5923017 ?An enemy blockhouse seized at Poelecappelle is quickly converted into a machine-gun nest?, 1917 (b/w photo) by Unknown photographer, (20th century); National Army Museum, London; (add.info.: ?An enemy blockhouse seized at Poelecappelle is quickly converted into a machine-gun nest?, 1917. Stereoscopic photograph, World War One, Western Front (1914-1918), 1917. The machine-gun was one of the dominant weapons on the First World War battlefield. When established in a fixed defensive position and sited specifically to cover potential enemy attack routes it was a fearsome weapon. Infantry assaults upon such positions invariably resulted in high casualties. From a collection of 101 stereoscopic photographs entitled ?The Great War?.); by National Army Museum .