Acknowledgements

We are grateful to the following for permission to reproduce copyright material:

Figures IB, 2G, 2E, 8D courtesy of the Lockheed Aircraft Corporation, USA; Figures 2B, 2C, ЗА, 3B, 6B, 11B, 12D courtesy of the former British Aircraft Corporation; Figures 3C, 6E, 9F, 13B courtesy of General Dynamics Corporation, USA; Figure 3D courtesy of Paul MacCready; Figures ЗЕ, 5H courtesy of the Grumman Corporation, USA; Figure 3F courtesy of Fiat Aviazione, Torino, Italy; Figures 4D, 13D, courtesy of the Bell Aerospace Division of Textron Inc., USA; Figure 4G courtesy of Beech Aircraft Corporation, USA; Figures 4H, 5B courtesy of Cessna Aircraft Company, USA; Figure 41 courtesy of the former Fairey Aviation Co. Ltd; Figures 5C, 8C courtesy of Flight; Figure 6A courtesy of Slingsby Sailplanes Ltd; Figure 6C (bottom) courtesy of Terry Shwetz, de Havilland, Canada; Figure 6F courtesy of Bell Helicopter Textron; Figure 6G courtesy of Nigel Cogger; Figures 7C, 13C courtesy of the Boeing Company; Figure 9H courtesy of SAAB, Sweden; Figure 91 courtesy of Piaggio, Genoa, Italy; Figure 11A courtesy of the Shell Petroleum Co. Ltd; Figure 11E courtesy of McDonnell Douglas Corporation, USA; Figure 12A courtesy of the Lockheed-California Company, USA; Figure 12B courtesy of British Aerospace Defence Ltd, Military Aircraft Division; Figure 12C courtesy of Avions Marcel Dassault, France; Figures 13A, 13E courtesy of NASA.

Quotation from The Stars in their Courses on p.391 (Sir James Jeans) reprinted courtesy of Cambridge University Press.