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A History of Aeronautics by E. Charles Vivian

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A History of Aeronautics
by E. Charles Vivian

FOREWORD

Although successful heavier-than-air flight is less than two
decades old, and successful dirigible propulsion antedates it by
a very short period, the mass of experiment and accomplishment
renders any one-volume history of the subject a matter of
selection. In addition to the restrictions imposed by space
limits, the material for compilation is fragmentary, and, in
many cases, scattered through periodical and other publications.
Hitherto, there has been no attempt at furnishing a detailed
account of how the aeroplane and the dirigible of to-day came to
being, but each author who has treated the subject has devoted
his attention to some special phase or section. The principal
exception to this rule--Hildebrandt--wrote in 1906, and a good
many of his statements are inaccurate, especially with regard to
heavier-than-air experiment.

Such statements as are made in this work are, where possible,
given with acknowledgment to the authorities on which they rest.
Further acknowledgment is due to Lieut.-Col. Lockwood Marsh,
not only for the section on aeroplane development which he has
contributed to the work, but also for his kindly assistance and
advice in connection with the section on aerostation. The
author's thanks are also due to the Royal Aeronautical Society
for free access to its valuable library of aeronautical
literature, and to Mr A. Vincent Clarke for permission to make
use of his notes on the development of the aero engine.

In this work is no claim to originality--it has been a matter
mainly of compilation, and some stories, notably those of the
Wright Brothers and of Santos Dumont, are better told in the
words of the men themselves than any third party could tell
them. The author claims, however, that this is the first
attempt at recording the facts of development and stating, as
fully as is possible in the compass of a single volume, how
flight and aerostation have evolved. The time for a critical
history of the subject is not yet.

In the matter of illustrations, it has been found very difficult
to secure suitable material. Even the official series of
photographs of aeroplanes in the war period is curiously
incomplete' and the methods of censorship during that period
prevented any complete series being privately collected.
Omissions in this respect will probably be remedied in future
editions of the work, as fresh material is constantly being
located.

E.C.V. October, 1920.

CONTENTS
Part I--THE EVOLUTION OF THE AEROPLANE
I. THE PERIOD OF LEGEND
II. EARLY EXPERIMENTS
III. SIR GEORGE CAYLEY--THOMAS WALKER
IV. THE MIDDLE NINETEENTH CENTURY
V. WENHAM, LE BRIS, AND SOME OTHERS
VI. THE AGE OF THE GIANTS
VII. LILIENTHAL AND PILCHER
VIII. AMERICAN GLIDING EXPERIMENTS
IX. NOT PROVEN
X. SAMUEL PIERPOINT LANGLEY
XI. THE WRIGHT BROTHERS
XII. THE FIRST YEARS OF CONQUEST
XIII. FIRST FLIERS IN ENGLAND
XIV. RHEIMS, AND AFTER
XV. THE CHANNEL CROSSING
XVI. LONDON TO MANCHESTER
XVII. A SUMMARY--TO 1911
XVIII. A SUMMARY--TO 1914
XIX. THE WAR PERIOD--I
XX. THE WAR PERIOD--II
XXI. RECONSTRUCTION
XXII. 1919-1920

Part II--1903-1920: PROGRESS IN DESIGN
I. THE BEGINNINGS
II. MULTIPLICITY OF IDEAS
III. PROGRESS ON STANDARDISED LINES
IV. THE WAR PERIOD

Part III--AEROSTATICS
I. BEGINNINGS
II. THE FIRST DIRIGIBLES
III. SANTOS-DUMONT
IV. THE MILITARY DIRIGIBLE
V. BRITISH AIRSHIP DESIGN
VI. THE AIRSHIP COMMERCIALLY
VII. KITE BALLOONS

PART IV--ENGINE DEVELOPMENT
I. THE VERTICAL TYPE
II. THE VEE TYPE
III. THE RADIAL TYPE
IV. THE ROTARY TYPE
V. THE HORIZONTALLY-OPPOSED ENGINE
VI. THE TWO-STROKE CYCLE ENGINE
VII. ENGINES OF THE WAR PERIOD

APPENDICES

PART I

THE EVOLUTION OF THE AEROPLANE

I. THE PERIOD OF LEGEND

The blending of fact and fancy which men call legend reached its
fullest and richest expression in the golden age of Greece, and
thus it is to Greek mythology that one must turn for the best
form of any legend which foreshadows history. Yet the
prevalence of legends regarding flight, existing in the records
of practically every race, shows that this form of transit was a
dream of many peoples--man always wanted to fly, and imagined
means of flight.

In this age of steel, a very great part of the inventive genius
of man has gone into devices intended to facilitate transport,
both of men and goods, and the growth of civilisation is in
reality the facilitation of transit, improvement of the means of
communication. He was a genius who first hoisted a sail on a
boat and saved the labour of rowing; equally, he who first
harnessed ox or dog or horse to a wheeled vehicle was a
genius--and these looked up, as men have looked up from the
earliest days of all, seeing that the birds had solved the
problem of transit far more completely than themselves. So it
must have appeared, and there is no age in history in which some
dreamers have not dreamed of the conquest of the air; if the
caveman had left records, these would without doubt have showed
that he, too, dreamed this dream. His main aim, probably, was
self-preservation; when the dinosaur looked round the corner,
the prehistoric bird got out of the way in his usual manner, and
prehistoric man such of him as succeeded in getting out of the
way after his fashion--naturally envied the bird, and concluded
that as lord of creation in a doubtful sort of way he ought to
have equal facilities. He may have tried, like Simon the
Magician, and other early experimenters, to improvise those
facilities; assuming that he did, there is the groundwork of
much of the older legend with regard to men who flew, since,
when history began, legends would be fashioned out of attempts
and even the desire to fly, these being compounded of some small
ingredient of truth and much exaggeration and addition.

In a study of the first beginnings of the art, it is worth while
to mention even the earliest of the legends and traditions, for
they show the trend of men's minds and the constancy of this
dream that has become reality in the twentieth century. In one
of the oldest records of the world, the Indian classic
Mahabarata, it is stated that 'Krishna's enemies sought the aid
of the demons, who built an aerial chariot with sides of iron
and clad with wings. The chariot was driven through the sky till
it stood over Dwarakha, where Krishna's followers dwelt, and
from there it hurled down upon the city missiles that destroyed
everything on which they fell.' Here is pure fable, not legend,
but still a curious forecast of twentieth century bombs from a
rigid dirigible. It is to be noted in this case, as in many,
that the power to fly was an attribute of evil, not of good--it
was the demons who built the chariot, even as at Friedrichshavn.
Mediaeval legend in nearly every cas,attributes flight to the
aid of evil powers, and incites well-disposed people to stick to
the solid earth--though, curiously enough, the pioneers of
medieval times were very largely of priestly type, as witness
the monk of Malmesbury.

The legends of the dawn of history, however, distribute the
power of flight with less of prejudice. Egyptian sculpture gives
the figure of winged men; the British Museum has made the winged
Assyrian bulls familiar to many, and both the cuneiform records
of Assyria and the hieroglyphs of Egypt record flights that in
reality were never made. The desire fathered the story then,
and until Clement Ader either hopped with his Avion, as is
persisted by his critics, or flew, as is claimed by his friends.

While the origin of many legends is questionable, that of others
is easy enough to trace, though not to prove. Among the
credulous the significance of the name of a people of Asia
Minor, the Capnobates, 'those who travel by smoke,' gave rise to
the assertion that Montgolfier was not first in the field--or
rather in the air--since surely this people must have been
responsible for the first hot-air balloons. Far less
questionable is the legend of Icarus, for here it is possible to
trace a foundation of fact in the story. Such a tribe as
Daedalus governed could have had hardly any knowledge of the
rudiments of science, and even their ruler, seeing how easy it
is for birds to sustain themselves in the air, might be excused
for believing that he, if he fashioned wings for himself, could
use them. In that belief, let it be assumed, Daedalus made his
wings; the boy, Icarus, learning that his father had determined
on an attempt at flight secured the wings and fastened them to
his own shoulders. A cliff seemed the likeliest place for a
'take-off,' and Icarus leaped from the cliff edge only to find
that the possession of wings was not enough to assure flight to
a human being. The sea that to this day bears his name
witnesses that he made the attempt and perished by it.

In this is assumed the bald story, from which might grow the
legend of a wise king who ruled a peaceful people--'judged,
sitting in the sun,' as Browning has it, and fashioned for
himself wings with which he flew over the sea and where he
would, until the prince, Icarus, desired to emulate him.
Icarus, fastening the wings to his shoulders with wax, was so
imprudent as to fly too near the sun, when the wax melted and he
fell, to lie mourned of water-nymphs on the shores of waters
thenceforth Icarian. Between what we have assumed to be the
base of fact, and the legend which has been invested with such
poetic grace in Greek story, there is no more than a century or
so of re-telling might give to any event among a people so
simple and yet so given to imagery.

We may set aside as pure fable the stories of the winged horse
of Perseus, and the flights of Hermes as messenger of the gods.
With them may be placed the story of Empedocles, who failed to
take Etna seriously enough, and found himself caught by an
eruption while within the crater, so that, flying to safety in
some hurry, he left behind but one sandal to attest that he had
sought refuge in space--in all probability, if he escaped at
all, he flew, but not in the sense that the aeronaut understands
it. But, bearing in mind the many men who tried to fly in
historic times, the legend of Icarus and Daedalus, in spite of
the impossible form in which it is presented, may rank with the
story of the Saracen of Constantinople, or with that of Simon
the Magician. A simple folk would naturally idealise the man
and magnify his exploit, as they magnified the deeds of some
strong man to make the legends of Hercules, and there,
full-grown from a mere legend, is the first record of a pioneer
of flying. Such a theory is not nearly so fantastic as that
which makes the Capnobates, on the strength of their name, the
inventors of hot-air balloons. However it may be, both in story
and in picture, Icarus and his less conspicuous father have
inspired the Caucasian mind, and the world is the richer for
them.

Of the unsupported myths--unsupported, that is, by even a shadow
of probability--there is no end. Although Latin legend
approaches nearer to fact than the Greek in some cases, in
others it shows a disregard for possibilities which renders it
of far less account. Thus Diodorus of Sicily relates that one
Abaris travelled round the world on an arrow of gold, and
Cassiodorus and Glycas and their like told of mechanical birds
that flew and sang and even laid eggs. More credible is the
story of Aulus Gellius, who in his Attic Nights tells how
Archytas, four centuries prior to the opening of the Christian
era, made a wooden pigeon that actually flew by means of a
mechanism of balancing weights and the breath of a mysterious
spirit hidden within it. There may yet arise one credulous
enough to state that the mysterious spirit was precursor of the
internal combustion engine, but, however that may be, the pigeon
of Archytas almost certainly existed, and perhaps it actually
glided or flew for short distances--or else Aulus Gellius was an
utter liar, like Cassiodorus and his fellows. In far later
times a certain John Muller, better known as Regiomontanus, is
stated to have made an artificial eagle which accompanied
Charles V. on his entry to and exit from Nuremberg, flying above
the royal procession. But, since Muller died in 1436 and
Charles was born in 1500, Muller may be ruled out from among the
pioneers of mechanical flight, and it may be concluded that the
historian of this event got slightly mixed in his dates.

