Sheet number: [36c SW1]. "1st Army H.Q. 10/8/17." "1st Field Survey Co., R.E. 2557." "Printed by no. 6 Advanced Section, A.R.&S.S." Detail and grid grey. Burnt-out area, possible MG emplacements & reference numbers in red. Shows cellars, sewers, etc. Copious printed notes in left & right margins relating to cellars etc. Stamps in margin: No. 7 Canadian Siege Battery, Oct 15th 1917. From Major J.C. Thomson MC (20th Siege Battery RGA)., Location: Research Collections; Fonds: WW1 Trench Maps: France; Box number: PC23; envelope_number: 721