Using a trench periscope, Gallipoli, 1915

Photograph, World War One, Gallipoli (1915).

Periscopes provided a less dangerous way of observing the Turks from the trenches. In its simplest form, a periscope could be just a stick with two angled pieces of mirror at the top and bottom.

From an album of photographs compiled by Lieutenant (later Lieutenant-General Sir) Reginald Arthur Savory, 14th Sikh Regiment.