Relief shown by hachures, soundings, and spot heights. At head of title: Azores. Includes 6 cross sections and 6 insets: Caldeira of Graciosa -- [Gomez Bay] -- Praya de Graciosa -- Angra de Terceira -- Praya de Terceira -- [Cabras Islands]. "1818." "Published according to Act of Parliament at the Hydrographic Office of the Admiralty, July 23rd, 1849." North oriented to the upper left.