Author
2 free books by Albert Francis Zahm, free to read online. Chapter 1 of any book is free, no account needed.
Aërial Navigation A Popular Treatise on the Growth of Air Craft and on Aëronautical Meteorology
Albert Francis Zahm
The First Man-Carrying Aeroplane Capable of Sustained Free Flight: Langley's Success as a Pioneer in Aviation From the Smithsonian Report for 1914, pages 217-222, Publication 2329, 1915