CORDELIA MOLLOY / SCIENCE PHOTO LIBRARY CORDELIA MOLLOY / SCIENCE PHOTO LIBRARY
Compass. The compass has a free-swinging magnetic needle (green) pointing to a dial. The dial is graduated in degrees and shows the cardinal points: north (N), south (S), east (E) and west (W). The needle aligns itself with the local lines of magnetic force to indicate the direction of the north and south magnetic poles.
Model release not required. Property release not required.