sextant

A navigational instrument containing a graduated 60-degree arc, used for measuring the altitudes of celestial bodies for use in determining the latitude and longitude of the observer.

In mathematics, the sixth part of a circle. Hence An important instrument of navigation and surveying, for measuring the angular distance of two stars or other objects, or the altitude of a star above the horizon, the two images being brought into coincidence by reflection from the transmitting horizon-glass, lettered b in the figure.

[capitalized] Same as Sextans, 2.

The sixth part of a circle.

An instrument for measuring angular distances between objects, — used esp. at sea, for ascertaining the latitude and longitude. It is constructed on the same optical principle as Hadley’s quadrant, but usually of metal, with a nicer graduation, telescopic sight, and its arc the sixth, and sometimes the third, part of a circle. See Quadrant.

The constellation Sextans.

a small sextant inclosed in a cylindrical case to make it more portable.

A navigational device for deriving angular distances between objects so as to determine latitude and longitude.

One sixth of a circle or disc; a sector with an angle of 60°.