IMPROVEMENTS IN APPARATUS FOR AERIAL NAVIGATION
Year: 1865

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the
County of Middlesex, Engineer and Patent Agent, for the Invention
of "IMPROVEMENTS IN APPARATUS FOR AERIAL NAVIGATION."-A com-
munication from abroad by Solomon Andrews, of Perth
Middlesex County, State of New Jersey, United States of America.
Amboy,
Sealed the 10th April 1866, and dated the 19th December 1865.
PROVISIONAL
SPECIFICATION
left by the snid William Clark at the
Office of the Commissioners of Patents, with his Petition, on the
19th December 1865.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR AERIAL NAVIGATION," to be as
follows:-
I effect locomotion in the atmosphere in any given direction by means of
the form or construction of the aerostat the motive power being the attrac-
tion of gravitation. To be more explicit, the difference between the
specific gravity of the aerostat and that of the atmosphere in which it floats
I use to propel the aerostat over the surface of the earth by ascending and
descending on inclined planes in the atmosphere by means of the shape
or form of the aerostat, or a disc
a disc thereto attached. A balloon or
spherical body lighter than an equal bulk of the atmosphere will ascend
perpendicularly to the horizon. If currents prevail in the atmosphere the

page_text: balloon will of course move in the same direction at the same rate of speed.
If heavier than the same bulk of air it displaces, it will descend in the
same way; but if made in any other shape, and kept suspended by the
centre of gravity in any oblique position, it will ascend or descend, as the
case may be, on the line of the least resistance. Thus, if made in a
flattened and elongated form, and kept in an oblique position, it will ascend
or descend in the plane of its longest axis, because it meets with less
resistance in that direction, and this produces a forward movement. If
such an aerostat be held perfectly horizontal it will move only perpendicu-
larly (supposing no current in the air), because it finds no opposing force
to the direction of gravitation, and gravitation always acts perpendicularly
to the horizon. It is then by an opposing force or resistance to gravitation
on one portion of the aerostat by which 1 compel the aerostat to move
forward on a semi-horizontal line. The resistance on the top or bottom of
the acrostat produced by the air on a surface much larger than the end of
it prevents so rapid a movement in a perpendicular direction; and so it
slides along on the atmosphere just as a sledge slides down the side of a
hill by the force of gravitation, or as a board rises obliquely out of the
water by the force of gravitation indirectly applied. When two cylindroids
are placed horizontally side by side there is formed between them a longi-
tudinal cavity both above and below. This concave surface offers more
resistance to the air than a convex or plane surface, consequently rapid
ascent and descent is prevented, and the power of ascent and descent is
expended by forcing the body to move obliquely upwards or downwards
in the line of least resistance, the cylindroids sliding as it were on an
atmospheric railway, the rail being formed of atmospheric air partially
condensed by pressure into this longitudinal cavity. When three cylin-
droids are placed side by side two such cavities are formed; one cylindroid
being convex is not sufficient to produce as much effect, there should be
therefore two or more. The single cylinder may be improved, however,
by the addition of a flange or membrane extending along the sides like a
bird's wings, or the guard of a steamboat, so as to produce more resisting
surface to the atmosphere. The addition of every cylinder after the first
one, of equal dimensions, adds one cavity and a resisting surface equal to
its length multiplied by its diameter; so after the first one there is no loss
of resisting surface from the convexity of the cylindroids. I prefer to
employ three aerostats of cylindrical form, disposed horizontally and pointed
at each end. They are joined together by a membrane or diaphragm at
their longitudinal equators, and covered by a net, from which four rows of

page_text: cords extend to a long and narrow car suspended below the centre, the
ballast and aeronaut being in the car as usual. It ascends and descends on
inclined planes in the atmosphere because of its form or construction
whenever it is poised obliquely. The angles of inclination are produced
by the position of the aeronaut in the car, or the removal of other weights.
and it is steered by a common rudder. To navigate the air with this
vessel it is only necessary to step to the rear end of the car, this elevates
the bow five to ten degrees, and by throwing out a little ballast the aerostat
will go ahead on the ascending plane. When the aeronaut has ascended
as high as he wishes to go he opens one of the valves and discharges some
gas, at the same time stepping toward the forward end of the car, which
will depress the bow, elevate the stern, and so change the angle of inclina-
tion, when the aerostat will go ahead on the descending plane. On a near
approach to the earth the aeronaut has only to step to the middle or rear
end of the car, and thus elevate the bow; while to stop the momentum at
any rate of velocity, it is simply necessary to sail horizontally for a short
distance, or throw out more ballast, and go ahead again on the ascending
plane. Having forward motion the aerostat is turned by the rudder just
like a boat on the water; stern-way may also be had if desired. Before
the ballast is exhausted the aeronaut should come down to a depot,
replenish the wasted gas and ballast, and go on again. One pound of
ascending or descending power will give to this vessel a forward movement
of one mile per hour, and each additional pound will increase her speed in
about the same ratio, so that by ascending or descending with a power of
two hundred pounds, a speed of two hundred miles per hour may be
attained; and common varnished linen is strong enough to resist the pres-
sure on the bow at that rapid rate, if brought to a point and held by
an inflexible framework.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on
the 19th June 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME. I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of December, in the year of

