[AVIATION]. [HELICOPTERS]. KEMP, Robert. “Direct Lift Aerodynamics and The “Bumble Bee Idea” of Robert Kemp’s, of Troy, N. Y. Affidavit and Petition Inside”. [Troy, NY, 1939]. Homemade large folio scrapbook of Kemp’s “Bumble Bee” high-efficiency lifting system for helicopters. 8 large brown kraft paper leaves including covers (hand-numbered 3-14 - the first leaf unnumbered). Bound at spine in brown tape. Approximately 608 x 460 mm. Leaves, worn, soiled, chipped, dampstained, mounted pages generally toned, worn, occasionally soiled. Mounted onto these pages are: 3 pages of typed signed affidavits by Kemp (each page signed by him), typed “Helicopter Company, Inc. List of Stockholders February, 1920”, three printed pages, “Statement Regarding Helicopter Company, Inc.”, a 5-page typed page report by the “National Advisory Committee for Aeronautics, Washington, D. C. / Report on The Helicopter Constructed by Mr. Peter Cooper Hewitt,” with pencil notes in an unknown hand, a page from “The Literary Digest” January 3, 1920 with an article about helicopters, “Flying without Wings”, 19 typed pages of Kemp’s “Petition / To the Commissioner of Patents … Apparatus and Progresses for Producing Aerodynamic Lift and Flight and Means, Methods and Materials for Making Said Apparatus” November 3, 1928, the first page signed by Kemp, 2 pages of later copied diagrams of engineering drawings of the “Bumble Bee” system with some of his manuscript notes. Kemp has detailed manuscript notes on eight leaves about his system as well as the description of the mounted contents as well as the history of their development, changes, etc. On the rear wrapper, Kemp states his purpose of this scrapbook: “The purpose of this Scrapbook is to show how inventors build upon each other’s inventions, until - a radically different invention comes along, then the particular field in which the new idea occurs takes an entirely new direction of development. Such a new idea is Robert Kemp’s ‘Bumble Bee’ System of Aerodynamic Lift and Flight. Robert Kemp, August 4, 1939”. He later assigned these patents to the Westinghouse Electric & Manufacturing Company. It is unclear if the “Bumble Bee” System was adopted, but he was awarded 8 patents during his career.