During the Second World War RAF aircrew were issued small emergency signalling mirrors that were carried in their Mae Wests, survival kits and dinghies. Later the tropical survival kit included the emergency heliograph, as seen here. This heliograph allowed downed airmen to send morse code signals to rescuers using the sunlight and was stored in a small cotton pouch:

The front of the pack has the word ‘Heliograph’ stencilled on the front in black ink:

Inside was the mirror itself, a small square metal mirror, with a hole in the centre and two sets of etched lines at right angles across the face:

This heliograph is missing the small stick with a hole in it that should be attached with a piece of string to the hole in the top left hand corner of the mirror and acts as a foresight, as illustrated on the instructions which are printed on the rear:

A slim pocket is sewn to the underside of the pouch’s top flap to hold the foresight:

This is a nice little addition to the collection and starts the long job of filling out my tropical survival set.