Evening star., 1922-09-10

| could have counted the record flight
in minutes on his fingers even IL he
| had lost eight of them in the war.
couple of joints left over, for the
longest German fight that year was
only o. seventy-tive seconds dura-
| ton.
| They spoke nothing Of aerial
yachting at that time, in spite of
the fact that klemperer was there
with the self-same machine in which,
a year later. he made flight of thir-
| teen minutes. The Germans were
merely gliding at that time. and their
performances did not stand healthy
comparison with those of their late
countryman, Lilienthal, nor more
especially with those of the American
aeronaut. Maloney. who in 1905 took
his plane up in a hot-air balloon near
Santa Barbara and made a twenty
minute glide to earth. But it Is to
their credit that they saw what the
real trouble was, and took the pains
to move their proving grounds up
near the summit of the Wasserkuppe
itself.
Though the feat of prolonged soar
ing flight has been brought to real
| ity, nothing radically new in con-
struction or in the understanding Of
the laws of flight has been demon
strated. 1t has not been shown that
gliders can be made to fly over fixed
routes to given detectives. There is
no indication that We will be able to
operate in winds of small velocity or
of a slight angle Of ascent, and unless
this can be done In conspicuous de-
gree the radius of operation of these
soarers must be very limited indeed
But what has been shown only too
clearly is that the conditions under
which man is now able to stay sus-
pended in the air in motorless ma
chimes are so narrow that 1t Is only
in exceptional areas that they may
be met at all. Despite the liberal
German use of superlatives. the out
look for improvement in soaring
flight is not at all rosy.
| COARING birds arc able to keep
~ themselves aloft on currents to
which any glider yet made is en-
| tirely insensitive. They yacht" in
winds rising at such a slight angle of
| inclination that 1t Is often hard to
prove that a wind exists at all. In
deed, the best observers are agreed
that birds can fly without effort over
practically fiat country, and 1t was
this mystifying fact which led Prof.
| Langley to advance his ingenious
theory of bird flight. set forth in his
famous treatise on The Internal
| Work of the Wind
That theory is especially interesting
in the present connection, because 1t
shows how far we have yet to pro-
gress before we may hopt to do any
cross-country flying worthy the name.
and a glance at its outstanding points
will be enlightening.
Prof. Langleys starting point is
| tho fact. discovered by himself, that
what we call a steady wind is really
made up of a series Of very uneven
puffs. Winds are gusty beyond any
| thing we would ever believe II not
shown the results of accurate meas
urements. The higher the velocity of
the wind the greater are the relative
fluctuations which occur in it. Prof.
Langley thought 1t very probable that
| birds are sufficiently nimble to take
advantage of these gusts in such a
way as to keep themselves in the air.
He explains his theory as follows:
Let us, for the sake of simplicity, At
flrst imagine q wind which not only
changes velocity but. in fact. changes
direction eamplatetx- And RqnkinRally,