See:
http://www.hq.nasa.gov/office/pao/History/SP-440/contents.htm
This is a good summary. They had better wind tunnels in Europe prior
to 1908 than I realized. Albert Zahm's tunnel at Catholic University
is discussed. I have read that it was much more precise and more
expensive than the Wrights'. I did not realize how much better! See:
http://www.hq.nasa.gov/office/pao/History/SP-440/ch2-3.htm
"Zahm's ingenious pressure gages had sensitivities of a millionth of
an atmosphere; that is, the pressure exerted by only 1/3 inch of air.
With this impressive research facility, Zahm did pioneering work on
the drag of dirigible hulls. . . ."
Zahm later became a bitter, lifelong enemy of the Wrights.
- Jed
