File comprises 2 reports on a proposed channel tunnel between England and France. The first is entitled "The Channel Tunnel by a Railway Military Expert", dated 1907 and discussing how such a tunnel would affect the UK's defences and how the English side of the tunnel could be defended in the event of an invasion. The second is entitled "Channel Tunnel; Reports by British and French engineers; Papers on National Defence" and compiled by General Sir William Butler, G.C.B., Major-General; Sir Alfred E. Turner K. C. B. and Vice-Admiral Sir Charles Campbell K. C. M. B which deals with engineering questions, military concerns and contains details of construction and models of governance for such a tunnel involving both the UK and French governments.