Der Vogelflug als Grundlage der Fliegekunst : ein Beitrag zur Systematik der Flugtechnik
Otto Lilienthal's 1889 study of bird flight as the basis of aviation, published in Berlin for engineers and naturalists and drawing on experiments he and his brother Gustav began in the 1870s. Line diagrams show curved wing cross-sections, airflow and force vectors, and bird wings in beat sequence, alongside German Fraktur-adjacent roman text blocks and numbered figure captions.
