George Spratt's Testing Machine - Tuesday, October 7, 1902
The History: In his personal diary Orville recorded light winds, 4-5 meters/second (9-11 miles/hour) or less at times.
Augustus Herring, Octave Chanute's associate, worked with George Spratt's "testing machine", a device used to calculate the forces on a wing shape (or other shape). Orville noted "Herring spent the day in taking observations in center of pressure and ratio of lift to drift [drag] on several surfaces on Mr. Spratt's testing machine."
Lorin Wright and George Spratt went to the beach to fish in the afternoon catching a mullet and bluefish. A pike and other small fish were washed ashore.
Wright brothers developed a lift and a drift (drag) balance for their wind tunnel tests in 1901. Placed in a wind tunnel their balance was used to measure the aerodynamic forces on different airfoils. The lift balance measured the amount of upward force the shape could create and the drift balance measured the air's resistance on the shape (drag).
Spratt's machine would locate the center of pressure (the center of all forces) acting on the object.
The Wright's and Spratt's machines were both used to calculate aerodynamic forces but accomplished this using two different methods.