page_text: our Lord One thousand eight hundred and sixty-five, in the twenty-ninth
year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Clark, Her special licence that I,
the said William Clark, my executors, administrators, and assigns, or
such others as I, the said William Clark, 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 APPARATUS FOR AERIAL
NAVIGATION." a communication to me from abroad by Solomon Andrews, of
Perth Amboy, Middlesex County, State of New Jersey, United States of
America, upon the condition (amongst others) that I, the said William
Clark, my executors, or administrators, by an instrument in writing under
my, or their, 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 William Clark, 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, reference being had to the Sheet of Drawings hereunto
annexed, and to the letters and figures marked thereon, (that is to say);-
In Figure 1 there are three areostats of a cylindrical form pointed at each
end, they are jointed together by a membrane or diaphragm at their longi-
tudinal equators, covered by a net, from which four rows of cords extend to
a long and narrow car suspended below the centre, the ballast and aeronaut
being in the car. It ascends and descends on inclined planes in the
atmosphere, because of its form or construction, whenever it is poised
obliquely. The angles of inclination are produced by the position of the
aeronaut in the car or the removal of other weights, and it is steered by a
common rudder. To navigate the air with this vessel it is only necessary
to step to the rear end of the car thus elevating the bow five to ten degrees,
and by throwing out a little ballast she will go ahead on the ascending
plane. When she has ascended as high as the aeronaut wishes to go, he
opens one of the valves and discharges some gas, at the same time stepping
toward the forward end of the car, which will depress the bow, elevate the
stern, and so change the angle of inclination, when she will go ahead on the

page_text: descending plane. On a near approach to the earth he has only to step to
the middle or rear end of the car, and thus elevate the bow; to stop her
momentum at any rate of velocity, sail horizontally for a short distance, or
throw out more ballast and go ahead again on the ascending plane.
Having forward motion she is turned by the rudder just like a boat on
the water. Stern-way may also be had if desired. Before the ballast is
exhausted the aeronaut may come down to a depot, replenish the wasted
gas and ballast, and go on again. One pound of ascending or descending
power will give to this vessel a forward movement of one mile per hour,
and each additional pound will increase her speed in about the same ratio,
so that by ascending or descending with a power of two hundred pounds a
speed of two hundred miles per hour may be attained; and common
varnished linen is strong enough to resist the pressure on the bow at that
rapid rate, if brought to a point and held so by some inflexible framework.
The foregoing I consider a full and comprehensive description of this
Invention, but as aerial vessels have never before been directed in their
course by the will of man, I shall go more into detail, even at the risk of
being verbose. I effect locomotion in the atmosphere in any given direc-
tion by means of the form or construction of the aerostat, the motive
power being the attraction of gravitation. To be more explicit, the
difference between the specific gravity of the aerostat and that of the
atmosphere in which it floats I use to propel the aerostat over the surface
of the earth by ascending and descending on inclined planes in the atmo-
sphere by means of the shape or form of the aerostat itself or a disc thereto
attached. A balloon or spherical body lighter than an equal bulk of the
atmosphere will ascend perpendicularly to the horizon. If currents prevail
in the atmosphere the balloon will of course move in the same direction at
the same rate of speed. If heavier than the same bulk of air it displaces it
will descend in the same way; but if made in any other shape and kept
suspended by the centre of gravity in any oblique position, it will ascend
or descend, as the case may be, on the line of least resistance. Thus if
made in a flattened and elongated form, and kept in an oblique position, it
will ascend or descend in the plane of its longest axis, because it meets
with less resistance in that direction, and this produces a forward move-
ment. If such an aerostat be held perfectly horizontal it will move only
perpendicularly (supposing no current in the air), because it finds no op-
posing force to the direction of gravitation, and gravitation always acts
perpendicularly to the horizon. It is then by an opposing force or resist-
ance to gravitation on one portion of of the aerostat by which I compel the

