OS 161943-1950Ordnance Survey: Trigonometrical and Levelling Divisions: Second Geodetic Levelling, Specimen Records
The records in this series were selected as being representative of the several hundred books covering the 82 lines of the Second Geodetic Levelling which took place between 1937 and 1952 as part of the Retriangulation of Great Britain. They contain the surveyor's basic levelling observations. They relate to parts of Sussex and Perthshire.