CERTAIN IMPROVEMENTS IN A MACHINE WHICH ACTS BY THE EXPANSION OR CONTRACTION OF THE AIR HEATED BY FIRE, AND WHICH MACHINE IS APPLICABLE TO THE RAISING OP WATER, OR GIVING MOTION TO MILLS OR OTHER MACHINES
Year: 1816

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, PIERRE
FRANCOIS MONTGOLFIER, of Leicester Square, in the County of Middlesex,
Engineer, and LOUIS HENRY DANIEL DAYME, of the same Place, Gentleman,
send greeting.
WHEREAS His most Excellent Majesty King George the Third, did, by
His Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Fourteenth day of
March, in the fifty-sixth year of His reign, give and grant unto us, the said
Pierre Francois Montgolfier and Louis Henry Daniel Dayme, our exors,
admors, and assigns, His especial licence, full power, sole privilege and autho-
rity, that we, the said Pierre Francois Montgolfier and Lewis Henry Daniel
Dayme, our exors, admors, and assigns, should and lawfully might, during
the term of years therein mentioned, make, use, exercise, and vend, within
England, Wales, and the Town of Berwick upon Tweed, and also in all our
Colonies and Plantations abroad, our Invention of "CERTAIN IMPROVEMENTS IN
A MACHINE WHICH ACTS BY THE EXPANSION OR CONTRACTION OF THE AIR HEATED
BY FIRE, AND WHICH MACHINE IS APPLICABLE TO THE RAISING OP WATER, OR GIVING
MOTION TO MILLS OR OTHER MACHINES;" in which said Letters Patent there is
contained a proviso, that if we, the said Pierre Francois Montgolfier and Louis
Henry Daniel Dayme, or one of us, shall not particularly describe and ascertain
the nature of our said Invention, and in what manner the same is to be per-
formed, by an instrument in writing under our hands and seals, or under the
hand and seal of one of us, and cause the same to be inrolled in His Majesty's

page_text: High Court of Chancery within six calendar months next and immediately
after the date of the said Letters Patent, that then the said Letters Patent,
and all liberties and advantages whatsoever thereby granted, shall utterly cease,
determine, and become void, as in and by the same Letters Patent, relation
being thereunto bad, may more fully and at large appear.
NOW KNOW YE, that in compliance of the said proviso, I, the said Pierre
Francois Montgolfier, have executed this instrument, by which I do, for myself
and for the said Louis Henry Daniel Dayme, describe our said Invention in
the following manner :-
The Figures of the Drawing hereunto annexed represent two different
constructions of a machine for raising water by the expansion or contraction
of air heated by fire, which machines are both constructed according to the
improvements which we have invented; but I shall first describe the complete
machine, and afterwards point out the particular parts in which our improve-
ments consist.
1, Figure 1, is the suction pipe, which draws water into the machine. This
water is forced out of the machine, and raised up through the ascending pipe
22, to a cistern or reservoir L placed at the required height; this is done by
the expansive force of air, which is heated by passing through the fire of the
furnace A. The fire is made to burn within a close vessel B, B, and has no
communication with the external air, but it is regularly supplied with fresh air,
which is forced through it in a condensed or compressed state by the pressure
of a column of water entering into the air chamber 3. The said air is in
part consumed to maintain the combustion of the fuel, and the remaining part
becoming expanded by the heat issues from the furnace into the chamber 4,
which is filled with water, and presses therein with sufficient force to drive the
water out of the chamber and cause it to mount up the pipe 2; but before
the action can be completely explained it is necessary to describe the structure
of the machine.
The furnace or fire-place A is formed within a vessel or cylinder B, B,
which is made of metal of sufficient strength, and is lined with fire bricks,
clay, sand, or other substance which will transmit the heat slowly. C is a
conical plug or stopper, to open and give access to the fire; it is held in its
place by a screw D. E is the passage through which the fresh air for the
supply of the fire is made to enter into the fire-place from the air chamber 3;
and F is the passage through which the air passes from the furnace into the
water chamber 4 (after it has been heated) to force the water contained
therein up the pipe 2. The two chambers 3, 4, and the pipe 2 are arranged
in the form of an equilatrial triangle around the cylinder or furnace B, B, as

