In this historical photo from the U.S. space agency, the test section and balance for the Atmospheric Wind Tunnel (AWT) #1 is shown on May 22, 1921. The 5 foot diameter circular test section and control room of NACA Tunnel No. 1. A Curtiss "Jenny" model can be seen mounted in the test section.
Both a real JN4H and a highly accurate model were put through identical tests. The NACA engineers used this data to make the necessary corrections to the wind tunnel.
The National Advisory Committee on Aeronautics (NACA) was a precursor to NASA. NACA was created by Congress in 1915.