The History: Octave Chanute responded to Wilbur's letter on May 12th. He suggested that Wilbur specify whether he wanted to use the English [Robinson, a cup type] or French anemometer [Richard of Paris, a rotating vane type] at the appropriate time. [An anemometer is an instrument used to determine the wind's speed. The English anemometer is a Robinson anemometer, a cup type. The French anemometer is by Richard of Paris and is a rotating vane type. See our student activities on anemometers: Paper Cup Anemometer and "Calibrate" An Anemometer.] Currently, Edward Huffaker was using Chanute's English anemometer.

Cup-anemometer by Munro 1870 and Drawing of Robinson's Original Cup-Anemometer Anemometer Photo and Drawing Courtesy the Armagh Observatory A Richard Of Paris Anemometer Anemometer Photos Courtesy Michael Bennett-Levy Of Early Technology

Chanute questions Wilbur's statement on "total drift resistance" from his May 12th letter. Wilbur had commented, "It is our idea that the total drift resistance of a large machine at its soaring speed will be less than that of a smaller machine at its speed, since the resistance of the operator's body will be less at the slow speed."

In the early days of mechanical flight experimentation, "drift" referred to a portion of the wings' drag (the air resistance or retarding force caused by the wings). "Head resistance" referred to the drag on the other parts of the machine, such as the wires, struts, uprights and the operator. Head resistance was not related to wing drag.

Chanute briefly discusses "drift" and "head resistance" inferring that less resistance on the operator at a slower speed would affect "head resistance" versus the "drift".

Chanute informs Wilbur that he is planning a trip and would be interested in meeting the Wrights. "When would be the best time?"

Quotation from the book The Papers of Wilbur and Orville Wright, Volume 1 by M. McFarland.