SCIENCE, INDUSTRY AND BUSINESS LIBRARY: GENERAL COLLECTION / NEW YORK PUBLIC LIBRARY / SCIENCE PHOTO LIBRARY SCIENCE, INDUSTRY AND BUSINESS LIBRARY: GENERAL COLLECTION / NEW YORK PUBLIC LIBRARY / SCIENCE PHOTO LIBRARY
Leonardo da Vinci's helicopter design. This helical air screw, by Italian inventor Leonardo da Vinci (1452-1519), dates from the late 15th century. The helical rotor for this precursor of the helicopter was to be driven by the muscular power of the pilot, and would not have had enough power to take off. This design was never published or constructed. After Leonardo's death his notes were not rediscovered until 1796. Successful helicopters were not developed until the 20th century. The notes are an example of Leonardo's mirror writing, where he wrote backwards, from right to left. The writing can be read normally if viewed in a mirror. This reprint of his design is from 'L'Aeronautique des origines a 1922' (1922) by French aeronaut Henry de La Vaulx (1870-1930).
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