page_text: united together at the lower
The air chamber 3 is made
and the passage F which
shewn in the plan, Figure 2; they are all three
part by a curved tube of three branches 5, 6, 7.
considerably higher than the water chamber 4,
conveys the air to the fire proceeds from the upper part of the air chamber,
5 and in the passage there is a valve e shutting downwards, to admit the
air to pass away from the air chamber 3 to the fire, but at the same time
to prevent it from returning from the fire to the air chamber. 18 is a
small valve within side the air chamber, which is made light enough to float
upon the water, and it will therefore shut if by accident the water should
rise up to it. 8 is a passage by which fresh air is introduced into the air
chamber; 3 and 9 is a valve to prevent its return; 10 is a valve opening
downwards from the same opening. This valve is made to shut to prevent
the further entrance of air when the desired quantity has passed. To measure
out this quantity of air, a cylinder 11 is placed beneath the valve 10, and a
ball 12, made very light, of cork, or of a bladder sewed up in leather, is placed
in the cylinder 11, so as to rise and fall freely therein. 13 is a piece placed
as a stop to prevent the ball falling out of the cylinder. When there is an
aspiration within the air chamber 3, the air is drawn through the valve 9 from
the cylinder 11; this makes a current of air through the cylinder, which raises
up the ball; but when this ball strikes the lower valve 10 it closes it, and no
more air can enter; the ball then descends slowly by its own weight, because
it is not closely fitted into the cylinder 11, and it rests upon the stop 13, as
shewn by the dotted lines, until another aspiration takes place within the air
chamber 3. It is plain that by regulating the stop 13, so that the ball will
rest at a greater or less height, the quantity of air which enters into the air
chamber each time before the valve 10 shuts can be exactly regulated. The
water chamber 4 has a valve at 14 to introduce the expanded or heated air
into it from the furnace, and on the opposite side a similar valve 15 from
the suction pipe i; both these valves open within side the chamber 4, so as to
prevent the air or water returning through them. In the top of the chamber
4 is a valve 16, which opens upwards to allow the burnt air to pass out of the
machine; and 17 is a valve within side, which has a float, and will be shut by
the water when the surface rises up to the top of the air chamber 4. The
two valves 26, 27, at the top of the pipe 2, are not absolutely essential to the
action of the machine; I shall therefore suppose the machine constructed
without them, and that the top of the pipe 2 turns over with a spout into the
cistern or reservoir L, also that there is a cock in some part of the pipe 2 or 6
to stop it
up and
prevent the descent the water. To explain the action of the
machine, suppose the pipe 1 and 2, and the two chamber 3 and 4, full of

page_text: water, it will shut the valves 14, 15, 17, and 18, and they will prevent it from
entering into the furnace: now shut the cock in the pipe 2 to prevent the
tall column of water therein from communicating with the chamber 3, 4, and
open the valve 17 by pressing down its stem, the water will then flow out
from the water chamber, and as there is a free communication between the
chamber 4 and 3, the surface of the water 3 will descend, and the air will
enter through the valve or passage 8 into the air chamber as fast as the water
flows out at 16. When the surface 3 comes to a level with the top of the
water chamber 4 no more water can flow out at 16, and it will remain
stationary; the part of the air chamber 3 above that level being full of atmo-
spheric air, the floating valve 17 being now left to itself will shut. In this
state of the machine withdraw the plug C by its screw and throw a quantity
of lighted coals or charcoal into the furnace, then replace the plug C and
close it by its screw D, and the machine is ready for action. The motion
is began by opening the cock in pipe 2, and allowing the high colum of
water 6 to enter the chamber 3, 4; the chamber 4 is already full, and can
receive no more water, but the water will rise up in the air chamber 3, and
compress the air therein, so as to drive nearly all of it through the valve e
and passage F into the fire; this will cause the fire to burn very fiercely by the
combustion of a part of the air, and the remaining part will be violently
expanded, and will exert a strong pressure within the furnace; the valve e will
close and prevent the return of the air, it must therefore enter through the
valve 14 into the water chamber 4, and by pressing suddenly upon the surface
of the water contained therein will expell and force it through the branches
6, 7, up the pipe 2 with a considerable velocity. At first the water in the
chamber 3 does not partake of this motion. As the surface of the water
descends in the water chamber 4 the pressure of the air therein must gradually
diminish, because it occupies an increasing space, and also because it is cooled
or contracted by the cold surface of the water chamber; but the rapid motion
given to the water through the pipes 4, 6, 7, and 2, causes it to continue its
motion by what is called its vis inertia even after the pressure of the air in the
water chamber 4 is diminished by its contraction and increased space to less
than the pressure of the atmospheric air. When this takes place there will be
an aspiration within all the parts of the machine, that is, a suction tending to
draw in the atmospheric air, which will, therefore, enter into the machine at
the parts where it finds the most free passage; the interior valve 17 opens,
but the valve 16 inmediately shuts, and prevents the enterance of the atmo-
spheric air by that passage into the water chamber 4. The air chamber 3 is
all this time full or nearly full of water, which has had no part of the motion

