Stereoscopic photograph: 'Under great difficulties our troops carry supplies over destroyed bridges on the Yser Canal'.
One of 100 stereoscopic photographs associated with World War One, Western Front (1914-1918).
From the collection of the former Buffs Regimental Museum.

Stereographs consist of two identical photographs paired in such a way that when seen through a special viewing instrument, a stereoscope, they appear as a three-dimensional images. By 1899 the photographs were mounted on thick card that was given a slight curvature to increase the illusion of depth.