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.
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.
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.
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.
The word 'circumferentor' comes from a Latin word meaning 'to carry around'.