This large scale secret map gives a comprehensive impression of a small strip of No-Man’s Land near Messines defended by the 2nd Army. This was the heavily fortified ground, in some cases as narrow as 200 feet, across which any advance had to be made.
The map shows natural features such as ditches, streams, grass (with grass length) and trees. But the most prominent features are the successive ‘x’ patterns indicating the barbed wire protecting enemy trenches. The wire (trip and concertina wire included) is strategically placed and in places five rows deep. The map provides indications of quality and height. British wire is not shown.
At the Somme on 1 July 1916, the British artillery bombardment had only cut the German wire at isolated points. The advancing infantry that managed to find these narrow gaps also found German machine guns trained upon them.