Thus far, we have but indicated how one may draw from the
richest stores from which the Aryan mind draws inspiration, the
Greek and Latin mythologies and poetic adaptations of history.
The existing legends of flight, however, are not thus to be
localised, for with two possible exceptions they belong to all
the world and to every civilisation, however primitive. The two
exceptions are the Aztec and the Chinese; regarding the first of
these, the Spanish conquistadores destroyed such civilisation as
existed in Tenochtitlan so thoroughly that, if legend of flight
was among the Aztec records, it went with the rest; as to the
Chinese, it is more than passing strange that they, who claim to
have known and done everything while the first of history was
shaping, even to antedating the discovery of gunpowder that was
not made by Roger Bacon, have not yet set up a claim to
successful handling of a monoplane some four thousand years ago,
or at least to the patrol of the Gulf of Korea and the Mongolian
frontier by a forerunner of the 'blimp.'

The Inca civilisation of Peru yields up a myth akin to that of
Icarus, which tells how the chieftain Ayar Utso grew wings and
visited the sun--it was from the sun, too, that the founders of
the Peruvian Inca dynasty, Manco Capac and his wife Mama Huella
Capac, flew to earth near Lake Titicaca, to make the only
successful experiment in pure tyranny that the world has ever
witnessed. Teutonic legend gives forth Wieland the Smith, who
made himself a dress with wings and, clad in it, rose and
descended against the wind and in spite of it. Indian mythology,
in addition to the story of the demons and their rigid dirigible,
already quoted, gives the story of Hanouam, who fitted himself
with wings by means of which he sailed in the air and, according
to his desire, landed in the sacred Lauka. Bladud, the ninth
king of Britain, is said to have crowned his feats of wizardry by
making himself wings and attempting to fly--but the effort cost
him a broken neck. Bladud may have been as mythic as Uther, and
again he may have been a very early pioneer. The Finnish epic,
'Kalevala,' tells how Ilmarinen the Smith 'forged an eagle of
fire,' with 'boat's walls between the wings,' after which he
'sat down on the bird's back and bones,' and flew.

Pure myths, these, telling how the desire to fly was
characteristic of every age and every people, and how, from time
to time, there arose an experimenter bolder than his fellows,
who made some attempt to translate desire into achievement. And
the spirit that animated these pioneers, in a time when things
new were accounted things accursed, for the most part, has found
expression in this present century in the utter daring and
disregard of both danger and pain that stamps the flying man, a
type of humanity differing in spirit from his earthbound fellows
as fully as the soldier differs from the priest.

Throughout mediaeval times, records attest that here and there
some man believed in and attempted flight, and at the same
time it is clear that such were regarded as in league with the
powers of evil. There is the half-legend, half-history of
Simon the Magician, who, in the third year of the reign of Nero
announced that he would raise himself in the air, in order to
assert his superiority over St Paul. The legend states that by
the aid of certain demons whom he had prevailed on to assist
him, he actually lifted himself in the air-- but St Paul prayed
him down again. He slipped through the claws of the demons and
fell headlong on the Forum at Rome, breaking his neck. The
'demons' may have been some primitive form of hot-air balloon,
or a glider with which the magician attempted to rise into the
wind; more probably, however, Simon threatened to ascend and
made the attempt with apparatus as unsuitable as Bladud's wings,
paying the inevitable penalty. Another version of the story
gives St Peter instead of St Paul as the one whose prayers
foiled Simon --apart from the identity of the apostle, the two
accounts are similar, and both define the attitude of the age
toward investigation and experiment in things untried.

Another and later circumstantial story, with similar evidence of
some fact behind it, is that of the Saracen of Constantinople,
who, in the reign of the Emperor Comnenus--some little time
before Norman William made Saxon Harold swear away his crown on
the bones of the saints at Rouen--attempted to fly round the
hippodrome at Constantinople, having Comnenus among the great
throng who gathered to witness the feat. The Saracen chose for
his starting-point a tower in the midst of the hippodrome, and
on the top of the tower he stood, clad in a long white robe which
was stiffened with rods so as to spread and catch the breeze,
waiting for a favourable wind to strike on him. The wind was so
long in coming that the spectators grew impatient. 'Fly, O
Saracen!' they called to him. 'Do not keep us waiting so long
while you try the wind!' Comnenus, who had present with him the
Sultan of the Turks, gave it as his opinion that the experiment
was both dangerous and vain, and, possibly in an attempt to
controvert such statement, the Saracen leaned into the wind and
'rose like a bird 'at the outset. But the record of Cousin, who
tells the story in his Histoire de Constantinople, states that
'the weight of his body having more power to drag him down than
his artificial wings had to sustain him, he broke his bones, and
his evil plight was such that he did not long survive.'

Obviously, the Saracen was anticipating Lilienthal and his
gliders by some centuries; like Simon, a genuine
experimenter--both legends bear the impress of fact supporting
them. Contemporary with him, and belonging to the history
rather than the legends of flight, was Oliver, the monk of
Malmesbury, who in the year 1065 made himself wings after the
pattern of those supposed to have been used by Daedalus,
attaching them to his hands and feet and attempting to fly with
them. Twysden, in his Historiae Anglicanae Scriptores X, sets
forth the story of Oliver, who chose a high tower as his
starting-point, and launched himself in the air. As a matter of
course, he fell, permanently injuring himself, and died some
time later.

After these, a gap of centuries, filled in by impossible stories
of magical flight by witches, wizards, and the like--imagination
was fertile in the dark ages, but the ban of the church was on
all attempt at scientific development, especially in such a
matter as the conquest of the air. Yet there were observers of
nature who argued that since birds could raise themselves by
flapping their wings, man had only to make suitable wings, flap
them, and he too would fly. As early as the thirteenth century
Roger Bacon, the scientific friar of unbounded inquisitiveness
and not a little real genius, announced that there could be made
'some flying instrument, so that a man sitting in the middle and
turning some mechanism may put in motion some artificial wings
which may beat the air like a bird flying.' But being a cautious
man, with a natural dislike for being burnt at the stake as a
necromancer through having put forward such a dangerous theory,
Roger added, 'not that I ever knew a man who had such an
instrument, but I am particularly acquainted with the man who
contrived one.' This might have been a lame defence if Roger had
been brought to trial as addicted to black arts; he seems to
have trusted to the inadmissibility of hearsay evidence.

Some four centuries later there was published a book entitled
Perugia Augusta, written by one C. Crispolti of Perugia--the
date of the work in question is 1648. In it is recorded that
'one day, towards the close of the fifteenth century, whilst
many of the principal gentry had come to Perugia to honour the
wedding of Giovanni Paolo Baglioni, and some lancers were riding
down the street by his palace, Giovanni Baptisti Danti
unexpectedly and by means of a contrivance of wings that he had
constructed proportionate to the size of his body took off from
the top of a tower near by, and with a horrible hissing sound
flew successfully across the great Piazza, which was densely
crowded. But (oh, horror of an unexpected accident!) he had
scarcely flown three hundred paces on his way to a certain point
when the mainstay of the left wing gave way, and, being unable to
support himself with the right alone, he fell on a roof and was
injured in consequence. Those who saw not only this flight, but
also the wonderful construction of the framework of the wings,
said--and tradition bears them out--that he several times flew
over the waters of Lake Thrasimene to learn how he might
gradually come to earth. But, notwithstanding his great genius,
he never succeeded.'

This reads circumstantially enough, but it may be borne in mind
that the date of writing is more than half a century later than
the time of the alleged achievement--the story had had time to
round itself out. Danti, however, is mentioned by a number of
writers, one of whom states that the failure of his experiment
was due to the prayers of some individual of a conservative turn
of mind, who prayed so vigorously that Danti fell appropriately
enough on a church and injured himself to such an extent as to
put an end to his flying career. That Danti experimented, there
is little doubt, in view of the volume of evidence on the point,
but the darkness of the Middle Ages hides the real truth as to
the results of his experiments. If he had actually flown over
Thrasimene, as alleged, then in all probability both Napoleon
and Wellington would have had air scouts at Waterloo.

Danti's story may be taken as fact or left as fable, and with it
the period of legend or vague statement may be said to end--the
rest is history, both of genuine experimenters and of
charlatans. Such instances of legend as are given here are not a
tithe of the whole, but there is sufficient in the actual history
of flight to bar out more than this brief mention of the legends,
which, on the whole, go farther to prove man's desire to fly than
his study and endeavour to solve the problems of the air.

II. EARLY EXPERIMENTS

So far, the stories of the development of flight are either
legendary or of more or less doubtful authenticity, even
including that of Danti, who, although a man of remarkable
attainments in more directions than that of attempted flight,
suffers--so far as reputation is concerned--from the
inexactitudes of his chroniclers; he may have soared over
Thrasimene, as stated, or a mere hop with an ineffectual glider
may have grown with the years to a legend of gliding flight. So
far, too, there is no evidence of the study that the conquest of
the air demanded; such men as made experiments either launched
themselves in the air from some height with made-up wings or
other apparatus, and paid the penalty, or else constructed some
form of machine which would not leave the earth, and then gave
up. Each man followed his own way, and there was no
attempt--without the printing press and the dissemination of
knowledge there was little possibility of attempt--on the part
of any one to benefit by the failures of others.

Legend and doubtful history carries up to the fifteenth century,
and then came Leonardo da Vinci, first student of flight whose
work endures to the present day. The world knows da Vinci as
artist; his age knew him as architect, engineer, artist, and
scientist in an age when science was a single study, comprising
all knowledge from mathematics to medicine. He was, of course,
in league with the devil, for in no other way could his range of
knowledge and observation be explained by his contemporaries; he
left a Treatise on the Flight of Birds in which are statements
and deductions that had to be rediscovered when the Treatise had
been forgotten--da Vinci anticipated modern knowledge as Plato
anticipated modern thought, and blazed the first broad trail
toward flight.

One Cuperus, who wrote a Treatise on the Excellence of Man,
asserted that da Vinci translated his theories into practice,
and actually flew, but the statement is unsupported. That he
made models, especially on the helicopter principle, is past
question; these were made of paper and wire, and actuated by
springs of steel wire, which caused them to lift themselves in
the air. It is, however, in the theories which he put forward
that da Vinci's investigations are of greatest interest; these
prove him a patient as well as a keen student of the principles
of flight, and show that his manifold activities did not prevent
him from devoting some lengthy periods to observations of bird
flight.

