Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1892-04-16
AIR SHIPS IN SIGHT.
Time Near at Hand When Science
Will Force the Millennium,
BALLOONS TO, DODGE THE TARIFF.
Following the Flight of Birds Into Him
liable Space.
PROFESSOR VERY ON AEROPLANES

the Allegheny Observatory, said last night
in lecture before the Academy Of Science
| and Art
Prot. Very is rather distinguished look
ing gentleman He is tall and erect He
wears long hair and long whiskers, and he
appears every inch a thorough student. He
wears heavy gold nose glasses, and he
dresses like a minister His audience last
| night was made up of men and women con-
| spicrous in learning, that filled every avail
able seat in the lecture room. Chancellor
Holland, Calvin Wells, James B. Scott and
others of that class occupied seats near the
platform.
''The Principles of Mechanical Flight"
was the subject of Prof Very's interesting
talk and by drawings, appliances and
| mechanical devices he demonstrated the
| possibility of air ships and proved at least
to the satisfaction of those present that the
question of aerial loccmotion has been
settled after exhaustive study and almost
endless scientific inquiry.
Recent Advances in Aerial Navigation.
Prof Very made an analysis Of the flight
of birds and gave description of various
birds and their modes of flight. He told OF
the advantages possessed by living mechan-
isms and the disadvantages of the vital
model. He talked Interestingly Of mechan-
ical substitutes for the organized model, the
propulsion and air propeller and the soaring
ana the aeroplane. He told of the recent ad-
vances of Profs Langley and Maxim toward
the art of flying, explained the dynamics of
air and concluded by arguing that mechan-
ical fight is necessary for the further ad-
vancement of mankind and for the unitiza-
tion of the race.
s:We have reached the full limit of speed
in every other waF," PROF Very said. "Ad-
vanced civilization demands mechanical
figh;. 1t has become a necessity, and ne
consummation of the theory will certainly
follow. The system which is completing it.
self is necessary to the union of all nations,
and when the great feat is accomplished as it
will be the Kings and Emperors or the
authorities of the nations will be SLOW to
declare war when they know that a foe, no
matter how distant, can sail rapidly through
space and from some invisible height drop
deadly bomb into their palace or home.
The Effect Upon the Tariff.
"The system, when completed, will ma
terially affect the vital issues in politics, as
the great air ships can import and export
all kinds of materials and drop them down
Just where they are wanted without inter-
ference from the revenue officers of any
country"
Upon the flight of birds and insects
Prof Very based his theory, and by appli-
ances he demonstrated last night that his
theory is correct 'In the insect world"
he said, 'there are living examples of almost
every sort of flight which has vet been con-
ceived bv men. There are insect balloonists,
the spider of which group some
times may be seen when the wind favors,
emitting from the spinnerets a band
of fluffy, thin silk, which is forthwith seized
with passing currents ofanir and carried aloft
until length of some yards having drawn
out, the pull of the wiind on the floating
cable is sufficient to lift the little salon. who
launches out into the upper ocean to see the
world and seek new habitats, but, like the
human balloonist, remains at the mercy of
the uncertain breeze.
"Among winged insects we have extreme
types in the hawk-moth. with a heavy body,
which hovers over our flower beds in sum-
mer twilight, supported on relatively small
and narrow wings which are kept in ex-
tremely rapid motion by strong muscles;
and on the other hand the broad-winged
swallow-tail butterfly, where the area of
wings bears large ratio to the weight,
leisurely Hopping, alternated with soar
ing sweeps of several yards extent upon
motionless wings. These extremes are re-
peated among birds, where we find varia-
tions of 1000 per cent in the ratio Of
weight to area. These variations are partly
due to the fact that in birds of the same
type the relative supporting surface dimin-
ishes as the weight increases.
The Motive Power Of a Bird.
s'The great pectoral muscles of the bird,
which furnish the motive power, contract in
a nearly straight line in the direction of the
longer axis of the ellipse. but the effect of
the combination is to produce fair
substitute for rotary motion, which is
the mechanical ideal The number of rev.
olutions per second depends partly upon
the size OF the bird but largely also on the |
shape of the wing. The wild duck and the |
pigeon, both short winged and relatively |
small winged birds, give seven and eight |
wing strokes per second, while the |
greater relative wing surface make five and |
three revolutions respectively. The last |
named bird can soar to limited extent. |
The duck and the pigeon are incapable of |
true soaring.
"The perfect soaring bird must have large
mass because otherwise there is not enough |
retaining power to carry the bird through
large circle, while it is obvious that small
circles with the necessity of very frequent
of force in reversing the mo-
tion would not be advantageous. The swift |
swallows soar but with frequent alterations |
OF Hopping to restore lost motion. The birds
which can soar continuously without a
single flop of wings are all of large size,
and conversely all birds of a large size that
can fly at all are soaring birds.
a Plain Pointer to Inventors.
ga very plain pointer is given
by this fact as to the direction in which
inventions of air ships on a large
scale are likely to achieve success.
We find in fact that, while for highspeed
the most advantageous form of aeroplane is
one whose transverse dimensions greatly
exceed its length in the line of flight
at low speed, the opposite arrangement
is best and this explains why bird in stop
ping or in starting its flight depresses its
tail and partly folds its wings, for the speed
being slower than the average it is desir-
able to have the longitudinal dimensions
greater relatively to the transverse and also
largely inclined to the direction of advance.
There are certain advantages possessed by
the living mechanism, which is filed for
motion through the air, but also some dis
point not always consid-
cred, and one which holds out hope that
men of his inventive genius may eventually
surprise his 1eathered rivals 10 or out of me-
cnanical flight.
Where Birds Excel Human Ingenuity.
1.-THE advantages possessed by the bird
are first an ability to feel the forces with
which it is dealing, and instinctively and