Coastal and land map navigation aid - has set of mirrors on three scales which rotate around common axis to provide sighting

摘要

The optical position finder has three scales (10) which pivot around a common axis of rotation (5). Each scale has a mirror fixed to it in an opposite position w.r.t. the common axis. The inclination of the mirrors permits simultaneous reflection of the images of the three points aimed at towards the eye of the observer. One mirror has a double face (1,2) and these faces are at 90 degrees to each other which permit sighting of two diametrically opposed points.