page_text: nerostat to move forward on a semi-horizontal line. The resistance on the
top or bottom of the aerostat produced by the air on a surface much
larger than the end of it prevents so rapid a movement in a perpendicular
direction, and so it slides along on the atmosphere just as a sled slides
down the side of a hill by the force of gravitation, or as a board rises
obliquely out of the water by the force of gravitation indirectly applied.
When two cylindroids are placed horizontally side by side, there is formed
between them a longitudinal cavity both above and below. This concave
surface offers more resistance to the air than a convex or plane surface,
consequently rapid ascent and descent is prevented, and the power of
ascent or descent is expended by forcing the body to move obliquely up-
wards or downwards in the line of least resistance, the cylindroids sliding
as it were on an atmospheric railway, the rail being formed of atmospheric
air partially condensed by pressure into this longitudinal cavity. When
three cylindroids are placed side by side two such cavities are formed;
one cylindroid being convex is not sufficient to produce as much effect,
there should be two or more. The single cylinder may be improved,
however, by the addition of a flanch or membrane extending along the sides
like a bird's wings, or the guard for a steamboat, so as to produce more
resisting surface to the atmosphere. The addition of every cylindroid after
the first one, of equal dimensions adds one cavity and a resisting surface
equal to its length multiplied by its diameter; so after the first one there
is no loss of resisting surface from the convexity of the cylindroids.
Figure is a perspective view of an air ship or acreon as she appeared
on the 4th of September 1863, on the ascending plane, having over two
hundred pounds ascending power and describing a spiral circle upwards
not less then one and a half miles in circumference. She made twenty
revolutions in one and a quarter minutes, when she was lost to view in the
upper strata of clouds; the first eleven revolutions were made in seven
minutes, the last three revolutions in three and a half minutes, the
weight in the car being about one hundred and thirty pounds, and the
weight of the cars fifty-eight pounds. Figure 2 is also a view on the
ascending plane; Figure 3 is a view on the descending plane; Figure 4, a
side or horizontal view; Figure 5, a rear view on the plane of the axis;
Figure 6, a front view on the plane of the axis; Figure 7, a view of a war
aerostat on the ascending plane; Figure 8, a view of a common balloon,
with an oblong plane or sail attached below on the ascending plane;
Figure 9 the car or basket with the smaller or inner car to hold the ballast,
such as is used in the aereon Figure 1.

page_text: single rope
tackles and
The ballast
The object of
Figures 4, 5, and 6 represent a side view and front and rear elevations
or sectional views as perfectly as can be done. The outlines are all that
can be shown, as nothing visible is contained within but the three valve
cords passing through from the top to the bottom of each cylindroid. The
main car a, Figure 1, is twelve feet long, the bottom a curved line or arc of
a circle of thirty degrees, and the width fifteen inches, the upper part being
made of willowwork spreading a little towards the top. An inner car b,
on runners like a sled, of the same curve as the bottom of the main car,
three feet long and just wide enough to slide inside; the main car is
secured in its place by a three-fold tackle at each end, the
passing over the top of the inner car, thus connecting both
holding the inner car in any position or place in the main car.
is placed in the inner car, which also serves for a seat.
placing the ballast in the inner car is to move it if necessary towards either
end of the main car, in order to change the inclination of the aerostat by
changing its centre of gravity. In ordinary cases the weight of the
aeronaut alone will be sufficient to produce this effect; he has only to
change his place fore or aft for the purpose. By moving a less or greater
distance from the centre of the car he can give the aerostat an inclination
of five, ten, or fifteen degrees, the latter being quite sufficient for all
ordinary purposes and seldom required. I found but one occasion to move
the inner car with the ballast from its central position, and that was when
she made her spiral flight when I was not in the car. The angles of
inclination may also be changed by hauling in the cords from the bow end
and slacking those on the stern end of the aereon, and vice versa; also by
hauling a weight out from the car towards the bow or stern by means of a
tackle or running rigging. In all the Figures the car is shown in its proper
position sixteen feet below the centre of the acrostat; but whether that is
the best distance of suspension can be only known by further experiment.
Figure 9 shows the cars on a larger scale; b, the inner car. Short cleats
are fastened on the bottom of the car, the runners of the inner car
straddling them. They are to give the aeronaut foothold to walk to the
upper end to change the angle of inclination of the acreon. The three
cylindroids (C, Figure 1) composing this air vessel or aereon were made of
varnished linen each one eighty feet long and thirteen feet in diameter.
Forty-eight feet of their central portions were perfectly cylindrical; at the
distance of sixteen feet from each end they began to taper to a point.
They were secured together at their longitudinal equators by membraneous
portions of the linen of which they were made. These membraneous

