A modern version of the Thomson type azimuth mirror, called an azimuth circle, used to take bearings of terrestrial and celestial objects from a compass, by SG Brown Limited, Watford, Hertfordshire, England, 1945-1951 A modern version of the Thomson type azimuth mirror, called an azimuth circle 1945-1951
A modern version of the Thomson type azimuth mirror, called an azimuth circle, used to take bearings of terrestrial and celestial objects from a compass, by SG Brown Limited, Watford, Hertfordshire, England, 1945-1951 A modern version of the Thomson type azimuth mirror, called an azimuth circle 1945-1951