On 04 Dec 2003 20:54:48 -0800, Bob Fry wrote:

Mike Rhodes writes:

And all they had to do was observe the bird in
its astonishing air-dance. Apparently they did not do that,

I'm pretty sure that in fact one or both of the Wrights did spend a
lot of time observing birds in flight ...

They did, but the records that the left about the value of doing
so disagree. Orville said it did help them. Wilbur said it was
like watching a magician. Only after you already knew what
the trick was could you see it in action. The dates of these
contradictory remarks are from long after 1901, when the
brothers made the fundamental decision to test wing
warping on a 5' glider.

... and that is how they invented
wing-warping for direction control.

The canonical story is that Wilbur was talking with a customer
who had come in to buy a new inner tube. While talking
with the customer, he absentmindedly played with the
cardboard box. He suddenly realized that the box was just
like a biplane glider with the fore-and-aft guy wires removed
and that twisting the wings as he was twisting the box would
present different angles of attack on each side to the
air flow, thus causing one side to gain lift and the other to
lose it.

Watching turkey vultures use their tip feathers to turn may
or may not have helped in reaching this insight. Ideas are
funny things, and they may have a lot more background than
even the discoverer realizes.

Marty