page_text: portions were left on the outer edge of the linen, overlapping about two
inches one of the longitudinal scams of the two outside cylindroids, also
in two opposite seams of the middle cylindroids. Where the cylindroids
began to diverge from each other, membranes or diaphragms d, Figure 1,
of cambric muslin, cut to fit the curved lines forward by the sixteen-feet
points, were sewn fast to the two-inch membranes, and fitted up with a flat
surface, the otherwise open spaces between them. A net of cotton twine
(plainly seen in the Figure) was thrown over the whole, extending from end
the end, and below the equators on the outside cylindrical portions, where
it terminated in thirty points on each side for the attachment of cords.
Between the cylindroids the net was brought down to the membranes by
two long strips of light wood two and a half inches wide in their central
portions by three-eighths of an inch in thickness, and diminishing in width
to one inch at their ends. These strips of wood were placed edgewise on
the net, and rested on it and on the limen membrane connecting the
cylindroids. Where these strips of wood come in contact with each other
(forty-eight feet of their length) they were fastened together by screws.
The ends of these strips were bent to the curved sides of the sixteen-feet
points of the cylindroids, and two meeting each other at the front and rear
ends of the middle cylindroid were fastened together at their ends by a
brass plate bent over their ends and screwed on. Two similar strips e,
were placed on the outside equators of the two outer cylindroids, and were
kept there by being passed through the meshes of the net. These joined
the inside strips of wood at the front and rear ends of the outside cylin-
droids, the same as the middle one before stated. To these strips of wood
or framework the net was secured on each side of the sixteen-feet points
of the cylindroids, as seen at Figure 1. In each of the six pointed ends
of the three cylindroids were conical pieces of cork five inches diameter at
their base, and the linen was tied tightly over them. Through these corks
strong cord passed out to secure the pointed ends of the cylindroids to the
framework. Thirty cords passed down from the net on the outside of each
outside cylindroid to the car below, one cord from each point of the net,
as shown in the Figure. Thirty cords were also passed up through each
of the two membranes between the cylindroids twenty inches apart;
they also passed through the net and were fastened to the longitudinal
strips of wood or frame above it. Thus there were four rows of cords of
thirty each, or a total number of one hundred and twenty cords, passing
down from the net to secure the car below. These cords are shown in
all the Figures of this machine. Where the strips of wood or frame joined

page_text: on the rear end of the middle cylindroid they were allowed to extend past
each other four inches, and were locked together at their crossing. Here
was screwed on the top and bottom plates of brass, with suitable holes
through them to support the rudder post g' on this four-inch extension of
the frame. The rudder post rested by a shoulder on the top plate h, and
the upper and lower ends were stayed by cords fastened to the frame on
the rear end of the middle cylindroid, about eight feet from the point
where the cords connected with the rudder post, they were fastened to
stiff pieces of leather having suitable holes in them for the rudder post to
turn in. The rudder was made of cambric muslin, triangular in form,
kept extended by reeds or bamboo projecting from the rudder post. It
contained only seventeen square feet of surface and was abundantly large.
It was controlled by cords or rudder ropes passing through pulleys
attached to the frame near the ends of the outside cylindroids, and thence
down to the rear end of the car, where they passed through-other pulleys
one on each side, and were extended along the border of the car to the
forward end where they were secured, leaving sufficient slack for the
motion of the rudder. The object of this was that the rudder ropes could
be always reached by the aeronaut without changing his place in the car.
The car was suspended on four rings or hoops (shown in the Figure) made
of strong wood five inches in diameter, and surrounded by ropes. From
these rings twenty-four cords passed down underneath the car, twelve at
each end. They were much stronger than the cords from the net. These
cords were woven through the upper rim of the basket or willow work,
and were secured also at the bottom of the car. The cords from the net
were attached to these rings or hoops, thirty to each ring, and these rings
constituted two or rather four foci for the suspension of the car. In the
side view, Figure 4, two foci can be seen, as also in the end views, Figures
5 and 6; but in Figures 1 and 3 the four are distinctly visible. The
attachment of these cords to the rings was peculiar, and the result of
experiments showed that the best plan was to cross them, as
Figure, every other cord on a side going to the most distant
on the same side. Thus if all the weight in the car was
extreme end of the car it would bear equally on the whole
aerostat whilst it changed its centre of gravity. In this
weight should be suspended by half the number of cords.
three cylindroids were open on the lower side or bottom,
diameter at their lower ends.
tubes K eleven feet long and one foot in
These tubes were kept open by spiral steel hoops or coils.
shown in the
ring or focus
placed in the
length of the
case the chief
Each of the
they having
There were

