4. That with similar conditions large surfaces may be controlled with
not much greater difficulty than small ones, if the control is effected
by manipulation of the surfaces themselves, rather than by a movement of
the body of the operator.

'5. That the head resistances of the framing can be brought to a point
much below that usually estimated as necessary.

'6. That tails, both vertical and horizontal, may with safety be
eliminated in gliding and other flying experiments.

'7. That a horizontal position of the operator's body may be assumed
without excessive danger, and thus the head resistance reduced to about
one-fifth that of the upright position.

'8. That a pair of superposed, or tandem surfaces, has less lift in
proportion to drift than either surface separately, even after making
allowance for weight and head resistance of the connections.'

Thus, to the end of the 1901 experiments, Wilbur Wright provided a
fairly full account of what was accomplished; the record shows an amount
of patient and painstaking work almost beyond belief--it was no question
of making a plane and launching it, but a business of trial and error,
investigation and tabulation of detail, and the rejection time after
time of previously accepted theories, till the brothers must have felt
the the solid earth was no longer secure, at times. Though it was Wilbur
who set down this and other records of the work done, yet the actual
work was so much Orville's as his brother's that no analysis could
separate any set of experiments and say that Orville did this and Wilbur
that--the two were inseparable. On this point Griffith Brewer remarked
that 'in the arguments, if one brother took one view, the other brother
took the opposite view as a matter of course, and the subject was
thrashed to pieces until a mutually acceptable result remained. I have
often been asked since these pioneer days, "Tell me, Brewer, who was
really the originator of those two?" In reply, I used first to say,
"I think it was mostly Wilbur," and later, when I came to know Orville
better, I said, "The thing could not have been without Orville." Now,
when asked, I have to say, "I don't know," and I feel the more I think
of it that it was only the wonderful combination of these two brothers,
who devoted their lives together or this common object, that made the
discovery of the art of flying possible.'

Beyond the 1901 experiments in gliding, the record grows more scrappy,
les