Historical reference: Do not rely on this information. It is very old. About this collection
Altazimuth, an astronomical instrument for observing the position of a heavenly body. It consists of a telescope capable of adjustment to view any point in the celestial hemisphere, and arranged with a vertical graduated circle to observe its altitude, i.e. its angle with the horizontal, and with a horizontal circle to show its azimuth, i.e. its declination from the north and south line.