Records of Humber Conservancy and the Humber Ports (Records deposited by Associated British Ports and its Predecessors) > Humber Conservancy > Humber Charts: Surveys conducted by the Humber Conservancy Board (including cross sections and sounding sheets) > Humber Conservancy Board: Humber Examinations > Humber Conservancy Board: Middle Humber Examinations Pt 1