Improvements in Balloon Flying Machines or Aërodromes.
Year: 1895

page_text: Date of Application, 14th Oct., 1895
Complete Specification Left, 13th Aug., 1896-Accepted, 19th Sept., 1896
PROVISIONAL SPECIFICATION.
Improvements in Balloon Flying Machines or Aërodromes.
1, HENRY MIDDLETON of 3, Wellesley Villas, Wellington Street, Slough, in
the County of Buckingham, a Civil, Mechanical and Electrical Engineer do
hereby declare the nature of this invention to be as follows:-
According to this invention I employ two gas vessels of a spherical, cylindrical
or other convenient shape, to more or less support a winged motor, or flying-
machine. The general arrangement of these "balloons" and their attached
flying-machine is similar to that described in my Specification No. 4645
of 1892; but on the other hand the improvements and additions I have introduced
differ in so many minor matters of detail, that I consider it advantageous to
embody them in the following specification. To avoid then, repetition and prolixity,
I refer to the description and drawings of my previously mentioned Specification
(viz. No. 4645 of 1892) in which I make the following changes and additions.
When the two "balloons" are approximately spherical in shape; I thicken and
strengthen the "necks "-which are then made very short,-and when the balloons
are in position these necks no longer are at the bottom of the balloons but are
drawn nearer together than represented in some of the figures of the Specification
No. 4645 of 1892 describing my former invention (where they are shown as placed
at about two semi-diameters of a balloon apart). This arrangement materially
shortens the length and diminishes the weight of the tube connecting the balloons
(which tube is also used as a girder, or part of the supporting frame of the
machinery of the motor apparatus). When the balloons are of
any considerable
size "the net" (or a similar framing of ropework of convenient shape performing
the functions of "a net ") is sometimes encased in the material of the balloon's
envelope, and so made fast to the gas holders, that it enables the balloons to have
their axes more easily inclined, as described, when full. But besides shortening
the framing tube, this method of machinery suspension, and balloon connection,
has another good effect; to wit, the weight of the motor combined with the
buoyancy of the balloons, causes "a couple" to be set up which tends to twist
the two balloons in opposite directions and to force them together. Of course this
compressing force is resisted by the elasticity of the contained gas, the result being
that as the gas leaks out of the two spheres, the balloons are flattened together
more; but the outer portions of the envelope remain tight, and smooth; and thus
the difficulty of preventing the balloons getting "flaccid" (which is the chief
function of the interior balloon, or ballonet, invented by Dupuy de Lôme) is
simply overcome. I now usually discard the top girder described in my previous
Specification (No. 4645 of 1892) connecting the top of the balloons, and in its
place I attach to the top of the balloons a cord, or rope, made more or less elastic
by the aid of india-rubber, or steel springs, or such other convenient material for
attaining the end in view, viz. :-to unite the two balloons into a single system,
and to put upon them such compressing force as may be necessary for purposes
aforesaid. However-while using the method described to maintain "taat
skin of the balloons, 1 sometimes adopt the enclosed "ballonnet" of de Lôme to
act as a "condenser" of the "exbaust-steam from the motor (when a steam
engine is used as prime mover"). Moreover, by making the said "ballonnet
with an elastic "skin," or envelope; I to a certain extent control the buoyancy
46
"
"
the

page_text: "
one for
of the system by utilizing the effects of the displacement of the gas in the mai
balloons, and the rarefaction thereof by radiation, and convection, from the surface
of the ballonnet. Of course when apparatus constructed on the principle of such
internal condenser" is used; there are supposed to be two "ballonnets
cach balloon with the proper piping and accessory apparatus. It is very doubtful
whether even with such modifications, the ballonnet system is advantageous; aud
whether when the secondary balloons, or ballonnets-of any convenient shape-
are used as condensers they are not more advantageously put outside and below
the primary balloons; or indeed be entirely abandoned for tubular or other shaped
condensers made of aluminium or other suitable substance; which latter indeed
seems to be the best plan. Lastly in this connection-it appears to me that the
internal condensers acting also as a skin tightener to the balloons are chiefly
valuable when cylindrical gas holders are employed, it being difficult to apply to
cylindrical gas holders the previous method described as used for spheres or
envelopes of approximately spherical shape.
66
:
1 ve already hinted nt-in my Specification of 1892 No. 4645 the necessity
for keeping the balloons full, by describing devices of valves, tubes etc., for
maintaining their shapes permanent and undistorted-or, when such is not possible;
at least with gas at the same pressure in both however, when the nature of
circumstances prevents the complete retention of the contents of these gasholders,
I have a few lines above described devices for the object of securing tightness of
such portions of the envelope as the wind acts on; of course for the purpose of
diminishing the frictional and other resistances caused by motion through the air;
for consider that smoothness of surface or the possession of what might be called
in nautical language "a fair figure" will have much to do with diminishing
resistance of forward motion; still, as additional resistance is added by friction,
1 propose not only to imbed the netting-which may be of flat bands as well as
cylindrical ropes in the envelope of the balloons so as to make the outside of the
said gas holder as smooth as practicable; but further, I would if possible coat it
(ie. the balloon envelope-be it silk, gold-beaters' skin, or other convenient
material or fabric) with silver, or gold, by reducing
such substances from a
solution of the nitrate, or nitro-muriate, of the metals named, by hydrogen gas;
(provided excessive cost or other reasons do not interfere with the practicability
of the process); or even 1 contemplate striving to use an extremly thin shell of
copper, or aluminium (if possible) for the purpose of rendering the balloons as
impenetrable as practicable to the radiant heat of the sun or the motor (chiefly
when actuated by steam) below them. For, it is extremely important to retain
the temperature, pressure, and weight of the gas in the balloons, and the total
weight of the apparatus as invariable as possible. Otherwise, an additional
amount of power has to be expended by the engines in holding the balloons up or
pushing them down, which power might be more advantageously expended on the
propulsion of the system; after then all possible efforts have been made to secure
the balloon envelopes gastight, and impermeable to external heat from the sun,
1 protect the gas-holders from the hot air from the engines, by means of an
incombustible sort of shield, or roof covering, which extends over the motor.