'A bird,' he says in his Treatise, 'is an instrument working
according to mathematical law, which instrument it is within the
capacity of man to reproduce with all its movements, but not
with a corresponding degree of strength, though it is deficient
only in power of maintaining equilibrium. We may say,
therefore, that such an instrument constructed by man is lacking
in nothing except the life of the bird, and this life must needs
be supplied from that of man. The life which resides in the
bird's members will, without doubt, better conform to their needs
than will that of a man which is separated from them, and
especially in the almost imperceptible movements which produce
equilibrium. But since we see that the bird is equipped for many
apparent varieties of movement, we are able from this experience
to deduce that the most rudimentary of these movements will be
capable of being comprehended by man's understanding, and that he
will to a great extent be able to provide against the destruction
of that instrument of which he himself has become the living
principle and the propeller.'

In this is the definite belief of da Vinci that man is capable
of flight, together with a far more definite statement of the
principles by which flight is to be achieved than any which had
preceded it--and for that matter, than many that have succeeded
it. Two further extracts from his work will show the exactness
of his observations:--

'When a bird which is in equilibrium throws the centre of
resistance of the wings behind the centre of gravity, then such
a bird will descend with its head downward. This bird which
finds itself in equilibrium shall have the centre of resistance
of the wings more forward than the bird's centre of gravity;
then such a bird will fall with its tail turned toward the
earth.'

And again: 'A man, when flying, shall be free from the waist
up, that he may be able to keep himself in equilibrium as he
does in a boat, so that the centre of his gravity and of the
instrument may set itself in equilibrium and change when
necessity requires it to the changing of the centre of its
resistance.'

Here, in this last quotation, are the first beginnings of the
inherent stability which proved so great an advance in design,
in this twentieth century. But the extracts given do not begin
to exhaust the range of da Vinci's observations and deductions.
With regard to bird flight, he observed that so long as a bird
keeps its wings outspread it cannot fall directly to earth, but
must glide down at an angle to alight--a small thing, now that
the principle of the plane in opposition to the air is generally
grasped, but da Vinci had to find it out. From observation he
gathered how a bird checks its own speed by opposing tail and
wing surface to the direction of flight, and thus alights at the
proper 'landing speed.' He proved the existence of upward air
currents by noting how a bird takes off from level earth with
wings outstretched and motionless, and, in order to get an
efficient substitute for the natural wing, he recommended that
there be used something similar to the membrane of the wing of a
bat--from this to the doped fabric of an aeroplane wing is but
a small step, for both are equally impervious to air. Again, da
Vinci recommended that experiments in flight be conducted at a
good height from the ground, since, if equilibrium be lost
through any cause, the height gives time to regain it. This
recommendation, by the way, received ample support in the
training areas of war pilots.

Man's muscles, said da Vinci, are fully sufficient to enable him
to fly, for the larger birds, he noted, employ but a small part
of their strength in keeping themselves afloat in the air--by
this theory he attempted to encourage experiment, just as, when
his time came, Borelli reached the opposite conclusion and
discouraged it. That Borelli was right--so far--and da Vinci
wrong, detracts not at all from the repute of the earlier
investigator, who had but the resources of his age to support
investigations conducted in the spirit of ages after.

His chief practical contributions to the science of
flight--apart from numerous drawings which have still a
value--are the helicopter or lifting screw, and the parachute.
The former, as already noted, he made and proved effective in
model form, and the principle which he demonstrated is that of
the helicopter of to-day, on which sundry experimenters work
spasmodically, in spite of the success of the plane with its
driving propeller. As to the parachute, the idea was doubtless
inspired by observation of the effect a bird produced by
pressure of its wings against the direction of flight.

Da Vinci's conclusions, and his experiments, were forgotten
easily by most of his contemporaries; his Treatise lay forgotten
for nearly four centuries, overshadowed, mayhap, by his other
work. There was, however, a certain Paolo Guidotti of Lucca,
who lived in the latter half of the sixteenth century, and who
attempted to carry da Vinci's theories--one of them, at least,
into practice. For this Guidotti, who was by profession an
artist and by inclination an investigator, made for himself
wings, of which the framework was of whalebone; these he covered
with feathers, and with them made a number of gliding flights,
attaining considerable proficiency. He is said in the end to
have made a flight of about four hundred yards, but this attempt
at solving the problem ended on a house roof, where Guidotti
broke his thigh bone. After that, apparently, he gave up the
idea of flight, and went back to painting.

One other a Venetian architect named Veranzio. studied da
Vinci's theory of the parachute, and found it correct, if
contemporary records and even pictorial presentment are correct.
Da Vinci showed his conception of a parachute as a sort of
inverted square bag; Veranzio modified this to a 'sort of square
sail extended by four rods of equal size and having four cords
attached at the corners,' by means of which 'a man could without
danger throw himself from the top of a tower or any high place.
For though at the moment there may be no wind, yet the effort of
his falling will carry up the wind, which the sail will hold, by
which means he does not fall suddenly but descends little by
little. The size of the sail should be measured to the man.' By
this last, evidently, Veranzio intended to convey that the sheet
must be of such content as would enclose sufficient air to
support the weight of the parachutist.

Veranzio made his experiments about 1617-1618, but, naturally,
they carried him no farther than the mere descent to earth, and
since a descent is merely a descent, it is to be conjectured that
he soon got tired of dropping from high roofs, and took to
designing architecture instead of putting it to such a use. With
the end of his experiments the work of da Vinci in relation to
flying became neglected for nearly four centuries.

Apart from these two experimenters, there is little to record in
the matter either of experiment or study until the seventeenth
century. Francis Bacon, it is true, wrote about flying in his
Sylva Sylvarum, and mentioned the subject in the New Atlantis,
but, except for the insight that he showed even in superficial
mention of any specific subject, he does not appear to have made
attempt at serious investigation. 'Spreading of Feathers, thin
and close and in great breadth will likewise bear up a great
Weight,' says Francis, 'being even laid without Tilting upon the
sides.' But a lesser genius could have told as much, even in
that age, and though the great Sir Francis is sometimes adduced
as one of the early students of the problems of flight, his
writings will not sustain the reputation.

The seventeenth century, however, gives us three names, those of
Borelli, Lana, and Robert Hooke, all of which take definite
place in the history of flight. Borelli ranks as one of the
great figures in the study of aeronautical problems, in spite of
erroneous deductions through which he arrived at a purely
negative conclusion with regard to the possibility of human
flight.

Borelli was a versatile genius. Born in 1608, he was
practically contemporary with Francesco Lana, and there is
evidence that he either knew or was in correspondence with many
prominent members of the Royal Society of Great Britain, more
especially with John Collins, Dr Wallis, and Henry Oldenburgh,
the then Secretary of the Society. He was author of a long list
of scientific essays, two of which only are responsible for his
fame, viz., Theorice Medicaearum Planetarum, published in
Florence, and the better known posthumous De Motu Animalium. The
first of these two is an astronomical study in which Borelli
gives evidence of an instinctive knowledge of gravitation,
though no definite expression is given of this. The second
work, De Motu Animalium, deals with the mechanical action of
the limbs of birds and animals and with a theory of the action
of the internal organs. A section of the first part of this
work, called De Volatu, is a study of bird flight; it is quite
independent of Da Vinci's earlier work, which had been forgotten
and remained unnoticed until near on the beginning of practical
flight.

Marey, in his work, La Machine Animale, credits Borelli with the
first correct idea of the mechanism of flight. He says:
'Therefore we must be allowed to render to the genius of Borelli
the justice which is due to him, and only claim for ourselves
the merit of having furnished the experimental demonstration of
a truth already suspected.' In fact, all subsequent studies on
this subject concur in making Borelli the first investigator who
illustrated the purely mechanical theory of the action of a
bird's wings.

Borelli's study is divided into a series of propositions in
which he traces the principles of flight, and the mechanical
actions of the wings of birds. The most interesting of these
are the propositions in which he sets forth the method in which
birds move their wings during flight and the manner in which the
air offers resistance to the stroke of the wing. With regard to
the first of these two points he says: 'When birds in repose
rest on the earth their wings are folded up close against their
flanks, but when wishing to start on their flight they first
bend their legs and leap into the air. Whereupon the joints of
their wings are straightened out to form a straight line at
right angles to the lateral surface of the breast, so that the
two wings, outstretched, are placed, as it were, like the arms
of a cross to the body of the bird. Next, since the wings with
their feathers attached form almost a plane surface, they are
raised slightly above the horizontal, and with a most quick
impulse beat down in a direction almost perpendicular to the
wing-plane, upon the underlying air; and to so intense a beat
the air, notwithstanding it to be fluid, offers resistance,
partly by reason of its natural inertia, which seeks to retain
it at rest, and partly because the particles of the air,
compressed by the swiftness of the stroke, resist this
compression by their elasticity, just like the hard ground.
Hence the whole mass of the bird rebounds, making a fresh leap
through the air; whence it follows that flight is simply a
motion composed of successive leaps accomplished through the
air. And I remark that a wing can easily beat the air in a
direction almost perpendicular to its plane surface, although
only a single one of the corners of the humerus bone is attached
to the scapula, the whole extent of its base remaining free and
loose, while the greater transverse feathers are joined to the
lateral skin of the thorax. Nevertheless the wing can easily
revolve about its base like unto a fan. Nor are there lacking
tendon ligaments which restrain the feathers and prevent them
from opening farther, in the same fashion that sheets hold in
the sails of ships. No less admirable is nature's cunning in
unfolding and folding the wings upwards, for she folds them not
laterally, but by moving upwards edgewise the osseous parts
wherein the roots of the feathers are inserted; for thus,
without encountering the air's resistance the upward motion of
the wing surface is made as with a sword, hence they can be
uplifted with but small force. But thereafter when the wings
are twisted by being drawn transversely and by the resistance of
the air, they are flattened as has been declared and will be
made manifest hereafter.'

Then with reference to the resistance to the air of the wings he
explains: 'The air when struck offers resistance by its elastic
virtue through which the particles of the air compressed by the
wing-beat strive to expand again. Through these two causes of
resistance the downward beat of the wing is not only opposed,
but even caused to recoil with a reflex movement; and these two
causes of resistance ever increase the more the down stroke of
the wing is maintained and accelerated. On the other hand, the
impulse of the wing is continuously diminished and weakened by
the growing resistance. Hereby the force of the wing and the
resistance become balanced; so that, manifestly, the air is
beaten by the wing with the same force as the resistance to the
stroke.'

He concerns himself also with the most difficult problem that
confronts the flying man of to-day, namely, landing effectively,
and his remarks on this subject would be instructive even to an
air pilot of these days: 'Now the ways and means by which the
speed is slackened at the end of a flight are these. The bird
spreads its wings and tail so that their concave surfaces are
perpendicular to the direction of motion; in this way, the
spreading feathers, like a ship's sail, strike against the still
air, check the speed, and so that most of the impetus may be
stopped, the wings are flapped quickly and strongly forward,
inducing a contrary motion, so that the bird absolutely or very
nearly stops.'

