Series Number Id: UNKNOWN. Sheet number: Part of Sheet 36. Edition number: 3. Loos-Lens Area; trench, counter-battery and enemy organisation map, 1917. "Trenches corrected to 2-10-17". "Field Survey Co., R.E. 5101 [numbers crossed out and replaced with green overprint] 5179". Detail, grid and contours grey; British trenches and trench names to a depth of 1000 yards blue; German trenches and trench names red; enemy organisation green. [Enemy battery] positions active and positions inactive, between 20-9-17 and 7-10-17, shown in black. Red stamp in margin: No. 7 Canadian Siege Battery, Oct 15 1917., Used by Major J.C. Thomson MC, OC 20th Siege Battery. WW1 Trench Map Collection: Box PC23, Envelope 717.