page_text: just described; but the aspiration having taken place, the atmospheric air in
the cylinder 11 lifts up the valve 9 and enters through 8 into the air chamber 3,
and bearing on the surface of the water therein, it will move through the
pipe 5, and accompany the motion of the water in the pipe 2, and the air
enters into the top of the chamber 3; this produces a current of air through
the cylinder 11, which raises up the ball 12 till it strikes the valve 10 and
shuts the same, so as to prevent any farther entrance of air, as I have before
described. The drawing in of this air passes almost instantaneously, and the
ascent of the column of water in the pipe 2 still continues by the vis inertia of
the moving column, and the water now sinks in both the chambers 3 and 4,
and increases the space which the air therein occupies, until the portion of air
last introduced into the chamber 3, and the air in the chamber 4 is expanded
or rarified, so that the pressure or elasticity thereof is so far diminished, that
the pressure of the atmospheric air upon the surface of the water in the well
will cause the water to mount up the suction pipe 1, and pour through the
valve 15 into the water chamber. This cold water falling through the air con-
tained in the chamber 4 suddenly cools and contracts the air into a small space,
and still farther diminishes the pressure of the air upon the surface of the water
in the water chamber. The vis inertia given to the column in the pipe 2, by the
sudden expansion of the air being at length expended in rising in opposition
to its own gravity, and in drawing air and water into the chambers 3 and 4, it
begins to return through 7, 6, and 5; as it descends in the pipe 2 it will rise
in both the chambers 3 and 4, and when it has so far risen therein as to
condense the air contained in the two till the elasticity equals that of the
atmosphere, the valve 9 shuts to prevent the air returning out of the air
chamber; the valve 15 shuts and prevents the air in the water chamber 4
going down into the suction pipe 1, and the valve 14 prevents it returning into
the furnace; at the same time the valve 16 opens and allows that air to escape
from the chamber 4, and the water follows it until it reaches the float 17 and
shuts that valve, which prevents any further passage; but as the returning
motion of the column 2 still continues, the whole of its remaining force will
act in the air chamber 3 to condense the air therein; this causes it to blow
through the valve e and passage F into the fire, which it causes it to burn
vividly, and the air becoming suddenly expanded, it will shut the valve e by the
time the greatest portion of the air has entered the furnace, and this prevents
any more air from coming in. The remainder of the air which occupies the
top of the air vessel 3 condenses, and by its elasticity will contribute to cause.
the re-ascent of the column of water in the pipe 2; but the ascent is really
occasioned, as in the first instance, by the expanded air, which passes through

