Langley Memoir on Mechanical Flight, Parts I and II - 1911 - IllustratedEbookLangley Memoir on Mechanical Flight, Parts I and II - 1911 - IllustratedbyS. P. LangleyRating: 0 out of 5 stars0 ratingsSave Langley Memoir on Mechanical Flight, Parts I and II - 1911 - Illustrated for later