A Project for Flying by Robert Hardley
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Robert Hardley >> A Project for Flying
A Project for Flying.
In Earnest at Last!
1871
Price, TWENTY-FIVE CENTS.
A Project for Flying.
In Earnest At Last.
The following appeared in one of our public journals of the date
indicated
_To the Editor of the Tribune._
SIR:--You rightly appreciate the interest with which the popular
mind regards all efforts in the direction of navigating the air.
One man of my acquaintance was deeply interested to know the
results of the California Experiment, because he alone, as he believed,
had questioned Nature and learned from her the great secret of aerial
navigation.
To-day's _Tribune_ brings us the full account of the machine, its
performance and _modus operandi_; and without the authority of my
friend, I can pronounce at once that the thing is simply ridiculous. It is
the same old useless effort, with the same impossible agents. But to-day,
within twenty miles of Trinity steeple, lives the man who can give to
the world the secret of navigating the air, in calm or in storm, with
the wind or against it; skimming the earth, or in the highest currents,
just as he wills, with all the ease, and all the swiftness, and all the
exactitude of a bird.
My friend is only waiting for an opportunity to perfect his plan, when
he will make it known.
Yours truly,
W.H.K.
_New York; June 14th_, 1869.
Two years have passed and no progress has been made in aerial
navigation.
The California Experiment failed. The great Airship "CITY OF NEW
YORK," had previously escaped the same fate, only because more prudent
than her successor she declined a trial. The promising and ambitious
enterprise of Mr. Henson has hardly been spoken of for a quarter of a
century. And notwithstanding the fact that the number of ascensions in
balloons in the United States and Europe must be counted by thousands,
and although the exigencies of recent wars have made them useful, yet
it must be confessed that the art of navigating the air remains in
much the same state in which the brothers Montgolfiers left it at the
close of the last century.
The reason for this want of progress in the art referred to, is not to
be sought in any want of interest in the subject, or of enthusiasm in
prosecuting experiments. Certainly not for want of interest in the
subject because _to fly_, has been the great desideratum of
the race since Adam. And we find in the literature of every age
suggestions for means of achieving flight through the air, in
imitation of birds; or for the construction of ingenious machines for
aerial navigation. And if history and traditions are to be credited,
it would be equally an error to suppose that our age alone had
attempted to put theory into practice in reference to navigating the
air.
Even the fables of the ancients abound with stories about flying: that
of Dedalus and his son Icarius, will occur to every reader. And the
representations of the POETS, and the allusions in HOLY WRIT equally
prove how natural and dear to the mind of man is the idea of
possessing "wings like a dove."
But it is safe enough to assert, that hitherto, all attempts at
_navigating_ the air have been failures.
Floating through the atmosphere in a balloon, at the mercy not only of
every _wind_ but of every _breath_ of air, is in no adequate
sense aerial navigation. And I do not hesitate to say, that balloons
are absolutely incapable of being directed.
All the analogies by which inventors have been encouraged in their
expectations are false, the rudders of ships and the tails of birds
are no exceptions. They will never be able to guide balloons as
sailors do ships, by a rudder, because ships do not float suspended
in the water as balloons float in the air; nor do birds _float_
through the air in any sense. They are not bouyant--lighter than the
element in which they move, but immensely heavier; besides they do not
guide themselves wholly by their tails. We may depend upon it, if we
ever succeed in navigating the air, it will be by a strict adherence
to the principles upon which birds fly, and a close imitation of the
means which they employ to effect that object.
It is true, that in respect to the means to be employed, animals
designed by the Creator for flight, have greatly the advantage of us,
but what natural deficiencies will not human ingenuity supply, and
what obstacles will not human skill overcome? It has already triumphed
over much greater than any that Nature has interposed between man and
the pleasures of aerial communication.
We have to a great extent, mastered the mysterious elements of nature.
We have conquered the thunderbolt and learned to write with the
burning fluid out of which it is forged.
We have converted the boundless ocean into a vast highway, traversed
for our use and on our errands, by the swift agent, and by great ships
driven against wind and tide by the mighty power of steam.
And yet a single generation ago, we knew nothing of all this, Our
grand-sires would have given these achievements a prominent place in
the list of impossible things.
