Series Number Id: GSGS 3652. Sheet number: part of sheet 36. "Map showing German grids" in red overprint, [June 1918]. "[1st] Field Survey Co., R.E. 6345" in red overprint. "Ordnance Survey, April, 1918." Detail and squaring grey; water blue., Location: Research Collections; Fonds: WW1 Trench Maps: France; Box number: PC23; envelope_number: 707.
Series Number Id: UNKNOWN. Sheet number: part of sheet 28. Map showing German map grids. In green overprint, "Diagram showing German grid and co-ordinate systems in use opposite [British] Fourth Army Front. Note, that four inches from the bottom of the sheet grid system changes. N. of this a Belgian system based on Brussels is used. S. of this the projection is the same as that used by the French, based on Paris as origin." Grey detail and squaring (without letters and numbers). Covers all of Ypres Salient, from Merckem in the north to Armentieres in the south and Menin in the east. Ypres is in left centre. "[Fourth] Field Survey Coy. R.E. (3039) 29-12-17 [followed in green overprint by] (8432)"., Location: Research Collections; Fonds: WW1 Trench Maps: France; Box number: PC23; envelope_number: 708.
German map of La Folie Farm area of Vimy Ridge, just north of Neuville St. Vaast. The map is based on a captured map ("nach einer beutekarte") dated July 13, 1915 and published as a preliminary edition on September 16, 1916. Sheet number 3. German designated sectors of Doberitz, Fischer, and Arnulf are labelled. Trenches are numbered rather than named, and are shown in more detail than on Allied maps due to secrecy restrictions. The map is said to have been found among the German dead after the battle by Lieutenant John William Southin, 14 Platoon, D Company, CEF of Ladysmith B.C. and was donated by his grandaughter, Mary Henricksen of Toronto. Location: Research Collections, Fonds: WWI Trench Maps France, Box 14, Envelope 7.