the resistance that such roof will encounter when the balloon system is propelled
forwards be not found to be too great, I would make it (said shield) of such size
as to act as a parachute, and in fact permit the whole balloon system to be burnt
over the heads of the aeronauts while they, themselves and their motor, be dropped
on the ground at a velocity-uncomfortably great perhaps for pleasure-but not
sufficient to destroy life, or limb, under any ordinary circumstances. Said
"shield," or "root," or "parachute," is supposed to have a valve-or valves
in the top controlled by a spring, or other method, so that it (such valve)
shall not be lifted by the impact of the ascending currents of heated air
under normal circumstances, but will open when the balloons are either burnt, or
burst, or other mishap causes the shield or roof to play the part of parachute as
aforesaid. Of course the whole fabric of the balloons when of cloth can be made
IT

page_text: incombustible by tungstate of soda, alum, or other suitable chemicals, and
sometimes the lower portions of the balloons may be made of asbestos cloth.
However, such precautions are not very necessary as with a shield composed of
very thin metal or asbestos cloth or such suitable incombustible material with
framing of metal in lightest form for strength; the danger from fire is perhaps
Little more need be said
small, provided only reasonable precautions be used.
concerning the shield, or fire guard, in this Provisional Specification, save that it
is usually concave below and convex above but not necessarily shaped like a
portion of a spherical surface but may be made like a portion of a hollow cylinder,
and further arrange it so that it is attached to the motor framework carrying car
for passengers etc. under the main tubular girder connecting the balloons and
supporting the engines, and in such fashion a slip catch connects motor and car to
said girder, but when the catch is disconnected it drops the motor with car and
covering shield (parachute). Or I put the shield above the tubular girder, and
make it a more or less permanent attachment thereto; in which latter case the car
only containing the passengers is made detachable; and said car contains a
parachute-generally closed-of sufficient size that if opened when the car falls, it
will prevent the occupants being damaged. Still another danger has to be guarded
against and that is when one of the balloons is so toru by shot or shell or caused
by other mishap to suddenly discharge its gas and thereby tilt the system into a
dangerous position. To prevent this mishap then 1 introduce an automatic
disconnector which is put into play when any sudden change of level takes place.
Of course though I do not bind myself to introduce all of these various devices in
any one balloon system, or aerodrome, but only such, or all, as subsequent
experimenting shows to be advantageous.
"
rudder-
In previous Specifications for flying machines (as No. 9725 of 1888; No. 21,885 of
1891; No. 9775 of 1893) or that for navigable balloons (see No. 4645 of 1892) or
in those for submarine & submergeable ships (as No. 4601 of 1887; No. 13945
of 1888; No. 5399 of 1891; No. 15253 of 1891; No. 12717 of 1893) I have
briefly (but I trust with abondant fulness to make their bearing on the described
practical applications thereof comprehensible)-explained such of my leas on the
subject of the mechanics of flight as appears necessary in this connection; and it
does not appear to me that much more on such topic need be said here to render
clear the advisability for some changes introduced in my last steam motors whose
general features differ more in the designing of details than any essential particulars
from the character of my previous machines. However-two or three of these
"details though not new in themselves, & previously spoken of (by me) in
connection with flying machines generally yet derive such additional importance
when such flying-machines are applied to balloons, that I ought perhaps to notice
them now.
The first of these details is the horizontal steering gear, or the
-so to speak-which while being an instrument for directing (steering ")
the aerodrome to right, or left, is a different contrivance from that suggested by
the conventional meaning, or etymological derivation, of the name of the ordinary
Indeed my
rudder" is not an oar at all; but a
form of apparatus in question.
screw,
driven by the engines. The state of affairs is this; as long as balloons are
used as an adjunct to flying machines such as 1 have invented their motions must
be largely affected by the wind: for when we have a balloon motor powerful enough
to force a navigable balloon system or aerodrome (i.e. aerodromeus=air runner=air
traverser), in the teeth of a driving gale, the employment of balloons as supports
to such flying machines would be an act of insanity: for a motor which could
deliver such an enormous output of energy as hypothesized could easily support,
without balloons, a flying machine pure & simple, & what is more, the great
& combustible-necessary for
weight of "food & fuel"-" working substance
the production of a lengthened output of energy at the stupendous rate required.