But, do you say, "the Creator never intended us to
fly--_therefore_, it is impossible."
For what did the Creator give us skill and boundless perseverance?
Was it designed that we should _swim_, more than that we should
furnish ourselves with wings and mount up as eagles? "We sink like
lead in the mighty waters," we only fall a little faster through the
air.
Still, I grant that the problem of aerial navigation will only be
solved when the principles of flight are clearly understood, and we
recognize precisely what are the obstacles which prevent us from
flying by artificial means.
Will these obstacles prove insuperable? It is at present believed by
the multitude that they will, but I entertain a different opinion,
most decidedly.
From my earliest youth this subject has occupied my thoughts. It
has been the study of my life, and I modestly trust that I have not
questioned nature and science in vain.
In the first place, I undertook to make myself familiar with the
obstacles to be overcome. I found the greatest of these to be gravity.
I found, however, that heavy fowls, who were unable to rise _from
the earth_, and only accomplished flight by taking advantage of an
eminence, sustained themselves without difficulty when once fairly
embarked. I also found that the best flyers were not equal to the feat
of keeping me company, when walking at my usual pace; hence I inferred
that _velocity_ was a necessary element in flight, and that
gravity, so fatal to human attempts to fly, might be made a powerful
auxiliary when rightly used.
Acting upon this hint, I made experiments with heavy barn yard fowls,
and finally constructed a light apparatus to be operated by myself,
using, principally, my feet as a motive power, which I repeatedly
tried with various and _constantly increasing_ degrees of
success.
Now I am satisfied that my system is right. It is my sober conviction
that the time to realize the dream and hope of ages has come.
Startling as the announcement may be, I propose not only to make short
excursions through the air myself, but to teach others to do the same.
Yet, knowing perfectly the obstacles in the way of flight, and knowing
equally well how to overcome them, I am yet well aware that I must
perfect my knowledge by practice before entire success can be
achieved.
This is only reasonable.
How was it with the swimmer; how was it with the agile and dexterous
skater; how with the acrobat, and what but practice has just enabled
WESTON to walk one hundred and twelve miles in twenty-four hours, and
four hundred miles in five days?
For want of a better name, I will call the machine upon which I am to
practice, the "Instructor." It is simple, but it gives the learner
just what he wants--an endless series of _inclined planes_.
It will prevent accidents, and until the student has mastered the
mechanical movements necessary to flight, will supplement his efforts
by partially balancing his weight.
It consists of a beam fifty feet long, poised and attached by a
universal joint to the top of a form post, say twenty feet or more in
height. Upon one end of this beam the practitioner stands, arrayed in
his wings. A movable weight at the other end completes the apparatus;
and yet this simple machine, will form the entering wedge to aerial
navigation.
And now methinks I see you smile, but, my unbelieving friends, let me
remind you that COPERNICUS, and GALILEO, and FRANKLIN, and FULTON,
and MORSE,--all better men than your humble servant, were laughed at
before me.
_Their_ work is done. Their monuments stand in all lands, and yet
_one_ of this band of truly great and worthy names still lives,
and to him I am indebted for many kind and encouraging words.
It is little besides this that I ask of _you_. The stock which
you are solicited to take in this enterprise is small. But enable me
by your patronage to devote myself for a time wholly to my project.
See to it, that I do not fail for want of support. Buy my little
pamphlet at its insignificant cost, ask your friends to do so; and
should any of you wish to contribute anything more to this cause,
which I have made my own, and which I am determined to push to
a triumphant issue, he may be sure that he will receive the
acknowledgments of a grateful and earnest man, who has himself devoted
to it the aspirations and efforts of a long life, and who is still
willing to take all the risks of failure upon himself.
The undersigned would be pleased to have friends interested in this
subject, call upon him, when the matter will be more fully described.
ROBERT HARDLEY,
17 PERRY STREET, or
114 Sixth Ave., cor. 9th St.
[Illustration: THE AERIAL MACHINE.]
REMARKS ON THE ELLIPSOIDAL BALLOON,
PROPELLED BY THE
_Archimedean Screw_,
DESCRIBED AS THE NEW AERIAL MACHINE,
NOW EXHIBITING AT THE ROYAL ADELAIDE GALLERY, LOWTHER ARCADE, STRAND.