page_text: the valve 14 into the water chamber 4, &c., pressing on the surface of the
water, forces the water to mount again in the pipe 2, and thus the machine
begins to make a second stroke. This second stroke will be similar in its action
to that which I have described, and so the motion of the machine continues.
Every time that a quantity of water is drawn into the machine through the
suction pipe 1, an equal quantity will pass out of the top of the pipe 2 into the
reservoir 4, and it is this quantity alone which will be permanently elavated;
for although a body of water is thrown up in the pipe 2 when the expansion
of the air forces it an equal quantity will return again in the same pipe when
the expansion has ceased, and the contraction takes place; but in the same
instant that a smaller quantity of water is drawn into the machine at the
bottom, an equal quantity is thrown out at the top of the pipe 2, and the
quantity which returns to produce the action of condensing the air will be just
equal to that which was thrown up, and thus the water in the pipes keeps up
a vibration or constant oscellation.
As the description just given of the action of the machine is much interrupted
by explanation, I shall describe the second stroke in more concise language:
The heated air proceeding through the valve 14 presses very suddenly and
forcibly on the water in the chamber 4, and gives it a rapid motion through
6, 7, and the pipe 2. This motion continues after the expansive force of the
air has ceased (from the increased space of the chamber which it occupies, and
by the cooling or contracting of the air), and the motion of the moving water
is sufficiently to increase the space so far as to produce a suction or aspiration
within the whole machine; then as the atmospheric air finds the most free
passage through the valve 9 into the air vessel 3, it will enter therein until the
ball 12 strike the valve 10 and stops it; the aspiration still continuing, it
draws the water up the suction pipe 1 through the valve 15 into the water
chamber 4, and in the same instant the column in the pipe 2 arrives at the top
of the pipe, and a quantity of water flies out at the top into the reservoir L
equal to the quantity drawn in, the water pouring into the water chamber 4
cools and contracts the air therein. The moving force of the column 2 being
at length expended in overcoming its gravity, and in drawing in the air at 3
and the water at 4, it returns, that is, it descends in the pipe 2, and ascends in
the chambers 3 and 4, and compresses the air contained therein until it will
become equally elastic with the atmospheric air. The burned air in the water
chamber 4 then lifts up the valve 16, and makes it escape until it is all gone,
and the water then lifts up the float and shuts the valve 17. As the water
cannot now rise any higher in the water chamber 4, the whole force of the
returning column applies itself to compress the air just before drawn into the

page_text: air chamber 3, and force it into the fire, and being thereby suddenly expanded
it enters through the valve 14, and begins a third stroke, by expelling the water
from the chamber 4 and making it mount up the pipe 2; the motion thus
given to the water produces an aspiration, which first draws the air through 9
into the chamber 3, and then draws fresh water through 15 into the chamber
4, and in the same instant a portion of the water flies out at the top of the
pipe 2. The moving force of the column 2 having expended itself, the column
2 returns, and the water returns into the 2 chambers 3 and 4; from the latter
it expels by the valve 16 the remains of that air which has passed through
the fire, and it draws the air contained in the air chamber 3 into the furnace
to produce another stroke, and thus the action of the machine continues. It is
to be observed that every time when the aspiration takes place the air will be
drawn out of the furnace (or rarified therein), and the fire will be damped or
burn very slowly until the fresh air is forced into the fire from the chamber C
in a compressed state by the enterance of the water into the same. The fire
then burns for a moment with great violence and heats the air, but it will
be damped the next moment by the drawing away of the air when the aspira-
tion takes place. 28 is a small air vessel, placed at the top of the suction pipe
1; its use is to equalize the suction of the water which it is drawn into the
machine very suddenly. This air vessel contains some water with air above
it, which air will expand itself when the aspiration takes place, and the con-
tained water will enter into the machine before the whole water in the pipe 1
is put in motion; but the pressure of the atmospheric on the water of the well
then causes it to rise quietly in the pipe 1 to restore the equilibrium, and
introduce water again into the air vessel ready for the next stroke. To supply
the internal fire with fresh fuel, a cylinder II is placed beneath it, and a piston
G is fitted thereon, with a screw I beneath, to force up the fuel contained in
the cylinder, and make it enter into the furnace. 39 is an opening in the side
of the cylinder II, and the piston G can be lowered down beneath the opening
39, so as to refil the cylinder with fuel, which may be coals, coke, charcoal, or
wood. 25 is another cylinder, fitted with a piston 20; this is to withdraw the
ashes of such parts of the fuel as will not consume; the bottom of this cylinder
is closed by a valve 24, through the center of which the rod 19 passes with a
stuffing box. The valve is kept shut by the action of a number of springs 34,
which are placed in a frame, as is seen in Fig. 3, with a screw 23 to regulate
their pressure. The screw 22, which actuates the rod 19 of the piston, passes
through the screw 23, and is jointed to the end of the rod 19 by a shackle
joint; the upper part of the cylinder 25 is enlarged in one direction to the
form of a tunnel, as shewn in Figure 3, and the piston being raised up into

