Message in a bottle: the discovery of a young medical officer’s map from the 1917 Battle of Hill 70

Summary: We report the serendipitous discovery of a map drawn by an army surgeon during the First World War. The map, entitled “Loos 36° NW3,’”was drawn by 24-year-old Captain Alexander Edward MacDonald in fall 1917 and was found in his old surgery textbook. MacDonald’s map depicts the positions of Canadian frontlines and medical units after the Battle of Hill 70. During the battle, Dr. MacDonald tended to the wounded in an aid post that he …