"Trenches corrected to 19-9-17." "Information to 14-10-17 in blue." "T.198. Issued 16/10/17, Corps Topo Section [Intelligence map]." Stamped in red in lower right corner: No 7 Canadian Siege Battery, Oct 18 1917. "[1st] Field Survey Co., R.E. 5078." Detail, grid & contours grey; German trenches & names red; British trenches & names blue; Intelligence in blue; roads & tracks yellow. Used by Major J.C. Thomson MC (OC 20th Siege Battery, 8-inch hows).