At the end of his study Borelli came to a conclusion which
militated greatly against experiment with any heavier-than-air
apparatus, until well on into the nineteenth century, for having
gone thoroughly into the subject of bird flight he states
distinctly in his last proposition on the subject that 'It is
impossible that men should be able to fly craftily by their own
strength.' This statement, of course, remains true up to the
present day for no man has yet devised the means by which he can
raise himself in the air and maintain himself there by mere
muscular effort.

From the time of Borelli up to the development of the steam
engine it may be said that flight by means of any
heavier-than-air apparatus was generally regarded as impossible,
and apart from certain deductions which a little experiment
would have shown to be doomed to failure, this method of flight
was not followed up. It is not to be wondered at, when
Borelli's exaggerated estimate of the strength expended by birds
in proportion to their weight is borne in mind; he alleged that
the motive force in birds' wings is 10,000 times greater than
the resistance of their weight, and with regard to human flight
he remarks:--

'When, therefore, it is asked whether men may be able to fly by
their own strength, it must be seen whether the motive power of
the pectoral muscles (the strength of which is indicated and
measured by their size) is proportionately great, as it is
evident that it must exceed the resistance of the weight of the
whole human body 10,000 times, together with the weight of
enormous wings which should be attached to the arms. And it is
clear that the motive power of the pectoral muscles in men is
much less than is necessary for flight, for in birds the bulk and
weight of the muscles for flapping the wings are not less than a
sixth part of the entire weight of the body. Therefore, it would
be necessary that the pectoral muscles of a man should weigh
more than a sixth part of the entire weight of his body; so also
the arms, by flapping with the wings attached, should be able to
exert a power 10,000 times greater than the weight of the human
body itself. But they are far below such excess, for the
aforesaid pectoral muscles do not equal a hundredth part of the
entire weight of a man. Wherefore either the strength of the
muscles ought to be increased or the weight of the human body
must be decreased, so that the same proportion obtains in it as
exists in birds. Hence it is deducted that the Icarian
invention is entirely mythical because impossible, for it is not
possible either to increase a man's pectoral muscles or to
diminish the weight of the human body; and whatever apparatus is
used, although it is possible to increase the momentum, the
velocity or the power employed can never equal the resistance;
and therefore wing flapping by the contraction of muscles cannot
give out enough power to carry up the heavy body of a man.'

It may be said that practically all the conclusions which
Borelli reached in his study were negative. Although
contemporary with Lana, he perceived the one factor which
rendered Lana's project for flight by means of vacuum globes an
impossibility--he saw that no globe could be constructed
sufficiently light for flight, and at the same time sufficiently
strong to withstand the pressure of the outside atmosphere. He
does not appear to have made any experiments in flying on his
own account, having, as he asserts most definitely, no faith in
any invention designed to lift man from the surface of the
earth. But his work, from which only the foregoing short
quotations can be given, is, nevertheless, of indisputable
value, for he settled the mechanics of bird flight, and paved
the way for those later investigators who had, first, the steam
engine, and later the internal combustion engine--two factors in
mechanical flight which would have seemed as impossible to
Borelli as would wireless telegraphy to a student of Napoleonic
times. On such foundations as his age afforded Borelli built
solidly and well, so that he ranks as one of the greatest--if
not actually the greatest--of the investigators into this
subject before the age of steam.

The conclusion, that 'the motive force in birds' wings is
apparently ten thousand times greater than the resistance of
their weight,' is erroneous, of course, but study of the
translation from which the foregoing excerpt is taken will show
that the error detracts very little from the value of the work
itself. Borelli sets out very definitely the mechanism of
flight, in such fashion that he who runs may read. His
reference to 'the use of a large vessel,' etc., concerns the
suggestion made by Francesco Lana, who antedated Borelli's
publication of De Motu Animalium by some ten years with his
suggestion for an 'aerial ship,' as he called it. Lana's mind
shows, as regards flight, a more imaginative twist; Borelli
dived down into first causes, and reached mathematical
conclusions; Lana conceived a theory and upheld it--
theoretically, since the manner of his life precluded experiment.

Francesco Lana, son of a noble family, was born in 1631; in 1647
he was received as a novice into the Society of Jesus at Rome,
and remained a pious member of the Jesuit society until the end
of his life. He was greatly handicapped in his scientific
investigations by the vows of poverty which the rules of the
Order imposed on him. He was more scientist than priest all his
life; for two years he held the post of Professor of Mathematics
at Ferrara, and up to the time of his death, in 1687, he spent
by far the greater part of his time in scientific research, He
had the dubious advantage of living in an age when one man could
cover the whole range of science, and this he seems to have done
very thoroughly. There survives an immense work of his entitled,
Magisterium Naturae et Artis, which embraces the whole field of
scientific knowledge as that was developed in the period in
which Lana lived. In an earlier work of his, published in
Brescia in 1670, appears his famous treatise on the aerial ship,
a problem which Lana worked out with thoroughness. He was
unable to make practical experiments, and thus failed to
perceive the one insuperable drawback to his project--of which
more anon.

Only extracts from the translation of Lana's work can be given
here, but sufficient can be given to show fully the means by
which he designed to achieve the conquest of the air. He begins
by mention of the celebrated pigeon of Archytas the Philosopher,
and advances one or two theories with regard to the way in which
this mechanical bird was constructed, and then he recites,
apparently with full belief in it, the fable of Regiomontanus
and the eagle that he is said to have constructed to accompany
Charles V. on his entry into Nuremberg. In fact, Lana starts
his work with a study of the pioneers of mechanical flying up to
his own time, and then outlines his own devices for the
construction of mechanical birds before proceeding to detail the
construction of the aerial ship. Concerning primary experiments
for this he says:--

'I will, first of all, presuppose that air has weight owing to
the vapours and halations which ascend from the earth and seas
to a height of many miles and surround the whole of our
terraqueous globe; and this fact will not be denied by
philosophers, even by those who may have but a superficial
knowledge. because it can be proven by exhausting, if not all,
at any rate the greater part of, the air contained in a glass
vessel, which, if weighed before and after the air has been
exhausted, will be found materially reduced in weight. Then I
found out how much the air weighed in itself in the following
manner. I procured a large vessel of glass, whose neck could be
closed or opened by means of a tap, and holding it open I warmed
it over a fire, so that the air inside it becoming rarified, the
major part was forced out; then quickly shutting the tap to
prevent the re-entry I weighed it; which done, I plunged its
neck in water, resting the whole of the vessel on the surface of
the water, then on opening the tap the water rose in the vessel
and filled the greater part of it. I lifted the neck out of the
water, released the water contained in the vessel, and measured
and weighed its quantity and density, by which I inferred that a
certain quantity of air had come out of the vessel equal in bulk
to the quantity of water which had entered to refill the portion
abandoned by the air. I again weighed the vessel, after I had
first of all well dried it free of all moisture, and found it
weighed one ounce more whilst it was full of air than when it
was exhausted of the greater part, so that what it weighed more
was a quantity of air equal in volume to the water which took
its place. The water weighed 640 ounces, so I concluded that
the weight of air compared with that of water was 1 to 640--that
is to say, as the water which filled the vessel weighed 640
ounces, so the air which filled the same vessel weighed one
ounce.'

Having thus detailed the method of exhausting air from a vessel,
Lana goes on to assume that any large vessel can be entirely
exhausted of nearly all the air contained therein. Then he
takes Euclid's proposition to the effect that the superficial
area of globes increases in the proportion of the square of the
diameter, whilst the volume increases in the proportion of the
cube of the same diameter, and he considers that if one only
constructs the globe of thin metal, of sufficient size, and
exhausts the air in the manner that he suggests, such a globe
will be so far lighter than the surrounding atmosphere that it
will not only rise, but will be capable of lifting weights.
Here is Lana's own way of putting it:--

'But so that it may be enabled to raise heavier weights and to
lift men in the air, let us take double the quantity of copper,
1,232 square feet, equal to 308 lbs. of copper; with this double
quantity of copper we could construct a vessel of not only
double the capacity, but of four times the capacity of the
first, for the reason shown by my fourth supposition.
Consequently the air contained in such a vessel will be 718 lbs.
4 2/3 ounces, so that if the air be drawn out of the vessel it
will be 410 lbs. 4 2/3 ounces lighter than the same volume of
air, and, consequently, will be enabled to lift three men, or at
least two, should they weigh more than eight pesi each. It is
thus manifest that the larger the ball or vessel is made, the
thicker and more solid can the sheets of copper be made, because,
although the weight will increase, the capacity of the vessel
will increase to a greater extent and with it the weight of the
air therein, so that it will always be capable to lift a heavier
weight. From this it can be easily seen how it is possible to
construct a machine which, fashioned like unto a ship, will float
on the air.'

With four globes of these dimensions Lana proposed to make an
aerial ship of the fashion shown in his quaint illustration. He
is careful to point out a method by which the supporting globes
for the aerial ship may be entirely emptied of air; this is to
be done by connecting to each globe a tube of copper which is
'at least a length of 47 modern Roman palm).' A small tap is to
close this tube at the end nearest the globe, and then vessel
and tube are to be filled with water, after which the tube is to
be immersed in water and the tap opened, allowing the water to
run out of the vessel, while no air enters. The tap is then
closed before the lower end of the tube is removed from the
water, leaving no air at all in the globe or sphere. Propulsion
of this airship was to be accomplished by means of sails, and
also by oars.

Lana antedated the modern propeller, and realised that the air
would offer enough resistance to oars or paddle to impart motion
to any vessel floating in it and propelled by these means,
although he did not realise the amount of pressure on the air
which would be necessary to accomplish propulsion. As a matter
of fact, he foresaw and provided against practically all the
difficulties that would be encountered in the working, as well
as the making, of the aerial ship, finally coming up against
what his religious training made an insuperable objection.
This, again, is best told in his own words:--

'Other difficulties I do not foresee that could prevail against
this invention, save one only, which to me seems the greatest of
them all, and that is that God would surely never allow such a
machine to be successful, since it would create many
disturbances in the civil and political governments of mankind.'

He ends by saying that no city would be proof against surprise,
while the aerial ship could set fire to vessels at sea, and
destroy houses, fortresses, and cities by fire balls and bombs.
In fact, at the end of his treatise on the subject, he furnishes
a pretty complete resume of the activities of German Zeppelins.

As already noted, Lana himself, owing to his vows of poverty,
was unable to do more than put his suggestions on paper, which
he did with a thoroughness that has procured him a place among
the really great pioneers of flying.

It was nearly 200 years before any attempt was made to realise
his project; then, in 1843, M. Marey Monge set out to make the
globes and the ship as Lana detailed them. Monge's experiments
cost him the sum of 25,000 francs 75 centimes, which he expended
purely from love of scientific investigation. He chose to make
his globes of brass, about .004 in thickness, and weighing 1.465
lbs. to the square yard. Having made his sphere of this metal,
he lined it with two thicknesses of tissue paper, varnished it
with oil, and set to work to empty it of air. This, however, he
never achieved, for such metal is incapable of sustaining the
pressure of the outside air, as Lana, had he had the means to
carry out experiments, would have ascertained. M. Monge's
sphere could never be emptied of air sufficiently to rise from
the earth; it ended in the melting-pot, ignominiously enough,
and all that Monge got from his experiment was the value of the
scrap metal and the satisfaction of knowing that Lana's theory
could never be translated into practice.

