In any, even the smallest, set or set of survival, it is desirable to include a signal mirror (heliograph) or its substitute. An important area of activity in…
heliograph
Signal Mirror, Ultimate Survival Technologies Starflash heliograph, overview and impressions.
The signal mirror, or as the heliograph calls it in special literature, which literally means writing with the sun, explains its purpose. Many types of signal mirrors are…