Series Number Id: GSGS 2742; Sheet number: 62c SE; Edition number: 2a, Location: Research Collections; Fonds: WW1 Trench Maps: France; Box number: PC09; envelope_number: 245, Trenches to 30th January 1917. OS February 1917. Manuscript in top margin: Capt. Field's File [Capt. Field was a staff officer at 'Maps GHQ' in charge of map records & distribution].