from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun An optical instrument consisting of a small mounted telescope rotatable in horizontal and vertical planes, used to measure angles in surveying, meteorology, and navigation.

from The Century Dictionary.

  • noun A surveying-instrument for measuring horizontal angles upon a graduated circle.

from the GNU version of the Collaborative International Dictionary of English.

  • noun An instrument used, especially in trigonometrical surveying, for the accurate measurement of horizontal angles, and also usually of vertical angles. It is variously constructed.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

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

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun a surveying instrument for measuring horizontal and vertical angles, consisting of a small telescope mounted on a tripod


from The American Heritage® Dictionary of the English Language, 4th Edition

[Probably coined by Leonard Digges (1520–1559), English mathematician and surveyor, as the name of a device for measuring horizontal angles, perhaps from Greek theā, a viewing + a second element of unknown origin.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

New Latin theodolitus, of unknown origin


  • The spot was actually located and determined by theodolite from the base camp, knowing the height of the mountain.

    The Assault on Everest

  • Thus the theodolite was the only instrument retained, and the camera, photographic films (exposed and unexposed), hypsometer, thermometers, rifle, ammunition and other sundries were all thrown away.

    The Home of the Blizzard Being the Story of the Australasian Antarctic Expedition, 1911-1914

  • The theodolite was a nine-inch one and weighed many pounds.

    A Labrador Doctor The Autobiography of Wilfred Thomason Grenfell

  • On shore, observers will be equipped with binoculars and an instrument called a theodolite, which will allow them to scan the horizon and calculate distance to the whales, and the whales 'latitude and longitude.

    All Today's News - Sightline Daily

  • Employed by the Board of Ordnance, William Roy began mapping the Highlands in 1747, pushing a surveyor's wheel and using a simple kind of theodolite called a circumferentor.

    Map of a Nation: A Biography of the Ordnance Survey by Rachel Hewitt - review

  • We then used a theodolite to survey the positions of the stake and mark appromiately 100-ft steps back towards the circle.

    Marking the PAPER Trail

  • All of these various methods came together in what most of us today think of as the quintessential surveying tool, the theodolite, a single device that allows a surveyor to both take bearings and measure elevations.

    Book review: Thunderer by Felix Gilman

  • In post-Culloden Scotland the map-makers had used a small, tripod-mounted telescope or prototype theodolite to measure sight-lines from landmark to landmark.

    Map of a Nation by Rachel Hewitt – review

  • We then used a theodolite to survey the positions of the stake and mark appromiately 100-ft steps back towards the circle.

    Archive 2009-03-12

  • The process required teams to coordinate with each other from opposite sides of the canyon, with a rodman, or rigger, perched on one wall holding a fifteen-foot pole with a flag at one end—used to probe to the back of the caves perforating the rock—while a surveyor across the river fixed him in the crosshairs of his camera-equipped theodolite.



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  • “The astonishing fact was that Mawson had taken forty-six days to drive himself on foot nearly 300 miles through the worst wilderness known to man, navigating by means of a damaged theodolite balanced on the corner of the cooker box, a compass rendered unreliable by the proximity of the South Magnetic Pole and a watch which had stopped at least two or three times. Though he kept a careful tally of his estimates for his daily marches, he had been reckoning progress by a sledge cyclometer that repeatedly jammed and broke. Yet here he was returning to base within 300 yards of his predicted line of travel.�?

    —Michael Howell and Peter Ford, The Ghost Disease, and Twelve Other Stories of Detective Work in the Medical Field, (New York: Penguin Books, 1985), 328

    September 11, 2008

  • Sounds like a great book, c_b. Would you recommend it?

    September 11, 2008

  • I liked it. It's old, though, and now I'm interested to find a similar book that's more up-to-date, so I can see if there have been any new discoveries in these particular cases since publication. For some (e.g. cholera, Robert the Bruce), probably not. But yes, it's well written and interesting.

    I suck at book reviews.

    September 11, 2008

  • I don't know much about this kind of books, but do you know "No Bone Unturned"?

    September 11, 2008

  • No, but looked it up on Amazon just now. Have you read it?

    September 11, 2008

  • That's a fine enough book review for me! :-)

    September 11, 2008

  • "... a mathematical instrument generally useful, and particularly so to engineers and artillerists, in surveying and taking heights and distances."

    Falconer's New Universal Dictionary of the Marine (1816), 553

    October 12, 2008

  • Of all the Century's definitions, I think I love this one the most.

    July 20, 2011

  • The parenthetical snark about "some geodesists" is pure joy.

    July 20, 2011

  • My favorite part is the conical bearing of Gamhey.

    July 20, 2011