page_text: also three valves of ordinary construction for balloons with openings five
inches square in the upper part of the three cylindroids, one in each, with
valve cords passing down to the car. The cord of the centre valve passed
down through the centre tube; those of the two outside cylindroids
were neither central nor vertical over the said tubes, but a little aft, and
on the outer side of the central line of the top. Each of these valve cords
passed through the opposite side of the cylindroid in a direct line to the
car, and where it passed out through the varnished linen thin pieces of
light wood four inches square were screwed together, one on the inside
and the other on the outside of the varnished linen of the cylindroid.
Between these pieces of wood in their centre was a piece of india-rubber
or caoutchouc one inch in diameter, in which was the hole for the valve
cord to pass through. These valve cords were covered with tallow where
they operate in these holes. In the bottom of the car was an angulometer
made as follows:-Between the cleats on the bottom were longitudinal
strips of wood placed three-quarters of an inch apart, near the central line,
and as high as the top of the cleats. This constituted grooves between
the cleats, in each one of which was placed a small ball or marble such as
boys play with, and as each of the several marbles rolled from their natural
positions towards either end of the car it was indicated whether the car
had an angle of inclination of five, ten, or fifteen degrees, the bottom of
the car being a curve line or arc of a circle of thirty degrees, as before
stated, and the angle of inclination of the aerostal being produced by the
position of the aeronaut or the ballast in the clongated car. A common
spherical balloon can be made to travel by its construction, though it is
the worst possible shape for locomotion. By making an oblong disc or
sail and suspending it below the balloon above the car, as shown at Figure
8, it will, if sufficiently large, force the balloon even against the wind.
Placed on the equator of the balloon it does not operate so well. The
balloon takes off more than half the effect of its sliding motion, and also
makes it very difficult to preserve its position, requiring much greater
weight below to hold it steady. The disc sail or flat frame on the top
will not answer the purpose, as it makes it top-heavy, all the weight of an
aerostat must be kept as much as possible below.
Figure 8 shows a twelve-fect diameter balloon of this description, which
carried up seventeen pounds, including the weight of the disc or sail,
and with three and a half pounds ascension power resisted a two-mile
current or breeze. Toy balloons of ten-inch diameter are made to move
across a room on this plan without any difficulty by nsing tissue paper for

page_text: the disc or oblong sail. In the balloon, Figure 8, the disc or oblong sail is
movable on an axis at the focal ring 1. The cords which support it above
pass through the blocks suspended to the net, one of which is shown at s.
The hauling cords pass down from the lower side of the disc to the car.
The car may be made like an ordinary basket as the aeronaut is stationary.
When elongated cylindroids are used they should be filled with spheres or
common balloons making a compound aerostat, not only to divide the
aerostat into compartments for safety, but to enable the aeronaut to control
the balancing of the machine. When tilted the gas in the simple acrostat
will rush to the upper end, and the atmospheric pressure on the outside
will collapse the bottom and make it heavy, or if it be admitted to the
inside below to keep it full at all times it will act as dead weight just the
same, for the air will not quickly and readily mix with the hydrogen gas,
and so become generally diffused. With carburetted hydrocarbon it may do
better, I have not tried it. I had fifteen, balloons of twelve féél diameter
and six balloons of seven feet diameter made of cambric muslin to fill my
three cylindroids (Figure 1) When I tried the first experiment fourteen
of them were inflated in the two outside cylindroids; I afterwards took
them out and made my other experiments with the cylindroids alone,
taking the risk, and obtaining one hundred and eighty pounds more
ascensive power.
From these experiments, I come to the following con-
clusion, viz.. the best shape or form for practical purposes for each simple
aerostat will be that wherein the greatest elongation can be had, and
at the same time preserve the bottom nearest to a perpendicular line
extending through the centre of gravity in any angle of inclination which
may be required. As these can never be made to coincide in all positions
or angles of inclination which may obtain, except in a perfect sphere, and
as in the greater elongation the bottom will necessarily be thrown farther
from the said lime, it is obvious that there will be found by experiments a
happy medium for the comparative length and diameter of any simple
aerostat. In a compound aerostat, as before described, greater deviation
may be allowed, and doubtless improved shapes will be made to approxi-
mate the above rule. The best shapes now known to me, and I know of
nobody else who knows from experience anything about it, is that of
Figure 7, the diameter of which is two-fifths of its length. In this an
angle of inclination of fifteen degrees may be had, while the centre of the
bottom will not approach the ends nearer than one-fifth or one-sixth of
the length; thus atmospheric air admitted through the open tubes below
K, and resting on the hottom, will never be entirely outside the said line,