Now the problem of fight-as a physical problem-was solved long ago: since the
year 1890 in fact. On the other hand the commercial solution of the problem is
quite a different matter, a matter indeed of opinion, & not a question of fact. Since
16

page_text: 1890 steam flying machines of the bird type could be made to fly for short distances:
that is they could support themselves in the air, & proceed up or down, to right, or
left in fact move in any way in tri-dimensional space. But the trouble is, that a
flying machine-nu orthopteron, or ornithopteron-(or indeed a flying machine of
any kind, aüroplanes included) when driven by a non condensing steam motor, won't
fly far so it appears to be necessary to use the buoyant propertities of balloons to
carry a condenser, or sufficient water & fuel-& apparatus concomitant to their
employ to make a steam-flying-machine, a military, not a commercial, success;
from a practical standpoint. Now a balloon-flying machine must confessedly be
likened to a steam ship of the early days of steam navigation; it must more or
less depend on the wind. When the wind is strong, it may be blown out of its
course, & in a gale, it can't "go" against it at all; and if it goes with it, no " rudder"
of the stationary oar type is of any practical use for scering purposes. My
aerodromes therefore fit with one (or more) screws, which turn about a line at
right angles to the longitudinal axis of said närodrome. Generally I use one screw
whose axis is horizontal, & at right angles to the length of the machine; but
occasionally I do arrange matters so that the screw can be used for depressing or
raising the end of the frame which carries it, instead of only moving it to right or
left, as required in horizontal steering; it being understood that said screw can be
moved into any intermediate position, so that it may either be used to direct the
balloon-machnie to right, or left, or incline its stern up or down, at will.
This screw can be put either behind or before the motor driving the balloons (as
shown in some of the drawings of the flying machines in my Specification No. 9775
of 1593); but I generally place it behind the driving engines of the aerodrome.
The second matter of detail propose to spenk of, relates to the wings of my
balloons. Owing to the very great amount of power which must be put forth at
times to prevent sudden gusts & currents of air lifting, or depressing, the balloons,
I find the concavo-convex wing is, on the whole, of apparently greater utility
than the flexible flat type of wing 1 commended for its high propelling properties
in ny Specification No. 4645 of 1892. Besides, by curving the extremities of a
concavo-convex wing backwards in suitable fashion, it can be made into a very
efficient instrument of propulsion without the loss of too great an amount of
sustaining power. Of course the bird wing may be imitated rather more closely
than have done; and I may consider it of advantage to employ some wings that
I have divised with joints, to my flying machines; still 1 must confess that my
orthoptera (straight winged dying apparatus) with the addition of a steering screw,
also capable of changing the inclination of the flying-machine, or aerodrome, as
well as steering it horizontally, seem to fulfil so completely the functions of the
more complicated structure of the wings of birds, that I have not yet felt the
necessity for converting my orthoptera, into ornithoptern, unless indeed these
aerodromes are best furnished therewith, as of course in consequence of their high
resistance to forward motion (as compared with my flying machines which support
themselves solely by the energy of their engines), they may require such type of
wing. The number of pairs of wings 1 employ is purely a question of engineering
advantage, and not, now a matter of invention. For I bave so frequently in my
specifications for submarine ships, and flying machines, described the devices I have
invented for the purpose of furnishing such vessels for fluid navigation with two
or more pairs of wings; that it would appear to be entirely a work of supererogation
to reintroduce these descriptions here; since any one with common engineering
knowledge ought to be capable of applying some of the two-winged forms of
apparatus 1 have invented to a pair of balloons. The only difficulty is-ns a
matter of judgement-BOL invention-to know which is best. And with my
present information I am inclined to consider a pair of wings quite sufficient for
navigating an aerodrome; though of course, questions of safety etc. etc. may
eventually indicate the advisability of using two pairs; and in such latter
contingency, it seems most satisfactory to use a separate cylinder system, turning
on trunnions, to move each pair of wings. However in using either one or two pair

page_text: of wings it is sometimes of advantage to keep the cylinders stationary, and turn
the wing plane only. In this case, I commonly drive the wing shaft faster than
the engine by multiplying gear. The disadvantages of such method are manifest ;
while its counterbalancing advantages seem chiefly to lie in the enormous inclination
which can then be given to the wing planes (the flexing angle amounting nearly
to 90°). A cylinder system similar to that represented in Fig. 4 of my Specification
No. 4645 of 1892; is a suitable one for this employ. But I generally find it then
convenient to invert the engine and use a large wheel on the crank axle (then
below the cylinders) to drive a pinion on a shaft which then occupies a position
parallel to the crank axle not far from the middle of the machine and this shaft
further actuates a crank and lever system somewhat similar to that represented in
Fig. 10 of my Specification No. 21,885 of 1891, but giving greater angles of wing
flexure than there possible. But again this same end of great wing-plane flexure,
can be obtained by the employ of the engine represented in Figs. 9, and 10, of my
Specification No. 5399 of 1891 where the "fins" (the specification relating to
submarine ships) are driven directly by the engine without using multiplying gear.