Robert Hooke is less conspicuous than either Borelli or Lana;
his work, which came into the middle of the seventeenth century,
consisted of various experiments with regard to flight, from
which emerged 'a Module, which by the help of Springs and Wings,
raised and sustained itself in the air.' This must be reckoned
as the first model flying machine which actually flew, except
for da Vinci's helicopters; Hooke's model appears to have been
of the flapping-wing type--he attempted to copy the motion of
birds, but found from study and experiment that human muscles
were not sufficient to the task of lifting the human body. For
that reason, he says, 'I applied my mind to contrive a way to
make artificial muscles,' but in this he was, as he expresses
it, 'frustrated of my expectations.' Hooke's claim to fame
rests mainly on his successful model; the rest of his work is of
too scrappy a nature to rank as a serious contribution to the
study of flight.

Contemporary with Hooke was one Allard, who, in France,
undertook to emulate the Saracen of Constantinople to a certain
extent. Allard was a tight-rope dancer who either did or was
said to have done short gliding flights--the matter is open to
question--and finally stated that he would, at St Germains, fly
from the terrace in the king's presence. He made the attempt,
but merely fell, as did the Saracen some centuries before,
causing himself serious injury. Allard cannot be regarded as a
contributor to the development of aeronautics in any way, and is
only mentioned as typical of the way in which, up to the time of
the Wright brothers, flying was regarded. Even unto this day
there are many who still believe that, with a pair of wings, man
ought to be able to fly, and that the mathematical data
necessary to effective construction simply do not exist. This
attitude was reasonable enough in an unlearned age, and Allard
was one--a little more conspicuous than the majority--among many
who made experiment in ignorance, with more or less danger to
themselves and without practical result of any kind.

The seventeenth century was not to end, however, without
practical experiment of a noteworthy kind in gliding flight.
Among the recruits to the ranks of pioneers was a certain
Besnier, a locksmith of Sable, who somewhere between 1675 and
1680 constructed a glider of which a crude picture has come down
to modern times. The apparatus, as will be seen, consisted of
two rods with hinged flaps, and the original designer of the
picture seems to have had but a small space in which to draw,
since obviously the flaps must have been much larger than those
shown. Besnier placed the rods on his shoulders, and worked the
flaps by cords attached to his hands and feet--the flaps opened
as they fell, and closed as they rose, so the device as a whole
must be regarded as a sort of flapping glider. Having by
experiment proved his apparatus successful, Besnier promptly
sold it to a travelling showman of the period, and forthwith set
about constructing a second set, with which he made gliding
flights of considerable height and distance. Like Lilienthal,
Besnier projected himself into space from some height, and then,
according to the contemporary records, he was able to cross a
river of considerable size before coming to earth. It does not
appear that he had any imitators, or that any advantage whatever
was taken of his experiments; the age was one in which he would
be regarded rather as a freak exhibitor than as a serious
student, and possibly, considering his origin and the sale of
his first apparatus to such a client, he regarded the matter
himself as more in the nature of an amusement than as a
discovery.

Borelli, coming at the end of the century, proved to his own
satisfaction and that of his fellows that flapping wing flight
was an impossibility; the capabilities of the plane were as yet
undreamed, and the prime mover that should make the plane
available for flight was deep in the womb of time. Da Vinci's
work was forgotten--flight was an impossibility, or at best such
a useless show as Besnier was able to give.

The eighteenth century was almost barren of experiment. Emanuel
Swedenborg, having invented a new religion, set about inventing
a flying machine, and succeeded theoretically, publishing the
result of his investigations as follows:--

'Let a car or boat or some like object be made of light material
such as cork or bark, with a room within it for the operator.
Secondly, in front as well as behind, or all round, set a
widely-stretched sail parallel to the machine forming within a
hollow or bend which could be reefed like the sails of a ship.
Thirdly, place wings on the sides, to be worked up and down by a
spiral spring, these wings also to be hollow below in order to
increase the force and velocity, take in the air, and make the
resistance as great as may be required. These, too, should be
of light material and of sufficient size; they should be in the
shape of birds' wings, or the sails of a windmill, or some such
shape, and should be tilted obliquely upwards, and made so as to
collapse on the upward stroke and expand on the downward.
Fourth, place a balance or beam below, hanging down
perpendicularly for some distance with a small weight attached
to its end, pendent exactly in line with the centre of gravity;
the longer this beam is, the lighter must it be, for it must
have the same proportion as the well-known vectis or steel-yard.
This would serve to restore the balance of the machine if it
should lean over to any of the four sides. Fifthly, the wings
would perhaps have greater force, so as to increase the
resistance and make the flight easier, if a hood or shield were
placed over them, as is the case with certain insects. Sixthly,
when the sails are expanded so as to occupy a great surface and
much air, with a balance keeping them horizontal, only a small
force would be needed to move the machine back and forth in a
circle, and up and down. And, after it has gained momentum to
move slowly upwards, a slight movement and an even bearing would
keep it balanced in the air and would determine its direction at
will.'

The only point in this worthy of any note is the first device
for maintaining stability automatically--Swedenborg certainly
scored a point there. For the rest. his theory was but theory,
incapable of being put to practice--he does not appear to have
made any attempt at advance beyond the mere suggestion.

Some ten years before his time the state of knowledge with
regard to flying in Europe was demonstrated by an order granted
by the King of Portugal to Friar Lourenzo de Guzman, who claimed
to have invented a flying machine capable of actual flight. The
order stated that 'In order to encourage the suppliant to apply
himself with zeal toward the improvement of the new machine,
which is capable of producing the effects mentioned by him, I
grant unto him the first vacant place in my College of Barcelos
or Santarem, and the first professorship of mathematics in my
University of Coimbra, with the annual pension of 600,000 reis
during his life.--Lisbon, 17th of March, 1709.'

What happened to Guzman when the non-existence of the machine
was discovered is one of the things that is well outside the
province of aeronautics. He was charlatan pure and simple, as
far as actual flight was concerned, though he had some ideas
respecting the design of hot-air balloons, according to
Tissandier. (La Navigation Aerienne.) His flying machine was to
contain, among other devices, bellows to produce artificial wind
when the real article failed, and also magnets in globes to draw
the vessel in an upward direction and maintain its buoyancy.
Some draughtsman, apparently gifted with as vivid imagination as
Guzman himself, has given to the world an illustration of the
hypothetical vessel; it bears some resemblance to Lana's aerial
ship, from which fact one draws obvious conclusions.

A rather amusing claim to solving the problem of flight was
made in the middle of the eighteenth century by one Grimaldi, a
'famous and unique Engineer' who, as a matter of actual fact,
spent twenty years in missionary work in India, and employed the
spare time that missionary work left him in bringing his
invention to a workable state. The invention is described as a
'box which with the aid of clockwork rises in the air, and goes
with such lightness and strong rapidity that it succeeds in
flying a journey of seven leagues in an hour. It is made in the
fashion of a bird; the wings from end to end are 25 feet in
extent. The body is composed of cork, artistically joined
together and well fastened with metal wire, covered with
parchment and feathers. The wings are made of catgut and
whalebone, and covered also with the same parchment and
feathers, and each wing is folded in three seams. In the body
of the machine are contained thirty wheels of unique work, with
two brass globes and little chains which alternately wind up a
counterpoise; with the aid of six brass vases, full of a certain
quantity of quicksilver, which run in some pulleys, the machine
is kept by the artist in due equilibrium and balance. By means,
then, of the friction between a steel wheel adequately tempered
and a very heavy and surprising piece of lodestone, the whole is
kept in a regulated forward movement, given, however, a right
state of the winds, since the machine cannot fly so much in
totally calm weather as in stormy. This prodigious machine is
directed and guided by a tail seven palmi long, which is
attached to the knees and ankles of the inventor by leather
straps; by stretching out his legs, either to the right or to
the left, he moves the machine in whichever direction he
pleases.... The machine's flight lasts only three hours, after
which the wings gradually close themselves, when the inventor,
perceiving this, goes down gently, so as to get on his own feet,
and then winds up the clockwork and gets himself ready again
upon the wings for the continuation of a new flight. He himself
told us that if by chance one of the wheels came off or if one
of the wings broke, it is certain he would inevitably fall
rapidly to the ground, and, therefore, he does not rise more
than the height of a tree or two, as also he only once put
himself in the risk of crossing the sea, and that was from
Calais to Dover, and the same morning he arrived in London.'

And yet there are still quite a number of people who persist in
stating that Bleriot was the first man to fly across the
Channel!

A study of the development of the helicopter principle was
published in France in 1868, when the great French engineer
Paucton produced his Theorie de la Vis d'Archimede. For some
inexplicable reason, Paucton was not satisfied with the term
'helicopter,' but preferred to call it a 'pterophore,' a name
which, so far as can be ascertained, has not been adopted by any
other writer or investigator. Paucton stated that, since a man
is capable of sufficient force to overcome the weight of his own
body, it is only necessary to give him a machine which acts on
the air 'with all the force of which it is capable and at its
utmost speed,' and he will then be able to lift himself in the
air, just as by the exertion of all his strength he is able to
lift himself in water. 'It would seem,' says Paucton, 'that in
the pterophore, attached vertically to a carriage, the whole
built lightly and carefully assembled, he has found something
that will give him this result in all perfection. In
construction, one would be careful that the machine produced the
least friction possible, and naturally it ought to produce
little, as it would not be at all complicated. The new
Daedalus, sitting comfortably in his carriage, would by means of
a crank give to the pterophore a suitable circular (or
revolving) speed. This single pterophore would lift him
vertically, but in order to move horizontally he should be
supplied with a tail in the shape of another pterophore. When
he wished to stop for a little time, valves fixed firmly across
the end of the space between the blades would automatically
close the openings through which the air flows, and change the
pterophore into an unbroken surface which would resist the flow
of air and retard the fall of the machine to a considerable
degree.'

The doctrine thus set forth might appear plausible, but it is
based on the common misconception that all the force which might
be put into the helicopter or 'pterophore' would be utilised for
lifting or propelling the vehicle through the air, just as a
propeller uses all its power to drive a ship through water.
But, in applying such a propelling force to the air, most of the
force is utilised in maintaining aerodynamic support--as a
matter of fact, more force is needed to maintain this support
than the muscle of man could possibly furnish to a lifting
screw, and even if the helicopter were applied to a full-sized,
engine-driven air vehicle, the rate of ascent would depend on
the amount of surplus power that could be carried. For example,
an upward lift of 1,000 pounds from a propeller 15 feet in
diameter would demand an expenditure of 50 horse-power under the
best possible conditions, and in order to lift this load
vertically through such atmospheric pressure as exists at
sea-level or thereabouts, an additional 20 horsepower would be
required to attain a rate of 11 feet per second--50 horse-power
must be continually provided for the mere support of the load,
and the additional 20 horse-power must be continually provided
in order to lift it. Although, in model form, there is nothing
quite so strikingly successful as the helicopter in the range of
flying machines, yet the essential weight increases so
disproportionately to the effective area that it is necessary to
go but very little beyond model dimensions for the helicopter to
become quite ineffective.

