Heliograph team, 1900 (c)

Photograph, Boer War (1899-1902), 1900 (c).

A heliograph used a mirror to reflect sunlight to a distant observer. By moving the mirror, flashes of light could be used to send Morse code. It was an ideal tool in the vast open spaces of South Africa as it allowed long distance communication without a fixed infrastructure. Heliographs were still being used by the British Army as late as the 1950s.

From an album of 60 photographs associated with 2nd Battalion The Middlesex Regiment.