And I need hardly again add, two pair of such engines can as easily be used to
drive two pair of wings; as a single pair of engines one pair of wings. Lastly, in
this connection, I sometimes add apparatus to flex one wiug more than the other:
when then such is desirable commonly use the two cylindered engine with
multiplying gear spoken of as being a modification of that represented in Fig. 4
of No. 4645 of 1892. For, by placing two large spur wheels on the hollow
trunnions (see Figs. 7, & 8 of No. 13,945 of 1888 as illustration of plan adopted)
supporting the wing levers, I turn these hollow trunnions about their axes by
causing to gear into the aforesaid spur wheels two pinions on a shaft which can be
rotated at will. Now if this shaft be divided at its middle, or other suitable point,
and the portion of the shaft turning one pinion be turned more than the other;
such motion will be followed by a corresponding increase or decrease of flexure of
the attached wing plane: it being of course understood that such motion may be
communicated to the aforesaid pinion shaft by a pair sprocket wheels and a chain
(or band-and-pulley system) which is controlled from the ". car of the balloons by
its occupants. Still, as the method of steering by wing flexure thus indicated is
more interesting from a theoretical than practical standpoint, I seldom use it,
finding the method of steering by the screw (previously described) is more
expeditious and easy. But even when it is not desirable to steer the balloons by
the wings, the chain and sprockets are still used (though the axle carrying the
pinions is then usually left undivided), as the use of the chain and sprocket system
form an easy way of flexing the wings from the car of the balloons suitable
winches and pawls being of course attached.
:
The third matter, or detail, for me to mention relates to the "boiler," or steam
generating apparatus. A "boiler" of water tubes surrounded by one (or more)
casings of metal, asbestos, or wire gauze, is generally adopted. Usually I make a
wire gauze case surround the lower portions of the tubes the upper portions of said
case being of thin sheet metal without perforations (like wire gauze), but covering
the boiler and carrying two chimneys whose ends are turned down like those of a
"magic lantern." Commonly it is not necessary to make these downward
projections of the "smoke stacks" very long but if it be desirable to do so, on
grounds of safety, then I either use jets of steam to create a draught, or close the
furnace and work with a "forced draught." Coal can of course be employed ns
the combustible, but an oil burner seems far better, as then there is no danger from
sparks and cinders; and further the fire can instantly be extinguished. There are
of course many oil burners or heaters in the market which can be advantageously
used for this purpose; or the oil may be blown in spray by the exhaust steam, or
be vaporized and used with an "atmospheric burner." When the oil is first to be
vaporized; it seems safer to do so by means of a water and steam bath in which
either caustic potash or some salt (in the chemical sense of that word) is dissolved
which raises the temperature of ebullition as high as convenient: some of the

page_text: exhaust steam from the engines being of course condensed therein, to keep up the
temperature.
Further description of water holders, condensers, piping & other ordinary
engineering adjuncts being apparently unnecessary I now conclude my Provisional
Specification.
Dated thin wish
1039
Improvements in Balloon Flying Machines or Aerodromes.
1, HENRY MIDDLETON, of 3 Wellesley Villas, Wellington Street, Slough, in
the County of Buckingham, a Civil, Mechanical, and Electrical Engineer do
hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement :-
According to this invention, I employ two gas vessels of a spherical, cylindrical,
or other convenient shape, to more or less support a winged motor, or flying-
machine. The general arrangement of these balloons" and their attached flying-
machine is similar to that described in my Specification No. 4045 of 1892: but
certain modifications are introduced which may be most briefly, and perhaps
intelligibly be described by stating the general conditions involved in the problems
to be solved, & then the methods by which such solutions have been attained.
The first problem then is that of the maintenance of the figure of the balloon
system, under the supposition that by means of engine power & other appliances to
be subsequently specified, the vertical motion of the balloon systein can bo
restrained within comparatively small limits, & further that it is capable of moving
in a given stration of air, or keeping approximately a definite distance above the
ground while moving horizontally from place to place. In my first specification
for balloon-flying-machines (to wit, No. 4645 of 1992) 1 described the expedient
of cutting the portative gas bag into two portions-i.e-using two balloons instead
of one & connecting the same two gasholders by means of a tube controlling the
passage of gas from one to the other: for, by this means not only is the resistance
of the moving system diminished (by the smaller cross-section which the gasholders
present in a plane normal to their line of motion) but further, any tendency to a
Sudden flow of gas from one end to the other of the portative system is brought
under complete control, & cannot take effect save when desired by the nöronnuts :
& indeed this matter is one of great practical importance; for when spindle shaped
gas vessels were first adopted, it was discovered that the liability to gas dis-
placement was so great when once the spindle shaped vessel or prolate-spheroidal
form gasbag became "accid," that the weight of the suspended "car," with its
contents, &c. &c.; was insufficient to prevent it: & the result was the gasholder
turned its longer axis more or less vertical with the sequela-which may be
imagined. Now it can be easily demonstrated by the principles of the mechanics
of fluids, that even when the gas containing vessel of the form specified remains
full, yet it is usually put in unstable equilibrium by a propelling force causing
forward motion. For, any tendency which is sufliciently great to cause the axis of
the spheroidal gashag to devinte slightly from parallelism with its direction of
motion, at once causes the genesis of a couple whose establishment tends to turn
the longer axis of the spindle shaped balloon into a position transverse to its
direction of motion & generally ends by setting it vertical; at least if aided by any
considerable motion of the mass of the enclosed gas which flaccidity of the envelope
-caused either by leakage or change of temperature-may permit; & even when
not so aided-as at first hypothesized-the size of the couple spoken of is generally

page_text: of magnitude so excessive as to be uncontrollable except at very slow speeds.
