San Diego, March 26, 1901
I am spending the winter in Southern California, on account of my wife's health, and have your valued favor of 19th inst.
The convenient anemometer for field use is the kind with very light flat vanes. The best is made by Richard in Paris (metric units). I have one of them, also a registering instrument graduated to British measures made in Liverpool. Both have been tested and are provided with a formula for corrections. I will lend them, either you like, when you are ready to experiment. You might procure for yourself a pressure gauge as a check. The Robinson anemometer only gives averages, while you can get a Richard instrument which can be attached to a machine in flight.
I return home about April 16th.
Wilbur's response, May 12, 1901