theodolite

plural theodolites

1. A surveying instrument, consisting of a small mounted telescope, used to measure horizontal and vertical angles.

   The height of those mountains was from five to seven thousand feet above our level, by angular measurement with a theodolite.

   1839, Robert FitzRoy, Phillip Parker King, Narrative of the Surveying Voyages of His Majesty’s Ships Adventure and Beagle, between the Years 1826 and 1836, […], volume II, London: Henry Colburn, […], →OCLC, page 356

   4 more examples

   I drew outlines (according to my usual custom) of all the hills on the horizon before us, and took angles on them with the theodolite.

   c. 1839, T. L. Mitchell, Three Expeditions into the Interior of Eastern Australia, volume 2

   It was a lieutenant and a couple of privates of the 8th Hussars, with a stand like a theodolite, which the artilleryman told me was a heliograph.

   1895–1897, H[erbert] G[eorge] Wells, “What I Saw of the Destruction of Weybridge and Shepperton”, in The War of the Worlds, London: William Heinemann, published 1898, →OCLC, book I (The Coming of the Martians), page 91

   Germany, of all countries, was most vitally concerned in it; but even a cave-dweller in La Fayette Square, seeking only a measure of motion since the Crusades, saw before his eyes, in the spring of 1903, a survey of future order or anarchy that would exhaust the power of his telescopes and defy the accuracy of his theodolites.

   1918, Henry Adams, The Education of Henry Adams

   The process of setting up a theodolite is carried out in three stages: centring the theodolite, levelling the theodolite and elimination of parallax.

   2018, John Uren, Bill Price, Surveying for Engineers, Bloomsbury, →ISBN, page 79