from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. An instrument used to measure horizontal angles, consisting of a brass circle and an index, all of one piece.
from the GNU version of the Collaborative International Dictionary of English
- n. A surveying instrument, for taking horizontal angles and bearings; a surveyor's compass. It consists of a compass whose needle plays over a circle graduated to 360°, and of a horizontal brass bar at the ends of which are standards with narrow slits for sighting, supported on a tripod by a ball and socket joint.
- n. A graduated wheel for measuring tires; a tire circle.
from The Century Dictionary and Cyclopedia
- n. An instrument used by surveyors for taking angles.
- n. A device for measuring the length of the tire of a wheel, consisting of a wheel of known circumference, which is rolled over the tire.
Sorry, no etymologies found.
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.
A circumferentor is, according to the OED: Surveying.
The ravines are deep, and the sides of the hills are covered with the same stone, of which a pile was erected on the summit of the head to mark the spot where the circumferentor was placed.
Kater's pocket compass [Note: A most valuable instrument, combining all the advantages of the circumferentor, without being so liable to be damaged and put out of order by carriage.], with the addition of an excellent sextant, pocket chronometer, and artificial horizon.
Augustine Washington had been a surveyor, and George had access to his father’s instruments: a circumferentor an eighteenth-century predecessor of the theodolite and an expensive precision instrument, chains, drawing boards and instruments, and so on.
4 A most valuable instrument, combining all the advantages of the circumferentor, without being so liable to be damaged and put out of order by carriage.
They had been obliged to escape so rapidly that Captain Clark lost his compass [that is, circumferentor] and umbrella, Chaboneau left his gun, with Captain Lewis 'wiping-rod, shot-pouch, and tomahawk, and the Indian woman had just time to grasp her child, before the net in which it lay at her feet was carried down the current. "