English Channel. 'Geological Map and Section illustrating the structure of the Strait of Dover and the proposed Channel Tunnel by W Topley, FGS Assoc. Inst C.E.': map of the Straits of Dover and parts of Kent, Sussex and France. Reference table to [geological] strata. Scale: 1 inch to 16 miles. Lithographed by Stanford's [Geographical Establishment]. Inset: cross section.