Portlock, JE (1869). Memoir of the Life of Major-General Colby, together with a Sketch of the Origin and Progress of the Ordnance Survey of Great Britain and Ireland: Portlock, JE (1869). Memoir of the Life of Major General Colby, together with a Sketch of the Origin and Progress of the Ordnance Survey of Great Britain and Ireland: a work with which General Colby was connected for Forty five Years. London: Skeely, Jackson and Halliday, 316pp + foldout figure, first edition. Hardback in embossed purple cloth covered boards. Spine and top edge of boards faded, with minor tears to top and base of spine. Slight foxing