Category:Theodolite

The*od"o*lite, n. Etym: [probably a corruption of the alidade. See Alidade.]

Defn: an instrument used, especially in trigonometrical surveying, For the accurate measurement of horizontal angles, and also usually Of vertical angles. It is variously constructed.

Note: the theodolite consists principally of a telescope, with cross Wires in the focus of its object glass, clamped in y's attached to a Frame that is mounted so as to turn both on vertical and horizontal Axes, the former carrying a vernier plate on a horizontal graduated Plate or circle for azimuthal angles, and the latter a vertical Graduated arc or semicircle for altitudes. The whole is furnished With levels and adjusting screws and mounted on a tripod.