AZIMUTH Circles, called also azimuths, or vertical circles, are great circles of the sphere intersecting each other in the zenith and nadir, and cutting the horizon at right angles. These azimuths are represented by the rhumbs on common sea-charts, and on the globe they are represented by the quadrant of altitude, when screwed in the zenith. On these azimuths is reckoned the height of the stars and of the sun when not in the meridian.