the·od·o·lite /θiˈɑdḷˌaɪt/
 經緯儀


 The·od·o·lite n.  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.

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 theodolite
      n : a surveying instrument for measuring horizontal and vertical
          angles, consisting of a small telescope mounted on a
          tripod [syn: transit]