It is difficult to acknowledge fully the assistance given by persons and
museums for the preparation of this book. However, I wish especially to
thank Hugo T. Byttebier, engine historian, Buenos Aires, Argentina;
Dipl. Ing. Hermann I. A. Dorner, diesel designer, Hanover, Germany;
Harold E. Morehouse, and C. H. Wiegman, Lycoming Engines, Williamsport,
Pennsylvania; Barry Tully, Goodyear Aircraft, Akron, Ohio; Richard S.
Allen, aviation author, Round Lake, New York; William H. Cramer, brother
of Parker D. Cramer, Wantagh, New York; Erik Hildes-Heim, Early Bird and
aviation historian, Fairfield, Connecticut.
I am particularly grateful to curators of the following museums who have
been so generous in their assistance: Deutsches Museum, Munich, Germany
(Dipl. Ing. W. Jackle); Henry Ford Museum, Dearborn, Michigan (Leslie,
R. Henry); U.S. Air Force Museum, Wright-Patterson Air Force Base,
Dayton, Ohio (Maj. Robert L. Bryant, Jr., director); Science Museum,
London, England (Lt. Comdr. (E) W. J. Tuck, Royal Navy). The preparation
of this paper could not have been accomplished without the aid of the
National Air Museum of the Smithsonian Institution and the help of
Philip S. Hopkins, director, and Paul E. Garber, head curator and
historian.