page_text: that part will allow the ashes to fall into the cylinder; to withdraw them, the
piston is drawn down by its screw and forces the ashes against the valve 24
till it opens and lets them out all round the edge of the valve.
The second machine, represented in Figure 3, has the same principles of
action, but the parts are differently arranged. For the facility of explanation,
the same characters are used for reference as in Figure 1, and I shall only
describe such parts as are different. The furnace A, B, C, is the same as the
former, but the ascending pipe 2 communicates immediately with the water
chamber 4 by an inverted syhon 6, 7, of two branches instead of 3, as in Fig. 1.
The air chamber 3 is placed immediately over the water chamber, the sepa-
ration between the two being made by valves 36, at the same time that there
is a free passage for the water through 37 and 38. 15 is the valve at the top
of the suction pipe, communicating equally with the two chambers 3 and 4.
The Drawing represents the machine at the moment when the air has been
forced through the furnace, and occupies the water chamber 4 in its expanded
state, and by its pressure on the surface 37 holds up the water contained above
in the air chamber 3; but this preserve cannot cause the air in 4 to mount up
through the valves 36, because the air in the space 9, 18, is condensed to an
equal degree of pressure with the air at 4. In the situation of the Drawing,
the expanded air in the water chamber 4 has just given a rapid ascending
motion to the column 6, 7, 2. This motion has continued so far that the aspi-
ration is just on the point of commencing. The first effect of this aspiration
is to cause the water 37 to flow over and pour down into space 4, and this,
producing a cooling and contraction of the expanded air, still further increases
the power of aspiration; the water therefore flows very rapidly down from 3
through the passage 38 and 37 into the water chamber 4, and the atmosphere
air entering at the valve 9 fills the upper part of the air chamber 3 as fast as
the water runs out from it below. When the surface of the water in the
air chamber 3 has descended below the float 12, it descends and shuts the air
valve 10, to prevent the entrance of any more air. As the aspiration still
continues, by the motion of the column 2 and the increasing coldness of the air
in the chamber 4, it draws up water through the suction valve 15, and whilst
this is entering an equal quantity of water is carried out at the top of the
pipe 2 into the reservoir L. When the force of the ascending column 2 is ex-
pended, and it begins to return it rises in the chamber 4, and expels the burnt
air therefrom through the valve 17, which is constructed the same as 16 and
17 in Figure 1; when all the burnt air is driven out, the valve 17 shuts (by
the water), and the water continuing its motion lifts up the valves 36 and
enters up into the air chamber 3, driving before it the air therein contained.

page_text: This air passes through the valve e and passage E into the furnace, where it
feeds the fire and becomes expanded, so as to press again in the water
chamber 4, and produce a repetition of the action just described, viz³, it
drives out the water from the said chamber and gives it a rapid motion up
the pipe 2. The aspiration then takes place, and the water 3 runs down
through 37 and 38, whilst fresh air enters into 3 at 9, until the float 12
falls and shuts the valve 10. The continuance of the aspiration next draws
up fresh water through 1 and 15, and an equal quantity passes out of the
pipe 2 at top. The motion being thus expended, the column returns into
the water chamber 4, from which it first expels the burnt air by the valve 17,
and when it has touched and shut that valve, the whole descending force
applies itself to rise through the valves 36 and enter the air chamber 3, from
which it drives the air through e, E, into the fire, and this repeats the stroke.
The principal difference of this machine from the former is, that the air
chamber 3, being placed immediately above the water chamber 4, the water
of the former, when it quits its place to admit the fresh air by the valve 9,
pours down into the chamber 4, and cools or contracts the air contained
therein, so as to make the aspiration which is to draw up the water through
the pipe 1 more sudden and complete. The valves 26 and 27 at the top of the
pipe 2, are to cause a momentary resistance to the ascending motion of the
column of water in the first instance, in order that the air thrown into the fire
may have time to become heated, and to pass into the water chamber 4 in
its full force before the water shall be driven out from it. For this purpose
the top of the pipe 2, Figure 1, is formed conical, and a plug or valve 26 is
fitted into it, which is packed round with hemp, and by its weight in falling
is made to jamb or stick fast into the cone. The moving force of the column of
water rising in the pipe 2 must be sufficient to dislodge this cone before the
motion can take place; the water is then thrown out at top, and falls over
into the reservoir L. When the return of the column takes place, the plug
26 drops into its place and shuts the passage, but at the same time the
valve 27 opens, and allows the water to return down the pipe 2 without any
obstruction. The valves 26, 27, Figure 3, produce the same effect, but in a
different manner. Both these valves shut in opposite directions against the
end of a cylinder 29, which is fitted in a leather collar 30 so as to be move-
able; and the motion is regulated by a rod 31 passing through a stuffing box,
and connected with a crank 32 and a small fly wheel 33. The interior valve
27 is made light to float on the water, but the height to which it can rise is
determined by a small chain, as is also the degree of descent which is per-
mitted to the external valve 36. By this means, when the cylinder 29 is raised

