Cased Gestirnspeilscheibe marked gzy

Beautiful cased Gestirnspeilscheibe in unissued condition. This large navigation device was used to navigate. In order to navigate one needs the angle between the length axis of the airplane and that of a fixed star such as the moon. To measure this angle between the longitudinal axis and the position of the moon the Gestirnspeilscheibe was used. This device was stored inside the fuselage of larger aircrafts such as bombers and transport planes.