Series Number Id: GSGS 3073. Edition number: 1, June 11th, 1915. "O.S.O. 1915." Another copy of Auchy - Lens sheet. Detail, grid & contours black; German trenches & battery positions red; water, 2-fig coordinates & grid capital letters blue; British front pecked black. Not printed on reverse, Location: Research Collections; Fonds: WW1 Trench Maps: France; Box number: PC15; envelope_number: 401, Manuscript on face: British routes and trenches in Vermelles - Hohenzollern area. Manuscript on reverse: 'Trench Mortar Detachment'.