ocr: A sextant, invented in - 1730, is an optical SEXTANT instrument used in navigation. It measures the angle of celestial bodies above the horizon from the observer's position. The sextant is so named because the early instrument had a calibrated arc that is one-sixth of a circle - a graduated 60°arc. Knowing the angular elevation of a known star, and the exact time, one can calculate the Latitude position of the observer.