However by cutting the gas reservoir into two portions as described (see my
Specification No. 4645 of 1892); & raising the position of the motive power, or
engine, (above the place it has commonly occupied in the devices of earlier
inventors), so that the direction of its thrust is more nearly coincident with the
line of resistance produced by the action of the air on the whole apparatus, or
balloon system; the stability of the air craft is greatly improved; while the
further expedient of making the points of support of the load (engine, car &c. &c.) lie
nearer together than the centres of buoyancy, causes the supporting forces to urge
the balloons together, and by thus slightly compressing their contained gases
causes their tension to maintain the outer surfaces of the balloons smooth, or at
least to present a fair figure" over those portions on which the air impinges
when the whole system is put in motion. But good as is the tendency of all these
arrangements, their range of action is insufficient to cope with all the consequences
which variation of volume, or alteration of levity, or which a few degrees change
of temperature, or the still more formidable effects which the ceasless inodifications.
of direction & velocity in the currents of the evermoving air, produce upon the
balloon system. Hence I find it necessary to increase the effect, & supplement the
number of the controlling agencies specified but as the primary function of these
is to alter the specific gravity of the balloons, 1 will describe them under the
devices whose object is to vary-with more or less speed-the specific levity of the
aerodrome. This then brings us to speak of what constitutes the second problem,
connected with the gas holders. It must not be forgotten, that the device for
maintaining the outer portions of the balloon envelopes "taut," does not diminish-
to any sensible extent the portative power of the balloons. It merely changes
their figure without altering their volume, or consequent buoyancy. But, when
the gas escapes or shrinks in consequence of a fall of temperature, the buoyancy of
the balloon system is altered. Meusnier appears, long before Dupuis de Lome, to
have suggested the use of a ballonnet, or separate receptacle within (or without) an
elongated, or spindle shaped, gas holder, for the purpose of containing air.
Meusnier's ballonnet was rather to alter the specific gravity of his balloon, than to
keep its shape intact which was the chief object of Dupuis de Lome's device:
& the means by which it is understood that Mensnier expected to effect the end he
had in view-to wit-by pumping in (or out) air from his ballonnet-scems imprac-
ticable in consequence of the rupture of the envelope which would take place
before the density of its contained air was sensibly altered. While thinking over
these matters, it occurred to me to vary the density of the air in the ballonnet by
beat; & then in searching for a safe way of applying said heat 1 hit on the device
of taking it from the exhaust steam of my motor engine, & thus letting the
ballonnet act as a condenser as well as a means of changing the specific
gravity of the balloon flying-machine. Thus the greatest present difficulty
in the way of flight-i.e. finding a condenser light & powerful enough to be of
practical utility-seemed overcome. And indeed yet a third function can be.
fulfilled by the ballonnet condenser, to wit-it can to a greater or less extent
support its own weight or even-if made large enough-possess intrinsic levity
of its own, since steam at atmospheric pressure has about half the specific
gravity of air. I have since learned that both Derval & Wellner had pre-
viously suggested the use of steam in a balloon, or ballonnet, but as their method
of flight & proposed flying machines are utterly unlike mine 1 return from this
digression, to describe more closely my own invention. In the drawings appended
to this specification 1 have represented the chief types of aerial condenser &
specific gravity alterer, I propose to use. Further, the same general remarks
apply to all of them; for their variation in shape is a mere matter of engineer's
design, & not invention, just as the proportioning of their capacities, & relative
sizes, as compared with the main balloons is an affair of engineering judgement, &
mathematical calculation. Well then, it being supposed that each of the two
balloons is provided with a separate chamber, or receptacle into which steam-
But

page_text: generally from the exhaust--can be sent, and further it being hypothesized that
The engine, or motor, driving the aërodrome has a condenser formed of very thin
tubes of cylindrical or other convenient shape, the manner of working the
nörodrome may be thus described. In the first place the two main balloons are
nearly filled with gas-the ballonnets being nearly or quite empty. The main
motor, or engine, being disconnected from the wings, is run very slowly for a few
moments to heat up its cylinders & put a little steain in the ballonnets. Supposing,
the amount of gas in the balloons & the steam in the ballonnets to have been
properly adjusted, the expansion of the ballonnets from the steam they contain, &
the heating effect of the latter on the gns of the main balloons, will make the outer
envelopes light, & cause the specific gravity of the whole aerodrome to but slightly
exceed that of the surrounding air. If then the wings be properly inclined & put
in gearing with the motive machinery, a few strokes of them will lift the aerodrome
into the air; & it can now proceed forward as desired. But now suppose the
additional amount of exhaust sent into the ballonnets cause them to expand so
much, & heat the hydrogen-or other gus-in the balloons to such an extent that
the aerodrome leaves the horizontal plane in which it was supposed to inve
previously been moving, & rises obliquely. Immediately the plane of wing stroke
is to be altered so that the wings now pull down the aerodrome by engine power
as well as propel it forwards. If the action of the engines is sufficient, (without
sacrificing too much of their propelling power), nothing more need be done; but
if not, the exlinust must be turned off from entering the ballonnets & now
discharged through the supplementary metallic tube condenser attached to the
engine. This condenser is supposed to be surrounded with the water intended for