page_text: and consequently the aerostat will be securely held in any position which
may be assumed by the aeronaut. This gives a centre of stability. Two
of these will make a perfect machine in its simplest form, each of them
made separately, pointed at the bow end, and rounded at the other; each
one covered by a separate net in the plainest and simplest manner, having
about six points on each side for the attachment of cords, and to be well
secured to the aerostat at both ends. This can be done by passing net-
work or cords entirely around the acrostat some few feet from each end.
When inflated for use they must be brought together side by side, and the
network and cords will naturally hold them in that position. A membrane
or diaphragm attached to the two ncts will connect them together and fill
up the otherwise open space between them. This membrane is made in
two halves, one half attached to each net at the horizontal equator of the
acrostat; of course one edge of each half membrane is a curved line, and
the other edge is a straight line. The curved edges are attached to the
nets. When brought together the straight edges of the membranes are
tied to a longitudinal strip of wood (W, Figure 7,) running the whole
length of the acrostats and extending a few feet beyond their ends; the
straight edges of the membranes extend to the points of this longitudinal
strip or bar of wood. To support the weight of this bar of wood towards
its ends, cords may connect it with the top of the nets. The rudder has
its seat on the stern end of this bar of wood. This membrane may be as
wide as you please, provided you keep the acrostats apart by some inflexible
fixtures; but there is sufficient resting surface for all ordinary purposes
by allowing them to come in contact at their sides in their central portions.
They will press together and be flattened there a few feet. If they be
kept a little distance apart without adding too much weight by fixtures,
of course the machine will operate much better. The longitudinal bar of
wood may be made in parts to be put together like a fishing rod. This
acreon just described is particularly designed as a war aerostat. It can be
taken apart readily and each aerostat folded up separately, and the bar of
wood in short pieces can be easily carried. It is highly probable, however,
that the longitudinal bar may be dispensed with; I have never tried the
experiment without some kind of extending framework, but in every
experiment I have found that some part previously used was unnecessary,
and I am now satisfied that all the framework really required is enough to
keep the bow points extended to resist the pressure of the air in a rapid
motion and to support the rudder. The aerostats will preserve their forms,
whatever shape they be, if kept full, and they are kept full at all times by

page_text: the admission of air through the open tubes at the bottom. I know that
for an ordinary rate of speed no framework is necessary, except that of
the rudder itself. The most important feature in the construction of this
machine, as well as that of Figure 1, is the longitudinal cavity extending
from end to end formed by the junction of two cylindrical bodies, both
on the upper and under side, as herein-before stated. In the machine.
Figure 1, there were double cavities, and she slid, as is were, on two
atmospheric rails. In the war aerostat, Figure 7, she will slide only on
one atmospheric rail.
Having described the nature of this Invention, and the manner of
performing the same, I declare that what I claim as the Invention to be
protected by the herein-before in part recited Letters Patent is,-
First, the conversion of the perpendicular motion of the balloon or
aerostat into a forward or horizontal motion by means of the construction
or the form thereof, so as to make it ascend and descend on inclined
planes in the atmosphere.
Secondly, the arrangement beneath a balloon of an elliptical or oblong
form to give it a semi-horizontal motion or a forward movement.
Thirdly, constructing a balloon in the form of a cylindroid, as described.
Fourthly, the combination of two or more cylindroids, so as to produce
a concavity between them for their resisting surface.
Fifthly, the changing of the inclination of the aereon or aerostat by
changing its centre of gravity, and the changing of the inclination of the
disc or oblong sail, substantially as shown and described.
Sixthly, the arrangement of an angulometer in the aerial car substantially
as described.
In witness whereof, I, the said William Clark, have hereunto set
my hand and seal, this Eighteenth day of June, in the year of our
Lord One thousand eight hundred and sixty-six.
0
Witness,
JAMES DAISH,
53. Chancery Lane,
London.
W. CLARK. (L.S.)