Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1892-06-19

weighted with q load heavier than itself
When 1t rises with any load it does it at the
expense of correspondingly increased e4-
penditure of energy, and such flights can,
not possibly be of long duration. The villa
geese are good aerial stayers in their mlgra-
tory flights, but rain, sleet or snow comPeis
them to descend. No bird is manufacturing
energy as fast as it is used in flight, put
uses previously accumulated stock, ana
the vulture MI. Loeber refers to is seldom
continuously on the wing one hour.
Bird Riding on tho Breeze.
And no bird was ever poised with motion
less wings while bearing load one-fourth
Of its own weight There are some species
of gulls that ride the air for half day with
out Tapping their wings, and how do they do
II? 1t Is always without exception, where
there Is . brisk breeze, never during calm.
They balance or poise on the force-o the
wind, Just tilt on the crest of the wind
wave, going mp and down, little forward
or backward, but it is the winds force that
has to sustain them.
The familiar chicken-hawk of our boy
hood days, that we watched sailing in
circle over the farm, high up and with wings
stationary, the philosophy of which we so
little understood, is not so much of puzzle
-
cycloidsl series of circles, always to leeward;
that is, his circles were not like hoops lying
on each other, but lined away, his motion
faster on one side than on tiie other, follow
ing the wind and he only availed himself Of
an upper current which he rode in series
Of cycloidal rings, and when there CHANGED
to be no current 1t was not his day out, and
he was then simply not Sin it,
There is hardly ever day so calm over
head that the clouds do not move, and at q
good speed too, while near the surface there
may be little or no air movement. But,
shoot any of these air cDsatures while on
the wing and there il an end to all anthexis.
Down drops the aerial navigator as soon as
there is an end to mechanical action. But
if this Boston inventor, in Is years of study,
has not yet learned that the body of the
bird, and not the air, is its fulcrum, it is to
be feared that he may be lame in some of
his other aerial ideas.
The Philosophy Of Flight.
Had he studied how he handles his arms
when he makes jump, he would have had
the initial movement in flying. A bird in
commencing fight from the ground, as
sumes q squatting posture and springs.
With the upward impetus of the body, it
lifts its wings, whose upper surfaces are
convex and the vanes of whose feathers
part to let the air pass through, so as to
meet still less anthexis, and the downward
stroke, presenting concave surface, the
filaments or vanes all closed, so much ex-
ceeds the upward stroke in effectiveness
the wing in going up also shortening BY
hinging in and coming down heightened
out-impels the body up, or on,
Just as the stroke of an oarsman
impels the boat forward The downward
wing strokes of the bird are so much more
effective by reason of form to the air and
closing of the flameutary spaces than the
upward stroke is, which corresponds to the
afr curve of the oar, that the bird-the boat
lis kept on its course duriug q succession
of such movements
As the oarsman, with Q little charge of
movement, with one or the other oar, can
change the direction of his craft, so a little
difference in the manipulation of the oars or
wings of bird, will change its direction
and movement
The jumper, when he leaves terra frma,
lifts bis wings and strikes down vigorously
to accelerate and prolong his flight, but his
avoirdupois is too much for his wing sur
.aoe to be of much avail; yet he shows his
good will and makes a movement full Of
significance.
Tho Hub Lawyer Is on
No, this gentleman from the center Of
the wheel has added nothing to the solution
of the problem of aerial navigation, and
any proposition to cleave through the air at
the rate of 300 miles an hour is absurdly
outside Of the physics of the case.
What would be the effect on the aver
age artificial structure, should gale strike
rushing along at the gait Of 300 miles an
hour? The one is as the other and the
speed would be one mile in IL seconds.
The Vvin0v of hurnnino bird do not
cleave the air at such rate of cleavage and
the cleaving must be yet faster than the
forward impulse of the ship as the oue-half
upward motion which is lost must be COM
pensated for, and the staunchest boiler plate
wings would fly to shreds and 10, 900 horse
power could not communicate to them any
such motion. N.