the boiler; & preferably this water had better be in the state of ice; there being
supposed to be a sufficient quantity to wholly condense the exhaust for a few
moments or in fact until the condensation of steam in the ballonnets causes them
to more or less collapse, while the effect of radiation of hent from the main
balloons & the chilling of the colder upper air, would bring the balloons back to
the state of flaccidity, they are supposed to have possessed, just before the nürial
voyage begun, were the balloons under the same pressure as at the surface of the
earth. But by hypothesis they are not under the same pressure, being some little
distance say, up in the air: & so it may happen that in consequence of the less
pressure, & the effect of the method of engine suspension forcing them together,
they may be in a zone of equilibrium with fairly tight envelopes, & at least
sufficiently nearly balanced in their floating state that a very slight change of
inclination of wing stroke plane-to pull them up or push them down-will be all
that is necessary for some time: or at least until the warming up of the water-or
ice-round the metallic condenser attached to the engine, or other circumstances
like the too rapid chilling of the gas in the main balloons; renders recourse
necessary again to the ballonnets. However it must not be omitted to state that
means are provided to charge these ballonnets with air by engine power, when
such is considered expedient, & that it is by the continuous alteration of the course
of the exhaust steam-to wit-sending it into the ballonnets alone, or the engine's
condenser alone, or through both, or discharging-& consequently wasting—it in
the air, that I count on reducing the changes of buoyancy of the acrodromo within
such restricted limits that they can be completely controlled by the wings of the
attached flying machine.
Of course the theoretical limit to such aürial voyage is the time required to
consume the oil-or coal or other convenient substance-used to heat the water in
the boiler of the main motor. Nor does it follow that if the condensing apparatus
be made perfect, & the outer envelope of the balloons completely impervious to
gas, that as the only loss of weight the aürodrome should-under such circum-
stances experience would be that which the consumed combustible possessed, it
would follow therefore that as the aerodrome gets continually lighter & lighter,
so it must be expected to ascend higher, & higher & by no means move in that
horizontal stratum of air within which we claim its movements can be controlled.

page_text: For, there is no reason why the main balloons may not be used to act as condensers,
just as well as the ballonnets, by leading suitable pipes controlled by 'taps,'
valves' &c.; from the exhaust ports of the engine: & by further fitting a small
& easily controlled tap or valve to the upper parts of the main balloons, &
arranging matters so that the hydrogen or other gas they may contain may be
slowly discharged from time to time, or continuously, if desired, we can slowly
replace the very buoyant gas in the main balloons by a less buoyant gas or
vapour-to wit the steam from the engines & thus-theoretically speaking at any
rate completely counteract the effect of the lightening of the aerodrome which
the burning of the oil, & dissipation of the products of combustion in the air, would
otherwise produce.
It may be held then that in still air-or with only a slight breeze-my aërial
vessel or nerodrome, is a complete solution of the problem of flight. But while
complete within the limitations stated it is very far from perfect; & the
imperfections become the more manifest in proportion as the said limitations are
exceeded. Still-it may perhaps be of advantage to point out, that as far as
experiments of recent years have shown, or calculations based on them are able to
discover; it does not appear that the resistance to forward motion of a spindle
shaped balloon is other than approximately the same in magnitude as that of an
aeroplane of the same weight & moved with the same velocity; whereas the difficulty
of controlling aeroplanes is so enormous, that they may be considered incomparably
the most dangerous of the two. Still, even the spindle shaped balloon has its
dangers the moment it ceases to simply float in the air, but is driven forwards by
engine power. Lastly-up to the present time, no spindle shaped balloon was-
properly speaking-navigable--three dimensions by engine power; but its vertical
motions had to be controlled by altering its specific gravity. The flying-machines
exhibited in 1890 capable of moving in any way in tridimensional space by
engine power; gave a solution of the problem of flight which had but one draw-
back though that was a very serious one-to wit-they could not condense but
very small portious of the evaporated steam, & consequently could fly but a very
little way. Great improvements in constructing metallic condensers have greatly
increased the amount of steam which can be reconverted into water in order to be
returned into the boiler; but yet I fear the whole of the steam cannot be condensed
with any metallic condenser of moderate dimensions. However, if the condenser
be made of immoderate dimensions & in fact is either made into a balloon-be it
metallic or otherwise or very large tubes-metallic or otherwise: then the
fying machine can condense the whole of its exhaust steam & fly as long as its
heating material-be it oil, or coal-will last.
With regard to the main motor engine of the aerodrome very little need be
added in these general remarks to what has previously been written in my
Provisional Specification. For it is difficult to describe details of mechanical
inventions in words, & as they moreover are to be subsequently set forth by the aid
of drawings, it would seem a useless iteration, to repeat the verbal picture attempted
in my Provisional Specification to portray mechanical concepts without the aid of
illustrations. To this general principle then only two exceptions will be taken in
adverting to the use of a flywheel at times to better control the motion of the
engine driving the wings: & the use of springs commonly inserted between the
wing levers & their driving linkwork to diminish the shock which inertia would
cause in the mechanical combination used for producing reciprocating motion.