REMARKS, &c.
The object proposed in the construction of the Machine which is here
presented to the public view, is simply to illustrate and establish
the fact, that, by a proper disposition of parts and the application
of a sufficient power, it is possible to effectuate the propulsion or
guidance of a Balloon through the air, and thus to prepare the way for
the more perfect accomplishment of this most interesting and desirable
result.
In the contrivance of this design, one of the first effects aimed
at was to reduce the resistance experienced by the Balloon in its
progress, which is greater or less according to the magnitude and
shape of its opposing surface. To this intent is the peculiar
_form_ of the Balloon, which is an _Ellipsoid_ or _prolate
spheroid_, the axis of which is twice its minor diameter; in
other words, twice as long as it is broad. By this construction the
opposition to the progress of the Balloon in the direction of either
end is only one _half_ of what it would be, had it been a Balloon
of the ordinary spherical form and of the same diametrical magnitude.
For the exact determination of this proportion we are more
particularly indebted to the researches of Sir George Cayley, a
distinguished patron of the art, who, a few years back, instituted a
series of experiments with a view to ascertain the comparative amounts
of resistance developed by bodies of different forms in passing
through the air; the results of which he communicated to the world in
an essay first published in the Mechanic's Magazine, and afterwards in
a separate pamphlet. According to these experiments it appears, that
the opposition which an ellipsoid or oval (of the nature of the
Balloon, if we may so call it, in the model) is calculated to
encounter in proceeding _endways_ through the atmosphere is only
_one-sixth_ of what a _plane_ or _flat_ surface of equal area with its
largest vertical section, would experience at the same rate; while the
resistance to the progress of a globe, such as the usual Balloon, would
be one third of that due to a similar circular plane of like diameter:
shewing an advantage, in respect of diminished resistance, in favour of
the former figure, to the extent we have above described; an advantage it
enjoys along with an increased capacity for containing gas--the cubical
contents of an ellipsoid of the proportions here observed, being exactly
double of those of an ordinary Balloon of equal diameter, and
consequently competent to the support of twice the weight.
Independent of the advantage of reduced resistance in this form, there
is another of nearly, if not quite, equal importance, in the facility
it affords of directing its course; an object scarcely, if at all,
attainable with a Balloon of the usual description however powerfully
invested with the means of motion; as any one will readily perceive
who has ever noticed or experienced the difficulty, or rather the
impossibility, of guiding a tub afloat in the water, compared with the
condition of a boat or other similarly constructed body, in the same
element. The efficacy of this provision and its necessity will appear
more forcibly when we observe that whenever the Balloon in the machine
here described is thrown out of its direct bearing by the shifting of
the net-work which connects it with the hoop, or by any other accident
whereby its position is altered with respect to the propelling power,
its course is immediately affected, and it ceases to progress in a
straight line, following the direction of its major axis, unless
corrected by the intervention of a sufficient rudder.
The second object, after establishing a proper form for the floating
body, was to contrive a disposition of striking surface that should
be able to realise the greatest amount of propulsive re-action, in
proportion to its magnitude and the force of its operation, which it
is possible to accomplish. To shew by what steps and in consequence of
what reasoning this point was determined as in the plan adopted, would
occupy considerably more space than the few pages we have to spare
would admit of our devoting to it. Suffice it to say that of all the
means of creating a resistance in the atmosphere capable of being
applied to the propulsion of the Balloon, the Archimedean Screw
was ascertained to be undoubtedly the best. It is true that by a
_direct_ impact or stroke upon the air, as for instance by the
action of a fan, or the wafting of any _flat_ surface at _right
angles_ to its own plane, the maximum effect is accomplished
which such a surface is capable of producing with a given power. The
mechanical difficulties, however, which attend the employment of such
a mode of operation are more than sufficient to counterbalance any
advantage in point of actual resistance which it may happen to
possess; at least in any application of it which has hitherto been
tried or proposed: so that here, as in the case of ships propelled
by steam, the _oblique_ impact obtained by the rotation of the
striking surface is found to be the most conducive to the desired
result; and of these, that arrangement which is termed the Archimedean
Screw is the most effective.