That is not to say that the lifting screw must be totally ruled
out so far as the construction of aircraft is concerned. Much
is still empirical, so far as this branch of aeronautics is
concerned, and consideration of the structural features of a
propeller goes to show that the relations of essential weight
and effective area do not altogether apply in practice as they
stand in theory. Paucton's dream, in some modified form, may yet
become reality--it is only so short a time ago as 1896 that Lord
Kelvin stated he had not the smallest molecule of faith in
aerial navigation, and since the whole history of flight
consists in proving the impossible possible, the helicopter may
yet challenge the propelled plane surface for aerial supremacy.

It does not appear that Paucton went beyond theory, nor is there
in his theory any advance toward practical flight--da Vinci
could have told him as much as he knew. He was followed by
Meerwein, who invented an apparatus apparently something between
a flapping wing machine and a glider, consisting of two wings,
which were to be operated by means of a rod; the venturesome one
who would fly by means of this apparatus had to lie in a
horizontal position beneath the wings to work the rod. Meerwein
deserves a place of mention, however, by reason of his
investigations into the amount of surface necessary to support a
given weight. Taking that weight at 200 pounds--which would
allow for the weight of a man and a very light apparatus--he
estimated that 126 square feet would be necessary for support.
His pamphlet, published at Basle in 1784, shows him to have been
a painstaking student of the potentialities of flight.

Jean-Pierre Blanchard, later to acquire fame in connection with
balloon flight, conceived and described a curious vehicle, of
which he even announced trials as impending. His trials were
postponed time after time, and it appears that he became
convinced in the end of the futility of his device, being
assisted to such a conclusion by Lalande, the astronomer, who
repeated Borelli's statement that it was impossible for man ever
to fly by his own strength. This was in the closing days of the
French monarchy, and the ascent of the Montgolfiers' first
hot-air balloon in 1783--which shall be told more fully in its
place--put an end to all French experiments with heavier-
than-air apparatus, though in England the genius of Cayley was
about to bud, and even in France there were those who understood
that ballooning was not true flight.

III. SIR GEORGE CAYLEY--THOMAS WALKER

On the fifth of June, 1783, the Montgolfiers' hot-air balloon
rose at Versailles, and in its rising divided the study of the
conquest of the air into two definite parts, the one being
concerned with the propulsion of gas lifted, lighter-than-air
vehicles, and the other being crystallised in one sentence by
Sir George Cayley: 'The whole problem,' he stated, 'is
confined within these limits, viz.: to make a surface support a
given weight by the application of power to the resistance of
the air.' For about ten years the balloon held the field
entirely, being regarded as the only solution of the problem of
flight that man could ever compass. So definite for a time was
this view on the eastern side of the Channel that for some years
practically all the progress that was made in the development of
power-driven planes was made in Britain.

In 1800 a certain Dr Thomas Young demonstrated that certain
curved surfaces suspended by a thread moved into and not away
from a horizontal current of air, but the demonstration, which
approaches perilously near to perpetual motion if the current be
truly horizontal, has never been successfully repeated, so that
there is more than a suspicion that Young's air-current was NOT
horizontal. Others had made and were making experiments on the
resistance offered to the air by flat surfaces, when Cayley came
to study and record, earning such a place among the pioneers as
to win the title of 'father of British aeronautics.'

Cayley was a man in advance of his time, in many ways. Of
independent means, he made the grand tour which was considered
necessary to the education of every young man of position, and
during this excursion he was more engaged in studies of a
semi-scientific character than in the pursuits that normally
filled such a period. His various writings prove that
throughout his life aeronautics was the foremost subject in his
mind; the Mechanic's Magazine, Nicholson's Journal, the
Philosophical Magazine, and other periodicals of like nature
bear witness to Cayley's continued research into the subject of
flight. He approached the subject after the manner of the
trained scientist, analysing the mechanical properties of air
under chemical and physical action. Then he set to work to
ascertain the power necessary for aerial flight, and was one of
the first to enunciate the fallacy of the hopes of successful
flight by means of the steam engine of those days, owing to the
fact that it was impossible to obtain a given power with a given
weight.

Yet his conclusions on this point were not altogether negative,
for as early as 1810 he stated that he could construct a balloon
which could travel with passengers at 20 miles an hour--he was
one of the first to consider the possibilities of applying power
to a balloon. Nearly thirty years later--in 1837--he made the
first attempt at establishing an aeronautical society, but at
that time the power-driven plane was regarded by the great
majority as an absurd dream of more or less mad inventors, while
ballooning ranked on about the same level as tight-rope walking,
being considered an adjunct to fairs and fetes, more a pastime
than a study.

Up to the time of his death, in 1857, Cayley maintained his
study of aeronautical matters, and there is no doubt whatever
that his work went far in assisting the solution of the problem
of air conquest. His principal published work, a monograph
entitled Aerial Navigation, has been republished in the
admirable series of 'Aeronautical Classics' issued by the Royal
Aeronautical Society. He began this work by pointing out the
impossibility of flying by means of attached wings, an
impossibility due to the fact that, while the pectoral muscles
of a bird account for more than two-thirds of its whole muscular
strength, in a man the muscles available for flying, no matter
what mechanism might be used, would not exceed one-tenth of his
total strength.

Cayley did not actually deny the possibility of a man flying by
muscular effort, however, but stated that 'the flight of a
strong man by great muscular exertion, though a curious and
interesting circumstance, inasmuch as it will probably be the
means of ascertaining finis power and supplying the basis
whereon to improve it, would be of little use.'

From this he goes on to the possibility of using a Boulton and
Watt steam engine to develop the power necessary for flight, and
in this he saw a possibility of practical result. It is worthy
of note that in this connection he made mention of the
forerunner of the modern internal combustion engine; 'The
French,' he said, 'have lately shown the great power produced by
igniting inflammable powders in closed vessels, and several
years ago an engine was made to work in this country in a
similar manner by inflammation of spirit of tar.' In a
subsequent paragraph of his monograph he anticipates almost
exactly the construction of the Lenoir gas engine, which came
into being more than fifty-five years after his monograph was
published.

Certain experiments detailed in his work were made to ascertain
the size of the surface necessary for the support of any given
weight. He accepted a truism of to-day in pointing out that in
any matters connected with aerial investigation, theory and
practice are as widely apart as the poles. Inclined at first to
favour the helicopter principle, he finally rejected this in
favour of the plane, with which he made numerous experiments.
During these, he ascertained the peculiar advantages of curved
surfaces, and saw the necessity of providing both vertical and
horizontal rudders in order to admit of side steering as well as
the control of ascent and descent, and for preserving
equilibrium. He may be said to have anticipated the work of
Lilienthal and Pilcher, since he constructed and experimented
with a fixed surface glider. 'It was beautiful,' he wrote
concerning this, 'to see this noble white bird sailing
majestically from the top of a hill to any given point of the
plain below it with perfect steadiness and safety, according to
the set of its rudder, merely by its own weight, descending at
an angle of about eight degrees with the horizon.'

It is said that he once persuaded his gardener to trust himself
in this glider for a flight, but if Cayley himself ventured a
flight in it he has left no record of the fact. The following
extract from his work, Aerial Navigation, affords an instance of
the thoroughness of his investigations, and the concluding
paragraph also shows his faith in the ultimate triumph of
mankind in the matter of aerial flight:--

'The act of flying requires less exertion than from the
appearance is supposed. Not having sufficient data to ascertain
the exact degree of propelling power exerted by birds in the act
of flying, it is uncertain what degree of energy may be required
in this respect for vessels of aerial navigation; yet when we
consider the many hundreds of miles of continued flight exerted
by birds of passage, the idea of its being only a small effort
is greatly corroborated. To apply the power of the first mover
to the greatest advantage in producing this effect is a very
material point. The mode universally adopted by Nature is the
oblique waft of the wing. We have only to choose between the
direct beat overtaking the velocity of the current, like the oar
of a boat, or one applied like the wing, in some assigned degree
of obliquity to it. Suppose 35 feet per second to be the
velocity of an aerial vehicle, the oar must be moved with this
speed previous to its being able to receive any resistance; then
if it be only required to obtain a pressure of one-tenth of a
lb. upon each square foot it must exceed the velocity of the
current 7.3 feet per second. Hence its whole velocity must be
42.5 feet per second. Should the same surface be wafted
downward like a wing with the hinder edge inclined upward in an
angle of about 50 deg. 40 feet to the current it will overtake
it at a velocity of 3.5 feet per second; and as a slight unknown
angle of resistance generates a lb. pressure per square foot at
this velocity, probably a waft of a little more than 4 feet per
second would produce this effect, one-tenth part of which would
be the propelling power. The advantage of this mode of
application compared with the former is rather more than ten to
one.

'In continuing the general principles of aerial navigation, for
the practice of the art, many mechanical difficulties present
themselves which require a considerable course of skilfully
applied experiments before they can be overcome; but, to a
certain extent, the air has already been made navigable, and no
one who has seen the steadiness with which weights to the amount
of ten stone (including four stone, the weight of the machine)
hover in the air can doubt of the ultimate accomplishment of
this object.'

This extract from his work gives but a faint idea of the amount
of research for which Cayley was responsible. He had the
humility of the true investigator in scientific problems, and so
far as can be seen was never guilty of the great fault of so
many investigators in this subject--that of making claims which
he could not support. He was content to do, and pass after
having recorded his part, and although nearly half a century had
to pass between the time of his death and the first actual
flight by means of power-driven planes, yet he may be said to
have contributed very largely to the solution of the problem,
and his name will always rank high in the roll of the pioneers
of flight.

Practically contemporary with Cayley was Thomas Walker,
concerning whom little is known save that he was a portrait
painter of Hull, where was published his pamphlet on The Art of
Flying in 1810, a second and amplified edition being produced,
also in Hull, in 1831. The pamphlet, which has been reproduced
in extenso in the Aeronautical Classics series published by the
Royal Aeronautical Society, displays a curious mixture of the
true scientific spirit and colossal conceit. Walker appears to
have been a man inclined to jump to conclusions, which carried
him up to the edge of discovery and left him vacillating there.

The study of the two editions of his pamphlet side by side shows
that their author made considerable advances in the
practicability of his designs in the 21 intervening years,
though the drawings which accompany the text in both editions
fail to show anything really capable of flight. The great point
about Walker's work as a whole is its suggestiveness; he did not
hesitate to state that the 'art' of flying is as truly
mechanical as that of rowing a boat, and he had some conception
of the necessary mechanism, together with an absolute conviction
that he knew all there was to be known. 'Encouraged by the
public,' he says, 'I would not abandon my purpose of making
still further exertions to advance and complete an art, the
discovery of the TRUE PRINCIPLES (the italics are Walker's own)
of which, I trust, I can with certainty affirm to be my own.'