However it must not be supposed that the form of engine figured with this speci-
fication is necessarily the best & most complete for propelling, guiding & generally
speaking governing an aerodrome. For such is by no means necessarily & probably
far from the case: the business of the inventor is to furnish a multiplicity of
solutions of the problem he is considering, & it is the duty of the engineer &
experimenter to pick out what solutions-designs-are most suitable to the
particular conditions of the work to be done, therefore it must be understood that
I do not limit myself to employing solely the type of engine figured in this
B

page_text: specification as the only one to be used with the combination of balloons, ballonnets
condensers, &c. &c. which I style an aerodrome; but I contemplate adapting any
of my previously invented flying-machine engines in the place of this one shoul
such seem most advisable. For these engines have been invented for the purpose
of carrying out a theory of flight which-as far as am aware-is wholly &
entirely original with me. Enuncinted some 13 years ago, my earliest patents of
inventions for applying such theory of flight to flying machines, are over 8 years
old & within that period very few inventors who have attacked the problem o
flight have made use of wings at all, the efforts of most of them having apparently
been directed to securing flight by means of inventions based on the principle of
the aeroplane.
DESCRIPTION OF THE DRAWINGS.
the
Fig. 1. is a side view-details too small to be distinctly shown being omitted-o
the two gas holders, ballonnets, and attached flying machine, all of which taken
together style an aerodrome. 4 is the flying engine; and are the balloons;
and and the ballonnets, or condensers; is the shield, or fire guard; g the
tubular girder connecting the balloons; d is the car for the passengers;
supplementary metallic condenser; and we one of the wings of the flying-machine.
r is the steering rudder e the engine, the outer case of the tubular boiler & the
top stay rope. Of course there are supposed to be many other stay ropes to keep
the system from twisting, and if the net be not imbedded in the substance of the
balloons, as it is supposed to be in this figure, its lower portions may be so fastened
as to aid in supporting the engine etc. Further the ballonnets may be made as
closed bags tied by their upper edges to the balloons; or as partitions; whichever
method is most convenient. As to the hollow tube containing the shaft actuating
the steering gear it may be passed through the ballonnet and the apertures then
made gas tight while the wires, or cords, to work the reversing clutch of the
steering fork may pass through staffing boxes in the walls of the ballonnet and
supplementary condenser. The more minute details of the engine etc., omitted in
this figure, being represented in Fig. 3 with the accompanying explanation.
Fig. 2 is n side view of the second form of my nerodrome; the balloons being
marked and as before; and e and e' being the ballonnets, or condensers, in this
ense enclosed within the balloons. They are represented full; but of course it is
intended that they should be collapsible, and receive the steam to fill them from
the exhaust of the engines. To keep these ballonuets in place rope stays are
supposed to be fastened to convenient parts of their outer surfaces and be connected
with suitably situated points on the interior of the main balloons. Also a tube
may be used to project any convenient distance upwards from the necks of the
ballonnets so as to discharge the exhaust at any suitable point of their interior and
10 this also they-the ballonnets-may be stayed. In all cases the balloons and
ballonnets are to be thickened where the ropes are attached to keep such from
tenring. As the same letters are used to designate the parts in this figure which
are similar or identical to those described in Figure 1, no further notice of their
meaning need here be inserted. However, in consequence of the somewhat lower
position of the engine, it is mounted ou three-or four if desired-wheels, two of
which u and are shown in the figure. It is of course supposed that these wheels
have pneumatic tires, springs, and every convenience for diminishing shock in case
the balloon system comes to the ground 100 fast. Further it may be noted that
some of the tubes of the supplementary condenser (4) are used to net as framing
for the wheeled base and notably the back lower tube is used as a girder to
strengthen the axle on which the back wheels run. The general arrangement of
car etc. being the same as in the previous figure, no further comments save that the
connections of steam, exhaust and other pipes are omitted as useless details of
completely understandable engineering work-seem necessary, and the more is this
the case as most of such matters are illustrated in Fig. 3.
