WW2 AUSTRALIAN ARMY ISSUED HELIOGRAPH AND SPARE MIRRORS
A heliograph (helios (Greek: ἥλιος), meaning "sun", and graphien (γράφειν), meaning "write") is a wireless telegraph that signals by flashes of sunlight (generally using Morse Code) reflected by a mirror. The flashes are produced by momentarily pivoting the mirror, or by interrupting the beam with a shutter.The heliograph was a simple but effective instrument for instantaneous optical communications over long distances during the late 19th and early 20th century. Its main uses were military, survey and forest protection work. Heliographs were standard issue in the British and Australian armies until the 1960s, and were used by the Pakistani army as late as 1975.
A very nice Heliograph still in its original WW2 issued steel container, comes with spare mirrors. Australian marked as shown in images. Hard to find this complete.