiently the pressure in the combustion chamber,
which pressure is arbitrary, the heat of the acriform fluid might be so reduced
by expansion during the performance of work, that there would be no
advantage in employing it subsequently to generate steam, and that all the
mechanical effect obtained might be obtained by the use of one apparatus.
But on the other hand the very high pressure needed in this case in the
combustion chamber, and the great range of expansion while the aeriform
fluid is performing work, are both attended with practical inconvenience.
There is therefore advantage on some accounts in employing the aeriform
fluid to perform two operations, utilizing the higher portion of its temperature
in an air engine at such a pressure that only a portion of the available
mechanical effect of the heat is utilized therein, and employing the reduced
heat with which the aeriform fluid issues from the air engine to produce
steain or other vapour working a separate piston in a cylinder, or performing
work in other ways. The air needed for combustion may be forced into the
combustion chamber by a force pump, but it may otherwise be forced into it
by the action of liquid set in motion by a blast of steam or aeriform matter,
the liquid thus set in motion acting on the principle of the Montgolfier ram.
In this case the ram requires to be modified so as to become an instrument
for forcing air instead of forcing water.
In the Montgolfier ram as at present constructed some air is forced into the
air vessel at each stroke, this air being admitted into the tube between the
air vessel and the main pipe when the flow of water through the main pipe
takes place by means of a valve opening inwards called the "snifting valve."
If this valve be increased in size, more air will be admitted by it, and more
air and less water will be forced by the ram at each stroke into the further
vessel. And by properly adjusting the size of the parts, air alone will be forced
by the ram at each stroke into the further vessel. A float may be employed
which when the water sinks to a certain point in the tube or chamber
by which air is admitted, closes the communication between that chamber
and the main pipe. As it may be difficult so to adjust the parts as to prevent
the entrance of some water into the further vessel, the adjustment may be so
made that the ram at each stroke shall force into the further vessel a consider-
able quantity of air and a small quantity of water, and a ball or float floating
on the water in this vessel may regulate its level in the usual way, so that
when its level reaches a certain point a valve is opened and further rise of
water prevented.
This arrangement is shewn at Figure 3. A represents the main pipe of the

page_text: ram leading to the head or reservoir, through which pipe the flow of water takes
place. When the flow of water is checked in this by the action of the valve
at its outlet the water is forced upwards through the vessel or tube B driving
the air contained in that vessel through the valve V¹ into the chamber C.
When the valve of the main pipe is again opened, and the flow of water again
takes place, the water in the vessel B falls back into the pipe A, while the
valve V2 opens inwards, and allows air to enter the vessel B. On the valve of
the main pipe being again stopped this air is again driven upwards into the
vessel C, and so on at each stroke. As it would be difficult so to adjust the
parts that the water at each stroke should exactly fill the vessel B, a portion
of water is allowed at each stroke to enter the vessel C, and inside this vessel
there is a pipe with a stop-cock or valve worked in the usual manner by a
float 1), so that when the water has attained a certain level in the vessel C the
pipe is opened and the excess of water being discharged through this the level
of the water can rise no higher; E is a float which prevents commixture of
the air and water in the chamber B, and which when at its lowest point closes
communication between that chamber and the pipe A. A diaphragm of leather,
india-rubber, or other similar substance might be employed for the same
purpose. A ram constructed in this manner for the purpose of forcing air or
aeriform fluids may be worked by a current of water or liquid, however that
current be set in motion. An apparatus of this description may be of use
where water-power is employed to work machinery by compressed air in coal
mines, tunnels, and similar situations.
In all engines worked by heated air or aeriform fluids it is desirable that
the temperature of the aeriform matter employed should be very high, the
heat in this case acting to greater advantage. On the other hand, there is
difficulty in working a piston in a cylinder by means of highly heated gases,
the tallow, oil, or other matters employed for the purpose of lubrication being
'speedily dissipated by the heat. To obviate this difficulty I propose that
between the central portion of the pistou and a disc or plate attached and
the piston rod above a considerable quantity of oil or other liquid should
be carried. The vapour generated when this liquid comes in contact with the
heated sides of the cylinder passes through a tube in the piston rod, or in some
other rod connected with the piston, and may be utilized either by being con-
densed or by being carried to the combustion chamber and burnt. Or other-
wise this vapour may pass away as waste into the upper portion of the cylinder.
This liquid is supplied through a tube in the piston rod or in some rod con-
nected with the piston. Below the central portion of the piston rod there
may be a similar chamber into which liquid is introduced, and from which

page_text: the vapour is conducted in a similar manner. Thus, in whichever direction
the piston moves, it will move over a lubricated surface, and the liquid in the
chambers by its contact with the cylinder will tend to keep the parts air-tight.
In the external portions of the piston, between the heated gases and the liquid,
substances which impede the passage of heat may be employed.
The valves employed in contact with the heated gases may l be constructed
in a similar manner; such valves may either slide or revolve.
Figure 4 represents the piston thus arranged. P is the central part of the
piston working air-tight in the cylinder. Above and below this are two
chambers A and B, separated from the heated gases by the bodies C and D),
which may partly be composed of inaterials that are bad conductors of heat.
In these chambers is a considerable body of liquid supplied through the piston
rod or through some rod attached to the piston.
Any vapour generated from this liquid may, as before-mentioned, be dis-
charged as waste into the cylinder, or passing through a tube in the piston
rod or some other rod attached to the piston, it may be utilized. When steam
is used the liquid employed may be one whose boiling point is higher than
the temperature of the steam. Metals and metallic compounds in a state of
fusion and the hydrocarbons obtained by subjecting petroleum and other
substances to a high heat may be used for this purpose.
Figure 5 represents a valve arranged in a similar manner. A is the body
of the valve; B, B, liquid on both sides of the valve; C, the channel through
which, when the valve is open, the heated aeriform fluid passes from the
passage E to the passage F; D is a space into which this fluid has free access,
and it thus presses equally both on the upper and lower sides of the valve.
Figure 6 represents another valve, C being the passage; B, B, the
chambers containing liquid.
In order that heated air may be advantageously employed as a motive-
power, great heat and pressure must be developed in the combustion
chamber and the vessels communicating with it, and it is necessary there-
fore that these should be so constructed as to be capable of resisting this.
For this purpose they may be made inside of fire-brick, or any other mate-
rial suited to obstruct the passage and resist the action of heat, and on the out-
side of strong metal, and they may consist of many chambers.
Having thus described the nature of my said Inveation, and the manner of
performing the same, I would have it understood what I claim is,-
First, the combined employment of products of combustion and steam in the
manner described for the production of motive power.

page_text: Second, the modification of the Montgolfier ram so as to make it an instru-
ment for compressing air or æeriform fluid.
Third, the construction of piston and valves as described.
In witness whereof, I, the said Matthew Piers Watt Boulton, have
hereunto set my hand and seal, this Eighteenth day of November,
in the year of our Lord One thousand eight hundred and sixty-
four.
MATTHEW PIERS WATT BOULTON. (1..8.)