Fig. 3 is a side view of one of my forms of balloon motor I have used in

page_text: connection with this invention, and have more or less described in the body of this
specification. As the same letters are used to designate the same parts that were
described in the two previous figures; only those referring to new details need be
noticed. n is one of the two steam cylinders, whose cranks give rotation to a
shaft carrying a wheel e, which gears into another of larger size ₁, and from the
shaft carrying the latter the reciprocating motion of the wings is derived. These
wings have their stroke planes changed by turning about a pair of hollow
trunnions (of which represents one) in a manner similar to that so often
described in my Specifications Nos. 4,604 of 1887; 9,725 of 1888; 13,915
of 1888; 5399 of 1891; 15253 of 1891; 21885 of 1891; 4645 of 1892;
9775 of 1893; 12717 of 1893 it seems wearisome to recapitulate the general
theory thereof here. However I may briefly add that in this present instance
the particular arrangement for driving the wings is as follows: The shaft
carrying the wheel has at its extremity a crank working in a link, which
raises a
cross shaped piece to the extremities of which the wing levers―
in this figure the wing levers are omitted to avoid complication--are attached by
gudgeons; this cross shaped piece then works up and down in slots cut in a
framing piece whose lower extremity is shown at (with "eyes" for attaching the
springs which check the shock the wings would otherwise experience), is made fast
to the larger wheel ; and further to the aforesaid framing piece are attached
two supporting pieces which bear the inner wing which turns the hollow trunnion t,
and which wing further carries the fulerun of the wing levers. One of the
supporting pieces is lettered in the drawing (Fig. 3), the other just below it is
represented but unlettered. Now as the framing piece 4 is attached to the wheel e
it follows that if we give motion to e, by means of the pinion es, sprocket
wheels & Co all of which can be put in motion by the winch l, we can cause the
wing stroke to take place in any suitable plane; it is of course to be understood
that the winch system is further provided not only with a system of pegs or pauls,
springs and holes to fix the turning axle in any position; but further the winch
axle may be so divided as to incline one wing independent of the other; or if this
be not desired, and it is instead wished to give the two wings always the same
inclination, a bar 3 may be used as an additional help to the two chains & four
sprocket wheels which in this latter case are supposed to be all geared together to
accomplish said object & aim, p is the pump drawing water from the tank of the
condenser by means of the pipe q whence it is forced into the boiler through the
pipe 71. On the same axle as the wheel e, is a bevil wheel gearing into one which
an axle (within the tube 1) carries. Further matters are so arranged that said
tube has a transverse frame attached to it in such fashion that when said tube z
is rotated by the worm and worm wheel, (through the rod and hand wheel y)
such rotation of the tube produces a corresponding turning of the frame carrying
the wheel But to the axle of z, (and a wheel similar to it but not shown in the
drawing) is attached an ordinary sliding clutch arrangement by means of which
may be rotated in one or other direction by the shaft in the tube, or indeed
entirely disconnected from said shaft when desired: hence it is easily seen that
the steering screw r acted on by the bands or chains running over the wheel and
the corresponding wheel at the end of the axle to which 3 is attached, is
rotated in one or other direction as desired by the aëronauts supposed to be in the
balloon car d. Further, from this car the aforesaid aüronauts can turn the steam on
to the cylinders by means of the rod n₁, which turns the steam tap (on the steam
pipe n) through the medium of the bevil gearing system depicted. Again, by
means of the handle rod x, the supply of water to the boiler can be regulated, and
likewise the distribution of the exhaust can be effected by means of suitable rods.
o is an air condensing pump for the purpose of filling the ballonnets with compressed
air when desired. n, is the exhaust pipe which can be put in connection with the
supplementary condenser k or the ballonnet condenser c. (A similar pipe going
from the other cylinder to the ballonnet ). And this connection is made only
friction tight and so contrived that if the motor is disengaged from the balloons,
ፃ

page_text: the pipes n and 174 (the latter not shown) are easily separated from the ballonnets.
and are two clamps which attach the inotor to the tube g; but from which they
are easily separable by turning the rod about itself; and this disengaging gear
is used to separate the motor from the balloons at any instant nud drop it parachute
fashion when desired: for, it is of course to be understood that the shields is
intended to act as a parachute as well as a fire guard.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, declare that what I
claim is :-
1st. An nürial vessel or balloon-flying-machine-which I call an aürodramme-
consisting of two gas holders of a spherical or other convenient shape placed one
before the other and moreover having the connecting tube or girder joining the two
balloons made so short that the buoyant force acting on said gas holders will cause
them to compress their confined gas and keep their outer envelopes tight substan-
tially as described.
2nd. In ກ ານ agrodrome or balloon-flying-maching the outwardly attached
ballonnets used also as condensers together with their accompanying and con-
comitant apparatus for enabling the exhaust steam of the engines to be reconverted
into water and thus permit of the engine to be worked by a more or less complete
cycle process substantially as described and represented in the drawing Fig. 1.
3rd. In no nürodrome or balloon-flying-machine the inwardly attached
ballonnets used also as condensers together with their necompanying and con-
comitant apparatus for enabling the exhaust steam of the engines to be reconverted
into water, and thus permit of the engine being worked by a more or less complete
cycle process, substantially as described and "represented in the drawings Figs. 2
& 3.
4th. The aerodrome motor with its wings steering gear, boiler, condenser and
other concomitant and accompanying apparatus, substantially as described and
represented in the drawing Fig. 1.
5th. The aerodrome motor with its wings, steering gear boiler, condenser and
other concomitant & accompanying apparatus substantially as described and
represented in the drawings Figs. 2 & 3.
6th. Steering rudder, or directing gear, with the apparatus appertaining thereto
substantially as described and represented in the drawings Figs. 1, 2 & 3.
7th. The top stay rope of elastic material used for drawing the balloons
together substantially as described and represented in the drawings Figs. 1, & 2.
8th. The method of flexing the wings with the winch, catch and other con-
comitant apparatus substantially as described and represented in the drawing
Fig. 3.
9th. The aerodrome as a whole substantially as described and represented in the
drawing Fig. 1.
10th. The aerodrome ns a whole substantially as described and represented in
the drawing Fig. 2.
Dated this 13th day of Augu 1898
HENRY MIDDLETON.