Stereoscopic photograph: Difficulties of the march on Pretoria.
From a collection of 37 stereoscopic photographs relating to the Boer War (1899-1902), Underwod and Underwood, 1900.

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. The Boer War was extensively ‘stereographed’ by employees of the American firm of Underwood and Underwood. Boxed sets of 50, 100, and 150 views were issued.