The result aimed at, being the development of the greatest amount of
re-action in the direction of the axis of revolution, it is not enough
to have determined the _general_ character of the instrument
to be employed; the proper disposition or inclination of its parts
becomes a question of the first importance. According as the
_turns_ of the screw are more or less oblique with respect to the
air they strike or the axis on which they revolve, more or less of the
resistance they generate by their rotation becomes _resolved_, as
it is technically expressed, in the direction of the intended course:
in other words, converted to the purpose in view, namely, the
propulsion of the Balloon.
Our limited space here again prevents us from entering into a detail
of the experiments by means of which the true solution of this
question has been arrived at, and the proper angle determined at which
the superficial spiral exercises the greatest amount of propulsive
force of which such an engine is capable. These experiments have been
chiefly carried on by Mr. Smith, the ingenious and successful adapter
of this instrument to the propulsion of steam vessels, for a series of
years, with the greatest care, and at a very considerable expense; and
the result of his experience gives an angle of about 67 deg. or 68 deg. for
the outer circumference of the screw, as that productive of the
maximum effect; a conclusion which is further verified by the
experiments of Sir George Cayley, of Mr. Charles Green, the most
celebrated of our practical aeronauts, and others who have employed
their attention upon the subject. This conclusion requires only one
modification, which ought to be noticed; namely, that in cases of
extreme velocity, the number of the angle may be still further
increased with advantage, until an inclination of about 73 deg. be
obtained; when it appears any further advance in that direction is
attended with a loss of power. With these facts in view, the impinging
surface of the Archimedean Screw, in the model under consideration,
has been so disposed as to form, at its outer circumference, an angle
of 68 deg. with the axis of revolution, gradually diminishing as it
approaches the centre, according to the essential character of such a
form of structure.
The novelty of the application of this instrument to the propulsion
both of ships and balloons, suggests the propriety of a few more
explanatory remarks to elucidate its nature and meet certain
objections which those who are ignorant of its peculiar qualities are
apt to raise in respect of it.
Previous to the adoption of this particular instrument, various
analogous contrivances had been resorted to in order to produce the
same effects. Of these, examples are afforded in the sails of the
windmill, the vane of the smoke jack, and of more modern introduction,
the _propellers_ designed by Mr. Taylor for the equipment of
steam-boats, and which Mr. Green has availed himself of to shew
the effect of atmospheric re-action in directing the course of the
balloon. Now all these and similar expedients are merely modifications
of the same principle, more or less perfect as they more or less
resemble the perfect screw, but all falling far short of the efficacy
of that instrument in its primitive character and construction. The
reason of this deficiency can be readily accounted for. All the
modifications alluded to, which have hitherto been applied to the
purposes of locomotion, are adaptations of _plane_ surfaces.
Now it is the character of _plane_ surfaces to present the
same angle, and consequently to impinge upon the air with the same
condition of obliquity throughout. But the _rate_ of revolution,
and consequently of impact, varies according to the distance from the
axis; being greatest at the outer edge, and gradually diminishing as
it approaches the centre of rotation, where it may be supposed to be
altogether evanescent. Now it is by the re-action of the air against
_one_ side of the impinging plane, that the progressive motion is
determined in the opposite direction, which re-action is proportioned
to the _rate_ of impact, the angle remaining the same. If then
we suppose a re-action corresponding to the _greatest rate_ of
revolution, which is that due to the _outermost_ portion of the
impinging surface (that most removed from the axis of rotation) we
shall have a _progressive_ motion in the whole apparatus greater
than the rate of impact of the _innermost_ or more central
portions of the revolving plane; and accordingly the re-action will be
thereabouts transferred from the back to the front of the propulsive
apparatus, and tend to retard instead of advancing the progress of
the machine to which it is attached. This inconvenience is felt and
acknowledged by all those who have employed this principle to obtain a
progressive motion, and accordingly a provision has been made against
it in the _removal_ or _reduction_ of the central portion
of the revolving vanes, with a view to let the air escape or pass
through as the instrument advances; a provision which is certainly
effectual to that end, but at the cost of the _surface_, which is
the ultimate source of the required re-action. All this is avoided
in the use of the perfect screw. There, the rate of rotation and the
