EIFFEL, Etudes sur l'hélice aérienne, [1921]

First edition.
Last book published by Gustave Eiffel on his aeronautical research.

"It is the whole of the results which is presented in the current work where I have recast my old works with the new ones, eliminating what seemed to me to be the least interesting and even correcting some of the results relating to the powers and efficiencies that I had given on the aerial propellers, according to the first tests of the Auteuil Laboratory" (extract from the foreword).