The pamphlet begins with Walker's admiration of the mechanism of
flight as displayed by birds. 'It is now almost twenty years,'
he says, 'since I was first led to think, by the study of birds
and their means of flying, that if an artificial machine were
formed with wings in exact imitation of the mechanism of one of
those beautiful living machines, and applied in the very same
way upon the air, there could be no doubt of its being made to
fly, for it is an axiom in philosophy that the same cause will
ever produce the same effect.' With this he confesses his
inability to produce the said effect through lack of funds,
though he clothes this delicately in the phrase 'professional
avocations and other circumstances.' Owing to this inability he
published his designs that others might take advantage of them,
prefacing his own researches with a list of the very early
pioneers, and giving special mention to Friar Bacon, Bishop
Wilkins, and the Portuguese friar, De Guzman. But, although he
seems to suggest that others should avail themselves of his
theoretical knowledge, there is a curious incompleteness about
the designs accompanying his work, and about the work itself,
which seems to suggest that he had more knowledge to impart than
he chose to make public--or else that he came very near to
complete solution of the problem of flight, and stayed on the
threshold without knowing it.

After a dissertation upon the history and strength of the
condor, and on the differences between the weights of birds, he
says: 'The following observations upon the wonderful difference
in the weight of some birds, with their apparent means of
supporting it in their flight, may tend to remove some
prejudices against my plan from the minds of some of my readers.
The weight of the humming-bird is one drachm, that of the condor
not less than four stone. Now, if we reduce four stone into
drachms we shall find the condor is 14,336 times as heavy as the
humming-bird. What an amazing disproportion of weight! Yet by
the same mechanical use of its wings the condor can overcome the
specific gravity of its body with as much ease as the little
humming-bird. But this is not all. We are informed that this
enormous bird possesses a power in its wings, so far exceeding
what is necessary for its own conveyance through the air, that
it can take up and fly away with a whole sheer in its talons,
with as much ease as an eagle would carry off, in the same
manner, a hare or a rabbit. This we may readily give credit to,
from the known fact of our little kestrel and the sparrow-hawk
frequently flying off with a partridge, which is nearly three
times the weight of these rapacious little birds.'

After a few more observations he arrives at the following
conclusion: 'By attending to the progressive increase in the
weight of birds, from the delicate little humming-bird up to the
huge condor, we clearly discover that the addition of a few
ounces, pounds, or stones, is no obstacle to the art of flying;
the specific weight of birds avails nothing, for by their
possessing wings large enough, and sufficient power to work
them, they can accomplish the means of flying equally well upon
all the various scales and dimensions which we see in nature.
Such being a fact, in the name of reason and philosophy why
shall not man, with a pair of artificial wings, large enough,
and with sufficient power to strike them upon the air, be able
to produce the same effect?'

Walker asserted definitely and with good ground that muscular
effort applied without mechanism is insufficient for human
flight, but he states that if an aeronautical boat were
constructed so that a man could sit in it in the same manner as
when rowing, such a man would be able to bring into play his
whole bodily strength for the purpose of flight, and at the same
time would be able to get an additional advantage by exerting
his strength upon a lever. At first he concluded there must be
expansion of wings large enough to resist in a sufficient degree
the specific gravity of whatever is attached to them, but in the
second edition of his work he altered this to 'expansion of flat
passive surfaces large enough to reduce the force of gravity so
as to float the machine upon the air with the man in it.' The
second requisite is strength enough to strike the wings with
sufficient force to complete the buoyancy and give a projectile
motion to the machine. Given these two requisites, Walker states
definitely that flying must be accomplished simply by muscular
exertion. 'If we are secure of these two requisites, and I am
very confident we are, we may calculate upon the success of
flight with as much certainty as upon our walking.'

Walker appears to have gained some confidence from the
experiments of a certain M. Degen, a watchmaker of Vienna, who,
according to the Monthly Magazine of September, 1809, invented a
machine by means of which a person might raise himself into the
air. The said machine, according to the magazine, was formed of
two parachutes which might be folded up or extended at pleasure,
while the person who worked them was placed in the centre. This
account, however, was rather misleading, for the magazine
carefully avoided mention of a balloon to which the inventor
fixed his wings or parachutes. Walker, knowing nothing of the
balloon, concluded that Degen actually raised himself in the air,
though he is doubtful of the assertion that Degen managed to fly
in various directions, especially against the wind.

Walker, after considering Degen and all his works, proceeds to
detail his own directions for the construction of a flying
machine, these being as follows: 'Make a car of as light
material as possible, but with sufficient strength to support a
man in it; provide a pair of wings about four feet each in
length; let them be horizontally expanded and fastened upon the
top edge of each side of the car, with two joints each, so as to
admit of a vertical motion to the wings, which motion may be
effected by a man sitting and working an upright lever in the
middle of the car. Extend in the front of the car a flat surface
of silk, which must be stretched out and kept fixed in a passive
state; there must be the same fixed behind the car; these two
surfaces must be perfectly equal in length and breadth and large
enough to cover a sufficient quantity of air to support the whole
weight as nearly in equilibrium as possible, thus we shall have a
great sustaining power in those passive surfaces and the active
wings will propel the car forward.'

A description of how to launch this car is subsequently given:
'It becomes necessary,' says the theorist, 'that I should give
directions how it may be launched upon the air, which may be done
by various means; perhaps the following method may be found to
answer as well as any: Fix a poll upright in the earth, about
twenty feet in height, with two open collars to admit another
poll to slide upwards through them; let there be a sliding
platform made fast upon the top of the sliding poll; place the
car with a man in it upon the platform, then raise the platform
to the height of about thirty feet by means of the sliding poll,
let the sliding poll and platform suddenly fall down, the car
will then be left upon the air, and by its pressing the air a
projectile force will instantly propel the car forward; the man
in the car must then strike the active wings briskly upon the
air, which will so increase the projectile force as to become
superior to the force of gravitation, and if he inclines his
weight a little backward, the projectile impulse will drive the
car forward in an ascending direction. When the car is brought to
a sufficient altitude to clear the tops of hills, trees,
buildings, etc., the man, by sitting a little forward on his
seat, will then bring the wings upon a horizontal plane, and by
continuing the action of the wings he will be impelled forward
in that direction. To descend, he must desist from striking the
wings, and hold them on a level with their joints; the car will
then gradually come down, and when it is within five or six feet
of the ground the man must instantly strike the wings downwards,
and sit as far back as he can; he will by this means check the
projectile force, and cause the car to alight very gently with a
retrograde motion. The car, when up in the air, may be made to
turn to the right or to the left by forcing out one of the fins,
having one about eighteen inches long placed vertically on each
side of the car for that purpose, or perhaps merely by the man
inclining the weight of his body to one side.'

Having stated how the thing is to be done, Walker is careful to
explain that when it is done there will be in it some practical
use, notably in respect of the conveyance of mails and
newspapers, or the saving of life at sea, or for exploration,
etc. It might even reduce the number of horses kept by man for
his use, by means of which a large amount of land might be set
free for the growth of food for human consumption.

At the end of his work Walker admits the idea of steam power for
driving a flying machine in place of simple human exertion, but
he, like Cayley, saw a drawback to this in the weight of the
necessary engine. On the whole, he concluded, navigation of the
air by means of engine power would be mostly confined to the
construction of navigable balloons.

As already noted, Walker's work is not over practical, and the
foregoing extract includes the most practical part of it; the
rest is a series of dissertations on bird flight, in which,
evidently, the portrait painter's observations were far less
thorough than those of da Vinci or Borelli. Taken on the whole,
Walker was a man with a hobby; he devoted to it much time and
thought, but it remained a hobby, nevertheless. His
observations have proved useful enough to give him a place among
the early students of flight, but a great drawback to his work
is the lack of practical experiment, by means of which alone
real advance could be made; for, as Cayley admitted, theory and
practice are very widely separated in the study of aviation, and
the whole history of flight is a matter of unexpected results
arising from scarcely foreseen causes, together with experiment
as patient as daring.

IV. THE MIDDLE NINETEENTH CENTURY

Both Cayley and Walker were theorists, though Cayley supported
his theoretical work with enough of practice to show that he
studied along right lines; a little after his time there came
practical men who brought to being the first machine which
actually flew by the application of power. Before their time,
however, mention must be made of the work of George Pocock of
Bristol, who, somewhere about 1840 invented what was described
as a 'kite carriage,' a vehicle which carried a number of
persons, and obtained its motive power from a large kite. It is
on record that, in the year 1846 one of these carriages conveyed
sixteen people from Bristol to London. Another device of
Pocock's was what he called a 'buoyant sail,' which was in
effect a man-lifting kite, and by means of which a passenger was
actually raised 100 yards from the ground, while the inventor's
son scaled a cliff 200 feet in height by means of one of these,
'buoyant sails.' This constitutes the first definitely recorded
experiment in the use of man-lifting kites. A History of the
Charvolant or Kite-carriage, published in London in 1851, states
that 'an experiment of a bold and very novel character was made
upon an extensive down, where a large wagon with a considerable
load was drawn along, whilst this huge machine at the same time
carried an observer aloft in the air, realising almost the
romance of flying.'

Experimenting, two years after the appearance of the
'kite-carriage,' on the helicopter principle, W. H. Phillips
constructed a model machine which weighed two pounds; this was
fitted with revolving fans, driven by the combustion of
charcoal, nitre, and gypsum, producing steam which, discharging
into the air, caused the fans to revolve. The inventor stated
that 'all being arranged, the steam was up in a few seconds,
when the whole apparatus spun around like any top, and mounted
into the air faster than a bird; to what height it ascended I
had no means of ascertaining; the distance travelled was across
two fields, where, after a long search, I found the machine
minus the wings, which had been torn off in contact with the
ground.' This could hardly be described as successful flight,
but it was an advance in the construction of machines on the
helicopter principle, and it was the first steam-driven model of
the type which actually flew. The invention, however, was not
followed up.

After Phillips, we come to the great figures of the middle
nineteenth century, W. S. Henson and John Stringfellow. Cayley
had shown, in 1809, how success might be attained by developing
the idea of the plane surface so driven as to take advantage of
the resistance offered by the air, and Henson, who as early as
1840 was experimenting with model gliders and light steam
engines, evolved and patented an idea for something very nearly
resembling the monoplane of the early twentieth century. His
patent, No. 9478, of the year 1842 explains the principle of the
machine as follows:--

In order that the description hereafter given be rendered clear,
I will first shortly explain the principle on which the machine
is constructed. If any light and flat or nearly flat article be
projected or thrown edgewise in a slightly inclined position,
the same will rise on the air till the force exerted is
expended, when the article so thrown or projected will descend;
and it will readily be conceived that, if the article so
projected or thrown possessed in itself a continuous power or
force equal to that used in throwing or projecting it, the
article would continue to ascend so long as the forward part of
the surface was upwards in respect to the hinder part, and that
such article, when the power was stopped, or when the
inclination was reversed, would descend by gravity aided by the
force of the power contained in the article, if the power be
continued, thus imitating the flight of a bird.