page_text: as high as the crank will admit, the upper valve 26 will close by its weight
on the contrary, when the cylinder is depressed as low as its crank 32 admits
the lower valve 27 will shut by its buoyancy. Suppose all the parts in the
situation of the Figure; if the pressure of the air in the chamber 4 causes
the column in the pipe 2 to rise, it will shut the valve 27, which will prevent
the passage, but the whole force being thus stopped by the valve 27, it lifts
up the cylinder, against which it bears. The motion of the cylinder is opposed
by the fly wheel 33, upon the axis of the crank 32, which fly wheel retards
the ascent, because it must be put in motion to allow the cylinder to rise, but
being once put in motion, the fly wheel by its momentum will force up the
cylinder still higher than the valve 27 can follow it, on account of the chain
before mentioned. The consequence is, that the passage will be opened, and
the water will then flow out freely, although for a moment it was resisted with
all the force necessary to put the fly in motion. In the same manner, when
the column returns the valves 26 falls and stops the passage, but the pressure
of the atmosphere being thus made to bear upon the valve, it presses down its
seat, which is the cylinder; this motion turns back the fly wheel, which carries
the cylinder down still lower than the valve 26 can follow it. This opens the
passage to allow the return of the column of water, and puts the apparatus in
the state represented, ready for another stroke. The fly wheel must have proper
stops to limit its motion as it is requisite. The construction and arrangement
of the different parts of the machine may be very much varied without
altering its principle or manner of action; the valves are represented in the
Drawings as if attached and fitted to conical plugs of metal, which can be
withdrawn to repair or examine them when necessary. When our said machine
is applied for turning mills or other machines, the water which it elevates must
be made to fall on a water wheel or other machine fit to produce circular
motion by a fall of water.
Having now explained the complete machine, 1 do hereby declare that we
do not make claim to the Invention of the furnace with an interior fire, nor
to such parts of the machine as are marked with the letters of the alphabet in
the Drawings, the same having been practiced before by Sir George Cayley;
but our improvements are, the air and water chambers, and other parts marked
in the Drawings by the numerals or figures, by means of which parts we can
apply expansive force of the air which has passed through the fire of such a s
furnace and become heated. This, in conjunction with the subsequent con-
traction of the air, produces the oscillation of a column of water, which in its
ascent draws in a quantity of air and of water, and throws up a small
quantity into the reservoir; also in its return or descent, the same column

page_text: compresses and drives into the furnace the proper quantity of air to produce
another stroke, in the manner heretofore explained.
In witness whereof, I, the said Pierre Francois Montgolfies, have here-
unto set my hand and seal, this Thirteenth day of September, in the
year of our Lord One thousand eight hundred and sixteen.
PIERRE FRANCOIS (L.s.) MONTGOLFIER.
AND BE IT REMEMBERED, that on the Thirteenth day of September,
in the year of our Lord 1816, the aforesaid Pierre Francois Montgolfier
(through the interpretation of John Farey), 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 the Specification aforesaid was stamped, according to the tenor of the
Statute made for that purpose.
Inrolled the Fourteenth day of September, in the year of our Lord One