Gustave EIFFEL (1832-1923) P.S., Paris June 6, 1918; 2 pages - Lot 174

Gustave EIFFEL (1832-1923) P.S., Paris June 6, 1918; 2 pages in-4, letterhead Laboratoire aérodynamique G.Eiffel. Test report on Noguès propeller no. 12. Eiffel specifies the dimensions of this two-bladed wooden propeller, and summarizes in a table the results of the tests: number of revolutions per minute, speed, thrust, power, etc. "The Noguès propeller, because of the number of blades, their great width and the high value of the relative pitch, is very powerful, but this is achieved at the expense of efficiency"... He compares it to a propeller from his laboratory and concludes that it "does not appear to be superior to current propellers"... Attached is a logarithmic diagram of Noguès propellers prepared by the Laboratoire aérodynamique G. Eiffel. "