A History of Aeronautics | Page 8

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: