The History: Wilbur responded to Chanute's requests in his letter of June 30th. He agrees with Chanute's reply to Captain Ferber regarding gliding lessons. At this point "we would prefer to carry on our experiments undisturbed".

Chanute had asked Wilbur if he could discuss wing warping in a scientific article he was writing. He noted someone might get hurt if wing warping was not explained. Wilbur preferred that Chanute not include information on this in the paper. [Lateral equilibrium or balance of side to side motion was controlled by the "wing-warping" mechanism on the Wrights' gliders.] Wing warping would require a very detailed explanation and Wilbur was concerned about beginners trying this technique. Since Chanute had been concerned about operator safety in his last letter, Wilbur offered additional advice for the beginning experimenter. This included:

• beginners should not use a tail on their vehicle;
• they should work first on longitudinal control [pitching up and down] and obtain lateral control [side to side] with small shifts in their body weight;
• beginners should not use machines greater than 20 feet long;
• learn "one thing at a time", Wilbur urged.

Chanute had also inquired about how to calculate the area affected by head resistance [drag] on their machines. Wilbur replied that the area of the uprights, rudder framing bottom skids [used to land on] and other parts [not including the wings] was about 8 sq. ft. The area affected by the drag was 1/3 this or 8/3 sq. ft. At 20 miles per hour the air resistance was 3 to 4 pounds. The wing drag was about 23 to 24 pounds and additional drag due to superimposing the wings over one another was 3 to 4 pounds. The total air resistance thus totaled to about 30 pounds.

Wilbur asked for a more detailed information regarding what Chanute meant by "the computation of a glide".

Chanute had provided a copy of a Stefan Drzewiecki paper on screws [propellers] which Wilbur returned. Wilbur reported that Drzewiecki thought and explained concepts of screws very different than he did. This made it difficult for Wilbur to understand Drzewiecki's work. Wilbur criticized the author telling Chanute, Drzewiecki did not seem to account for the weight of the water's effect on the angle of attack. Wilbur wrote that the paper "leaves much to be desired as a complete discussion of the subject".

Wilbur closes the letter and shares with Chanute that under the circumstances, he feels Samuel Langley should learn of the Wrights' progress through the normal journal circulation and not be given an advanced copy of the paper.

Whether Wilbur understood Drzewiecki's paper or not, Drzewiecki would be awarded a prize by the French Academy of Sciences in 1920 for his theory of moving propellers based on the resistance of fluids called "Theorie generale de l'helice" (The General Theory of Propellers). His theory on propellers known as "blade theory" is still used today especially in understanding helicopter blades. Drzewiecki demonstrated that a propeller blade could be thought of as actually being a series of many different airfoil sections.

In additional to propeller theory, Drzewiecki developed a kilometric counter for cabs, an instrument which automatically mapped the route traveled by the ship at sea, a 4-man submarine moved by a propeller with a periscope towers and works on "Aeroplanes in Nature" and "Birds Considered as Animated Aeroplanes".

Recall the evolution of the Wright gliders: the 1900 and 1901 did not have a tail. In 1900 the brothers had attempted longitudinal (front and back, up and down pitch of the nose of the vehicle) and wing warping lateral [side to side, the up and down motion of the wings].

Langley was being funded by the United States War Department and the Smithsonian for his own work on a manned powered flying machine. Chanute had referred to Langley as "cheeky" in inviting the Wright's to explain their machine to him. Understandably the brothers wished to continue their experiments in privacy.