angle of impact mutually corresponding, may be said to play into each
other's hands; the spiral becoming more extended as the impact becomes
less forcible, that is as it approaches the centre, where both
altogether vanish or disappear; thus obviating the possibility of any
interruption to the course of the machine from the contrarious impact
of the air, however quick or however slow the motions, either of the
screw itself or of the machine which is propelled by its operation. In
attestation of this fact and as showing the immunity of the perfect
screw from the disparaging effects experienced by the other modes of
accomplishing the same object, I will only mention a circumstance
related to me by Mr. Smith himself, to whom I am glad to acknowledge
myself indebted for so much valuable information respecting this
instrument, which, by the light he has thrown upon its use and the
improvements he has introduced into its construction, he may be truly
said to have made his own. Upon a late occasion, when trying one of
the larger class of vessels which had just been furnished by him upon
this principle, some persons not perceiving the true nature of the
figure employed, contended that some opposition must be experienced by
the central portion of the screw, which revolved so much less rapidly
than the rate of the ship itself. In order to convince them of their
error, Mr. Smith caused a portion of the surface in question, next the
axis, to a certain distance, to be cut away, leaving an opening, by
which, for the water to escape. The result was, immediately the loss
of one mile an hour in the rate of the ship; thus shewing that even
the most apparently feeble portion of the impinging surface of this
instrument contributes, in its degree, to the constitution of the
aggregate force of which it is productive.
This peculiarity of construction is the main cause of the advantage
which the Archimedean Screw possesses over all its types or
imitations; but it is not the only one. The _entirety_ or
_unbroken continuity_ of its surface is another, not much less
influential. The value of this will be the more readily appreciated
when we consider that air, unlike water and other non-elastic fluids,
undergoes a rarefaction or impoverishment of density, and consequently
of resisting power, accordingly as it is swept away by the rapid
passage of impinging planes; the parts immediately _behind_, and
to a considerable distance, being thereby relieved from the support
they had previously experienced, and extending (and consequently
becoming thinner) in order to fill up the space thus partially cleared
away. Now it is evident that if other planes be brought into operation
in the parts of the atmosphere thus impoverished, before they have
had time to recover their pristine or natural density, they will
of necessity act with diminished vigour; the resistance being ever
proportioned to the density of the resisting medium. This is the
condition into which, more or less, all systems of revolving planes
are necessarily brought, that consist of more than one; and is a
grand cause of the little real effect they have been made capable
of producing, whenever tried. The nature of this objection, and the
extent to which it operates, will appear most strikingly from the
following fact. Mr. Henson's scheme of flight is founded upon the
principle of an inclined plane, started from an eminence by an
extrinsic force, applied and _continued_ by the revolution
of impinging vanes, in form and number resembling the sails of a
windmill. In the experiments which were made in this gallery with
several models of this proposed construction, it was found that so far
from _aiding_ the machine in its flight, the operation of these
vanes actually _impeded_ its progress; inasmuch as it was always
found to proceed to a greater distance by the mere force of acquired
velocity (which is the only force it ever displayed), than when
the vanes were set in motion to aid it--a simple fact, which it is
unnecessary to dilate upon. It is to the agency of this cause, namely,
the broken continuity of surface, that, I have no doubt, is also to be
ascribed the failure of the attempt of Sir George Cayley to propel a
Balloon of a somewhat similar shape to the present, which he made at
the Polytechnic Institution a short while since, when he employed
a series of revolving vanes, four in number, disposed at proper
intervals around, but which were found ineffectual to move it. Had
these separate surfaces been thrown into _one_, of the nature
and form of the Archimedean Screw, there is little doubt that the
experiment would have been attended with a different result. In
accordance with the principles here illustrated, the Archimedean
Screw properly consists of only _one_ turn; more than one being
productive of no more resistance, and consequently superfluous. A
single unbroken turn of the screw, however, when the diameter is of
any magnitude, would require a considerable length of axis, which in
its adaptation to the Balloon, would be practically objectionable;
accordingly _two half turns_, nearly equivalent in power to one
whole turn, has been preferred; as in most instances it has been by
Mr. Smith, himself, in his application of it to the navigation of the
seas,