Now, the first part of my invention consists of an apparatus so
constructed as to offer a very extended surface or plane of a
light yet strong construction, which will have the same relation
to the general machine which the extended wings of a bird have
to the body when a bird is skimming in the air; but in place of
the movement or power for onward progress being obtained by
movement of the extended surface or plane, as is the case with
the wings of birds, I apply suitable paddle-wheels or other
proper mechanical propellers worked by a steam or other
sufficiently light engine, and thus obtain the requisite power
for onward movement to the plane or extended surface; and in
order to give control as to the upward and downward direction of
such a machine I apply a tail to the extended surface which is
capable of being inclined or raised, so that when the power is
acting to propel the machine, by inclining the tail upwards,
the resistance offered by the air will cause the machine to rise
on the air; and, on the contrary, when the inclination of the
tail is reversed, the machine will immediately be propelled
downwards, and pass through a plane more or less inclined to the
horizon as the inclination of the tail is greater or less; and
in order to guide the machine as to the lateral direction which
it shall take, I apply a vertical rudder or second tail, and,
according as the same is inclined in one direction or the other,
so will be the direction of the machine.'

The machine in question was very large, and differed very little
from the modern monoplane; the materials were to be spars of
bamboo and hollow wood, with diagonal wire bracing. The surface
of the planes was to amount to 4,500 square feet, and the tail,
triangular in form (here modern practice diverges) was to be
1,500 square feet. The inventor estimated that there would be a
sustaining power of half a pound per square foot, and the
driving power was to be supplied by a steam engine of 25 to 30
horse-power, driving two six-bladed propellers. Henson was
largely dependent on Stringfellow for many details of his
design, more especially with regard to the construction of the
engine.

The publication of the patent attracted a great amount of public
attention, and the illustrations in contemporary journals,
representing the machine flying over the pyramids and the
Channel, anticipated fact by sixty years and more; the
scientific world was divided, as it was up to the actual
accomplishment of flight, as to the value of the invention.

Strongfellow and Henson became associated after the conception
of their design, with an attorney named Colombine, and a Mr
Marriott, and between the four of them a project grew for
putting the whole thing on a commercial basis--Henson and
Stringfellow were to supply the idea; Marriott, knowing a member
of Parliament, would be useful in getting a company
incorporated, and Colombine would look after the purely legal
side of the business. Thus an application was made by Mr
Roebuck, Marriott's M.P., for an act of incorporation for 'The
Aerial Steam Transit Company,' Roebuck moving to bring in the
bill on the 24th of March, 1843. The prospectus, calling for
funds for the development of the invention, makes interesting
reading at this stage of aeronautical development; it was as
follows:

PROPOSAL.

For subscriptions of sums of L100, in furtherance of an
Extraordinary Invention not at present safe to be developed by
securing the necessary Patents, for which three times the sum
advanced, namely, L300, is conditionally guaranteed for each
subscription on February 1, 1844, in case of the anticipations
being realised, with the option of the subscribers being
shareholders for the large amount if so desired, but not
otherwise.
---------
An Invention has recently been discovered, which if ultimately
successful will be without parallel even in the age which
introduced to the world the wonderful effects of gas and of
steam.

The discovery is of that peculiar nature, so simple in principle
yet so perfect in all the ingredients required for complete and
permanent success, that to promulgate it at present would wholly
defeat its development by the immense competition which would
ensue, and the views of the originator be entirely frustrated.

This work, the result of years of labour and study, presents a
wonderful instance of the adaptation of laws long since proved
to the scientific world combined with established principles so
judiciously and carefully arranged, as to produce a discovery
perfect in all its parts and alike in harmony with the laws of
Nature and of science.

The Invention has been subjected to several tests and
examinations and the results are most satisfactory so much so
that nothing but the completion of the undertaking is required
to determine its practical operation, which being once
established its utility is undoubted, as it would be a necessary
possession of every empire, and it were hardly too much to say,
of every individual of competent means in the civilised world.

Its qualities and capabilities are so vast that it were
impossible and, even if possible, unsafe to develop them
further, but some idea may be formed from the fact that as a
preliminary measure patents in Great Britain Ireland, Scotland,
the Colonies, France, Belgium, and the United States, and every
other country where protection to the first discoveries of an
Invention is granted, will of necessity be immediately obtained,
and by the time these are perfected, which it is estimated will
be in the month of February, the Invention will be fit for
Public Trial, but until the Patents are sealed any further
disclosure would be most dangerous to the principle on which it
is based.

Under these circumstances, it is proposed to raise an
immediate sum of L2,000 in furtherance of the Projector's views,
and as some protection to the parties who may embark in the
matter, that this is not a visionary plan for objects
imperfectly considered, Mr Colombine, to whom the secret has
been confided, has allowed his name to be used on the occasion,
and who will if referred to corroborate this statement, and
convince any inquirer of the reasonable prospects of large
pecuniary results following the development of the Invention.

It is, therefore, intended to raise the sum of L2,000 in twenty
sums of L100 each (of which any subscriber may take one or more
not exceeding five in number to be held by any individual) the
amount of which is to be paid into the hands of Mr Colombine as
General Manager of the concern to be by him appropriated in
procuring the several Patents and providing the expenses
incidental to the works in progress. For each of which sums of
L100 it is intended and agreed that twelve months after the 1st
February next, the several parties subscribing shall receive as
an equivalent for the risk to be run the sum of L300 for each of
the sums of L100 now subscribed, provided when the time arrives
the Patents shall be found to answer the purposes intended.

As full and complete success is alone looked to, no moderate or
imperfect benefit is to be anticipated, but the work, if it once
passes the necessary ordeal, to which inventions of every kind
must be first subject, will then be regarded by every one as the
most astonishing discovery of modern times; no half success can
follow, and therefore the full nature of the risk is immediately
ascertained.

The intention is to work and prove the Patent by collective
instead of individual aid as less hazardous at first end more
advantageous in the result for the Inventor, as well as others,
by having the interest of several engaged in aiding one common
object--the development of a Great Plan. The failure is not
feared, yet as perfect success might, by possibility, not ensue,
it is necessary to provide for that result, and the parties
concerned make it a condition that no return of the subscribed
money shall be required, if the Patents shall by any unforeseen
circumstances not be capable of being worked at all; against
which, the first application of the money subscribed, that of
securing the Patents, affords a reasonable security, as no one
without solid grounds would think of such an expenditure.

It is perfectly needless to state that no risk or responsibility
of any kind can arise beyond the payment of the sum to be
subscribed under any circumstances whatever.

As soon as the Patents shall be perfected and proved it is
contemplated, so far as may be found practicable, to further the
great object in view a Company shall be formed but respecting
which it is unnecessary to state further details, than that a
preference will be given to all those persons who now subscribe,
and to whom shares shall be appropriated according to the larger
amount (being three times the sum to be paid by each person)
contemplated to be returned as soon as the success of the
Invention shall have been established, at their option, or the
money paid, whereby the Subscriber will have the means of either
withdrawing with a large pecuniary benefit, or by continuing his
interest in the concern lay the foundation for participating in
the immense benefit which must follow the success of the plan.

It is not pretended to conceal that the project is a
speculation--all parties believe that perfect success, and
thence incalculable advantage of every kind, will follow to
every individual joining in this great undertaking; but the
Gentlemen engaged in it wish that no concealment of the
consequences, perfect success, or possible failure, should in
the slightest degree be inferred. They believe this will prove
the germ of a mighty work, and in that belief call for the
operation of others with no visionary object, but a legitimate
one before them, to attain that point where perfect success will
be secured from their combined exertions.

All applications to be made to D. E. Colombine, Esquire, 8
Carlton Chambers, Regent Street.

The applications did not materialise, as was only to be expected
in view of the vagueness of the proposals. Colombine did some
advertising, and Mr Roebuck expressed himself as unwilling to
proceed further in the venture. Henson experimented with models
to a certain extent, while Stringfellow looked for funds for the
construction of a full-sized monoplane. In November of 1843 he
suggested that he and Henson should construct a large model out
of their own funds. On Henson's suggestion Colombine and
Marriott were bought out as regards the original patent, and
Stringfellow and Henson entered into an agreement and set to
work.

Their work is briefly described in a little pamphlet by F. J.
Stringfellow, entitled A few Remarks on what has been done with
screw-propelled Aero-plane Machines from 1809 to 1892. The
author writes with regard to the work that his father and Henson
undertook:--

'They commenced the construction of a small model operated by a
spring, and laid down the larger model 20 ft. from tip to tip
of planes, 3 1/2 ft. wide, giving 70 ft. of sustaining surface,
about 10 more in the tail. The making of this model required
great consideration; various supports for the wings were tried,
so as to combine lightness with firmness, strength and rigidity.

'The planes were staid from three sets of fish-shaped masts, and
rigged square and firm by flat steel rigging. The engine and
boiler were put in the car to drive two screw-propellers, right
and left-handed, 3 ft. in diameter, with four blades each,
occupying three-quarters of the area of the circumference, set
at an angle of 60 degrees. A considerable time was spent in
perfecting the motive power. Compressed air was tried and
abandoned. Tappets, cams, and eccentrics were all tried, to work
the slide valve, to obtain the best results. The piston rod of
engine passed through both ends of the cylinder, and with long
connecting rods worked direct on the crank of the propellers.
From memorandum of experiments still preserved the following is
a copy of one: June, 27th, 1845, water 50 ozs., spirit 10 ozs.,
lamp lit 8.45, gauge moves 8.46, engine started 8.48 (100 lb.
pressure), engine stopped 8.57, worked 9 minutes, 2,288
revolutions, average 254 per minute. No priming, 40 ozs. water
consumed, propulsion (thrust of propellers), 5 lbs. 4 1/2 ozs.
at commencement, steady, 4 lbs. 1/2 oz., 57 revolutions to 1 oz.
water, steam cut off one-third from beginning.

'The diameter of cylinder of engine was 1 1/2 inch, length of
stroke 3 inches.

'In the meantime an engine was also made for the smaller model,
and a wing action tried, but with poor results. The time was
mostly devoted to the larger model, and in 1847 a tent was
erected on Bala Down, about two miles from Chard, and the model
taken up one night by the workmen. The experiments were not so
favourable as was expected. The machine could not support
itself for any distance, but, when launched off, gradually
descended, although the power and surface should have been
ample; indeed, according to latest calculations, the thrust
should have carried more than three times the weight, for there
was a thrust of 5 lbs. from the propellers, and a surface of
over 70 square feet to sustain under 30 lbs., but necessary
speed was lacking.'

Stringfellow himself explained the failure as follows:--

'There stood our aerial protegee in all her purity--too
delicate, too fragile, too beautiful for this rough world; at

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