Correspondence with and relating to Lord Kelvin, C. G. Grey, William Cochrane, J. K. Smythies, C. C. Turner, May Harbord, R. P. Hearne, Lord Montagu of Beaulieu, Claude Grahame-White, A. D. Maclean, T. W. K. Clarke, Lady Mary Bailey, T. I. Blanchard, T. W. Pilcher, H. W. L. Moeddebeck, Charles S. Rolls, E. V. Hammond, Alan H Burgoyne, Commission Permanente Internationale d'Aeronautique, V. Straus Frank and others