Two original pencil sketches by Wright given to Charles Dollfus in 1920: one on a 6 x 5 sheet, consisting of an aerodynamic-looking diagram surrounded by numbers; and the other on a 7.25 x 11 sheet, showing a box diagram with various lines and arrows. In overall fine condition, with moderate toning to both, and edge chips and tears to the larger sheet. Dollfus (1893–1981) was a French aviator and longtime conservator of the Musée de l'Air. RR Auction COA.